CN101058153B

CN101058153B - Rotary tool

Info

Publication number: CN101058153B
Application number: CN2007101055444A
Authority: CN
Inventors: 米夏埃尔·斯特姆; 马丁·劳特瓦尔德; 斯蒂凡·D·根斯曼; 诺贝特·哈恩; 罗伯特·艾伦·乌泽尔曼; 阿希姆·容; 罗伯特·布拉杜斯
Original assignee: Black & White Co ltd
Current assignee: Black & White Co ltd; Black and Decker Inc
Priority date: 2002-09-13
Filing date: 2003-09-10
Publication date: 2012-11-07
Anticipated expiration: 2023-09-10
Also published as: CN101058153A; CN100343025C; GB2419170A; GB0221225D0; GB2419170B; GB0525196D0; GB2392966B; CN1694786A; GB2392966A

Abstract

The invention provides a handheld electric tool, which comprises a main shaft (40) for rotating and driving a tool; a main shaft rotation transmission system (14, 5, 10) for rotating and driving the main shaft; and devices (16, 17) for detecting the blocking situation. An overload clutch in the main shaft rotation transmission system can be operated under a first operating mode, wherein when the torque is lower than a first predetermined torque, the rotation drive force is transmitted to the main shaft by the overload clutch; when the torque is higher than the first predetermined torque, the rotation drive force is no longer transmitted. The overload clutch can also be operated under a second operating mode, wherein when the torque is lower than a second predetermined torque different from the first predetermined torque, the rotation drive force is transmitted to the main shaft by the overload clutch; when the torque is higher than the second predetermined torque, the rotation drive force is no longer transmitted. The overload clutch can also be operated under a third operating mode, wherein when the overload clutch detects the blocking situation, the rotation drive force is no longer transmitted to the main shaft.

Description

Throw

The application is that application number is the dividing an application for the Chinese invention patent application of " throw " that " 03825083.7 (PCT/EP03/10029) ", the applying date be on September 10th, 2003, denomination of invention.

Technical field

The present invention relates to a kind of the have instrument of rotation driving or the hand held electric tool of drill bit, specifically the present invention relates to electronic rotation fullering tool.

Background technology

Electric hammer has a shell usually and is installed in the hollow cylindrical main shaft in this shell.This main shaft allows the shank of instrument or drill bit (for example chit drill or drill hammer) is inserted in its front end, thereby makes it to remain in the front end of main shaft and to a certain extent can axially-movable.This main shaft can be single cylindrical parts, perhaps can be processed by two or more coaxial cylindrical parts, and they form the electric hammer main shaft together.For example, the front portion of main shaft can form the independent tool holding main body that is used for maintenance instrument or drill bit.

These electric hammers are provided with beater mechanism, are used for the rotary driving force from motor is transformed into reciprocal driving force, are used to drive in main shaft, to move back and forth for the piston of hollow piston.Piston back and forth drives percussion hammer through the air chamber (closed air cushion) of the sealing between piston and percussion hammer.Can select to pass on the instrument or drill bit of this electric hammer from the impulsive force of percussion hammer through hit piece (beatpiece).

Electric hammer can adopt the integrated mode of impacting with boring, and also can be a drill mode in some cases, in this pattern, makes the foremost part of main shaft or this main shaft and the drill bit that is inserted in afterwards wherein rotate.In the integrated mode of impacting and holing, drill bit will rotate when receiving repeated stock.Rotary drive mechanism will pass to main shaft from the rotary driving force of motor so that this main shaft or its top partial rotation.

Problem with hand held electric tool of rotary drilling-head is, at instrument between the operating period, thereby when drill bit penetrates into that this drill bit no longer rotates with respect to workpiece in the workpiece, occurs (blocking) situation of blocking sometimes.In this case, the rotary driving force to drill bit makes the shell of instrument rotate with respect to static drill bit.For example knownly from US5914882, US5584619, EP771619 and GB2086277 to detect these congestion situations, then in case detect this situation and just stop to apply rotary driving force to drill bit.This can realize that through making motor braking this motor provides rotary driving force through geared system to drill bit, but owing to need the time to stop motor, so must involve delay.Optional is or in addition, can engage the principal shaft braking that makes rotation with a part of electric hammer shell through making main shaft in some aspects.The optimal way that cut-out offers the rotary driving force of drill bit is to use the releasable clutch apparatus in the power train between electric hammer motor and main shaft.

Summary of the invention

The object of the present invention is to provide a kind of improvement design that is used for when detecting congestion situations cutting off the clutch of the rotary driving force that offers drill bit.

According to an aspect of the present invention, a kind of safety clutch assembly that is used for electric tool is provided, the main shaft that this instrument has the working component that is used for rotary drive tool rotates the main axis rotation power train that drives said main shaft with being used to, and said assembly comprises:

One safety clutch; It has first pattern and at least one second pattern; In first pattern; When the torque that will be lower than first predetermined value is applied on the clutch, rotary driving force is passed to main shaft, and when the torque that will be higher than said first predetermined value is applied on the clutch, cut off the transmission of rotary driving force to main shaft, in second pattern; When the torque that will be lower than corresponding second predetermined value littler than said first pre-determined torque is applied on the clutch, rotary driving force is passed to main shaft, and when the torque that will be higher than said second predetermined value imposes on clutch, cut off the transmission of rotary driving force to said main shaft; And

At least one actuator devices is used to make said safety clutch between said first pattern and at least one said second pattern, to change.

The safety clutch assembly that has first high torque mode and at least one second low torque pattern through setting; Thereby such advantage is provided, and this instrument can be operated in response to being chosen in when the interruption of the working component that detects this instrument or the initial turn-on at this instrument between high torque mode and the safer low torque pattern.

In preferred embodiments, safety clutch comprises: at least one driving gear is applicable to that the rotation power train by said instrument drives; At least one first driven gear is used for rotary driving force is passed to said main shaft; First jockey; Be used in said first pattern; Said first driven gear of at least one said driving gear and at least one is linked to each other and when the torque that will be higher than said first predetermined value is applied on the said clutch, make said driving gear and said driven gear is thrown off; At least one corresponding second driven gear is used for rotary driving force is passed to said main shaft; And at least one corresponding second jockey; Be used for when the torque that will be lower than corresponding said second predetermined value is applied on the clutch, said second driven gear of at least one said driving gear and at least one being linked to each other and when the torque that will be higher than said second predetermined value is applied on the said clutch, making said driving gear and the disengagement of said second driven gear at least one said second pattern.

Preferably, at least one said jockey links to each other the corresponding driven gear of at least one driving gear and at least one through the corresponding one group of locking element that acts between at least one said driving gear and at least one the corresponding said driven gear.

A plurality of said locking elements can comprise ball bearing.

A plurality of said locking elements can comprise roller (roller).

Said actuator devices can be used in said first pattern, making at least one said second driven gear to fix with respect to the turned position of at least one said first driven gear.

In preferred embodiments; At least one said first driven gear is installed on the common axis with at least one said second driven gear, and wherein at least one said second driven gear is nonrotatably mounted tO on the said axle in its first pattern and in its second pattern, can rotates with respect to said axle.

This assembly can also comprise that at least one is used for the detector means of obstruction of working component of testing tool, and wherein at least one said actuator devices is used in response to the obstruction that detects said working component said safety clutch being switched to its said second pattern.

At least one said actuator devices can be used for when connecting said instrument, said safety clutch being switched to its said second pattern.

This provides such advantage, makes this instrument when the instrument initial turn-on, to be automatically set to safer low torque and is provided with.

This assembly can also comprise that at least one is used for said safety clutch is urged to the biasing device of its said second pattern.

According to another aspect of the present invention, a kind of transition components is provided, is used for making the safety clutch assembly of electric tool between its first pattern and its at least one second pattern, to switch, this assembly comprises:

One actuator means, it can with the first pattern corresponding first location of clutch pack and with at least one corresponding second place of corresponding second pattern of clutch pack between move;

At least one connector members is used for activating in response to the actuating of said actuator means at least one actuator devices of said clutch pack; And

One locking devicen is used for releasedly said actuator means being remained at least one said second place.

This assembly can also comprise at least one biasing device, is used for the said actuator devices of said clutch pack is urged to its at least one said second pattern.

At least one said biasing device can comprise a flexible joystick.

At least one said connector members can comprise a cable (cable).

Said locking devicen can comprise that at least one can discharge bearing (abutment), is used for supporting the elastic component that is located on the said actuator means.

This assembly can also comprise the tripper that is used for untiing said locking devicen.

Said tripper can comprise and is used for electromagnet that said bearing is moved.

Said tripper activated when instrument is connected.

According to a further aspect of the invention, a kind of electric tool is provided, it comprises:

One main shaft is used for rotating the output link that drives said instrument;

One main axis rotation power train is used for rotating the said main shaft of driving; And

An aforesaid safety clutch assembly.

This instrument can also comprise aforesaid transition components.

According to a further aspect of the invention, provide a kind of hand-held to be preferably motor-driven electric tool, it comprises:

One main shaft is used for rotation and drives an instrument or drill bit;

One main axis rotation power train is used for rotating the said main shaft of driving;

Drive the safety clutch in the system in said main axis rotation, be used for when being lower than pre-determined torque, rotary driving force being passed to said main shaft and when being higher than pre-determined torque, cutting off the transmission of rotary driving force; And

Be used to detect the device of congestion situations;

It is characterized in that said safety clutch is arranged to when detecting congestion situations to cut off applies rotary driving force to main shaft.

Having the electric tool of rotation driving main shaft, be under the situation of high power instrument (for example electric hammer) at them especially, usually has a safety clutch in the said power train that is used for rotating the said main shaft of driving.If the user hangs on to this instrument, then this safety clutch can be useful in congestion situations, because when tool outer casing begins to rotate, rotation drives the required torque of said main shaft and will increase.Be higher than predetermined threshold if this torque increases to, then this safety clutch will stop to transmit rotary driving force, and this driving force will no longer pass to main shaft.This safety clutch also is used for when receiving high torque (HT), reducing the infringement to the building block (the for example motor of instrument) of instrument.According to a first aspect of the invention, falling safety clutch changes over and cuts off the rotary driving force that imposes on main shaft in response to detecting congestion situations.This safety clutch can be arranged in the arbitrary portion from the instrument motor to main shaft of gear train, and for example can be the well known in the art the sort of safety clutch of installing round main shaft.

In order to cut off the rotary driving force that imposes on main shaft, can reduce the pre-determined torque of safety clutch in response to detecting congestion situations, be higher than the transmission that this pre-determined torque is just cut off rotary driving force.This safety clutch can also provide the function of known safety clutch according to the pre-determined torque size of when not detecting any congestion situations, setting.According to the present invention, can adopt the known most of safety clutch that are used for the power train of throw to reduce the torque that they make rotary driving force in response to detecting congestion situations transmission stops.The torque that makes safety clutch stop to transmit rotary driving force can be reduced in response to detecting congestion situations and be substantially zero.

The present invention is particularly useful for electric hammer, because the problem that their normally high-power instruments and known existence are blocked.These electric hammers generally include a hammer mechanism that is usually located in the main shaft, are used on the instrument at the front end place that is installed in main shaft or drill bit, producing impact repeatedly.This main shaft is preferably processed by the least possible part, but it can comprise the independent tool holding part that coaxially is provided with and is positioned at this part forward direction with that part of main shaft that hammer mechanism wherein mainly is set.

Be known that use is the device that is used to detect congestion situations that for example utilizes inertia mass of machinery fully, these devices can mechanically act on the safety clutch in these situation.This mechanical device can comprise the inertia mass that is pivotably mounted in the tool outer casing.According to one embodiment of the invention; The device that is used to detect congestion situations can comprise the inertia mass that is pivoted in the tool outer casing and comprises the breech lock of the actuator that is used to engage safety clutch, and is provided with the spring that is used for the actuator of clutch is pushed to off-position.These building blocks are so arranged; Thereby when congestion situations occurring; Inertia mass is changeed so that breech lock breaks away from actuator and spring is pushed to off-position with actuator at the shell maincenter, and this actuator makes the rotary driving force that is applied on the main shaft cut off in this position.This can provide a kind of mode that detects congestion situations fast and accurately.

It is also known that, use a kind of like this calutron, it for example used an inertia mass and when congestion situations occurring the motion of sensing quality to produce electrical output signal.

It is also known that the detection of electrons congestion situations.For example, the device that is used to detect congestion situations can comprise a sensor for example accelerometer, torque sensor, current of electric or voltage sensor or other is at the sensor that is used for detecting congestion situations known in this field.The operating conditions of this sensor sensing instrument, the for example vibration of accelerometer testing tool, and torque sensor can detect the relative torque between the building block of this instrument.The output signal of autobiography sensor inputs to the electronics assessment unit in the future, and this electronics assessment unit is used for analyzing from the signal of sensor and when detecting congestion situations, produces electrical output signal.In US5914882, EP771619 and US5584619, disclosed the example of these electronics assessment units.

Device being used to detect congestion situations produces under the situation of electrical output signal in response to detecting congestion situations; This safety clutch can comprise an electromechanical connecting device; For example act on the electromagnet on the magnetic element, this jockey reduces the torque that safety clutch is slided in response to the output signal.

Usually safety clutch will comprise a driven gear and a driving gear and a Connection Element; For example receive the flexible member or the clutch ball (clutch ball) of spring member biases, be used for when being lower than said pre-determined torque, making driven gear to be connected and when being higher than said pre-determined torque, make said driven gear and driving gear to throw off with driving gear.According to one embodiment of the invention, the device that is used to detect congestion situations acts on the Connection Element and is applied to the rotary driving force on the main shaft when detecting congestion situations, to cut off.This Connection Element can be a flexible member, it through the locking element on a group be installed in driven gear and the driving gear driven gear and driving gear are connected and can with said driven gear and driving gear in another engage so that between them, transmit rotary driving force.The device that is used to detect congestion situations can be used for making Connection Element for example flexible member with respect to driven and driving gear motion so that change the torque that this safety clutch is slided.Perhaps, driven gear can be connected with the output of safety clutch through driving connector, and the device that is used to detect congestion situations acts on the driving connector in response to detecting congestion situations, with the transmission of cut-out rotary driving force.

Especially in electric hammer, hope that sometimes this electric hammer has the torque that different being used for will impose on the rotary driving force cut-out of main shaft in different purposes.Therefore; In one embodiment of the invention; Safety clutch can have: first operator scheme, and wherein safety clutch passes to main shaft and the transmission of the driving force of when being higher than said first pre-determined torque, stopping the rotation with rotary driving force when being lower than first pre-determined torque; Second operator scheme, wherein this safety clutch passes to main shaft with rotary driving force when being lower than second pre-determined torque different with said first pre-determined torque, and the transmission of the driving force of when being higher than said second pre-determined torque, stopping the rotation; And the 3rd operator scheme, wherein safety clutch cuts off the rotary driving force that passes to main shaft when detecting congestion situations.

This electric tool can be for having the electric hammer of a non-rotary mode; And the mode change mechanism of this electric hammer can be arranged to when selecting non-rotary mode, and the torque that for example makes safety clutch stop to transmit rotary driving force through reduction makes safety clutch cut off the rotary driving force that passes to main shaft.Therefore, safety clutch according to the present invention can be used for when pattern switches to non-rotary mode, stopping rotary driving force being passed to the electric hammer main shaft in addition as the mode change mechanism part of electric hammer in being contained in electric hammer the time.

According to a further aspect of the invention, provide a kind of hand-held to be preferably motor-driven electronic electric hammer, it comprises:

One main shaft is used for rotating the instrument of driving or drill bit;

One hammer mechanism is used on the instrument at the front end place that is installed in main shaft or drill bit, producing impact repeatedly;

One main axis rotation power train is used for driving rotatably said main shaft;

One mode change mechanism is used for making clutch in the main axis rotation power train, selectively to separate so that cut off the rotary driving force that passes to said main shaft; And

Be used to detect the device of congestion situations,

It is characterized in that said clutch is arranged to when detecting congestion situations, separate.

Electric hammer is known to have a mode change mechanism, and these mechanisms are used for rotary driving force is selectively offered the main shaft of electric hammer.For example, in a drill mode or rotary hammer blow mode of this electric hammer, mode change mechanism is done in order to be bonded on the clutch in the main axis rotation power train, so that rotary driving force passes to said main shaft.In a hammering pattern, the mode change mechanism effect is so that the clutch disengaging.Many these mode change mechanisms that are used for selectively cutting off the driving force that imposes on main shaft are being known in the art, and go for the present invention.In addition as known in the art, electric hammer also can have the mode change mechanism part that is used for selectively making the hammer mechanism separation.According to a second aspect of the invention, receive mode change mechanism and do to pass to the clutch in the spindle system of rotary driving force of main shaft, can also be used to when detecting congestion situations, breaking off the rotary driving force that passes to main shaft in order to cut-out.Therefore, the invention has the advantages that this clutch is used for two purposes, promptly pattern changes and cut-out rotary driving force when detecting congestion situations.

Explanation to the device that is used to detect congestion situations also can be applied to this second aspect of the present invention above.

In one embodiment, this clutch comprises a spindle transmission gear device, and it can be installed on the main shaft axially slidably and selectively engage so that drive said main shaft rotatably with part spindle system.In this situation, the device that is used to detect congestion situations act on the spindle transmission gear device so that this spindle transmission gear device along the main shaft axially-movable and when detecting congestion situations and part spindle system throw off.According to this embodiment, mode changing apparatus also can act on the spindle transmission gear device so that the spindle transmission gear device is broken away from along the main shaft axially-movable and with part spindle system.

This clutch can be for top to the described the sort of safety clutch of first aspect present invention in addition.

One main shaft is used for driving rotatably an instrument or drill bit;

Safety clutch in said main axis rotation power train is used for when being lower than pre-determined torque, rotary driving force being passed to said main shaft and when being higher than pre-determined torque, cutting off the transmission of rotary driving force;

One mode change mechanism is used for selectively cutting off the rotary driving force that passes to said main shaft;

It is characterized in that said safety clutch has:

First operator scheme, wherein safety clutch passes to main shaft and the transmission of the driving force of when being higher than said first pre-determined torque, stopping the rotation with rotary driving force when being lower than first pre-determined torque;

Second operator scheme, wherein this safety clutch passes to main shaft with rotary driving force when being lower than second pre-determined torque different with said first pre-determined torque, and the transmission of the driving force of when being higher than said second pre-determined torque, stopping the rotation; And

The 3rd operator scheme, wherein safety clutch cuts off the rotary driving force that passes to main shaft in response to mode change mechanism.

In an embodiment of this third aspect of the present invention; Safety clutch can comprise a driving gear and a driven gear and a Connection Element; Be used for when being lower than said pre-determined torque, making driven gear to be connected and when being higher than said pre-determined torque, make said driven gear and driving gear to throw off with driving gear; Comprise that also one drives connector; Be used for making driven gear to be connected with the output of said clutch, wherein said mode changing apparatus acts on the said driving connector to change the transmission of the predetermined torque and the driving force of stopping the rotation.Two driven gears can be arranged; And one of them driven gear can be connected with the output of clutch through driving connector; Thereby this safety clutch has first pre-determined torque; And another or this two driven gears can be connected with the output of clutch through driving connector; Thereby this safety clutch has second pre-determined torque different with first pre-determined torque, and perhaps these two driven gears can all not be connected with the output of clutch through driving connector, thus the transmission of the driving force of stopping the rotation.

Description of drawings

Only the preferred embodiments of the invention are described below with reference to accompanying drawings with embodiment rather than determinate mode, wherein:

Fig. 1 demonstrates partly cut-away's longitudinal cross-section of the electric hammer that passes first embodiment of the invention;

Fig. 2 demonstrates the longitudinal cross-section of first embodiment of the safety clutch of the electric hammer that passes Fig. 1;

Fig. 3 demonstrates the longitudinal cross-section of second embodiment of the safety clutch of the electric hammer that passes Fig. 1;

Fig. 4 demonstrates partly cut-away's longitudinal cross-section of the electric hammer that passes another embodiment of the invention;

Fig. 5 demonstrates the longitudinal cross-section of the electric hammer that passes another embodiment of the present invention;

Fig. 6 demonstrates the lateral cross of mechanical blockage situation checkout gear of the electric hammer of Fig. 5;

Fig. 7 demonstrates the longitudinal cross-section of another embodiment of the safety clutch of the electric hammer that passes Fig. 5;

Fig. 8 demonstrates the longitudinal cross-section of another embodiment of the safety clutch of the electric hammer that passes Fig. 5;

Fig. 9 demonstrates the longitudinal cross-section of another embodiment of passing the safety clutch in the electric hammer that is used in Fig. 1 or Fig. 5;

Figure 10 demonstrates the decomposition diagram of building block of the safety clutch of Fig. 9;

Figure 11 demonstrates the 4th embodiment of the safety clutch in the electric hammer that is suitable for being used in Fig. 1 or 5;

Figure 12 is the cross-sectional front view of the safety clutch of another embodiment of the invention;

Figure 13 is the cross sectional side view of the electric hammer of another embodiment of the invention;

Figure 14 is the partial cut-away perspective view of the safety clutch assembly of another embodiment of the invention;

Figure 15 is the decomposition diagram of the clutch pack of Figure 14;

Figure 16 A to C demonstrates first driven gear of the clutch pack of Figure 14 and 15 in detail;

Figure 17 A to 17C demonstrates second driven gear of the clutch pack of Figure 14 and 15 in detail;

Figure 18 demonstrates the perspective schematic view of transition components of the electric hammer of Figure 13;

Figure 19 demonstrates the show in schematic partial sections of the part electric hammer of Figure 14;

Figure 20 is the perspective schematic view of locking devicen of the transition components of Figure 18;

Figure 21 is the view that is shown specifically the release mechanism of the bolt lock mechanism that is used for Figure 20; With

Figure 22 is the logic diagram that is used for the release mechanism of Figure 21.

Parts identical in these accompanying drawings are represented by identical label.

Specific embodiments

Electric hammer shown in Figure 1 comprises motor 2, spindle series and the crank gear that is contained in by in the metal-toothed roller box (not shown) in the plastic casing 4.The back handle shell that back handle 6 and trigger switch device 8 are housed is assemblied on shell 4 rear portions.The cable (not shown) extends through cable duct tube (cableguide) and motor is connected with external power source.Therefore, when cable is connected with power supply and trigger switch device 8 when being pressed, motor 2 startings drive the armature of this motor with rotation.The metal-toothed roller box is processed and rigid support dressing building block within it by the magnesium steel with steel insert (steel insert).

Driving gear 9 is press fitted on the motor pinion 3 and has the gear teeth, and the gear teeth meshing of the driving gear 12 of these gear teeth and safety clutch device 14 drives this driving gear 12 with rotation mode.When being transmitted to two torques between the

gear

12,13 and being lower than a predetermined threshold and do not detecting under the congestion situations 12 driven gears 13 that drive safety clutch device 14 with rotation mode of driving gear.Driven gear 13 is press fitted on the spindle axle 5, and it is formed with cone pinion 7 at its place, end away from driven gear 13.This cone pinion and 10 engagements of taper spindle travelling gear, this travelling gear is nonrotatably mounted tO on the main shaft 40.To illustrate in greater detail with reference to Fig. 2 and 3 pairs of safety clutch devices 14 below.

The gear teeth of driving gear 9 also drive driving gear 20 with the gear teeth meshing of crank gearing gear 20 and with rotation mode.Travelling gear 20 is nonrotatably mounted tO on the crank gearing main shaft 22, and this crank gearing main shaft then is installed in rotation in the gear-box.Crankshaft cheek 30 is nonrotatably mounted tO the place, end away from travelling gear 20 of transmission main shaft, is formed with the eccentric orfice that is used to hold an eccentric crank pin 32 on the crankshaft cheek 30.This crank-pin 32 extends into the hole of the rear end that is positioned at connecting rod or crank arm 34 from crankshaft cheek, thereby connecting rod 34 can rotate around crank-pin 32.The relative front end of connecting rod 34 is formed with and is used for the hole that lets rotary shaft pin 36 therefrom extend through, thereby this connecting rod 34 can pivot around rotary shaft pin 36.Be assembled in the accommodation hole that is formed in a pair of relative arm through the end with rotary shaft pin 36 this rotary shaft pin 36 is assemblied on the rear portion of piston 38, these arms extend to the back of piston 38.This piston can be installed in the cylindrical, hollow main shaft 40 with moving back and forth, thereby it can move back and forth in this hollow main shaft.The "O seal is assemblied in the annular groove in the periphery that is formed on piston 38, so that between the inner surface of piston 38 and hollow main shaft 40, form gas-tight seal.

Therefore, when actuating motor 2, armature pinion 3 drives driving gear 9 rotatably, and this driving gear drives crank gearing main shaft 22 rotatably through travelling gear 20.Transmission main shaft drives crankshaft cheek 30 rotatably, and will be transformed into the reciprocal driving force that is applied on the piston 38 from the rotary driving force of crankshaft cheek 30 by the crank arm device that crank-pin 32, connecting rod 34 and rotary shaft pin 36 constitute.Like this, when pushing trigger switch 8 and start this motor 2, this piston 38 is reciprocally driven along hollow main shaft 40 back and forth.Driving gear 9 also drives the driving gear 12 of clutch apparatus 14, and this driving gear 12 drives the driven gear 13 of clutch apparatus.The driven gear 13 of clutch apparatus is driving main shaft power transmission shaft 5 rotatably, and this spindle axle is driving main shaft travelling gear 10 and therefore through cone pinion 7 driving main shaft 40 rotatably.

In the hollow main shaft 40 of piston 38 fronts, be provided with a percussion hammer 58, thereby it can move back and forth in hollow main shaft 40 also.O-ring packing is located in the groove of the periphery formation of percussion hammer 58, thereby between percussion hammer 58 and main shaft 40, forms gas-tight seal.In the operating position of percussion hammer 58, when percussion hammer was arranged in the rear portion of air vent (not shown) of main shaft, the air chamber 44 of a sealing was formed between the back of front and percussion hammer 58 of piston 38.Therefore, the reciprocating motion of piston 38 back and forth drives percussion hammer 58 through the air chamber 44 of sealing.When electric hammer gets into idle mode (that is, when from workpiece, electric hammer drill being taken out), percussion hammer 58 is advanced through said air vent.As known in the art, this makes said gas chamber ventilation, and therefore in idle mode this percussion hammer 58 no longer back and forth drive by piston 38.

So guide hit piece 64, thereby it can move back and forth in the previous section of main shaft.Drill bit or instrument 68 can be removably mounted in the tool gripping member 66, thereby drill bit or instrument 68 can carry out limited reciprocating motion in the tool holding part of main shaft.When percussion hammer 58 was in its mode of operation and is back and forth driven by piston 38, as known in the art, this percussion hammer clashed into the rear end of hit piece 64 and the rear end that this hit piece 64 passes to these impacts drill bit or instrument 68 repeatedly.These impacts pass to material to be processed by drill bit or instrument 68 then.

In the layout of Fig. 1, through the sensor operating conditions of these electric hammers of angular accelerometer 16 monitoring for example.Signal through input interface (input interface) autobiography sensor in future 16 sends the electronics assessment unit that can form microcontroller 17 to.This microcontroller analysis is from the signal of accelerometer 16 and be programmed in the time will congestion situations occurring, produce the output signal.For example, can use at the next output signal that in the time will congestion situations occurring, produces of the structure described in US5584619, US5914882 or the EP771619.This caution signal has triggered motor 2 power supplies of being given electric hammer by the circuit 18 of power supply energy supply.This circuit 18 provides electric current to electromagnet 19 when being triggered, this makes clutch apparatus 14 separate to interrupt passing to spindle axle 5 from the driving force of driving gear 9.

In Fig. 2, demonstrate an embodiment of the safety clutch device of the device that is applicable to Fig. 1.The driving gear 12 of safety clutch device 14 is installed in rotation in the electric hammer shell through bearing 15.Driving gear 12 is mounted to around actuator shaft 21 and rotates, and this actuator shaft can axially slide with respect to driving gear.The driven gear 13 of safety clutch device 14 is installed in rotation in the electric hammer shell through bearing 23.This driven gear 13 also is mounted to the hole 24 of rotating and be formed with the first end that is used for holding slidably actuator shaft 21 around actuator shaft in axial sliding 21.

Between the driving gear 12 of safety clutch device 14 and driven gear 13, transmit rotary driving force through a plurality of location ball (locking ball) 25.Driving gear 12 is formed with a cylindrical sleeve part 12a, and it extends in the cylindrical sleeve part 13a of driven gear 13.These location balls 25 are installed in radially to form and pass in the respective aperture of this cylindrical sleeve part 12a.These balls are mounted to and can move along radial direction.Actuator shaft 21 has the diameter-increasing portion 21a that can in the cylindrical sleeve part 12a of driving gear 12, slide.Cylindrical sleeve 26 is installed on the diameter-increasing portion 21a of coaxial with it actuator shaft, and is installed in the space between actuator shaft 21 and cylindrical sleeve part 12a.Cylindrical sleeve 26 is flexible; And be used for location ball 25 is biased into position radially outward, these location balls are bonded among the corresponding one group of depression 13b in the inside surface of the sagittal plane of the cylindrical sleeve part 13a that is formed on driven gear in this position.These depressions 13b (referring to the left side of Fig. 2) by one group of inclined ridges portion separately.When location ball 25 engaged with these depressions 13b, rotary driving force transmitted between driving gear 12 and driven gear 13, and through spindle axle 5 rotary driving force is passed to main shaft 40.

When actuator shaft 21 was in the position shown in Fig. 2, this clutch apparatus 14 was as safety clutch.When being lower than pre-determined torque, resilient sleeve 26 will locate ball 25 be biased into driven gear 13 in depression 13b engage, will pass on to driven gear 13 from the rotation of driving gear 12 thus.Therefore, through spindle axle 5 rotary driving force is passed to main shaft 40.But; When being higher than pre-determined torque; Be not enough to location ball 25 is biased among the depression 13b in the driven gear 13 from the biasing force of resilient sleeve 26, and these balls can radially inwardly move to climb up the inclined-plane and in the spine between these depressions 13b (referring to the right of Fig. 2).Therefore, driven gear 13 rotates with respect to driving gear 12, and has cut off rotary driving force to spindle axle 5 and therefore to the transmission of main shaft 40.

The safety clutch device of Fig. 2 also is used for when detecting congestion situations, cutting off and applies rotary driving force to main shaft 40.Thereby when analyzing this microprocessor through 17 pairs of signals of microprocessor and confirm just congestion situations to occur, will export signal from microprocessor and input to circuit 18 from accelerometer 16.This makes circuit 18 apply electric current to electromagnet 19.Electromagnet is installed in the electric hammer shell 4, makes it surround an end of actuator shaft 21, this end is away from the end in the hole that is contained in driven gear 13 24.Magnetic element 27 is installed on the end of the actuator shaft 21 that is surrounded by electromagnet 19.When electromagnet 19 provides electric current, between electromagnet 19 and magnetic element 27, produce magnetic force, this magnetic force is directed downwards the pulling magnetic element along the arrow A of Fig. 2.Actuator shaft 21 moves down the substrate (base) against the cylindrical sleeve 12a of driving gear 12 up to the diameter-increasing portion 21a of actuator shaft 21.This motion of actuator shaft 21 makes resilient sleeve 26 move along being directed downwards of arrow A and engages with location ball 25 up to the top edge that is resilient sleeve.Therefore, be applied to the radially outward biasing force of location on the ball 25 by bias voltage sleeve 26 and obviously reduce, and the location ball radially inwardly motion leave the depression 13a among the cylindrical sleeve 13a of driven gear 13.Therefore therefore, cut off through spindle axle 5 and offer driven gear 13 and offer the rotary driving force of main shaft 40.Therefore, in case to electromagnet 19 electric current is provided from circuit 18, then clutch apparatus 14 separates and no longer through clutch apparatus 14 rotary driving force is passed to main shaft 40.Like this, avoided causing potential danger owing to congestion situations occurring.Back-moving spring can be set makes actuator shaft 21 turn back to its home position.

Should be noted that the separation of the clutch apparatus 14 of Fig. 2 also can be used for electric hammer is switched to its hammering mode position, wherein rotary driving force is not passed to main shaft 40.This patterns of change can adopt electromagnet 19 that actuator shaft 21 motions are carried out with the mode of electromagnetism, perhaps can carry out through utilizing mechanical part to make actuator shaft move mechanically.

In Fig. 3, demonstrate second embodiment of the safety clutch device of the device that is applicable to Fig. 1.Driving gear 12, driven gear 13 and actuator shaft 21 are installed in the shell as Fig. 2 embodiment is said.Rotary driving force transmits between the driving gear 12 of safety clutch device 14 and driven gear 13 through a plurality of location ball 25.Driving gear 12 is formed with a cylindrical sleeve part 12a, and it extends in the cylindrical sleeve part 13a of driven gear 13.These location balls 25 are installed in and form in the respective aperture of passing cylindrical sleeve part 12a so that can move along radial direction.Actuator shaft 21 has the diameter-increasing portion 21a that can in the cylindrical sleeve part 12a of driving gear 12, slide.One cylindrical sleeve 26 is positioned at coaxial with it cylindrical sleeve part 12a, and in the space between actuator shaft 21 and cylindrical sleeve part 12a.Cylindrical sleeve 26 is flexible; And the diameter-increasing portion 21a of actuator shaft is bearing on the inner surface of resilient sleeve 26; To strengthen biasing force from resilient sleeve; This biasing force is used for location ball 25 is biased into position radially outward, and the corresponding one group of depression 13b in this position in the inside surface of these location balls and the sagittal planes of the cylindrical sleeve part 13a that is formed on driven gear engages.These depressions 13b by one group of inclined ridges portion separately.When these location balls 25 engage with these depressions 13b (referring to the left side of Fig. 3), rotary driving force transmits between driving gear 12 and driven gear 13, and through spindle axle 5 rotary driving force is passed to main shaft 40.

When the diameter-increasing portion 21a of this actuator shaft 21 was in by the position shown in the dotted line a among Fig. 3, this clutch apparatus 14 was as safety clutch.When being lower than pre-determined torque, the resilient sleeve of strengthening by the diameter-increasing portion 21a of actuator shaft 21 26 will locate ball 25 be biased into driven gear 13 in depression 13b engage, will pass to driven gear 13 from the rotation of driving gear 12 thus.Therefore, rotary driving force passes to main shaft 40 through spindle axle 5.But; When being higher than pre-determined torque; Becoming from the biasing force of resilient sleeve 26 is not enough to location ball 25 is biased among the depression 13b in the driven gear 13, and these balls can radially inwardly move (referring to the right of Fig. 3) to climb up the inclined-plane and in the spine between these depressions 13b.Therefore, driven gear 13 rotates with respect to driving gear 12, and has cut off rotary driving force to spindle axle 5 and therefore to the transmission of main shaft 40.

The safety clutch device of Fig. 3 also is used for when detecting congestion situations, cutting off and applies rotary driving force to main shaft 40.Electromagnet 19 is installed in the electric hammer shell 4, makes it surround an end of actuator shaft 21, this end is away from the end in the hole that is contained in driven gear 13 24.One magnetic element 27 is installed on the end of the actuator shaft 21 that is surrounded by electromagnet 19.When electromagnet 19 provides electric current, between electromagnet 19 and magnetic element 27, produce magnetic force, this magnetic force along the direction of the arrow A of Fig. 3 with magnetic element to pulling down to by the position shown in the dotted line b among Fig. 3.Actuator shaft 21 moves downward the basal edge that abuts against the cylindrical sleeve 12a of driving gear 12 up to the diameter-increasing portion 21a of actuator shaft 21.This motion of actuator shaft 21 makes the diameter-increasing portion 21a of actuator shaft 21 move along being directed downwards of arrow A and just is pressed against on the lower edge of resilient sleeve 26 up to it.Therefore, be applied to the radially outward biasing force of location on the ball 25 by bias voltage sleeve 26 and obviously reduce, and the radially inwardly motion (referring to the right of Fig. 3) of location ball, leave the depression 13a among the cylindrical sleeve 13a of driven gear 13.Therefore therefore, cut off through spindle axle 5 to driven gear 13 and offer the rotary driving force that main shaft 40 provides.Therefore, in case to electromagnet 19 electric current is provided from circuit 18, then clutch apparatus 14 separates and no longer through clutch apparatus 14 rotary driving force is passed to main shaft 40.Like this, avoided causing potential danger owing to congestion situations occurring.Back-moving spring can be set makes actuator shaft 21 turn back to its home position.

Should be noted that the separation of the clutch apparatus 14 of Fig. 3 also can be used for electric hammer is switched to its hammering mode position, does not wherein have rotary driving force to pass to main shaft 40.This patterns of change can adopt electromagnet 19 that actuator shaft 21 motions are carried out with the mode of electromagnetism, perhaps can carry out through utilizing mechanical part to make actuator shaft move mechanically.

Realize cutting off the rotary driving force that offers main shaft 40 through being utilized in the existing building block of the power train that is used for hammer mechanism (for example safety clutch).In the embodiment of Fig. 1 to 3, the safety clutch device is made amendment, so that the rotary driving force that is applied on the main shaft 40 is cut off in its torque that also can when detecting congestion situations, through reduction safety clutch slided.

In Fig. 4, demonstrate electric hammer according to second aspect present invention.Electric hammer among Fig. 4 and the difference of Fig. 1 are that 40 rotation power train is different from motor 2 to main shaft.Driving force from driving gear 9 passes to spindle axle 5 through the gear 41 that is press fitted on the spindle axle.At it away from place, end of gear 41, this spindle axle 5 be formed with can with the pinion 7 of spindle transmission gear 10 engagements.This spindle transmission gear 10 is installed on the sliding sleeve 43, and this sliding sleeve can endwisely slip and still be installed on the main shaft 40 to rotational fixation.As shown in Figure 4, the installation of spindle transmission gear 10 on sliding sleeve 43 can be the installation of rotation and axial restraint, and it is so arranged, thereby makes the rotation rotation of spindle transmission gear 10 drive sliding sleeve 43 and therefore rotate driving main shaft 40.Perhaps; As known in the art; This installation can be passed through so safety clutch of layout, thereby thereby when being lower than pre-determined torque, rotate driving sliding sleeve 43 rotation driving main shaft 40 in the rotation of spindle transmission gear 10, and when being higher than pre-determined torque, slide with respect to sliding sleeve; Thereby when being higher than said pre-determined torque, main shaft 40 no longer is driven in rotation.

Have two kinds of patterns at the electric hammer shown in Fig. 4, i.e. a hammering pattern and rotary hammer blow mode.Fig. 4 demonstrates the rotary hammer blow mode, and wherein the pinion 7 of spindle axle 5 and spindle transmission gear 10 engagements that are bevel gear drive said main shaft 40 thereby pass through sliding sleeve 43 rotations.Therefore, the instrument 68 that is installed in the front end of main shaft is driven in rotation and accepts simultaneously the repeated stock from the hit piece 64 of hammer mechanism through main shaft.Pattern change knob 45 is installed in the electric hammer shell 4 rotatably and is formed with cam pin 47, and this pin extends into electric hammer shell 4.This cam pin 47 is contained in and is positioned at the groove that pattern changes first rear end of connecting rod 49.The front end that this pattern changes connecting rod is formed with a finger 49a, this finger can with the protruding periphery at the front end place that is positioned at sliding sleeve 43.In the position shown in Fig. 4, pattern is changed knob can not engage with sliding sleeve 43 to the finger 49a of its rotary hammer blow mode position and connecting rod 49.Therefore this sliding sleeve is biased into as shown in Figure 4 its rotary hammer blow mode position backward by helical spring 50.This helical spring 50 is installed round main shaft 40, and in effect between circlip on the main shaft of spring front end 51 and the sliding sleeve 43 at the spring rear end place, so that bias slide sleeve backward.

Can change knob 45 through rotation mode electric hammer is changed over a hammering pattern, thus the left side motion of cam pin 47 in Fig. 4.Cam pin 47 changes connecting rod 49 with pattern and engages to make it travel forward (left side in Fig. 4).Pattern changes the finger 49a of connecting rod and the edge join of sliding sleeve 43 promotes it forward with the biasing force that overcomes spring 50.Spindle transmission gear 10 is axially fixed on the sliding sleeve, so spindle transmission gear 10 breaks away from sliding sleeve 43 under the situation of pinion 7 of spindle axles and travel forward, and therefore cuts off and to main shaft rotary driving force is provided.As known in the art, in the forward facing position of spindle transmission gear 10, spindle transmission gear can mesh with the one group of cooperation tooth that is installed in the shell 4, thereby in its hammering pattern, this main shaft can not be rotated.

When making pattern change knob get back to its rotary hammer blow mode position, as shown in fig. 4, sliding sleeve 43 is pushed back into Fig. 4 position by spring 50.

Electric hammer in Fig. 4 has with top with reference to the said identical congestion situations checkout gear of Fig. 1; It comprises accelerometer 16, microprocessor 17, circuit 18 and electromagnet 19; Except electromagnet 19 surrounds spindle transmission gear 10, and circuit 18 is repositioned between microprocessor and the electromagnet.Spindle transmission gear 10 and/or sliding sleeve 43 part are at least formed by magnetic material.Therefore; When detecting congestion situations; Circuit 18 provides electric current to electromagnet 19, and this between electromagnet 19 and the magnetic material in spindle transmission gear and/or sliding sleeve, produces magnetic force so that the biasing force that sliding sleeve 43 and spindle transmission gear 10 overcome spring 50 engagement of the pinion 7 of (left side in Fig. 4) motion and disengaging and spindle axle 5 forward.Like this, when detecting congestion situations, through making the disengagement that is in transmission connection between spindle axle 5 and spindle transmission gear 10, thereby be breaking at the rotary driving force between motor 2 and the main shaft 40.Thereby this device only needs to add electromagnet 19 and magnetic material joined cut off the rotary driving force that offers main shaft in spindle transmission gear 10 and/or the sliding sleeve 43; Need not increase any other parts, perhaps existing electric hammer building block done any variation.In the embodiment of Fig. 4, this is to realize through using existing pattern change building block to switch on and off the rotary driving force that offers electric hammer main shaft 40.

Optional is that as known in the art, the electric hammer of Fig. 4 can be designed to also have a drill mode, in this pattern, the electric hammer transmission mechanism is broken off.

Similar at the electric hammer shown in Fig. 5 and Fig. 1, except opposite with the calutron that is used to detect congestion situations, it has the pure mechanical device that is used to detect congestion situations.Replace accelerometer 16, microcontroller 17, circuit 18 and the electromagnet 19 of Fig. 1 embodiment, the electric hammer of Fig. 5 has the mechanical device of seeing from the front among Fig. 6.

The device that detects congestion situations in being used to shown in Fig. 5 and 6 comprises the inertia mass 72 that is formed on control stick 74 lower ends; The upper end of this control stick 74 pivots with respect to the electric hammer shell through trunnion 76 and installs, thereby quality 72 pivots around the axis that is parallel to main-shaft axis 78 extensions 80 with control stick 74.This quality is connected with installing component 84 through spring 82, and this installing component is installed with respect to electric hammer shell 4 rigidity.The first end of spring 82 is fixed on the installing component 84, and the second end of this spring 82 is fixed on the quality 72.When this electric hammer of operation, therefore this quality vibration pivots around trunnion 76 owing to the vibration that from the electric hammer operation, occurs.This spring 82 is arranged to the vibration of this quality 72 that decays, and therefore minimizes in the pivot degree of electric hammer chien shih error-free running period quality 72 around trunnion 76.The upper end of control stick 74 above trunnion 76 is formed with a breech lock flange 86, this flange during the electric hammer normal running with the engaging in the face of breech lock flange 88 of following lower end with reference to Fig. 7 and the 8 described actuator shafts 21 that are formed on clutch apparatus 14.The actuator shaft 21 of this clutch apparatus 14 is mounted to slidably in the building block of clutch and in lining 90 and moves along the direction of arrow X.Upwards push actuator shaft 21 through strong spring 92 along the direction of clutch apparatus 14.

During the normal running of electric hammer, the damping action through spring 82 limits the pivoting action of quality 72 around trunnion 76.But when congestion situations occurring, drill bit 68 rotational fixation and make the electric hammer shell driven by motor 2 rotation around drill bit 68 through the main axis rotation transmission device in material to be processed.This makes the bottom of electric hammer shell 4a rotate around main-shaft axis 78 with very high acceleration, thereby moves along the direction of leaving Fig. 5 paper in said bottom.The inertia force of quality 72 makes this quality promptly pivot around pin 76 along the direction of the arrow Y in Fig. 6 along the direction that gets into the paper among Fig. 5, thus compression spring 82.The upper end of control stick 74 above pin 76 pivots with respect to the direction of trunnion 76 along arrow Z, and this makes the breech lock flange 86 of control stick 74 and the breech lock flange 88 of actuator shaft 21 break away from.As following said the same with 8 with reference to Fig. 7, strong spring 92 promotes actuator shafts 21 and makes it moving upward then, thereby makes clutch 14 separate, and has therefore cut off the rotary driving force and the shell 4 that pass to main shaft 40 from motor 2 and no longer has been driven in rotation.

On actuator shaft 21, be provided with a control stick 94, be used at the congestion situations checkout gear that resets Fig. 6 in response to detecting congestion situations after having cut off rotary driving force.This control stick 94 can extend in the outside of electric hammer shell 4 or engage with the sliding knob that can activate from the outside of shell 4, thus can with control stick 94 and so actuator shaft to drop-down.Spur axle 21 o'clock downwards in the power that overcomes strong spring 92; Be formed on the inclination outer rim 96 on the actuator shaft 21; 98 engage with the upper end of control stick 74 so that the biasing force that control stick 74 overcomes spring 82 pivots around trunnion 76 along the direction of arrow Z; So that the

breech lock flange

86,88 of actuator shaft 21 and control stick 74 is engaged again.

In Fig. 7, demonstrate the safety clutch device in the electric hammer that is suitable for use in Fig. 5.Driving gear 12, driven gear 13 and actuator shaft 21 are installed in the shell as said to Fig. 2 embodiment, and have extra guide bushing 90, are used for guiding slidably as top with reference to Fig. 5 and 6 described actuator shafts 21.Rotary driving force transmits between the driving gear 12 of safety clutch device 14 and driven gear 13 by a plurality of location ball 25.Driving gear 12 is formed with cylindrical sleeve part 12a, and it extends in the cylindrical sleeve part 13a of driven gear 13.These location balls 25 are installed in the respective aperture of passing this cylindrical sleeve part 12a formation, thereby can move along radial direction.Actuator shaft 21 has the reduced diameter portion that can in the cylindrical sleeve part 12a of driving gear 12, slide and divides 21b.A plurality of spring elements 100 were opened and are installed pivotly with respect to reduced diameter portion branch (21b) through ball 102 round 21 circle spacings of actuator shaft.Each spring element comprises the helical spring 106 that is installed in the guiding overcoat (guide jacket) 104 and between these balls 102 and location ball 25, radially extends with respect to actuator shaft 21.Each ball 102 is contained in and is arranged in the corresponding depression that reduced diameter portion divides 21b and the depression at the radial inner end place of the elastic overcoat 104 that is positioned at respective springs element 100.This makes these locking members 100 between the left side of Fig. 7 and the position shown in the right, to pivot.In the position shown in Fig. 7 left side; These spring elements 100 will be located ball 25 and will be biased into position radially outward, and the corresponding one group of depression 13b in this position in the inside surface of these location balls and the sagittal planes of the cylindrical sleeve part 13a that is formed on driven gear engages.These depressions 13b by one group of inclined ridges portion separately.When location ball 25 engaged with these depressions 13b, rotary driving force transmitted between driving gear 12 and driven gear 13, and through spindle axle 5 rotary driving force is passed to main shaft 40.

When the reduced diameter portion of actuator shaft 21 divided 21b to be in the position shown in Fig. 7 left side, this clutch apparatus 14 was as safety clutch.When being lower than pre-determined torque, spring element 100 will locate ball 25 be biased into driven gear 13 in depression 13b engage, will pass on to driven gear 13 from the rotation of driving gear 12 thus.Therefore, through spindle axle 5 rotary driving force is passed to main shaft 40.But; When being higher than pre-determined torque; Biasing force from spring element 100 is not enough to location ball 25 is biased into the depression 13b in the driven gear 13, and these balls can radially inwardly move to climb up the inclined-plane and to cross the spine between these depressions 13b.Therefore, driven gear 13 rotates with respect to driving gear 12, and has cut off rotary driving force to spindle axle 5 and therefore to the transmission of main shaft 40.

The safety clutch device of Fig. 7 also is used for when detecting congestion situations, cutting off and applies rotary driving force to main shaft 40.As top said the same with 6 with reference to Fig. 5, when congestion situations occurring, inertia mass 72 pivots along direction Y, thereby makes the upper end of control stick 74 pivot along direction Z, makes that therefore the breech lock flange 86,88 on control stick 74 and actuator shaft 21 separates.One strong spring 92 is used for upwards spurring the diameter-increasing portion 21c of actuator shaft; And therefore this actuator shaft is upwards moved in the position shown in Fig. 7 the right, the lower end of this strong spring 92 is axially fixed on the diameter-increasing portion 21c and its top axial is fixed on the driving gear 12.This motion of actuator shaft 21 makes the reduced diameter portion of actuator shaft 21 divide 21b to move upward and makes spring element pivot around pivot ball 102.The pivot of these spring elements 100 causes spring 104 to stretch, and this has reduced spring element 100 and has acted on the biasing force on the ball 25 of location.Like this, from these spring elements 100 act on that the radially outward biasing force of location on the ball 25 obviously reduces and these location balls radially inwardly motion leave the depression 13a the cylindrical sleeve 13a of driven gear 13.Therefore therefore, cut off through spindle axle 5 and offer driven gear 13 and offer the rotary driving force of main shaft 40.Therefore, in case the breech lock flange 86,88 of control stick 74 and clutch actuation axle 21 separates, then no longer rotary driving force is passed to main shaft 40 through clutch apparatus 14.Like this, avoided occurring owing to congestion situations causes potential danger.

In Fig. 8, demonstrate second embodiment of the safety clutch device in the electric hammer that is suitable for use in Fig. 5.Driving gear 12, driven gear 13 and actuator shaft 21 are installed in the shell as said to Fig. 2 embodiment; And have extra guide bushing (guiding bushing) 90, be used for guiding slidably as top with reference to Fig. 5 and 6 described actuator shafts 21.Rotary driving force transmits between the driving gear 12 of safety clutch device 14 and driven gear 13 by a plurality of location ball 25.Driving gear 12 is formed with cylindrical sleeve part 12a, and it extends in the cylindrical sleeve part 13a of driven gear 13.These location balls 25 are installed in the respective aperture of passing this cylindrical sleeve part 12a formation, thereby can move along radial direction.Actuator shaft 21 is formed with garden shape parts (annulea) 121a to 121c that three diameters increase, wherein between 121b with other mutually diameter group reduce.Garden shape parts 121a to 121c can slide in the cylindrical sleeve part 12a of driving gear 12.First group of a plurality of spring 110 were opened and are radially extended with respect to actuator shaft 21 two garden shape parts 121c and the 121b below from actuator shaft 21 to corresponding induction element 112 round 21 circle spacings of actuator shaft.Second group of a plurality of spring 114 were opened and are radially extended with respect to actuator shaft 21 two garden shape parts 121a and the 121b in the above from actuator shaft to corresponding induction element 112 round 21 circle spacings of actuator shaft.The radial outer end of each spring is installed round the corresponding latch that extends radially inwardly 116 that is formed on the respective guide element 112.Each induction element is formed with two latches 116, is used to engage the last latch and the following latch that is used to engage the end that is located immediately at one of them spring 110 below said one of them spring 114 of the end of one of them spring 114.The biasing force radially outward that first group of a plurality of spring 110 apply than more than second spring 114 a little less than.According to the axial location of actuator shaft 21, strong spring 114 or weak spring 110 pass through induction element 112 bias voltage location ball 25 radially outward.

When these

breech lock flanges

86,88 joints and spring 92 stretching, extensions, garden shape parts 121c moves downward and abuts against the substrate of driving gear sleeve 12 from its position among Fig. 8.In this position, strong spring 114 is ball 25 radially inner sides in the location, and clutch apparatus 14 is as safety clutch.When being lower than pre-determined torque, strong spring 114 will locate ball 25 be biased into driven gear 13 in depression 13b engage, will pass to driven gear 13 from the rotation of driving gear 12 thus.Therefore, rotary driving force is delivered to main shaft 40 through spindle axle 5.But; When being higher than pre-determined torque; Becoming from the biasing force of spring 114 is not enough to location ball 25 bias voltages are advanced the depression 13b in driven gear 13, and each induction element 112 inwardly pivots and these balls can radially inwardly move to climb up the inclined-plane and to cross the spine between these depressions 13b.Therefore, driven gear 13 rotates with respect to driving gear 12, and has cut off the rotary driving force that offers spindle axle 5 and therefore offer main shaft 40.

The safety clutch device of Fig. 8 also is used for when detecting congestion situations, cutting off and applies rotary driving force to main shaft 40.As top said the same with 6 with reference to Fig. 5, when congestion situations occurring, inertia mass 72 pivots along direction Y, thereby makes the upper end of control stick 74 pivot along direction Z, makes that therefore the breech lock flange 86,88 on control stick 74 and actuator shaft 21 separates.One strong spring 92 is used for upwards spurring the diameter-increasing portion 21c of actuator shaft and therefore this actuator shaft is upwards moved in the position shown in Fig. 8, and the lower end of this strong spring is axially fixed on the diameter-increasing portion 21c and its top axial is fixed on the driving gear 12.This motion of actuator shaft 21 makes weak spring 110 with respect to the radially inwardly motion of location ball 25.Like this, compare with the biasing force that spring 114 applies, spring 110 act on that the radially outward biasing force of location on the ball 25 obviously reduces and these location balls radially inwardly motion leave the depression 13a among the cylindrical sleeve 13a of driven gear 13.Therefore therefore, cut off through spindle axle 5 and offer driven gear 13 and offer the rotary driving force of main shaft 40.Therefore, in case the breech lock flange 86,88 of control stick 74 and clutch actuation axle 21 separates, then no longer rotary driving force is passed to main shaft 40 through clutch apparatus 14.Like this, avoided causing potential danger owing to congestion situations occurring.

Should be noted that through actuator shaft 21 is made amendment, Fig. 2 and 3 clutch apparatus can be suitable for use in the electric hammer of Fig. 5, and the clutch apparatus of Fig. 7 and 8 is suitable for use in the electric hammer of Fig. 1.

Fig. 9 and 10 demonstrates another embodiment of the clutch apparatus in the electric hammer that is suitable for use in Fig. 1, as long as the bottom of actuator shaft 21 is processed by magnetic element.Fig. 9 and 10 embodiment also are suitable for use in the device of Fig. 5, as long as increased the spring assembly that is used for actuator shaft is biased into top position.

Power transmission shaft 5 is formed with the pinion 7 that is used for spindle transmission gear 10 engagements in the top.This axle is installed in rotation in the shell through bearing 23 and 15.Thereby power transmission shaft 5 be hollow and actuator shaft 21 be installed in and can in power transmission shaft 5, endwisely slip in the power transmission shaft, and the lower end of actuator shaft extends beyond the end away from pinion 7 of power transmission shaft 5.Driving gear 12 is installed in rotation on the power transmission shaft 5.

The first minor diameter driven gear 13 is installed on the power transmission shaft 5 so that selectively therewith rotate according to the position of actuator shaft 21.First group of clutch ball 25a is located at the corresponding one group of through hole 103a that is arranged in driving gear 12, and these through holes are positioned at the radially inner side of second group of through hole 103.Volute spring 107 passes through packing ring 105 towards driven gear 13c, the axial biased downward clutch of 13d ball 25.This spring extends to the radial outer end that is resisted against on the packing ring 105 from the radial inner end that it is resisted against on the shoulder that is formed on the power transmission shaft 5.Packing ring 105 is located in the annular groove that matches in the upside that is formed on driving gear 12.Spring 107 is biased among first group four the clutch ball 25a each among of one group of four depression 109 in the upper surface that is formed on minor diameter driven gear 13.Like this, when being lower than first pre-determined torque, first group of clutch ball 25a passes to minor diameter driven gear 13 from driving gear with rotary driving force.When being higher than first pre-determined torque, first group of clutch ball 25a will deviate from and cross the depression 109 that is formed in the minor diameter driven gear 13, therefore cut off the driving force between driving gear 12 and minor diameter driven gear 13.As described below the same, can pass to power transmission shaft 5 according to the position of actuator shaft 21 from the rotary driving force of minor diameter driven gear 13.

First couple of transmission ball 113a is arranged in the corresponding a pair of hole 105a of going up of power transmission shaft.These transmission balls can with one group four transmission depression 115a in the radially inner edge that is formed on minor diameter driven gear 13 in two engage, thereby rotation drives power transmission shaft 5 and therefore transmission ball 113a is pushed to position radially outward when diameter-increasing portion 121a is positioned at the radially inner side of transmission ball 113a.When the reduced diameter portion of actuator shaft 21 divided 121b to be in radially inner side with respect to transmission ball 113a, the transmission ball can radially inwardly move and separate with the transmission depression 115a of minor diameter driven gear 13, thereby does not have rotary driving force to pass to power transmission shaft 5.

Second largest diameter driven gear 13d is installed on the power transmission shaft 5 so that selectively therewith rotate according to the position of actuator shaft 21.This second largest diameter driven gear is positioned on the following power transmission shaft 5 and with respect to minor diameter driven gear 13a and extends radially outwardly.The periphery of major diameter driven gear 13d extends axially towards driving gear 12 round the circumference of minor diameter driven gear 13.Second group of clutch ball 25b is arranged in corresponding one group of through hole 103b of driving gear 12, and these through holes with respect to first group of through hole 103a radially outward.Volute spring 107 is biased in second group of four clutch ball 25 each through packing ring 105 among in one group of four depression 111 in the upper surface of the periphery that is formed on major diameter driven gear 13d.Like this, when being lower than second pre-determined torque, this second group of clutch ball 25b will pass to major diameter driven gear 13b from the rotary driving force of driving gear.When being higher than second pre-determined torque, this second group of clutch ball 25b will deviate from and cross the depression 111 that is formed among the major diameter driven gear 13d, therefore will be breaking at the driving force between driving gear 12 and the major diameter driven gear 13d.Second pre-determined torque will be higher than first pre-determined torque because at the radial distance between the axis of power transmission shaft 5 and the second group of clutch ball 25b greater than the radial distance between the axis of power transmission shaft and first group of clutch ball 25a.As described below the same, can will pass to power transmission shaft 5 from the rotary driving force of major diameter driven gear 13d according to the position of actuator shaft 21.

Second couple of transmission ball 113b is positioned at the corresponding a pair of hole 105b down of power transmission shaft.These transmission balls can with one group four transmission depression 115b in the radially inner edge that is formed on major diameter driven gear 13d in two engage, thereby rotation drives power transmission shaft 5 and therefore transmission ball 113b is pushed to position radially outward when the diameter-increasing portion 121a of actuator shaft is positioned at transmission ball 113a radially inner side.When the reduced diameter portion of actuator shaft 21 divides 121b to be positioned at radially inner side with respect to transmission ball 113b; These transmission balls can radially inwardly move and separate with the transmission depression 115a of major diameter driven gear 13d, thereby do not have rotary driving force to pass to power transmission shaft 5.

In the primary importance of the actuator shaft 21 of Fig. 9 that on the right of Fig. 9, demonstrates and 10 clutch, have only minor diameter driven gear 13 to drive power transmission shaft 5 through first group of transmission ball 113a rotation.Transmission ball 113a in the primary importance shown in Fig. 9 the right is urged into the transmission depression 115a of minor diameter driven gear 13 and engages.This is because the diameter-increasing portion 121a of actuator shaft is positioned at radially inner side and therefore radially outward promotes these transmission balls with respect to first group of transmission ball 113.The reduced diameter portion that second group of transmission ball 113b can radially move inwardly to actuator shaft 21 is divided 121b and is left the transmission depression 115b among the major diameter driven gear 13d, therefore between major diameter driven gear 13d and power transmission shaft 5, does not transmit any rotary driving force.In this primary importance of the clutch of Fig. 9 and 10, when being lower than the first low pre-determined torque, first group of clutch ball 25a will pass to minor diameter driven gear 13c from the rotary driving force of driving gear.When being higher than first pre-determined torque, first group of clutch ball 13c deviates from and crosses the depression 109 that is formed among the minor diameter driven gear 13c, therefore will be breaking at the driving force between driving gear 12 and the minor diameter driven gear 13c.Therefore, in primary importance, Fig. 9 and 10 clutch apparatus are as the safety clutch in the first relatively low pre-determined torque lower slider.

In the second place of the actuator shaft 21 of the clutch of the Fig. 9 shown in Fig. 9 left side and 10, minor diameter driven gear 13 can pass through first and second groups of transmission ball 113a with major diameter driven gear 13d, 113b rotation driving power transmission shaft 5.Transmission ball 113a in the second place shown in Fig. 9 left side, 113b are forced into the transmission depression 115a with minor diameter driven gear 13 and major diameter driven gear 13d, and 115b engages.This be because the diameter-increasing portion 121a of actuator shaft with respect to these two groups of transmission ball 113a, 113b is positioned at radially inner side and therefore radially outward promotes this two groups of transmission balls.In this second place of the clutch of Fig. 9 and 10, when being lower than than bigger second pre-determined torque of first pre-determined torque, each group clutch ball 25a, 25b will pass to its corresponding driven gear 13c, 13d from the rotary driving force of driving gear 12.When being higher than second pre-determined torque, these clutch balls 25a, 25b will deviate from and cross to be formed on corresponding driven gear 13c, the depression 109,111 among the 13d, and therefore will be breaking at driving gear 12 and corresponding driven gear 13c, the driving force between the 13d.Therefore, in the second place, Fig. 9 and 10 clutch apparatus are as the safety clutch in the second pre-determined torque lower slider that is higher than first pre-determined torque.

In order between first and second positions of the clutch of Fig. 9 and 10, to move, actuator shaft moves along being directed downwards of arrow W.For example the same shown in Figure 11 a; This can be connected on the connecting rod 1201 through the lower end with actuator shaft 21c and realize; This connecting rod is operated through the knob 1221 that is activated by the electric hammer user; So that actuator shaft 21 motion slidably in power transmission shaft 5, thereby regulate the slip torque of this safety clutch between first and second pre-determined torque.In the device of Figure 11 a, cam pin 1221a is used for upwards spurring connecting rod 1201 and when knob 1221 rotates, overcomes the biasing force of spring 1241 thus, actuator shaft 21 is upwards spurred from its position among Figure 11 a leave in the position shown in Figure 11 a.When the position shown in Figure 11 a is got back in knob 1221 motion, spring 1241 make connecting rod and therefore actuator shaft turn back to the position shown in Figure 11 a.The position of Figure 11 a will be in the high torque (HT) position shown in Fig. 9 left side, thereby and connecting rod 1201 and actuator shaft 21 will be entered into the low torque position shown in Fig. 9 the right by the position that Figure 11 a is left in pulling upwards.Optional is that the lower end of actuator shaft 21 can directly be connected with knob.

Fig. 9 and 10 clutch apparatus have the 3rd position, and the reduced diameter portion of actuator shaft divides 21b with respect to these two groups of transmission ball 113a in this position, and 113b is positioned at radially inner side.Therefore, these transmission balls can radially inwardly move and break away from driven gear 13c, the transmission depression 115a of 13d, and 115b, and, do not have the rotary driving force transmission between 13d and the power transmission shaft at driven gear 13c.The 3rd position of actuator shaft 21 edges direction from low torque position Fig. 9 the right shown in the phase shift opposite, cut off the rotary driving force that offers power transmission shaft 5 and therefore offer main shaft 40 with arrow W.

Fig. 9 and 10 clutch apparatus can move in the 3rd position through changing connecting rod 1261 in the pattern shown in Figure 11 a and the 11b.This pattern changes connecting rod can be through changing knob by the pattern that the electric hammer user activates and between its position in Figure 11 a and 11b, activateding.In the position of Figure 11 a, pattern changes connecting rod 1261 separates with actuator shaft 21, and this position will change the only boring or the rotation hammering position of connecting rod for pattern.Therefore, the connecting rod 1261 that is remained in the position of Figure 11 a by spring 1281 only can not interfered as top with reference to the described device that is used to change pre-determined torque of Figure 11 a in boring and/or the rotary hammer blow mode.In the position of Figure 11 b; The biasing force that has made connecting rod 1261 overcome spring 1281 through pattern change knob moves in its hammering mode position, and wherein connecting rod 1261 engages with the bottom 21c of actuator shaft 21 so that it is from moving upward in the position shown in Fig. 9 the right.This has cut off from driving gear 12 to power transmission shaft 5 driving force, so main shaft 40 or the drill bit 68 that is installed in wherein have no rotation output.The linkage 1201,1221 that is used between the low torque of the rotary mode of electric hammer and high torque (HT) position, switching can interference pattern changes connecting rod 1261 not make electric hammer be moved into the operation of its non-rotary mode.When pattern change knob turns back to the rotary mode position, the biasing force of spring 1281 will make pattern change the position that connecting rod 1261 is got back to its Figure 11 a.

The 3rd position of this clutch apparatus also can be used for when detecting congestion situations, cutting off the rotary driving force that passes to main shaft 40.If detect congestion situations with the electronics mode; Then can give electromagnet power supply round actuator shaft 21 bottoms; Be assemblied in the magnetic element on the actuator shaft bottom with resistance, and the biasing force that makes actuator shaft overcome

spring

1241 and 1281 moves upward to its 3rd position.Should be noted that, be used between first and second positions device for switching 1201,1221 and change

linkage

1261,1281 with the pattern that is used to switch to the 3rd position and can not hinder actuator shaft to move to position above it in response to the energising of electromagnet.

As the replacement of electromagnet, can use the mechanical device of the congestion situations that is used to detect Fig. 6 to combine with the clutch apparatus of Fig. 9 and 10.Here, separate if the breech lock flange becomes in congestion situations with bottom 21c, then the breech lock flange 86 of connecting rod 74 will engage the bottom 21c of actuator shaft 21, thereby and this axle will receive bias voltage and move upward in the 3rd position.

Figure 12 demonstrates another design of safety clutch 14, and this clutch can be used to and carried out the pattern change or selectively be breaking at the rotary driving force between driving gear 12 and the driven gear 13 in response to congestion situations.Driving gear 12 is installed in rotation on the power transmission shaft 5 and has and is installed in the clutch ball 25 that extends axially in the hole of passing driving gear.Driven gear 13 is nonrotatably mounted tO on the power transmission shaft 5, and on its surface facing to driving gear 12, is formed with one group of depression 13b that is used for holding these clutch balls 12.One volute spring 107 promotes driven gear 13 towards driving gear 12.Below driving gear 12 and in primary importance shown in Figure 12, be provided with an actuating ring 130, this ring 130 is pushed into clutch ball 25 with depression 13b in driven gear 13 and engages.This actuating ring 130 can move downward a position along direction V, and it no longer is pushed into the clutch ball with depression 13b in driven gear 13 and engages in this position.

In the position shown in Figure 12, clutch is as safety clutch.When being lower than pre-determined torque, volute spring 107 is pushed into clutch ball 25 with depression 13b in driven gear 13 and engages, and will pass to driven gear 13 from the rotation of driving gear 12 thus.Therefore, rotary driving force passes to main shaft 40 through spindle axle 5.But; When being higher than pre-determined torque; Becoming from the biasing force of volute spring 107 is not enough to clutch ball 25 is biased among the depression 13b in the driven gear 13, and power and axially-movable that driven gear 13 can overcome spring 107 are to cross clutch ball 25.Therefore, driven gear 13 rotates with respect to driving gear 12, and has cut off the rotary driving force that passes to spindle axle 5 and therefore pass to main shaft 40.When actuating ring moves to the second place, because clutch ball 25 can not be bonded among the depression 13b in the driven gear 13, so between driving gear 12 and driven gear 13, do not transmit rotary driving force.Therefore, when detecting congestion situations, lead ring moves to break off rotary driving force to the second place.This can be through realizing with reference to Fig. 1,5 and 6 described machineries or electromechanical assembly as top.Perhaps optional in addition is when switching to the non-rotary mode of electric hammer, can make binding ring 130 move to the second place through mode changing apparatus.

Referring now to Figure 13, the electric hammer of another embodiment of the invention comprises that a motor 2, a spindle of being surrounded by plastic casing 8 are 4 and one crank gear 6.Back handle 10 and trigger switch device (not shown) are assemblied in the rear portion of shell 8.The cable (not shown) extends through cable duct tube and motor 2 is connected with the power supply of outside.Therefore, when cable was connected with power supply and pushes the trigger switch device, motor 2 activated the armature with rotary drive motor 2.

Main driving gear 12 is press fitted on the motor pinion 14 and has tooth, and the tooth engagement of the driving gear 16 of this tooth and safety clutch device 18 drives driving gear 16 with rotation.When at these two gears 16, if when torque transmitted is lower than predetermined threshold between 20 and do not detect any congestion situations, then driving gear 16 rotations drive the bevel gear 20 of safety clutch devices 18.This

bevel gear

20 and 22 engagements of taper spindle travelling gear, this taper spindle travelling gear 22 is installed in rotation on the cylindrical, hollow main shaft 40 and can freely rotates around main shaft.This taper spindle travelling gear 22 rotates driving main shaft 40 through rotation transmission clutch described below.To explain in more detail this safety clutch device 18 below.

The tooth of driving gear 12 also drives this crank gearing gear 24 with the indented joint of crank gearing gear 24 with rotation.This crank gearing gear 24 is nonrotatably mounted tO on the crank gearing main shaft 26.Crankshaft cheek 30 is nonrotatably mounted tO the place, end away from crank gearing gear 24 of transmission main shaft 26, and this crankshaft cheek is formed with the eccentric orfice that is used to hold eccentric crank pin 32.This crank-pin 32 extends into the hole of the rear end that is positioned at connecting rod or crank arm 34 from crankshaft cheek 30, thereby connecting rod 34 can pivot around crank-pin 32.The relative front end of connecting rod 34 is formed with and is used for the hole that lets rotary shaft pin 36 therefrom extend through, thereby this connecting rod 34 can pivot around crank-pin 32.Be assembled in the accommodation hole that is formed in a pair of relative arm 42 through the end with rotary shaft pin 36, this rotary shaft pin 36 is assemblied on the rear portion of piston 38, these arms extend to the rear portion of piston 38.This piston 38 can be installed in the cylindrical, hollow main shaft 40 with moving back and forth, thereby it can move back and forth in this hollow main shaft.O-ring packing 44 is assemblied in the annular groove in the periphery that is formed on piston 38 so that between the inner surface of piston 38 and hollow main shaft 40, form gas-tight seal.

Therefore, when actuating motor 2, armature pinion 3 drives main driving gear 12 rotatably, and this main driving gear 12 drives crank gearing main shaft 26 rotatably through crank gearing gear 24.Transmission main shaft 26 drives crankshaft cheek 30 rotatably, and will be transformed into the reciprocal driving force that is applied on the piston 38 from the rotary driving force of crankshaft cheek 30 by the crank arm device that crank-pin 32, connecting rod 34 and rotary shaft pin 36 constitute.Like this, through pushing when being positioned at the trigger switch (not shown) of back on the handle 10 and starting this motor 2, this piston 38 is reciprocally driven along hollow main shaft 40 back and forth.This main driving gear 12 has also driven the driving gear 16 of clutch apparatus 18, and this driving gear 16 drives the bevel gear 20 of clutch apparatus.When spindle transmission gear 22 and main shaft 40 drives when being connected, the bevel gear 20 rotation driving main shaft travelling gears 22 of clutch apparatus and so rotate driving main shaft 40.When the mechanism that is used for spindle transmission gear 22 is connected with main shaft 40 connected, this electric hammer was operated in cutter drill jig formula, and when it broke off, this electric hammer was operated in a cutter pattern.

To illustrate in greater detail two torque clutch of the clutch apparatus 18 of the electric hammer of Figure 13 with reference to Figure 14 to 17C below.

The bevel gear 20 that forms part clutch apparatus 18 forms as one for circular axle 100 with cross section.This upper end of 100 is installed in rotation on through a bearing in the shell 8 of electric hammer, and this bearing comprises that rigidity is installed in inner ring 102, the rigidity of axle on 100 and is installed in the outer ring 104 on the shell and makes the ball 106 that outer ring 102 can freely be rotated around inner ring 102.This bearing was positioned near bevel gear 20 following.

Driving gear 16 is installed in rotation on the axle 100 and can freely rotates around axle 100.Driving gear 16 is in connection with the downside of the inner ring 102 of bearing, and through below in greater detail the remainder of clutch mechanism and axially (downwards) slide off.

Driving gear 16 so is shaped, and makes it surround an annular space, this space by the flat bottoms 108 of stretching out from axle 100 outward radials, on its outer surface be formed with driving gear 16 tooth lateral wall 110 and be positioned near the madial walls 112 of axle 100 and surround.

Annular space being positioned near the driving gear 12 the flat bottoms 108 is provided with a packing ring 114, and this packing ring surrounds madial wall 112 and axle 100.One belleville washer (belleville washer) 116 is installed on the top of packing ring 114.The inner edge of this belleville washer is located at below the inner ring 102 of bearing, and the outer rim of this belleville washer is resisted against on the outer rim of the packing ring 114 on the outer wall 110 that is positioned at driving gear 16.This driving gear 16 axially remains on the outer wall 110 of axle 100 with respect to this belleville washer, thereby belleville washer 116 is compressed, thereby makes it towards the flat bottoms 108 of driving gear 16 downward bias pressure to be applied on the packing ring 114.

In the flat bottoms 108 of driving gear 16, be formed with two groups of holes; Group 118 has five in first, and each longitudinal axis distance along radial direction and axle equally is provided with and is in angle intervals round the longitudinal axis of axle 100 and opens; The second outer group 120 has five, and each longitudinal axis distance along radial direction and axle equally is provided with and is in angle intervals round the longitudinal axis of axle 100 and opens.The longitudinal axis radial distance apart of outer set 120 and axle 100 is greater than inside group 118.

Ball 122 is located in each hole and below packing ring 114.The diameter of all these balls 122 is all identical, and its diameter causes the top of these balls 122 or bottom to stretch out upper surface or lower surface above the flat bottoms 108 of driving gear 16 greater than the thickness of the flat bottoms 108 of driving gear 16 thus.

First sliding gasket 124 is installed near the main shaft 100 below driving gear 16.This first sliding gasket 124 comprises circular hole 123, and extend into two splines 125 in this hole 123, and these splines are installed in 100 last times of main shaft at this packing ring and are arranged in two respective slots 127 that are formed on main shaft 100.Like this, first sliding gasket 124 is nonrotatably mounted tO on the main shaft, thereby this main shaft 100 when first sliding gasket 124 rotates.

With reference to Figure 16 A to 16C, on a side of first sliding gasket 124, be formed with groove 126 (referring to Figure 16 B) with U-shaped cross-section round periphery.This cannelure 126 is divided into five parts 128, the degree of depth of each part 128 of this groove from lower position 129 to top position 131 differences.The shape of each part 128 of this groove 126 is identical with other part 128 of groove 126.The same shown in Figure 16 C, the lower position 129 of a part 128 of groove is positioned near the top position 131 of next part.The two connects through inclined-plane 134.When sliding gasket 124 be installed in the axle 100 last times, the side of first sliding gasket 124 is facing to driving gear 16.The diameter of first sliding gasket 124 is less than the diameter of driving gear 16, and so sets, thereby is installed in 100 a last time when sliding gasket 124, and groove 126 is facing to interior group of hole 118.Those five parts 128 that form groove 126 with form driving gear 16 in in five holes 118 in group hole corresponding, thereby when assembling clutch 18, a ball 122 is arranged in each part 128 of groove 126.

Below first sliding gasket 124, second sliding gasket 140 is installed on main shaft 100.This second sliding gasket 140 is the dish type with sloped sidewall 142 of flat bottoms of surrounding 144.As being clear that among Figure 14, in the time of on being installed in main shaft, first sliding gasket 124 is positioned at the space that is surrounded by sidewall 142 and flat bottoms 144 surfaces.Second sliding gasket 140 can rotate freely around main shaft 100.In about the symmetrical flat bottoms 144 of the rotation of second sliding gasket 140, be formed with the rectangular channel 146 that is stacked on the circular hole 147.On the top of sloped sidewall 142, be formed with the flange 148 that radially outward stretches out.

With reference to Figure 17 A to C, on the top side of radial flange 148, be formed with the groove 150 that cross section is a U-shaped, its shape similar with on first sliding gasket 124 round radial flange 148.Cannelure 150 is divided into five parts 151, the degree of depth of each part of this groove from lower position 152 to top position 154 differences.Each part 151 its shape of this groove 150 are identical with other part of groove.The lower position 152 of a part of this groove is positioned near the top position 154 of next part.The two connects through inclined-plane 156.Equally this second sliding gasket 140 is installed in axle last time when as shown in the figure, the side of flange 148 with groove 150 is facing to driving gear 16.The diameter of this flange 150 is so set, thereby when this second sliding gasket 140 being installed in 100 a last time, this groove 150 is facing to outer group of hole 120 in the driving gear 16.Five parts 151 that form groove 150 are corresponding with five holes 120 in the interior group hole that forms driving gear 16, thereby when this clutch of assembling, in each part of groove 150, are provided with a ball 122.

The size on the inclined-plane 134 in the groove 126 of first sliding gasket 124 is less than the size on the inclined-plane in the groove that is formed on second sliding gasket 140 150 156, each part of the groove in first sliding gasket 124 from the height change of low side 120 to high-end 131 less than each part of the groove second sliding gasket from the bottom 152 to high-end 154 height change.

When the assembling clutch; Be arranged in driving gear 16 that the ball 122 in group hole 118 is positioned at the groove 126 (ball of each part) of first sliding gasket 124, and the ball 122 that in driving gear 16, is arranged in outermost group hole 120 is positioned at the groove 150 (ball of each part) of second sliding gasket 140.

Rigidity is equipped with ring folder (circularclip) 160 on main shaft 100 below second sliding gasket 140; It with sandwich with first and second sliding gaskets 124; 140 with driving gear 16 remain on bearing below, thereby prevent that this three from moving axially along main shaft.The rotation of ring folder causes the rotation of main shaft 100.

Axle 100 lower end is installed in rotation on through second bearing in the shell 8 of electric hammer, and this second bearing comprises that rigidity is installed in inner ring 170, rigidity on the axle 100 and is installed in the outer ring 172 on the shell 8 and makes the ball 174 that outer ring 172 can freely be rotated around inner ring 170.This bearing was positioned near ring folder 160 following.

When being fully assembled this clutch and not transmitting any rotating torques through it, each ball in the endoporus 118 of this driving gear 16 is arranged in the bottom position 134 by the appropriate section 128 of the groove of first sliding gasket 124 of dotted line 180 expressions.When ball 122 is positioned at the bottom position 134 of part 128 of groove 126, top that is positioned near the ball 122 the packing ring 114 and flush facing to the packing ring 114 of the flat bottoms 108 of driving gear 16.Owing to push these balls 122 to their nethermost position again, so these balls 122 are arranged in nethermost position 134 along the biasing force of the belleville washer 116 of this packing ring 114 of downward direction bias voltage.

Equally; When being fully assembled clutch and not transmitting any rotating torques through it; Each ball 122 in the outermost face 120 of driving gear 16 equally is in such position shown in dotted line 182, be in the bottom position 156 of the appropriate section 151 of the groove 150 in second sliding gasket 140.When these balls 122 are positioned at the bottom position 156 of part 151 of groove 150, near the top of the ball 122 of packing ring 114 and flush in the face of the flat bottoms 108 of the driving gear 16 of this packing ring 114.Owing to push these balls 122 to their nethermost position again, so these balls 122 are arranged in nethermost position 156 along the biasing force of the belleville washer 116 of this packing ring 114 of downward direction bias voltage.

The length that runs through this main shaft 100 is formed with a tubular conduit 186.In the bottom of tubular conduit 186, be provided with a bar 188.This bar stretches out main shaft 100 below main shaft 100.One seal 189 is installed in the substrate of main shaft 100 and surrounds this bar 188.Sealing part 189 has prevented the dirt intrusion.

One sleeve, 190 rigidity are installed in the upper end of this bar 188.Along stretching out two latches 192 with sleeve 190 vertical relative directions.Sleeve 190 is located at the such position in the main shaft 100 along the length of main shaft 100, is surrounded by ring folder 160 at this place's sleeve 190 and latch 192.In the side of ring folder 160, be formed with two vertical slots 194.The top of these slits 194 extends to the top of ring folder 160.The bottom of these slits 194 to extending below, ends at substrate along ring folder 160 parts.In each slit 194, be provided with one of them latch 192.These latches 192 extend through at main shaft 100 and ring and press from both sides the slit 194,127 on 160.Bar 188 can vertically slide up and down with sleeve 140 and two latches 192.Nethermost position is the positions of two latches 192 against the bottom of the slit 194 of ring folder 160, and the substrate of the slit 194 in pressing from both sides through ring prevents further to move down, and is shown in figure 14.The highest position is these two latches 192 are located at the rectangular slot 145 of second sliding gasket 140 except the top that is positioned at slit 160 position, thereby prevents further to move upward through the downside of first sliding gasket 124.In the top of tubular conduit 186, between the top of main shaft 100 and sleeve 190, be provided with a spring 196.This spring 196 with sleeve 190, two latches 192 and bar 188 towards they nethermost position bias voltages.No matter these latches 192 are to be in above it position or to be in its lower position place, because these latches 192 are arranged in these slits 194, so the rotation of these latches 192 causes ring folder 160 to rotate, this causes the rotation of main shaft 100 conversely.

The motion of bar 188 between its bottom position and uppermost position makes clutch 18 change to the high torque (HT) clutch from low torque.Below explanation is used for mechanism that this bar is moved both vertically.This clutch is operated through sending to main shaft 100 all-in-one-piece bevel gears 20 from rotatablely moving of driving gear 16.When the torque on the clutch 18 is lower than predetermined value, this driving gear 16 will drive bevel gear 20 rotatably.When the torque on the clutch is higher than predetermined value, this driving gear 16 will rotate but bevel gear 20 will keep motionless, thereby this clutch 18 rotates along with driving gear 16 and slides.Can make through the sliding motion of bar 188 between bottom position and uppermost position and let the predetermined value of the torque that clutch 18 slides preset between the numerical value to change at two.

To the mechanism of these clutch 18 work be described below.

The low torque operation

When clutch 18 was used as the low torque clutch, this bar 188 was arranged in its extreme lower position.In the time of in being in this position, the rectangular opening 146 in these latches 192 and second sliding gasket 140 breaks away from.Therefore, second sliding gasket 140 can freely rotate around main shaft 100.Therefore between second sliding gasket 140 and main shaft 100, do not transmit any rotatablely moving.Therefore, all between driving gear 16 and bevel gear 20 rotatablely move and just transmit through first sliding gasket 124.

Motor 2 drives driving gear 16 through main driving gear 12 rotations.This driving gear 16 can freely rotate around main shaft 100.Therefore, can not directly will rotatablely move and pass to main shaft 100 from driving gear 16.When driving gear rotates, be positioned at the ball 122 of organizing hole 118 most that is formed on driving gear 16 and also rotate with driving gear 16.Under normal circumstances; When just at conveying rotary motion; These balls 122 remain on through packing ring 114 in the bottom position 134 of the part 128 that is formed on the groove 126 in first sliding gasket 124, this packing ring 114 under the bias force of belleville washer 116 by biased downward.Rotation direction is such, makes these balls 122 be pushed against on the inclined-plane 134 of groove 126, climbs up inclined-plane 134 thereby the biasing force through belleville washer 116 prevents these balls 122.Therefore, when the ball in the group 118 in rotates, these inclined-planes 134 and therefore first sliding gasket 124 also rotate.When first sliding gasket 124 is nonrotatably mounted tO main shaft 100 owing to the slit 127 of spline 125 in main shaft 100 engages, along with first sliding gasket 124 rotates, so main shaft 100 and therefore bevel gear 22 also rotate.Therefore will rotatablely move from driving gear 16 and pass to bevel gear 22 through in, organizing ball 122, inclined-plane 134 and first sliding gasket 124 in the hole 118.

But; Torque on being applied to clutch 18 (with the resistance form of the rotational motion that stops bevel gear 22) is when being higher than certain value, with ball 122 be sent to needed power on the inclined-plane 134 on first sliding gasket 124 greater than being applied to by belleville washer 116 on the ball 122 so that they remain on the power in the bottom position 129 of part 128 of groove 126.Therefore, these balls 122 are crossed these inclined-planes 134 and are continued along the inclined-plane of next part 128 then to engage with next inclined-plane 134 up to it downwards.If this torque still is higher than scheduled volume, then repeat this process, thereby the biasing force that this ball 122 overcomes belleville washer 116 is crossed these inclined-planes 134 and is rolled then through next part.At this moment, first sliding gasket 124 keeps motionless, so main shaft 100 also keeps motionless with bevel gear 22.Therefore, rotatablely moving of driving gear 16 is not transmitted to bevel gear 22.

Though in low torque is set second sliding gasket 140 rotatablely moving of driving gear 16 passed in the main shaft 100 inoperative, its still rotation under the effect of driving gear 16.

High torque operation

When clutch 18 was used as the high torque (HT) clutch, this bar 188 was arranged in its extreme higher position.In the time of in being in this position, these latches 192 engage with rectangular opening 146 in second sliding gasket 140.Therefore, second sliding gasket 140 is rotatably mounted on the main shaft 100 through the latch 192 in the slit 194,127 that is positioned at rectangular channel 146, ring folder 160 and main shaft.Therefore can be between second sliding gasket 140 and main shaft 100 transferring rotational motion.Therefore, rotatablely moving between driving gear 16 and bevel gear 20 can be transmitted through first sliding gasket 124 and/or second sliding gasket 140.

Driving gear 16 is through identical with its rotatablely move mechanism that passes to first sliding gasket 124 and second sliding gasket 140 of ball 122 and inclined-plane 134.

Motor 2 drives driving gear 16 through main driving gear 12 rotations.This driving gear 16 can freely rotate around main shaft 100.Therefore, can not directly will rotatablely move and pass to main shaft 100 from driving gear 16.When driving gear 16 rotates, be positioned at the ball 122 of organizing hole 118 and outermost group hole 120 most that is formed on driving gear 16 and also rotate with driving gear 16.Under normal circumstances; When just at conveying rotary motion; These balls 122 remain on the bottom position 129 of the part 128,151 that is formed on the groove 126,156 in first sliding gasket 124 and second sliding gasket 140 through packing ring 114; In 152, this packing ring 114 under the bias force of belleville washer 116 by biased downward.Rotation direction is such; Make these balls 122 be pushed against on the inclined-plane 134,156 of groove 126,150 of first sliding gasket 124 and second sliding gasket 140; Thereby the biasing force through belleville washer 116 prevents these balls 122 and climbs up inclined-plane 134,156.Therefore, when these balls 122 rotate, these inclined-planes 134,156 and therefore first and second sliding gaskets 124,140 also rotate.When first and second sliding gaskets 124,140 neither are installed in rotation on main shaft 100, along with first and second sliding gaskets 124,140 rotate, so main shaft 100 and therefore bevel gear 22 also rotate.Therefore through the outermost group with in organize ball 122, inclined-plane 134,156 and first and second sliding gaskets 124,140 in the hole 118,120 and will rotatablely move from driving gear 16 and pass to bevel gear 22.

But; Torque on being applied to clutch 18 (with the resistance form of the rotational motion that stops bevel gear 22) is when being higher than certain value; Ball 122 is sent to inclined-plane 134; Needed power makes them remain on the power in the bottom position 129,152 of part of these grooves greater than being applied to by belleville washer 116 on 156 on the ball 122.Needed amount of torque is higher than the amount of torque in low torque is set in high torque (HT) is set.This be since the size on the inclined-plane 156 between the part 151 of groove 150 in second sliding gasket 140 greater than the size on the inclined-plane 134 between the part 128 of the groove 126 in first sliding gasket 124; Thereby need this belleville washer 116 to be compressed to more, and the power that therefore it is so done.Therefore, when this power surpassed this bigger numerical value, ball 122 was crossed inclined-plane 134,156 and is continued along next one inclined-plane partly then and engages up to them and next inclined-plane 134,156 downwards.If this torque still is higher than scheduled volume, then repeat this process, thereby the biasing force that these balls 122 overcome belleville washer 116 is crossed these inclined-planes 134,156 and is rolled across next part then.At this moment, first and second sliding gaskets 124,140 keep motionless, so main shaft 100 also keeps motionless with bevel gear 22.Therefore, rotatablely moving of driving gear 16 do not send bevel gear 22 to.

Torque changes mechanism

To the mechanism of the torque settings of regulating clutch 18 be described now.

Downside with reference to Figure 14 and 18, two torque clutch 18 is positioned at clutch outer member 200.Bar 188 passes the substrate of shell 200 and stretches out.Engaging with cam 202 bottom of bar.Cam 202 is installed on the axle 204 that can pivot around its longitudinal axis 206.Bar 186 and therefore cam 200 under spring 196 effects of the main shaft that is positioned at clutch 18 100, setover towards their extreme lower position.The pivoting action of axle 204 causes the pivoting action of cam 202; Cam 202 is climbed up in the end of this feasible bar 188 that can engage with cam 202 slips; Thereby make bar 188 overcome upwards vertical slip of biasing force of spring 196, set thereby clutch 18 is changed to high torque (HT) from low torque.

One flexible joystick 208 is installed on axle 204.The cable 210 of Bowden cable (bowden cable) 212 is installed on the end of flexible joystick 208.The pulling campaign pulling control stick 208 of cable 210 makes itself and axle 204 rotate around axis 206.This causes cam 202 to pivot, and this makes bar 188 move vertically upward conversely.The lax control stick 208 and the axle 204 of making of cable 210 pivots, thereby because the biasing force of spring 196 makes cam 202 move to its extreme lower position through bar 188.Thereby flexible joystick 208 enough rigidity can make axle 204 and therefore cam 202 motions to change the torque settings of clutch 18.But, if two latches 192 do not align with rectangular opening 146 on second sliding gasket 140, then prevented these latches 192 and therefore bar 188 advance to its uppermost position.But the device of pulling cable 210 can not be found out this situation.Therefore, in this case, control stick 208 bendings, thus make latch 192 make cable 210 be pulled its maximum simultaneously against the downside of second sliding gasket 140.When giving motor 2 energisings, second sliding gasket 140 will rotate, thereby make latch 192 align with rectangular opening 146, and at this moment these latches 192 are owing to the biasing force of crooked control stick 208 gets in the rectangular opening 146.

With reference to Figure 18 and 19, Bowden cable 212 is wound to the back of electric hammer main body 8 round the outer wall 214 of motor 2.Locate the finger gripping member 216 that (referring to Figure 14) is equipped with a pivot in main body 8 facing to the rear portion of back handle 10, it can pivot around vertical axis 218.The cable 210 of Bowden cable 212 is connected to the finger gripping member 216 of pivot.Two ends of the sleeve of Bowden cable 212 are fixed on the shell 8.Therefore the pivoting action of finger gripping member 216 spurs control stick 208 thus through sleeve pulling cable 210.Spring 196 in the clutch is through bar 188, flange 202 and control stick 208 pulling cables 210, and this pulls to primary importance with pivot finger gripping member 216 conversely.When the cable 210 of finger gripping member 216 pulling Bowden cables, the biasing force that this finger gripping member can overcome spring is pushed to the second place.Therefore the pivoting action of finger gripping member 216 makes clutch 18 move to the high torque (HT) setting from the low torque position.Finger gripping member 216 lax when being positioned at the second place (clutch 18 is in the high torque (HT) position) make it can push strut 188 downwards and therefore downwards during actuating cam 202 because the biasing force of spring 196 march to its primary importance.

To the bolt lock mechanism that in the high torque (HT) position, is used for finger-like holder 216 be described now.

One vertical manipulation bar 220 is installed below finger gripping member 216.This vertical manipulation bar is installed on the main body 8 of electric hammer through trunnion axis 222.Axle 222 and therefore vertical manipulation bar 220 can be switched to the second place from these vertical manipulation bar 220 vertical primary importances wherein around horizontal axis 224, in this second place, 220 top of control stick is from the main body 8 inner back handles 10 that point to.

With reference to Figure 20, on the top of vertical axis 220, be formed with a protrusion 226.A slice spring 228 is installed, on two arms 230 that its level of being suspended on is stretched out below finger gripping member 216.When finger gripping member 216 pivoted around vertical axis 218, the direction shown in the arrow E of these two arms 230 in Figure 10 was moved.This sheet spring 228 has and is formed on the coupling part 232 of stretching out in it downwards.

When vertical manipulation bar 220 was in its normal operating position, it was vertical.When this finger gripping member 216 clutch 18 be in its low torque be provided with in the time when being in its primary importance, when this sheet spring 228 is seen in Figure 20 towards the left side of control stick 220.

When clutch 18 will move to the high torque (HT) setting, finger gripping member 216 pivoted around vertical axis 218, thereby this sheet spring is towards the top motion of control stick 220.At this moment, first side 236 of the protrusion 226 on first side 234 of coupling part 232 and the top that is positioned at control stick 220 engages.When finger gripping member 216 continues to pivot; 228 bendings of sheet spring, thus coupling part 232 moves upward and is positioned at above the protrusion 226, turns back to its original-shape then; And second side 237 of coupling part 232 engages with second side 238 of protrusion 226, and is shown in figure 20 the same.

The direction pulling finger gripping member 216 of the arrow F of the biasing force of the spring 196 in the clutch in Figure 20.But the power of this spring 196 is not enough to spur the sheet spring and locks it on the protrusion 226.

For being set from high torque (HT), clutch 18 moves to the low torque setting; Operating personnel promote finger gripping member 216; Thereby force sheet spring 228 to turn back on the protrusion 226, the spring in the clutch is moved finger gripping member 216 to wherein clutch and is in the position that low torque is set afterwards.

Hope to guarantee that these two torque clutch are being returned to the low torque setting when electric hammer applies electric energy, make operating personnel consciously clutch 18 moved to high torque (HT) when needed like this and set.

In addition, moved to that low torque is set but clutch remains on high torque (HT) when setting, need prevent the electric hammer operation in the finger gripping member.

With reference to Figure 19 and 21, a solenoid 250 is installed in the lower end of vertical manipulation bar 220.This solenoid comprises a coil 252 and magnetic plunger 254.Spring 256 is installed between housing 258 and the plunger 254 of coil 252 and with plunger 254 and is biased in the coil 252.An end 260 of plunger 254 is connected on the lower end of vertical manipulation bar 220.The longitudinal axis of this plunger 254 is levels.

When solenoid did not receive current excitation, the power through spring 256 made plunger 254 move to inside position.This makes the end motion of vertical manipulation bar 220, thereby makes and be switched to wherein by control stick 220 vertical manipulation bar 220 is vertical positions.In this position, being installed in finger gripping member 216 following sheet springs 228 can engage with the protrusion 226 on being positioned at control stick 220 tops.

When this solenoid receives current excitation; This plunger 254 is drawn into coil 252; Thereby make it to spur the lower end of control stick; This makes control stick 220 pivot around axis 224 conversely, leaves the sheet spring 228 (equally pivot as shown in Figure 20 and leave drawing) that is installed in below the finger gripping member 216 thereby the top that causes having the control stick 220 of protrusion 226 pivots.Thereby this clutch is in the high torque (HT) setting in its second place if this finger gripping member 216 remains on, and then through keeping this sheet spring 228 with protrusion, the actuating of this solenoid 250 then makes control stick pivot and protrusion 226 and sheet spring 228 are broken away from.Therefore this makes finger gripping member 216 be back to its primary importance, makes clutch 18 under the effect of the biasing force of 196 pairs of clutches of spring and move to the low torque setting.

One sensor (not shown) is installed on the flexible joystick 208 and is used for detecting the end position of control stick 208.One sensor (not shown) is installed on the finger gripping member 216 and is used for detecting the position of finger gripping member 216.Whether one sensor is installed in the trigger switch and detects electric current and be applied on the electric hammer.These three sensors of one circuit monitoring, and activate solenoid 150 based on a plurality of predetermined condition, as demonstrating in detail among Figure 22.

In normal running, solenoid does not activated.

If to electric hammer energising (that is, it does not plug in), then circuit is providing electric current to monitor to operate this electric hammer (that is, this electric hammer plugs in) time.

When electric circuit inspection arrived this electric current, whether two sensors of its inspection on flexible joystick 208 and finger gripping member 216 showed all that clutch 18 is in low torque and sets.If then this circuit is inoperative.If not or one of them no word, then circuit activates solenoid, thereby guarantees that the finger gripping member can get back to its extreme lower position.In case these two sensors show that all this torque clutch is in low torque and sets, then this circuit breaks off solenoid, thereby makes the finger gripping member normally to act on.

This circuit also monitoring consistently is positioned at two sensors on flexible joystick 208 and the finger gripping member 216.If it is first to set but this clutch of sensor indicate on flexible joystick 208 is in high torque (HT) to be set at the sensor indicate on the finger gripping member 216, electric hammer is quit work, could use electric hammer up to this clutch reset.

This sensor is arranged on flexible joystick 208 rather than the clutch 18; If because latch 192 not with second sliding gasket 140 in rectangular opening 146 align; Then this this clutch of sensor indication is in the low torque setting; And flexible joystick 208 can be biased into the high torque (HT) setting with it, and when this electric hammer operation, will make clutch 18 move to high torque (HT) and set.

Those of ordinary skills should be understood that; Top embodiment just describes with the mode of embodiment; Rather than limit, and under the situation that does not break away from the scope of the present invention that is defined by the following claims, can make various replacements and variation.For example, it being understood that with reference to described pair of torque clutch 18 of Figure 13 to 17 to have plural torque settings.

Claims

1. hand held electric tool, it comprises:

One main shaft (40) is used for rotation and drives an instrument (68);

One hammer mechanism (38,58,64), it is used on the instrument at the front end place that is installed in main shaft to produce impact repeatedly;

One main axis rotation power train (14,5,10) is used for driving rotatably said main shaft (40);

One mode change mechanism (45,47,49,1261,1281), it is used for making the said safety clutch (10,43,7,14) of said main axis rotation power train selectively to separate so that cut off the rotary driving force that passes to said main shaft (40); And

Be used to detect the device (16,17) of congestion situations;

It is characterized in that said clutch comprises a spindle transmission gear device; It can be installed on the main shaft axially slidably and selectively engage so that drive said main shaft rotatably with part main axis rotation power train; The said device (16,17) that is used to detect congestion situations act on the spindle transmission gear device so that this spindle transmission gear device along the main shaft axially-movable and when detecting congestion situations and part main axis rotation power train throw off.

2. hand held electric tool as claimed in claim 1 is characterized in that, said main shaft (40) is used for rotation and drives a drill bit.

3. hand held electric tool as claimed in claim 1 is characterized in that, said hand held electric tool is an electric hammer.

4. hand held electric tool as claimed in claim 1; It is characterized in that; Said spindle transmission gear device comprises a spindle transmission gear (10) that is installed on the sliding sleeve (43), and said sliding sleeve (43) can endwisely slip and still be installed on the said main shaft (40) to rotational fixation.

5. like each described hand held electric tool in the claim 1 to 4; It is characterized in that; The device that is used to detect congestion situations when detecting congestion situations, produces electrical output signal and said safety clutch (14) comprises an electromechanical connecting device (18,19; 21), it offers the rotary driving force of said main shaft in response to said output signal cut.

6. hand held electric tool as claimed in claim 5 is characterized in that, said electromechanical connecting device comprises an electromagnet (19).

7. like each described hand held electric tool in the claim 1 to 4; It is characterized in that the device that is used to detect congestion situations comprises the sensor (16) of the operating conditions that is used for the sensing hand held electric tool and is used to analyze from the signal of sensor and when detecting congestion situations, produces the electronics assessment unit (17) of electrical output signal.

8. hand held electric tool as claimed in claim 5; It is characterized in that the device that is used to detect congestion situations comprises the sensor (16) of the operating conditions that is used for the sensing hand held electric tool and is used to analyze from the signal of sensor and when detecting congestion situations, produces the electronics assessment unit (17) of electrical output signal.

9. hand held electric tool as claimed in claim 6; It is characterized in that the device that is used to detect congestion situations comprises the sensor (16) of the operating conditions that is used for the sensing hand held electric tool and is used to analyze from the signal of sensor and when detecting congestion situations, produces the electronics assessment unit (17) of electrical output signal.

10. hand held electric tool as claimed in claim 4; It is characterized in that; Said spindle transmission gear device part at least is to be formed by magnetic material, and the device that is used to detect congestion situations comprises accelerometer (16), microprocessor (17), circuit (18) and electromagnet (19), wherein; Said circuit (18) is positioned between microprocessor (17) and the electromagnet (19), and said electromagnet (19) surrounds said spindle transmission gear device; The device that is used to detect congestion situations makes when detecting congestion situations; Said circuit (18) provides electric current to said electromagnet (19); The biasing force of spring (50) travels forward and the engagement of the pinion (7) of disengaging and spindle axle (5) so that said sliding sleeve (43) and said spindle transmission gear (10) overcome thereby between said electromagnet (19) and the magnetic material in said spindle transmission gear device, produce magnetic force; Through making the disengagement that is in transmission connection between said spindle axle (5) and said spindle transmission gear (10), thereby cut off rotary driving force.

11. a hand held electric tool, it comprises:

One main shaft (40) is used for rotation and drives an instrument (68);

Safety clutch (14) in said main axis rotation power train is used for when being lower than pre-determined torque, rotary driving force being passed to said main shaft and when being higher than pre-determined torque, cutting off the transmission of rotary driving force; And

Be used to detect the device (16,17) of congestion situations;

It is characterized in that the device that is used to detect congestion situations is a mechanical device (72,74,82), it comprises:

One inertia mass (72), it is pivoted in the said tool outer casing (4) and comprises and be used for the breech lock (86) that engages with the actuator (21) of safety clutch; And

One spring (92), setting is used for the actuator of clutch is pushed to off-position;

These building blocks are so arranged; Thereby when congestion situations occurring; Inertia mass is changeed at the shell maincenter makes breech lock (86) disengaging actuator and said spring (92) that actuator is pushed to off-position, and this actuator cuts off and will be applied to the rotary driving force on the main shaft in this position.

12. hand held electric tool as claimed in claim 11 is characterized in that, said safety clutch (14) also comprises: driven gear (13) and driving gear (12) and Connection Element (21,26,100; 110,112,114,107,130); Said Connection Element is used for when being lower than said pre-determined torque, making said driven gear to be connected with said driving gear and said driven gear and driving gear can be thrown off, and wherein is used to detect the device (18,19,21 of congestion situations; 72,74,82) act on said Connection Element (21,26; 100,110,112,114; 107,130) upward be applied to the rotary driving force on the main shaft when detecting congestion situations, to cut off, wherein, said Connection Element is a resilient sleeve (26).

13. hand held electric tool as claimed in claim 12 is characterized in that, said Connection Element (21; 26,100,110; 112,114,107; 130) be connected said driven gear and driving gear through the one group of locking element (25) on a group be installed in said driven gear and the driving gear, and can with said driven gear and driving gear in another engage so that between them, transmit rotary driving force.

14. hand held electric tool as claimed in claim 12 is characterized in that, is used to detect the device (18,19,21,72 of congestion situations; 74,82) be used for making said Connection Element (21,26,10,100; 110,112,114,107,130) with respect to said driven and driving gear motion.

15. hand held electric tool as claimed in claim 13 is characterized in that, is used to detect the device (18,19,21,72 of congestion situations; 74,82) be used for making said Connection Element (21,26,10,100; 110,112,114,107,130) with respect to said driven and driving gear motion.

16. hand held electric tool as claimed in claim 11; Wherein said safety clutch (14) comprising: driven gear (13) and driving gear (12) and Connection Element (105; 107), said Connection Element is used for when being lower than said pre-determined torque, making said driven gear to be connected with said driving gear and said driven gear and driving gear can be thrown off; And drive connector (21,113,115), be used for making said driven gear to be connected with the output of said safety clutch; Wherein be used to detect the device (18,19,21,72 of congestion situations; 74,82) acting on said driving connector (21,113,115) goes up to cut off the transmission of rotary driving force.

17. hand held electric tool as claimed in claim 16 is characterized in that, has two driven gear (13c; 13d), and one of them driven gear can be through driving connector (21,113; 115) be connected with the output (5) of clutch, thereby this safety clutch has first pre-determined torque, and another or this two driven gears can pass through to drive connector (21; 113,115) be connected with the output of clutch, thereby this safety clutch has second pre-determined torque different with first pre-determined torque; Perhaps these two driven gears can be all through not driving connector (21; 113,115) be connected with the output of clutch, thus the transmission of the driving force of stopping the rotation.

18. hand held electric tool as claimed in claim 17 is characterized in that, in response to the device (18,19 that is used to detect congestion situations; 21,72,74,82) actuating; Any of driven gear all is not connected with the output of clutch through driving connector (21,113,115).

19. hand held electric tool as claimed in claim 18 is characterized in that, said hand held electric tool is an electric hammer and comprises in addition:

One hammer mechanism (38,58,64) is used for going up the generation repeated stock at the instrument (68) at the front end place that is installed in said main shaft (40); And

One mode changing apparatus (1261,1281) is used for making electric hammer between the rotary mode of this electric hammer and non-rotary mode, to change;

Wherein said safety clutch (14) switches to said electric hammer non-rotary mode and cuts off the rotary driving force that offers said main shaft in response to said mode changing apparatus.