CA1281920C - Ratchet wrench - Google Patents
Ratchet wrenchInfo
- Publication number
- CA1281920C CA1281920C CA000508917A CA508917A CA1281920C CA 1281920 C CA1281920 C CA 1281920C CA 000508917 A CA000508917 A CA 000508917A CA 508917 A CA508917 A CA 508917A CA 1281920 C CA1281920 C CA 1281920C
- Authority
- CA
- Canada
- Prior art keywords
- anvil
- hammer
- jaw
- shaft
- cam
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
- B25B21/00—Portable power-driven screw or nut setting or loosening tools; Attachments for drilling apparatus serving the same purpose
- B25B21/004—Portable power-driven screw or nut setting or loosening tools; Attachments for drilling apparatus serving the same purpose of the ratchet type
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
- B25B21/00—Portable power-driven screw or nut setting or loosening tools; Attachments for drilling apparatus serving the same purpose
- B25B21/02—Portable power-driven screw or nut setting or loosening tools; Attachments for drilling apparatus serving the same purpose with means for imparting impact to screwdriver blade or nut socket
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Percussive Tools And Related Accessories (AREA)
- Details Of Spanners, Wrenches, And Screw Drivers And Accessories (AREA)
Abstract
ABSTRACT
The powered ratchet wrench 10 is constructed of several components. A throttle lever 20 controls the air flow to a rotary air motor 30. The rotary output of the motor is transmitted to the hammer assembly 40 of an impact clutch mechanism. A spring 50 biases an anvil shaft 60 into association with the hammer assembly 40. The anvil can be directly driven by the motor through the hammer assembly or can be driven intermittently by a series of rotational impacts from the hammer assembly. The rotation of the anvil shaft causes the reversible ratchet mechanism 70 to rotate in the desired direction, thus tightening or removing a threaded fastener. Only a small reaction force is transmitted by the tool to the operator once the fastener is tightened.
The powered ratchet wrench 10 is constructed of several components. A throttle lever 20 controls the air flow to a rotary air motor 30. The rotary output of the motor is transmitted to the hammer assembly 40 of an impact clutch mechanism. A spring 50 biases an anvil shaft 60 into association with the hammer assembly 40. The anvil can be directly driven by the motor through the hammer assembly or can be driven intermittently by a series of rotational impacts from the hammer assembly. The rotation of the anvil shaft causes the reversible ratchet mechanism 70 to rotate in the desired direction, thus tightening or removing a threaded fastener. Only a small reaction force is transmitted by the tool to the operator once the fastener is tightened.
Description
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Docket No. 0186-IR-TH
RATCHET WRENCH
FIELD OF THE INVENTION
This invention pertains to a powered ratchet wrench for tightening or removing threaded parts~ An impact clutch mechanism connects the ratchet mechanism with a rotary power source.
BACKGROUND OF THE INVENTION
Conventional powered ratchet wrenches, such as that disclosed in Japanese Utility ~odel Ga~ette No.
1976-16,555, have a motor operated by compressed air in the base of the housing. Nhen a throttle lever is pressed, compressed air flows to the motor, and the output shaft of the motor turns a transmission shaft by way of speed reducing gears. Slow speed and high torque are transmitted to the transmission shaft. The eccentric rotation of a crankshaft at the front end of the transmission shaft oscillates a ratchet yoke. The movement of the ratchet yoke causes the ratchet spindle or tool head of a ratchet mechanism to rotate so that a bolt, nut, or other threaded part is tightened or removed.
In a conventional ratchet wrench, the gear drive continues to transmit motor torque directly to the operator even after the fastener ha~ been tightened to a specified tightening torque. ~hat is, 1~ khe throttle lever is held open after the fastener has been firmly tightened, compressed air continues to 3~
Docket No. 0186-IR-TH
drive the motor and the gears, which in turn drive the transmission shaft and ratchet mechanism. Thus, a considerable reaction force is transmitted to the operator as the tool tries to rotate around the tightened, stationary fastener. The operator's hand can ba je ked forward by the wrench, or the operator may lose his grip. Even if the operator quickly releases the lever as soon as tight2ning is finished, a reaction force is still transmitt2d to khe hand. It is difficult to prevent the hand ~rom bsing pulled along or from losing its grip. Hence, the operator usually releases the lever before tightening is finished. The operator then turns the tool manually to finish tightening. The tiyhtening force applied by these prior art tools can therefore be inconsistentO
In some situations, conventional powered ratchet wrenches are unsuitable for use in tight places where there is room for only one hand. Because the ratchet wrench cannot be gripped tightly in such cramped places, and since it is dif~icult to release the throttle lever at exactly the right time, the hand is often jerked or loses its grip. The operator's hand can be forcefully thrown against an obstruction and injured, or the ratchet wrench can forcefully striXe a projecting part and be damaged.
There is therefore a need ~or a powered ratchet wrench which minimizes the motor torque reackion ~orce transmitted to the operator. It is desirable to provide a powered ratchet wrench which minimizes the torque reaction force transmitted to the operator's hand so that the hand is not pulled along with ths tool while the motor is still operating and torque is still acting on the fastener.
Docket No. 0186-IR-TH
RATCHET WRENCH
FIELD OF THE INVENTION
This invention pertains to a powered ratchet wrench for tightening or removing threaded parts~ An impact clutch mechanism connects the ratchet mechanism with a rotary power source.
BACKGROUND OF THE INVENTION
Conventional powered ratchet wrenches, such as that disclosed in Japanese Utility ~odel Ga~ette No.
1976-16,555, have a motor operated by compressed air in the base of the housing. Nhen a throttle lever is pressed, compressed air flows to the motor, and the output shaft of the motor turns a transmission shaft by way of speed reducing gears. Slow speed and high torque are transmitted to the transmission shaft. The eccentric rotation of a crankshaft at the front end of the transmission shaft oscillates a ratchet yoke. The movement of the ratchet yoke causes the ratchet spindle or tool head of a ratchet mechanism to rotate so that a bolt, nut, or other threaded part is tightened or removed.
In a conventional ratchet wrench, the gear drive continues to transmit motor torque directly to the operator even after the fastener ha~ been tightened to a specified tightening torque. ~hat is, 1~ khe throttle lever is held open after the fastener has been firmly tightened, compressed air continues to 3~
Docket No. 0186-IR-TH
drive the motor and the gears, which in turn drive the transmission shaft and ratchet mechanism. Thus, a considerable reaction force is transmitted to the operator as the tool tries to rotate around the tightened, stationary fastener. The operator's hand can ba je ked forward by the wrench, or the operator may lose his grip. Even if the operator quickly releases the lever as soon as tight2ning is finished, a reaction force is still transmitt2d to khe hand. It is difficult to prevent the hand ~rom bsing pulled along or from losing its grip. Hence, the operator usually releases the lever before tightening is finished. The operator then turns the tool manually to finish tightening. The tiyhtening force applied by these prior art tools can therefore be inconsistentO
In some situations, conventional powered ratchet wrenches are unsuitable for use in tight places where there is room for only one hand. Because the ratchet wrench cannot be gripped tightly in such cramped places, and since it is dif~icult to release the throttle lever at exactly the right time, the hand is often jerked or loses its grip. The operator's hand can be forcefully thrown against an obstruction and injured, or the ratchet wrench can forcefully striXe a projecting part and be damaged.
There is therefore a need ~or a powered ratchet wrench which minimizes the motor torque reackion ~orce transmitted to the operator. It is desirable to provide a powered ratchet wrench which minimizes the torque reaction force transmitted to the operator's hand so that the hand is not pulled along with ths tool while the motor is still operating and torque is still acting on the fastener.
9~
SUMMARY OF THE INVF.NTION
In aceordance with -the invention there is provided a powexed ratchet wrench comprising, in axial alignment to form an elongated hand]e;
a rotary motor having a rotatahle output shaft;
a rotary impact cluteh meehanism also having a rotatable output shaft and rotated by the rotatable output shaft of the rotary motor;
a reversible ratehet mechanism having an oscillatable ratchet yoke and ls oscillatably driven through the yoke by ,he output shaft of the impact clutch; and a single ended tool dxive spindle is d.riven by the ratehet mechanism and has i'LS drive axis normal to the axes of the rotaxy motor and the impact elutch.
In accordanee with the fuxthex embodiment, thexe is provided a powexed ratehet wrench compxising:
a rotary motor;
an impact mechanlsm axially allgned with and engaged with the output shaft of the rotaxy motor, the impact meehanism further comprising:
a hammex eage in rotaxy dxiven engagement with the motox output shaft and has at least one hamme.r jaw;
a rotatable and axially slidable anvil shaft axially aligned with and eentexed in the hammer eage and has at least one anvil jaw, one axially extending anvil eam, and an eceentxic shaft output end;
an impact eluteh means fox causing intexmittent engagement between the hammer jaw and the anvil jaw through the eombined aetion of a biasing spring and the anvil eam to pxoduee xotaxy impacts on the anvil output shaft; and a reversible ratehet meehanism having a single ouput spindle and a yoke in oseillating driven engagement with the output end of the anvil shaft.
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This invention provides a powered ratched wrench such -that, when used to tighten or remove a part or fastener, an impact clut-ch mechanism provldes the connection between the tool motor and the ratchet mechanism. To tighten a fastener, the impact clutch mechanism provides an ini~ial direct connection between the motor and the ratchet mechanism to se-t or snug-up the fastener during "run down". The ratchet mechanism is thereafter rotated by a series of xotational impac,s delivexed by the impact clutch.
To xemove a fastener, the impacts break the fas-tener loose, while the direct drive "runs up" the fastener.
If the -throttle lever is not released when fastener tigh-tening is completed, only minimal torque reaction foree is transmitted to the operator due to the impact eluteh. Thus, the tool ean pxefoxm eonsistent tightening quiekly and reliably, withou~ manual assistance.
More particularly, the ratehet wreneh aceoxding to this invention is eonstrueted so that the motor and ratehet meehanism are eonneeted with an impaet eluteh rather than a speed xedueing gear deviee, as in the eonventional wreneh. The impaet clutch allows the ratehet meehanism to rotate either under direet motor power or by rotational impaets. An impaet ean be produeed rapidly and extremely smoothly during eaeh motor rotation, so that the threaded part ean be firmly tightened by the ratehet. Thus, while the ratehet is tightening the part, and after the part is fully tightened, the eonneetion between the motor and the ratehet is intermittently broken~ so that the - 3a -.
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Docket No. 0186-IR-TH
ratchet is rotating with minimum reaction to the operator.
Thus, if the throttle lever is not released when tightening is completed, only a minimal reac~ion force is transmitted to the operator. This allows complete tightening to be carried out consistently and reliably.
This wrench is also suitable for use in tight places with room for only one hand on the tool. The hand won't be thrown against the work piece and injured, as could happen previously. Also, the danger of the ratchet wrench striking an obstruction and being damaged is avoided.
BRIEF_DESCRIPTIONQ F THE DRAWINGS
Figure 1 shows a longitudinal cross section of the ratchet wrench.
Fi~ure 2 shows a perspective view of the base end of the anvil shaft, which is an essential part o~ the invention.
Figure 3 ~hows a aross section along line III-III
of Figure 1, showing the hammer cage and cam ~all o~
the impact clutch mechanism, which constitute assential parts of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Figure 1 shows a longitudinal cross section through a preferred embodiment of the ratchet wrench.
The ratchet wrench 10 is constructed of several components which will ~irst be described generally. A
' : ' ' ' ' .' ' ~8~9~) throt-tle lever 20 controls the air flow to a rotary air motor 30. The rotary output of the motor is transmit-ted to the hammer assembly 40 of an impact clutch mechanism. A spring 50 biases an anvil shaft 60 into association with the hammer assembly 40. The anvil shaft can be directly driven by the mo-tor through the hammer assembly or can be driven in-texmittently by a series of rotational impacts from the hammer assembly. The rotation of the crank on the anvil causes the reversible ratchet mechanism 70 to reciproca-te or oscillate back and forth, -thus tightening or removing a th~eaded part of fastener.
Only a small xeaction force is transmitted by the tool to the operator once the fastener is tight.
More specifically the tool 10 includes a motor housing 11 and a ratchet housing 12, secured together in fixed relation such as by a threaded coupling ring 13 and eoupling nuts 14.
A throttle lever 20 opens and closes a throttle valve 22. When ,hrottle valve 22 is in the open position, compressed air enters the tool at air inlet 24 which is connected to a suitable compressed air souree. The eompressed air flows in-to the rotary air motor 30 and transfers its energy to the rotor. The spent air is exhausted from exhaust 26.
The rotary motor 30 is located in the motor housing 11. In the preferred embodiment, an air motor is shown,. but any rotary power source such as a hydraulic or electric motor could also be used.
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Docket No. 0186-IR-TH
Air motor 30 has a rotor 3~ and an extending output shaft 31. The two ends of rotor 34 are supported by bearings 33 which in turn are supported by snd plates 32. The rotor is mounted for rotation in the cylinder 35, the spen ends of whîch are covered by the end plates 32. The cylinder has an eccentric bore, as is typical of conventional air motors.
plurality of ~anes 36 are slidably mounted in radial slots in the rotor. The vanes slide radially back and forth in the slots as the rotor turns due to centrifugal force and the eccentric inner surface of cylinder 35. As the inlet air pushes against vanes 36, it causes rotor 34 to rotate, thus causing output shaft 31 to rotate therewith.
Numeral 41 designates the hammer cage. It is cup shaped, having a cylindrical wall portion and a base portion which together form an inner surface designated by numeral 44-. Within the hammer cage on the inner surface 44 are two diametrically opposed axial grooves. The axial grooves extend only part way down the cylindrical wall portion, forming semi-circular shoulders at a specified distance above the base portion. The hammer cage 41 in this preferred embodiment is directly driven by the output shaft 31, as for example by a splined sonnection.
Alternatively, however, the hammer cage could be gear driven.
Formed in the base portion of the hammer cage is a circular raceway 47, which is concentric about the axis of rotation. Coinciding with the raceway, but extending for only a limited number of degrees, is a '~L,q'~
Docket No. 0186-IR-TH
larger-dimensioned cam ~all pocket ~6. The cam ball pocket t~pically describes an arc in the range of 45 to 180 degrees. A cam ball 43 is held in the pocket and rolls freely through the arc.
The anvil shaft 60 carries an axially extending cam 62. The cam ~2 is preferably a one-sided cam and projects axially from the end of the anvil shaft. The cam forms a cam peak with preferably one gradually rising inclined surface adjacent the cam peak and one sharply falling surface adjacent the other side of the peak. The inclined surface occupies about a 90 degree arc on the anvil shaft. The sharp surface facilitates escape of the cam. The cam 62 and the raceway 47 are dimensioned so that when the hammer cage rotates with the cam extending into the raceway, the hammer cage rotates freely without interference from the cam. In other words, as the raceway rotates relative to the cam, the raceway permits the cam to extend into it without interference.
The anvil shaft carries at least one, and preferably two anvil jaws 63. The anvil jaws are diametrically opposed and radially extendingO The outer radial surfaces o~ the anvil jawc are dimensioned so that the inner chamber 44 of the hammer cage can rotate freely about the anvil jaws.
The anvil shaft al50 carries an eccentric crank 61 at the shaft end opposite the cam 62. The anvil shaft 60 is supported by needle bearing 54 so that it slides ~reely in the axial direction as well as freely rotates. The anvil shaft is also journaled for rotation and axial movement by a bore in hammer cage top 42.
Docket No. 0186-IR-TH
Numeral 50 designates a helical coil biasing spring of a size to fit around a reduced diameter portion of the anvil shaft 60 and abut against a shoulder on the shaft. This biasing spring normally urges the anvil shaft 60 toward the base portion of the hammer cage 41, such that the extending cam 62 normally projects into the raceway 47.
At least one, ~nd preferably two hammer jaws 45 are received in the axial grooves of the hammer cage 41. The hammer jaws are harden pins and when in place are half embedded in the cylindrical wall portion and half exposed in the inner chamber 44. The hammer jaws rest on the shoulders of the axial grooves so as not to extend to the base portion o~ the hammer cage. An uninterrupted cylindrical surface is provided below the shoulders at the base of the inner chamber 44.
This surface allows the hammer cage 41 to rotate relative to the anvil jaws 63 when the biasing spring urges the anvil shaft toward the base portion of the hammer cage without impacting on the anvil jaws.
The hammer cage top 42 has a short, snug-fitting, reduced diameter portion that is inserted into the inner chamber 44 of the hammer cage. The~cage top also has two diametrically opposite pilot bores that axially align with the axial grooves of the ha~mer cage. The hammer jaws 45 are also received into these pilot bores to fix the hammer jaws in an axial position and to lock the hammer cage and hammer cage top together against relative rotation.
Figure 1 illustrates the ratchet wrench in a position when the biasing spring 50 is extended and ~o~
Docket No. 0186-IR-TH
the cam 62 is positioned in the raceway 47. The anvil jaws 63 are biased by the spring toward the base of the hammer cage such that during rotation of the hammer cage, the hammer jaws 45 do not intercept the anvil jaws 63. The uninterrupted cylindrical portion of the hammer cage 41, that portion located below the hammer jaws, rotates radially adjacent to the anvil jaws.
When tha anvil jaws 63 move axially forward, due to the cam 62 riding up on cam ball 43 and compressing the biasing spring 50, the orbit of the rotating hammer jaws 45 intercepts the new position of the anvil jaws. When the cam ~2 moves the anvil shaft axially forward during each rotation of the hammer cage, the hammer jaws 45 produce a series of rotational impact against the anYil jaws 63.
Eccentric crank 61 is positioned at the end of the anvil shaft 60 opposite the cam 62. The crank slidas axially in the bore of a drive bushing 52 so as to allow for ~he axial movement of the anvil shaft.
Drive bushing 52 slides vertically in a bushing pocket 72 of ratchet yoke 71 so a~ to accommodate the up and down movement of the crank 61 as it rotatesO
The oscillating movement of the ratchet yoke is transferred to the ratchet mechanism 70. The ratchet mechanism rotates a ratchet spindle or tool head 73 in a conventional manner as is well known in the prior art.
_g_ Docket No. 0186~IR-TH
By turning the ratchet reverse knob 74 to the appropriate setting, the direction of rotation of the ratchet spindle can be determined. The tool can be operated to tighten or remove a fastener by setting the ratchet reverse knob 74.
PERATION
To set a threaded fastener, the ratchet mechanism is first simply directly driven by the motor through the impact clutch to rotate or "run down" the fastener to a snug position. Next, to fully tighten the fastener, impacts are applied by the impact clutch mechanism to further rotate the ratchet mechanism and ~urther torque the fastener.
Fiyure 1 illustrates the 'Grun down" position of the tool. The anvil shaft 60 is in its normal axial position, that is biased toward the base portion of the hammer cage with the one-sided cam 62 extending into the raceway 47. The cam ball 43 is contained in the limited arc cam ball pock~t 46. When the air motor rotates, output shaft 31 causes hammer cage 41 to rotate with it due to the splined connection. The trailing shoulder of the rotating cam ball pocket engages and drives the cam ball in the direction of rotation directly of the hammer cage. The cam ball next engages but does not roll up the inclined surface of the one-sided cam 62 The rotating cam ball imparts rotation to the anvil shaft 60. The rotation of the crank 61 at the end of the anvil shaft causes the ratchet mechanism to "run down" the ~astener.
Until the ratchet mechanism and the anvil shaft 60 encounter sufficient resistance from the fastener as it becomes snug, the motor is directly Docket No. 0186-IR-TH
driving the ratchet mechanism through the cam ball o~
the impact clutch mechanismO
When the ratchet mechanism and the anvil shaft 60 ancounter sufficient resis~ance, the gradual inclined surface o~ the cam 62 begins to ride up on the cam ball 43 due to the continued rotation of the cam ball with the hammer cage. The anvil shaft and the attached anvil jaws 63 are moved axially forward away from the base portion of the hammer cage. In other words, the cam ball cooperates with the cam to move the cam and attached anvil shaft axially forward as the cam rides up on the cam ball as it revolves within the cam ball pocket and rotates with the hammer cage.
When the cam peak overrides the top of the cam ball, the cam momentarily maintains its axial momentum and clears the cam ball, which continues to rotate beneath the cam. The cam is momentarily in "free flight" before an impact occurs. There are a few degrees of clearance between the trailing shoulder of the cam ball pocket and the hammer jaws. The anvil jaws 63 have been moved axially away from the hammer base portion and are now in an axial position which intercepts the orbit of thP xotating hammer jaws 45.
The exposed portions of the hammer jaws 45 intercept the new position of the anvil jaws and an impact is delivered to the anvil jaws.
This impact drives the anvil shaft 60 in the direction of rotation of the hammer cage until sufficient resistance is met. This re~istance is the resistance the fastener encounters as it tightens and is transferred from the fastener through the ratchet mechanism to the anvil shaft 60. When sufficient resistance is met, Docket No. 0186-IR-TH
the anvil shaft stops rotating and the hammer jaws and anvil jaws will begin to disengaga.
At that time, the force in the compressed biasing spring 50 o~ercomes the axial momentum of the anvil shaft and begins to push the cam back towards the hammer cage base. As the cam peak moves toward the base, the steep escape surface adjacent the cam peak kicks the cam ball in the direction of the leading edge of the cam ball pocket. The cam peak then again enters the xaceway 47.
As the hammer cage continues to rotate, the cam 62 once again encounters the cam ball 43. The cam ball rotates in the cam ball pocket with the cam until the ball reaches the trailing edge of the pocket. If there still is sufficient resistance due to fastener tension, the cam ball will again force the cam to ride up on the cam ball and the impact sequence will be repeated until the fastener can not be furthar tightened. The cam ball thus times the impacts. ~t ultimate tighening torque, the impact clutch mechanism will continue to cause the hammer to impact on the anvil. The ratchet mechanism will not provide any more tightening torque to the fastener. However, the tool operator will not experience any torque reaction due to the tool turning on the tightened fastener.
Rather the operakor will experience only the minimal reactions due to the impact clutch.
Other emhodiments are considered to be within the scope of this invention~ For axample, anvil shaft 60 can b~ constructed o~ two pieces to ~acilitate the manufacture and assembly o~ the tool. A separate cam Docket No. 0186 IR-TH
portion having the cam peak and anvil jaws can be positioned inside the inner chamber 44 of the hammer cage and splined to a shaft portion extending through the bore of the hammer cage top. Furthermore, biasing spring 50 can be positioned anywhere along the shaft portion of the anvil sha~t 60. For example, in the embodiment with a two piece anvil shaft, the biasing spring can be positioned on the splined connection between the cam portion and the shaft portion The purpose of the impact clutch mechanism is to translate rotary motion to interrupted rotaxy motion having less torque reaction. The impact clutch mechanism described in connection with the preferred embodiment can be broadly categorized as a unique embodiment o~ a cam engage, spring disengage impact clutch. Other embodiments of the cam engage, spring disengage type impact clutch are also considered to be within the scope of this invention. For example, in the pre~erred embodiment, the anvil shaft moves axially. An alternate embodiment can provide for the hammer jaws to move axially rather than the anvil shaft.
Additionally, other types of impact clutch mechanisms, such as the cam engage, cam disengage impact clutch of Mauer (U.S. Patent 3,661,217 issued May 9, 1972), and the spring engage, spring disengage impact clutch o~ Pott (U.S.- Patent 3,369,615 issued February 20, 196~), are considered to be within the scope of this invention. The Pott impact clutch is particularly suitable`for electric driven ratchet wrenches.
Docket No. 0186-IR-TH
One advantage of this invention over the prior art includes minimizing the torque reaction to the tool operator when a fastener is tight and the tool continues to run. TAis allows the tool to be safely operated with one hand and also in cunfined and aw~ard situations. The tool will also produce a consistent tightening torque. The operator will not have to stop the tool before the fastener is tight and manually tighten the fastener out o~ concern for his own safety and well-being. Additionally, the tool allows a faster "run-down" of the fasteners than prior art powered ratchets.
From the foregoing, those skilled in the art will recognize the improvements over prior art tools and the considerable advantages.
Changes and modi~ications in the specifically described embodiments can be carried out without departing from the SCOpQ of the invention which is intended to be limited only by the scope o~ the appended claims.
SUMMARY OF THE INVF.NTION
In aceordance with -the invention there is provided a powexed ratchet wrench comprising, in axial alignment to form an elongated hand]e;
a rotary motor having a rotatahle output shaft;
a rotary impact cluteh meehanism also having a rotatable output shaft and rotated by the rotatable output shaft of the rotary motor;
a reversible ratehet mechanism having an oscillatable ratchet yoke and ls oscillatably driven through the yoke by ,he output shaft of the impact clutch; and a single ended tool dxive spindle is d.riven by the ratehet mechanism and has i'LS drive axis normal to the axes of the rotaxy motor and the impact elutch.
In accordanee with the fuxthex embodiment, thexe is provided a powexed ratehet wrench compxising:
a rotary motor;
an impact mechanlsm axially allgned with and engaged with the output shaft of the rotaxy motor, the impact meehanism further comprising:
a hammex eage in rotaxy dxiven engagement with the motox output shaft and has at least one hamme.r jaw;
a rotatable and axially slidable anvil shaft axially aligned with and eentexed in the hammer eage and has at least one anvil jaw, one axially extending anvil eam, and an eceentxic shaft output end;
an impact eluteh means fox causing intexmittent engagement between the hammer jaw and the anvil jaw through the eombined aetion of a biasing spring and the anvil eam to pxoduee xotaxy impacts on the anvil output shaft; and a reversible ratehet meehanism having a single ouput spindle and a yoke in oseillating driven engagement with the output end of the anvil shaft.
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This invention provides a powered ratched wrench such -that, when used to tighten or remove a part or fastener, an impact clut-ch mechanism provldes the connection between the tool motor and the ratchet mechanism. To tighten a fastener, the impact clutch mechanism provides an ini~ial direct connection between the motor and the ratchet mechanism to se-t or snug-up the fastener during "run down". The ratchet mechanism is thereafter rotated by a series of xotational impac,s delivexed by the impact clutch.
To xemove a fastener, the impacts break the fas-tener loose, while the direct drive "runs up" the fastener.
If the -throttle lever is not released when fastener tigh-tening is completed, only minimal torque reaction foree is transmitted to the operator due to the impact eluteh. Thus, the tool ean pxefoxm eonsistent tightening quiekly and reliably, withou~ manual assistance.
More particularly, the ratehet wreneh aceoxding to this invention is eonstrueted so that the motor and ratehet meehanism are eonneeted with an impaet eluteh rather than a speed xedueing gear deviee, as in the eonventional wreneh. The impaet clutch allows the ratehet meehanism to rotate either under direet motor power or by rotational impaets. An impaet ean be produeed rapidly and extremely smoothly during eaeh motor rotation, so that the threaded part ean be firmly tightened by the ratehet. Thus, while the ratehet is tightening the part, and after the part is fully tightened, the eonneetion between the motor and the ratehet is intermittently broken~ so that the - 3a -.
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Docket No. 0186-IR-TH
ratchet is rotating with minimum reaction to the operator.
Thus, if the throttle lever is not released when tightening is completed, only a minimal reac~ion force is transmitted to the operator. This allows complete tightening to be carried out consistently and reliably.
This wrench is also suitable for use in tight places with room for only one hand on the tool. The hand won't be thrown against the work piece and injured, as could happen previously. Also, the danger of the ratchet wrench striking an obstruction and being damaged is avoided.
BRIEF_DESCRIPTIONQ F THE DRAWINGS
Figure 1 shows a longitudinal cross section of the ratchet wrench.
Fi~ure 2 shows a perspective view of the base end of the anvil shaft, which is an essential part o~ the invention.
Figure 3 ~hows a aross section along line III-III
of Figure 1, showing the hammer cage and cam ~all o~
the impact clutch mechanism, which constitute assential parts of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Figure 1 shows a longitudinal cross section through a preferred embodiment of the ratchet wrench.
The ratchet wrench 10 is constructed of several components which will ~irst be described generally. A
' : ' ' ' ' .' ' ~8~9~) throt-tle lever 20 controls the air flow to a rotary air motor 30. The rotary output of the motor is transmit-ted to the hammer assembly 40 of an impact clutch mechanism. A spring 50 biases an anvil shaft 60 into association with the hammer assembly 40. The anvil shaft can be directly driven by the mo-tor through the hammer assembly or can be driven in-texmittently by a series of rotational impacts from the hammer assembly. The rotation of the crank on the anvil causes the reversible ratchet mechanism 70 to reciproca-te or oscillate back and forth, -thus tightening or removing a th~eaded part of fastener.
Only a small xeaction force is transmitted by the tool to the operator once the fastener is tight.
More specifically the tool 10 includes a motor housing 11 and a ratchet housing 12, secured together in fixed relation such as by a threaded coupling ring 13 and eoupling nuts 14.
A throttle lever 20 opens and closes a throttle valve 22. When ,hrottle valve 22 is in the open position, compressed air enters the tool at air inlet 24 which is connected to a suitable compressed air souree. The eompressed air flows in-to the rotary air motor 30 and transfers its energy to the rotor. The spent air is exhausted from exhaust 26.
The rotary motor 30 is located in the motor housing 11. In the preferred embodiment, an air motor is shown,. but any rotary power source such as a hydraulic or electric motor could also be used.
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, .: ~
Docket No. 0186-IR-TH
Air motor 30 has a rotor 3~ and an extending output shaft 31. The two ends of rotor 34 are supported by bearings 33 which in turn are supported by snd plates 32. The rotor is mounted for rotation in the cylinder 35, the spen ends of whîch are covered by the end plates 32. The cylinder has an eccentric bore, as is typical of conventional air motors.
plurality of ~anes 36 are slidably mounted in radial slots in the rotor. The vanes slide radially back and forth in the slots as the rotor turns due to centrifugal force and the eccentric inner surface of cylinder 35. As the inlet air pushes against vanes 36, it causes rotor 34 to rotate, thus causing output shaft 31 to rotate therewith.
Numeral 41 designates the hammer cage. It is cup shaped, having a cylindrical wall portion and a base portion which together form an inner surface designated by numeral 44-. Within the hammer cage on the inner surface 44 are two diametrically opposed axial grooves. The axial grooves extend only part way down the cylindrical wall portion, forming semi-circular shoulders at a specified distance above the base portion. The hammer cage 41 in this preferred embodiment is directly driven by the output shaft 31, as for example by a splined sonnection.
Alternatively, however, the hammer cage could be gear driven.
Formed in the base portion of the hammer cage is a circular raceway 47, which is concentric about the axis of rotation. Coinciding with the raceway, but extending for only a limited number of degrees, is a '~L,q'~
Docket No. 0186-IR-TH
larger-dimensioned cam ~all pocket ~6. The cam ball pocket t~pically describes an arc in the range of 45 to 180 degrees. A cam ball 43 is held in the pocket and rolls freely through the arc.
The anvil shaft 60 carries an axially extending cam 62. The cam ~2 is preferably a one-sided cam and projects axially from the end of the anvil shaft. The cam forms a cam peak with preferably one gradually rising inclined surface adjacent the cam peak and one sharply falling surface adjacent the other side of the peak. The inclined surface occupies about a 90 degree arc on the anvil shaft. The sharp surface facilitates escape of the cam. The cam 62 and the raceway 47 are dimensioned so that when the hammer cage rotates with the cam extending into the raceway, the hammer cage rotates freely without interference from the cam. In other words, as the raceway rotates relative to the cam, the raceway permits the cam to extend into it without interference.
The anvil shaft carries at least one, and preferably two anvil jaws 63. The anvil jaws are diametrically opposed and radially extendingO The outer radial surfaces o~ the anvil jawc are dimensioned so that the inner chamber 44 of the hammer cage can rotate freely about the anvil jaws.
The anvil shaft al50 carries an eccentric crank 61 at the shaft end opposite the cam 62. The anvil shaft 60 is supported by needle bearing 54 so that it slides ~reely in the axial direction as well as freely rotates. The anvil shaft is also journaled for rotation and axial movement by a bore in hammer cage top 42.
Docket No. 0186-IR-TH
Numeral 50 designates a helical coil biasing spring of a size to fit around a reduced diameter portion of the anvil shaft 60 and abut against a shoulder on the shaft. This biasing spring normally urges the anvil shaft 60 toward the base portion of the hammer cage 41, such that the extending cam 62 normally projects into the raceway 47.
At least one, ~nd preferably two hammer jaws 45 are received in the axial grooves of the hammer cage 41. The hammer jaws are harden pins and when in place are half embedded in the cylindrical wall portion and half exposed in the inner chamber 44. The hammer jaws rest on the shoulders of the axial grooves so as not to extend to the base portion o~ the hammer cage. An uninterrupted cylindrical surface is provided below the shoulders at the base of the inner chamber 44.
This surface allows the hammer cage 41 to rotate relative to the anvil jaws 63 when the biasing spring urges the anvil shaft toward the base portion of the hammer cage without impacting on the anvil jaws.
The hammer cage top 42 has a short, snug-fitting, reduced diameter portion that is inserted into the inner chamber 44 of the hammer cage. The~cage top also has two diametrically opposite pilot bores that axially align with the axial grooves of the ha~mer cage. The hammer jaws 45 are also received into these pilot bores to fix the hammer jaws in an axial position and to lock the hammer cage and hammer cage top together against relative rotation.
Figure 1 illustrates the ratchet wrench in a position when the biasing spring 50 is extended and ~o~
Docket No. 0186-IR-TH
the cam 62 is positioned in the raceway 47. The anvil jaws 63 are biased by the spring toward the base of the hammer cage such that during rotation of the hammer cage, the hammer jaws 45 do not intercept the anvil jaws 63. The uninterrupted cylindrical portion of the hammer cage 41, that portion located below the hammer jaws, rotates radially adjacent to the anvil jaws.
When tha anvil jaws 63 move axially forward, due to the cam 62 riding up on cam ball 43 and compressing the biasing spring 50, the orbit of the rotating hammer jaws 45 intercepts the new position of the anvil jaws. When the cam ~2 moves the anvil shaft axially forward during each rotation of the hammer cage, the hammer jaws 45 produce a series of rotational impact against the anYil jaws 63.
Eccentric crank 61 is positioned at the end of the anvil shaft 60 opposite the cam 62. The crank slidas axially in the bore of a drive bushing 52 so as to allow for ~he axial movement of the anvil shaft.
Drive bushing 52 slides vertically in a bushing pocket 72 of ratchet yoke 71 so a~ to accommodate the up and down movement of the crank 61 as it rotatesO
The oscillating movement of the ratchet yoke is transferred to the ratchet mechanism 70. The ratchet mechanism rotates a ratchet spindle or tool head 73 in a conventional manner as is well known in the prior art.
_g_ Docket No. 0186~IR-TH
By turning the ratchet reverse knob 74 to the appropriate setting, the direction of rotation of the ratchet spindle can be determined. The tool can be operated to tighten or remove a fastener by setting the ratchet reverse knob 74.
PERATION
To set a threaded fastener, the ratchet mechanism is first simply directly driven by the motor through the impact clutch to rotate or "run down" the fastener to a snug position. Next, to fully tighten the fastener, impacts are applied by the impact clutch mechanism to further rotate the ratchet mechanism and ~urther torque the fastener.
Fiyure 1 illustrates the 'Grun down" position of the tool. The anvil shaft 60 is in its normal axial position, that is biased toward the base portion of the hammer cage with the one-sided cam 62 extending into the raceway 47. The cam ball 43 is contained in the limited arc cam ball pock~t 46. When the air motor rotates, output shaft 31 causes hammer cage 41 to rotate with it due to the splined connection. The trailing shoulder of the rotating cam ball pocket engages and drives the cam ball in the direction of rotation directly of the hammer cage. The cam ball next engages but does not roll up the inclined surface of the one-sided cam 62 The rotating cam ball imparts rotation to the anvil shaft 60. The rotation of the crank 61 at the end of the anvil shaft causes the ratchet mechanism to "run down" the ~astener.
Until the ratchet mechanism and the anvil shaft 60 encounter sufficient resistance from the fastener as it becomes snug, the motor is directly Docket No. 0186-IR-TH
driving the ratchet mechanism through the cam ball o~
the impact clutch mechanismO
When the ratchet mechanism and the anvil shaft 60 ancounter sufficient resis~ance, the gradual inclined surface o~ the cam 62 begins to ride up on the cam ball 43 due to the continued rotation of the cam ball with the hammer cage. The anvil shaft and the attached anvil jaws 63 are moved axially forward away from the base portion of the hammer cage. In other words, the cam ball cooperates with the cam to move the cam and attached anvil shaft axially forward as the cam rides up on the cam ball as it revolves within the cam ball pocket and rotates with the hammer cage.
When the cam peak overrides the top of the cam ball, the cam momentarily maintains its axial momentum and clears the cam ball, which continues to rotate beneath the cam. The cam is momentarily in "free flight" before an impact occurs. There are a few degrees of clearance between the trailing shoulder of the cam ball pocket and the hammer jaws. The anvil jaws 63 have been moved axially away from the hammer base portion and are now in an axial position which intercepts the orbit of thP xotating hammer jaws 45.
The exposed portions of the hammer jaws 45 intercept the new position of the anvil jaws and an impact is delivered to the anvil jaws.
This impact drives the anvil shaft 60 in the direction of rotation of the hammer cage until sufficient resistance is met. This re~istance is the resistance the fastener encounters as it tightens and is transferred from the fastener through the ratchet mechanism to the anvil shaft 60. When sufficient resistance is met, Docket No. 0186-IR-TH
the anvil shaft stops rotating and the hammer jaws and anvil jaws will begin to disengaga.
At that time, the force in the compressed biasing spring 50 o~ercomes the axial momentum of the anvil shaft and begins to push the cam back towards the hammer cage base. As the cam peak moves toward the base, the steep escape surface adjacent the cam peak kicks the cam ball in the direction of the leading edge of the cam ball pocket. The cam peak then again enters the xaceway 47.
As the hammer cage continues to rotate, the cam 62 once again encounters the cam ball 43. The cam ball rotates in the cam ball pocket with the cam until the ball reaches the trailing edge of the pocket. If there still is sufficient resistance due to fastener tension, the cam ball will again force the cam to ride up on the cam ball and the impact sequence will be repeated until the fastener can not be furthar tightened. The cam ball thus times the impacts. ~t ultimate tighening torque, the impact clutch mechanism will continue to cause the hammer to impact on the anvil. The ratchet mechanism will not provide any more tightening torque to the fastener. However, the tool operator will not experience any torque reaction due to the tool turning on the tightened fastener.
Rather the operakor will experience only the minimal reactions due to the impact clutch.
Other emhodiments are considered to be within the scope of this invention~ For axample, anvil shaft 60 can b~ constructed o~ two pieces to ~acilitate the manufacture and assembly o~ the tool. A separate cam Docket No. 0186 IR-TH
portion having the cam peak and anvil jaws can be positioned inside the inner chamber 44 of the hammer cage and splined to a shaft portion extending through the bore of the hammer cage top. Furthermore, biasing spring 50 can be positioned anywhere along the shaft portion of the anvil sha~t 60. For example, in the embodiment with a two piece anvil shaft, the biasing spring can be positioned on the splined connection between the cam portion and the shaft portion The purpose of the impact clutch mechanism is to translate rotary motion to interrupted rotaxy motion having less torque reaction. The impact clutch mechanism described in connection with the preferred embodiment can be broadly categorized as a unique embodiment o~ a cam engage, spring disengage impact clutch. Other embodiments of the cam engage, spring disengage type impact clutch are also considered to be within the scope of this invention. For example, in the pre~erred embodiment, the anvil shaft moves axially. An alternate embodiment can provide for the hammer jaws to move axially rather than the anvil shaft.
Additionally, other types of impact clutch mechanisms, such as the cam engage, cam disengage impact clutch of Mauer (U.S. Patent 3,661,217 issued May 9, 1972), and the spring engage, spring disengage impact clutch o~ Pott (U.S.- Patent 3,369,615 issued February 20, 196~), are considered to be within the scope of this invention. The Pott impact clutch is particularly suitable`for electric driven ratchet wrenches.
Docket No. 0186-IR-TH
One advantage of this invention over the prior art includes minimizing the torque reaction to the tool operator when a fastener is tight and the tool continues to run. TAis allows the tool to be safely operated with one hand and also in cunfined and aw~ard situations. The tool will also produce a consistent tightening torque. The operator will not have to stop the tool before the fastener is tight and manually tighten the fastener out o~ concern for his own safety and well-being. Additionally, the tool allows a faster "run-down" of the fasteners than prior art powered ratchets.
From the foregoing, those skilled in the art will recognize the improvements over prior art tools and the considerable advantages.
Changes and modi~ications in the specifically described embodiments can be carried out without departing from the SCOpQ of the invention which is intended to be limited only by the scope o~ the appended claims.
Claims (6)
1. A powered ratchet wrench comprising, in axial alignment to form an elongated handle;
a rotary motor having a rotatable output shaft;
a rotary impact clutch mechanism also having a rotatable output shaft and rotated by said rotatable output shaft of said rotary motor;
a reversible ratchet mechanism having an oscillatable ratchet yoke and being oscillatably driven through said yoke by the output shaft of said impact clutch; and a single ended tool drive spindle driven by said ratchet mechanism and having its drive axis normal to the axes of said rotary motor and said impact clutch.
a rotary motor having a rotatable output shaft;
a rotary impact clutch mechanism also having a rotatable output shaft and rotated by said rotatable output shaft of said rotary motor;
a reversible ratchet mechanism having an oscillatable ratchet yoke and being oscillatably driven through said yoke by the output shaft of said impact clutch; and a single ended tool drive spindle driven by said ratchet mechanism and having its drive axis normal to the axes of said rotary motor and said impact clutch.
2. The powered ratchet wrench according to claim 1, wherein said impact clutch mechanism further comprises:
a rotatable hammer assembly connected to said output shaft of said rotary motor and arranged to drive an anvil member continuously at high speed under no load or low load conditions and to deliver a series of rotational impacts to said anvil member whenever the driven load exceeds a threshold torque level;
an output shaft on said rotatable anvil member adapted to convert the rotary output of the anvil to oscillatory movement of the ratchet yoke.
a rotatable hammer assembly connected to said output shaft of said rotary motor and arranged to drive an anvil member continuously at high speed under no load or low load conditions and to deliver a series of rotational impacts to said anvil member whenever the driven load exceeds a threshold torque level;
an output shaft on said rotatable anvil member adapted to convert the rotary output of the anvil to oscillatory movement of the ratchet yoke.
3. The powered ratchet wrench according to claim 2, wherein said impact clutch for delivering a series of rotational impacts comprises:
at least one hammer jaw disposed on and rotatable with said hammer assembly;
at least one anvil jaw disposed on and rotatable with said anvil member;
a spring for biasing said anvil jaw axially out of engagement with said hammer jaw; and a cam for repeatedly axially moving said anvil jaw into engagement with said hammer jaw to deliver a rotational impact to said anvil jaw.
at least one hammer jaw disposed on and rotatable with said hammer assembly;
at least one anvil jaw disposed on and rotatable with said anvil member;
a spring for biasing said anvil jaw axially out of engagement with said hammer jaw; and a cam for repeatedly axially moving said anvil jaw into engagement with said hammer jaw to deliver a rotational impact to said anvil jaw.
4. A powered ratchet wrench for tightening or removing threaded fasteners, comprising:
a rotary motor having a rotatable output shaft;
a rotatable hammer cage coaxially connected to said output shaft for rotation therewith;
a rotatable anvil shaft coaxially supported with respect to said hammer cage and having a first end associated with said rotatable hammer cage;
at least one hammer jaw disposed on said hammer cage;
at least one anvil jaw disposed on said anvil shaft;
a spring axially biasing said anvil shaft so that said hammer jaw and said anvil jaw are axially out of alignment;
cam means associated with said anvil shaft for axially moving said anvil shaft so that said anvil jaw moves axially into alignment with said hammer jaw to deliver a series of rotational impacts to said anvil jaw;
an eccentric crank member fixed to a second end of said rotatable anvil shaft for eccentric rotation therewith;
means for converting the eccentric rotation of said crank member to substantially oscillating movement;
an oscillatable ratchet yoke operatively connected to said converting means, and a ratchet mechanism operated by the oscillating movement of said ratchet yoke and driving a ratchet spindle for tightening or removing threaded fasteners.
a rotary motor having a rotatable output shaft;
a rotatable hammer cage coaxially connected to said output shaft for rotation therewith;
a rotatable anvil shaft coaxially supported with respect to said hammer cage and having a first end associated with said rotatable hammer cage;
at least one hammer jaw disposed on said hammer cage;
at least one anvil jaw disposed on said anvil shaft;
a spring axially biasing said anvil shaft so that said hammer jaw and said anvil jaw are axially out of alignment;
cam means associated with said anvil shaft for axially moving said anvil shaft so that said anvil jaw moves axially into alignment with said hammer jaw to deliver a series of rotational impacts to said anvil jaw;
an eccentric crank member fixed to a second end of said rotatable anvil shaft for eccentric rotation therewith;
means for converting the eccentric rotation of said crank member to substantially oscillating movement;
an oscillatable ratchet yoke operatively connected to said converting means, and a ratchet mechanism operated by the oscillating movement of said ratchet yoke and driving a ratchet spindle for tightening or removing threaded fasteners.
5. In a powered ratchet wrench, the combination of:
a rotary motor having a rotatable output shaft driven by said motor;
a rotatable hammer cage having a cylindrical wall portion and a flat base portion and coaxially connected at said base portion to said output shaft for rotation therewith;
a rotatable anvil shaft coaxially supported with respect to said hammer cage for rotational and axial movement and having a peak-shaped cam projecting axially from a first end;
at least one anvil jaw projecting radially from said first end of said anvil shaft;
an inner chamber in said hammer cage enclosing said first end of said anvil shaft and having a raceway in said base portion of said hammer cage to allow relative rotation of said cam;
a cam ball pocket coinciding with said raceway through a limited arcuate distance in said base portion of said hammer cage;
at least one hammer jaw disposed on an inner axial surface of said inner chamber of said hammer cage;
a disengaging spring axially biasing said anvil shaft toward said base portion of said hammer cage so that said hammer jaw and said anvil jaw are axially out of alignment;
a cam ball disposed in said cam ball pocket in the path of rotation of said cam for driving said anvil shaft when said hammer jaw and said anvil jaw are axially out of alignment and for axially moving said cam against the bias of said disengaging spring so that said anvil jaw moves axially into alignment with said hammer jaw to deliver a series of rotational impacts to said anvil shaft;
a crank fixed to a second end of said rotatable anvil shaft for eccentric rotation therewith;
a drive bushing for converting the eccentric rotation of said crank to substantially oscillating movement;
an oscillatable ratchet yoke operatively connected to said drive bushing; and a ratchet mechanism operated by the oscillating movement of said ratchet yoke and driving a ratchet spindle for tightening or removing threaded fasteners.
a rotary motor having a rotatable output shaft driven by said motor;
a rotatable hammer cage having a cylindrical wall portion and a flat base portion and coaxially connected at said base portion to said output shaft for rotation therewith;
a rotatable anvil shaft coaxially supported with respect to said hammer cage for rotational and axial movement and having a peak-shaped cam projecting axially from a first end;
at least one anvil jaw projecting radially from said first end of said anvil shaft;
an inner chamber in said hammer cage enclosing said first end of said anvil shaft and having a raceway in said base portion of said hammer cage to allow relative rotation of said cam;
a cam ball pocket coinciding with said raceway through a limited arcuate distance in said base portion of said hammer cage;
at least one hammer jaw disposed on an inner axial surface of said inner chamber of said hammer cage;
a disengaging spring axially biasing said anvil shaft toward said base portion of said hammer cage so that said hammer jaw and said anvil jaw are axially out of alignment;
a cam ball disposed in said cam ball pocket in the path of rotation of said cam for driving said anvil shaft when said hammer jaw and said anvil jaw are axially out of alignment and for axially moving said cam against the bias of said disengaging spring so that said anvil jaw moves axially into alignment with said hammer jaw to deliver a series of rotational impacts to said anvil shaft;
a crank fixed to a second end of said rotatable anvil shaft for eccentric rotation therewith;
a drive bushing for converting the eccentric rotation of said crank to substantially oscillating movement;
an oscillatable ratchet yoke operatively connected to said drive bushing; and a ratchet mechanism operated by the oscillating movement of said ratchet yoke and driving a ratchet spindle for tightening or removing threaded fasteners.
6. A powered ratchet wrench comprising:
a rotary motor;
an impact mechanism axially aligned with and engaged with the output shaft of said rotary motor, said impact mechanism further comprising:
a hammer cage in rotary driven engagement with said motor output shaft and having at least one hammer jaw;
a rotatable and axially slidable anvil shaft axially aligned with and centered in the hammer cage and having at least one anvil jaw, one axially extending anvil cam, and an eccentric shaft output end;
an impact clutch means for causing intermittent engagement between the hammer jaw and the anvil jaw through the combined action of a biasing spring and the anvil cam to produce rotary impacts on the anvil output shaft; and a reversible ratchet mechanism having a single output spindle and a yoke in oscillating driven engagement with the output end of the anvil shaft.
a rotary motor;
an impact mechanism axially aligned with and engaged with the output shaft of said rotary motor, said impact mechanism further comprising:
a hammer cage in rotary driven engagement with said motor output shaft and having at least one hammer jaw;
a rotatable and axially slidable anvil shaft axially aligned with and centered in the hammer cage and having at least one anvil jaw, one axially extending anvil cam, and an eccentric shaft output end;
an impact clutch means for causing intermittent engagement between the hammer jaw and the anvil jaw through the combined action of a biasing spring and the anvil cam to produce rotary impacts on the anvil output shaft; and a reversible ratchet mechanism having a single output spindle and a yoke in oscillating driven engagement with the output end of the anvil shaft.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60103158A JPH0635115B2 (en) | 1985-05-15 | 1985-05-15 | Ratchet wrench hammer structure |
| JP60-103158 | 1985-05-15 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1281920C true CA1281920C (en) | 1991-03-26 |
Family
ID=14346693
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000508917A Expired - Lifetime CA1281920C (en) | 1985-05-15 | 1986-05-12 | Ratchet wrench |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | USRE33711E (en) |
| EP (1) | EP0202130B1 (en) |
| JP (1) | JPH0635115B2 (en) |
| CA (1) | CA1281920C (en) |
| DE (1) | DE3674634D1 (en) |
Families Citing this family (23)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62246480A (en) * | 1986-04-16 | 1987-10-27 | 信濃空圧工業株式会社 | Clamping device |
| US4791836A (en) * | 1987-04-01 | 1988-12-20 | Chicago Pneumatic Tool Company | Ratchet mechanism |
| JPS63256373A (en) * | 1987-04-14 | 1988-10-24 | 信濃空圧工業株式会社 | Clamping device |
| SE504620C2 (en) * | 1995-04-26 | 1997-03-17 | Atlas Copco Tools Ab | Pneumatic torque pulse tool |
| US6105595A (en) | 1997-03-07 | 2000-08-22 | Cooper Technologies Co. | Method, system, and apparatus for automatically preventing or allowing flow of a fluid |
| US5890848A (en) * | 1997-08-05 | 1999-04-06 | Cooper Technologies Company | Method and apparatus for simultaneously lubricating a cutting point of a tool and controlling the application rate of the tool to a work piece |
| US6082986A (en) | 1998-08-19 | 2000-07-04 | Cooper Technologies | Reversible double-throw air motor |
| US6241500B1 (en) | 2000-03-23 | 2001-06-05 | Cooper Brands, Inc. | Double-throw air motor with reverse feature |
| US6742609B2 (en) | 2001-05-11 | 2004-06-01 | United Diamond Ltd. | Rotational impact drill assembly |
| US6889778B2 (en) * | 2003-01-31 | 2005-05-10 | Ingersoll-Rand Company | Rotary tool |
| DE10309012B3 (en) * | 2003-03-01 | 2004-08-12 | Hilti Ag | Control method for hand-held electric hammer drill using microcontroller for repetitive opening and closing of clutch between electric motor and tool chuck |
| US7080578B2 (en) * | 2004-09-10 | 2006-07-25 | Sp Air Kabusiki Kaisha Corporation | Hand tool with impact drive and speed reducing mechanism |
| US20100064864A1 (en) * | 2008-09-15 | 2010-03-18 | Sp Air Kabushiki Kaisha | Double Hammer Clutch Impact Wrench |
| US8261849B2 (en) * | 2008-10-27 | 2012-09-11 | Sp Air Kabushiki Kaisha | Jumbo hammer clutch impact wrench |
| US8051746B2 (en) * | 2009-06-30 | 2011-11-08 | Ingersoll Rand Company | Ratchet wrench with collar-actuated reversing mechanism |
| EP2635410B1 (en) | 2010-11-04 | 2016-10-12 | Milwaukee Electric Tool Corporation | Impact tool with adjustable clutch |
| TW201338926A (en) * | 2012-03-16 | 2013-10-01 | Basso Ind Corp | Ratchet wrench with switching device |
| TWM447817U (en) * | 2012-09-21 | 2013-03-01 | Basso Ind Corp | Pneumatic ratchet wrench having retractable head portion |
| US9272400B2 (en) | 2012-12-12 | 2016-03-01 | Ingersoll-Rand Company | Torque-limited impact tool |
| US20150165603A1 (en) * | 2013-12-17 | 2015-06-18 | Ming-Ta Cheng | Power device with a unicorn impact unit |
| US9737978B2 (en) | 2014-02-14 | 2017-08-22 | Ingersoll-Rand Company | Impact tools with torque-limited swinging weight impact mechanisms |
| US12076839B2 (en) * | 2018-12-24 | 2024-09-03 | Js Products, Inc. | Power ratchet |
| JP2023025360A (en) * | 2021-08-10 | 2023-02-22 | パナソニックＩｐマネジメント株式会社 | impact rotary tool |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3174597A (en) | 1961-12-19 | 1965-03-23 | Chicago Pneumatic Tool Co | Impact clutch |
| US3212590A (en) * | 1963-07-29 | 1965-10-19 | Reed Roller Bit Co | Impact wrench |
| US3414066A (en) * | 1966-08-31 | 1968-12-03 | Chicago Pneumatic Tool Co | Impact wrench |
| US3428137A (en) * | 1967-10-12 | 1969-02-18 | Chicago Pneumatic Tool Co | Impact wrench |
| JPS5435380Y2 (en) * | 1971-04-13 | 1979-10-27 | ||
| JPS5235708B2 (en) * | 1971-09-27 | 1977-09-10 | ||
| JPS4918313U (en) * | 1972-05-17 | 1974-02-16 | ||
| US4063601A (en) * | 1976-08-23 | 1977-12-20 | Dresser Industries, Inc. | Rotary impact tool |
| US4184552A (en) * | 1977-05-17 | 1980-01-22 | Marquette Metal Products Company | Manually actuated impact tool |
| US4313505A (en) * | 1979-08-27 | 1982-02-02 | Rodac Pneumatic Tools | Rotary impact clutch |
| US4346630A (en) * | 1979-12-17 | 1982-08-31 | Rodac Pneumatic Tools | Ratchet wrench |
| US4382476A (en) * | 1981-12-03 | 1983-05-10 | Swenson Oscar J | Manual torque magnifying impact tool |
-
1985
- 1985-05-15 JP JP60103158A patent/JPH0635115B2/en not_active Expired - Lifetime
-
1986
- 1986-05-12 CA CA000508917A patent/CA1281920C/en not_active Expired - Lifetime
- 1986-05-15 EP EP86303726A patent/EP0202130B1/en not_active Expired
- 1986-05-15 DE DE8686303726T patent/DE3674634D1/en not_active Expired - Lifetime
-
1990
- 1990-09-04 US US07/578,363 patent/USRE33711E/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| EP0202130A1 (en) | 1986-11-20 |
| JPH0635115B2 (en) | 1994-05-11 |
| JPS61260982A (en) | 1986-11-19 |
| EP0202130B1 (en) | 1990-10-03 |
| DE3674634D1 (en) | 1990-11-08 |
| USRE33711E (en) | 1991-10-08 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |