CA1129682A - Hammer drill or chipping hammer device - Google Patents
Hammer drill or chipping hammer deviceInfo
- Publication number
- CA1129682A CA1129682A CA350,874A CA350874A CA1129682A CA 1129682 A CA1129682 A CA 1129682A CA 350874 A CA350874 A CA 350874A CA 1129682 A CA1129682 A CA 1129682A
- Authority
- CA
- Canada
- Prior art keywords
- disk
- working cylinder
- driving shaft
- actuating piston
- axis
- 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
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25D—PERCUSSIVE TOOLS
- B25D11/00—Portable percussive tools with electromotor or other motor drive
- B25D11/06—Means for driving the impulse member
- B25D11/062—Means for driving the impulse member comprising a wobbling mechanism, swash plate
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25D—PERCUSSIVE TOOLS
- B25D11/00—Portable percussive tools with electromotor or other motor drive
- B25D11/005—Arrangements for adjusting the stroke of the impulse member or for stopping the impact action when the tool is lifted from the working surface
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Percussive Tools And Related Accessories (AREA)
- Drilling And Boring (AREA)
- Crushing And Pulverization Processes (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
In a device which can be used as a hammer drill or a chipping hammer, a percussion mechanism is located within a working cylinder in the housing of the device. A tool can be placed in one end of the working cylinder and the tool can be rotated without any percussive action or it can be given a combined rotative and percussive action. The percussive action is transmitted over a driving mechanism to an actuating piston which reciprocates a percussion piston through an intermediate air cushion. The drive mechanism includes a driving shaft with a disk pivotally connected to the shaft and in engagement with the actuating piston for selectively effecting the percussive action on the tool.
In a device which can be used as a hammer drill or a chipping hammer, a percussion mechanism is located within a working cylinder in the housing of the device. A tool can be placed in one end of the working cylinder and the tool can be rotated without any percussive action or it can be given a combined rotative and percussive action. The percussive action is transmitted over a driving mechanism to an actuating piston which reciprocates a percussion piston through an intermediate air cushion. The drive mechanism includes a driving shaft with a disk pivotally connected to the shaft and in engagement with the actuating piston for selectively effecting the percussive action on the tool.
Description
~6~2 , ~ -The present invention is directed to a device which can be used as a hammer drill or a chipping hammer and includes a percussion mechanism preferably driven by an electric motor.
The percussion mechanism is composed basically of an actuating piston supported and reciprocally movable within a working cylinder. The actuating piston transfers the percussive energy through the medium of an air cushion to a percussion piston acting on a tool. The actuating piston is in engagement with a disk mounted on a driving shaft and the disk rotates with the shaft.
Percussion mechanisms driven by an electric motor, as mentioned above, are also called electro-pneumatic systems.
Usually, the actuating piston is reciprocated by a crank drive.
Since in crank drives the axle of the crank shaft always extends perpendicularly to the axis of the actuating piston, such an arrangement requires a lot of space. If the percussion drive is combined with a rotating drive, then a complicated miter gear unit is needed.
To eliminate these disadvantages, it has been suggested to use a swash-plate in tead of the crank drive for reciprocating `~
the actuating piston. As compared to a cran~ drive, a swash-~` plate Xas the advantage that the driving mechanism can be constructed much more compactly.
Known percussion mechanisms have the common disadvant-~` age that the percussiv~ ~orce is not continuously variable. This failing applies to percussion mechanisms with a crank drive as well as to those using a swash-plate.
Therefore, it is the primary object of the present invention to provide a pexcussion mechanism where the percussive force can be regulated.
?6~ `
In accordance with the present invention, the per-cussive force is regulated by pivotally supporting a driving disk for the actuating piston on a drive shaft. A control member secured to the drive shaft so that it rotates with i-t, is axially movable on -the shaft and regulates the extent to which the disk is pivoted relative to the axis of the shaft.
With the aid of the control member the dis~ can be displaced from a neutral position into a working position.
In the neutral position the plane of the disk extends per-pendicularly to the axis of the driving shaft so that no reciprocating movement is transmitted to the actuating piston.
In the working position, the disk can be pivoted to a positio~
where it effects the maximum reciprocating movement of the actuating piston. Intermediate posit:ions of the disk can be established between the neutral posit:ion and the maximum pivotally displaced position of the d:isk. In the neutral position where the actuating piston experiences no reciprocating movement, the total o~tput of the driving motor of the device is available for the rotation of the tool mounted in the device.
With the exception of a position parallel to the axis of the driving shaft, theoretically, the pivot axle of the disk can be ~n any position. For optimum adjustabili.ty of the disk, however, it is practical to arrange the pivot axle extending normally to the axis of the driving shaft. With such an arrange-ment of the pivot axle depending on the axial movement of the control member it is possible to achieve an optimum pivotal deflection of the disk.
In the operation o~ the device capable of use as a hammer drill or a chipping hammer, it is advantageous to be able to operate the device in a range from a minimum to a maximum percussive force. To afford such variable percussion operation, it is advantageous if a spring element acts to return the disk to its neutral position from a pivoted working position. The restoring force produced by the spring element is supported by the centrifugal force acting on the disk. The spring element can be a compression spring arranged around and coaxially to the driving shaft. A compression spring requires little space and can be easily replaced~
Various embodiments can be provided for the control member. In an especially practical embodiment, the control element is shaped as a drum with its surface facing the disk extending obliquely of a plane normal to the axis of the driving shaft. Such an embodiment makes it very simple to produce the control member. The inclination of the surface of the control member facing the disk is established relative to the pivot axle of the disk. Accordingly, for the maximum deElection of the disk, it is possible that the facing surfaces of the control mem~er and the disk are in contact.
~Yial movement of the control member can be effected in different ways from the exterior ~f the device. In a particularly practical embodiment, however, the movement of the control~ember is achieved by supporting the working cylinder so that it is axially movable. The working cylinder is moved by pressing one end of the cylinder against another surface so that it is moved in its axial direction against the orce of a spring. When the force displacing the working cylinder is removed, the spring effects the return of the working cylinder.
Normally, the displacement is effected by pressing the device including the working cylinder against a workpiece. When the device is lifted off the wor~piece, the spring biased displacement ~2~Z
of the working cylinder assures that further percussive action is prevented. In this arrangement, the working cylinder is in operative contact with the control member.
Hammer drills are often used for work involving purely rotational movement. To prevent any percussive force in the device when only rotational movement is desired, it is advantageous if an adjustable stop for the working cylinder is provided. The stop is arranged so tha-t in one position it prevents any axial movement of the working cylinder while in another position it permits axial movement of the woxking cylinder for axial displacement of the control member along the driving shaft. Therefore, the stop assures the operation of the device in two operating conditions, "rotation only" and "rotation-percussion".
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodi~ents of the invention.
IN THE DRAWING5~
Fig. 1 is a side view of a device useful as a hammer drill or a chipping hammer, partly in section, with the device illustrated in the "rotation only" operating condition; and, Fig. 2 is a side view, partly in section, of the same device as shown in Fig. 1, however, ilIustrated in the "rotation-percussion" operating condition.
The device shown in Fig. 1, capable of being used as a ~2~ 1Z
.
hammer drill or a chipping hammer, includes a housing 1 having a handle 2 at its right-hand end as viewed in the drawing. A
trigger-like switch 3 and an electrical connection line 4 are provided in the handle 2. As viewed in Fig. 1, the left-hand end of the device is its front end and its right-hand end is its . .
rear end. In the rear portion of the housing 1 an electric motor 5 is located. A shaft 5a extends from the electric motor 5 toward the front end of the housing and the front end of the shaft i5 constructed as a pinion 6. Pinion 6 is in meshed engagement with a gear 7 secured on a driving shaft 8, with the axis of the shaft 8 extending in the rear end-front end direction `~
of the housing parallel to and offset from shaft 5a. Consequently, the driving shaft 8 is driven via the pinion 6 and the gear 7.
On the shaft 8, forwardly of the gear 7 is an annular disk 9 having an oversize central opening 9a. Disk 9 is pivotally mounted on the driving shaft 8 about a pin at axle pin 10 extending perpendicularly of the axis oE rotation of the driving shaft 8.
The size of opening 9a ensures that the disk 9 is pivotally displaceable about the pivot axle 10 between a neutr~l position ie perpendicular to shaft 8 and a number of working po~itions at varying angles to shaft 8. In Fig. 1 the disk 9 is shown in the neutral position and it is normally biased into this position by a compression spring 11 coaxial with and laterally surround-ing the shaft 8 and extending between gear 7 and disc 9. Located on the opposite side of the disk 9 from the spring 11 is a control member 12 which is axially movable along the driving shaft 8.
The control member 12 is drivingly connected to the driving shaft 8 by a wedge drive key 13 so that it rotates with the shaft 8 but can slide axially along it. The front end of the driving shaft 8 is provided with an elongated tooth or splined arrangement ~z~
8a extending around the circumference of the shaft, and ex-tending axially therealong a prede-termined distance. Each end of shaft 8 is suitably carried in bearings 8b and 8c located in -the housing.
Control member 12 has a control surface 12 lying in a plane having a longitudinal axis angled relative to shaft 8, and a lateral axis para~llel to a~le pin 10. A working cylinder 14 is located wi-thin the housing above the driving shaft 8 and coaxial with shaft Sa. The axes of the working cylinder 14 and the driving shaft 8 are disposed in parallel relation. The working cylinder has a front end F (at the lef-t hand of the drawing) projecting from the front end of the housing 1 and a rear end R loca-ted within the housing forwardly of the electric motor 5. An actua-ting piston 15 is positioned in the rear part of the working cylinder and a percussion piston 16 is located within the working cylinder forwardly oE the actuating piston.
The adjacent facing surfaces of the actuating piston 15 and the percussion piston 16 are spaced apart forming an air cushion therebetween. Air cushion 17 transfers the reciprocating motion of the actuating piston 15 to the percussion piston 16 so that the percussion piston 16 can transmit percussive force. On the outside sur~ace of the working cylinder 14 near its rear end R, an outwardly projecting toothed rim 14a is provided which forms a pinion and this rim is in meshed engagement with the elongated toothed surface or spline 8a on the front end portion of the driving shaft 8. Consequently, the rotation of the driving shaft 8 causes the working cylinder 14 to be rotated due to the meshed engagement of the toothed surface 8a and the toothed rim or pinion 14a. Working cylinder 14 is mounted in the housing 1 so that it can be moved to and fro for a limited -- 6 ~
., ~
distance in its axial direction.
For this purpose it is supported in a roller ~earing 21 and a ball bearing 22 spaced apart from one another. Bearing 21 engages an elongated cylindrical raceway 23 on cylinder 14 so that on axial displacement of cylinder 14 the raceway 23 will remain in engagement with bearing 21.
searing 22 is fastened around a forwar~ portion of cylinder 14 and is secured against shoulder 24 by means of circlip 25. Bearing 22 is slideably supported in a cylindrical portion 26 of housing 1, and is axial displaceable therein in unison with cylinder 14. In the neutral position of the device illustrated in Figure 1, the working cylinder 14 is kept in a forward position by means of a compression spring 18 encircling the working cylinder and pressing on bearing 22, and circlip 25.
An adjustable stop member 19 is rotatably mounted in ~he housing.
Stop 19 has a projection l9a extending into the axial path of movement of the working cylinder. ~rojection l9a i9 mounted of~set on disc l9b which is part of stop 19. ~y rotation of stop 19 it is possible to move projection l9a into and out of ; 20 engagement with the rear end of cylinder 14 and thus to secure cylinder 14 in the position shown in Figure 1. In this position, which is called the neutral position, there will be no reciprocation of the piston 15. The cylinder 14 will simply rotate, thus causing rotation of a tool bit (not shown) secured in the tool carrier 14b. In this position, the disc 9, ~eing urged by spring 11 into its forward position perpendicular to shaft 8, also urges control member 1~ forwardly on shaft 8, and control member 1 2 is free to move forwardly until it reaches the rear end of cylinder 14. In this position therefore disc 9 will simply rotate in groove I5a of piston 15, without causing any ~7~6~32 reciprocation. `~
In Figure 2, the device illustrated in Figure 1 is shown in the "rotation-percussion" position. Movement into this second position is achieved by changing the position of the stop 19, as well as by pressing the device against a surface, such as a workpiece. By noting the different positions of the stop 19 in Figures l-and 2, it can be appreciated that in Figure,2 it is possible to displace the working cylinder 14 axially rearwardly from the position shown in Figure 1. In Figure 2, a tool 20 is shown inserted into the tool carrier 14b.
With the stop 19 positioned as in Figure 2 the projection l9a is swung rearwardly. When the tool 20 extending from the front end of the working cylinder 14, is pressed against a surface r the working cylinder moves axially inwardly into the housing until its rear end contacts the downwardly extending pro,jection l9a on the stop 19. As the working cylinder moves inwardly into the housing, the rear end of the working cylinder in contact with the forwardly facing surface of the control member 12 moves the control mem~er axially rearwardly relative : ~ to the drlving sha~t 8. The surface 12a of the control member facing the disk 9 is i ~lined obliquely to a plane extending normally of the axis of the driving shaft 8. As the surface 12a contacts~the aisk 9, the disk pivots about its pivot axle 10 , oversize opening 9a permits this pivoting or tilting action, relative to shaft 8. Since the disk 9 and the control member 12 rotate in this position in unison with the driving shaft 8, the disk performs a wobbling movement. As it rotates, the disk 9 engages a groove 15a in the lateral surface of the actuating piston 15. Due to the wobbling movement of the disk 9 as it rotates, a reciprocating movement is transmitted to the ~2~
actuating piston 15. Accordingly, in the "rotation-percussion"
position shown in Figure 2, the disk 9 is displaced about the pivot axle 10 to a maximum extent and the reciprocating strokes of the actuating piston are also at a maximum. Between this maximum `'rotation-percussion" position and the neutral or "ro-tation only" position shown in Figure 1, the angular deflection of the disk 9 and consequently, the percussion stroke, can be varied by changing the contact pressure or the extent to which the disk is angularly deflected. When the device is lifted - 10 off the surface, the working cylinder 14 is displaced axially outwardly by the compression spring 18 to the position shown in Figure 1. Further, the centrifugal force acting on the disk 9 and the effect of the compression spring 11 also act on the disk and through it on the control member, cause the return of the disk 9 to the perpendicular neutral position of Figure 1. Therefore, this embodiment of the present invention permits a continuous adjustment of the degree of percussive force acting on the material being processed by the device.
Having described what is believed to be the best mode by which the invention may be performed, it will be seen that the i~vention may be particularly defined as follows:
A device for use as a hammer drill or chipping hammer including a ~ousing, an axially elongated working cylinder positioned within said housing and having a front end and a rear end, a percussion mechanism located within said working cylinder, means for operating said percussion mechanism, said percussion mechanism comprising an actuating piston mounted and reciprocally movable within said working cylinder, a percussion piston located within said working cylinder between said actuating piston and the front end of said working cylinder, ~iL?d~3i'2 said percussion piston being s~ ced axially from said actuating piston forming an air cushion therebe-tween so that the .reciprocating action of said actuating piston is -transmitted via the air cushion to said percussion piston, said operating means comprising a driving shaft spaced laterally from said working cylinder, and a disk mounted on said driving shaft and disposed in contact with said actuating piston, wherein the improvement comprises that said disk extends transversely of said driving shaft and includes an axle pivotally connecting said disk to said driving shaft so that the plane of said disk relative to the axis of said driving shaf-t can be angularly displaced for effeeting variable axial displacement of said ae-tuating piston within said working cylinder, and a eon~rol member positioned on and rotatable with said driving shaEt, and said eontrol member being displaeeable in the axial direetion of said drivin~ shaft for movement into contact with said disk for pivotally displacing said disk .relativ0 to the axis of said driv.ng shaft.
While speeifie embodiments of the invention have been shown and described in detail to illustrate the application of the inventive prineiples, it will be understood that the inventi~on may be embodied o~herwise without departing from sueh prine~ples.
The percussion mechanism is composed basically of an actuating piston supported and reciprocally movable within a working cylinder. The actuating piston transfers the percussive energy through the medium of an air cushion to a percussion piston acting on a tool. The actuating piston is in engagement with a disk mounted on a driving shaft and the disk rotates with the shaft.
Percussion mechanisms driven by an electric motor, as mentioned above, are also called electro-pneumatic systems.
Usually, the actuating piston is reciprocated by a crank drive.
Since in crank drives the axle of the crank shaft always extends perpendicularly to the axis of the actuating piston, such an arrangement requires a lot of space. If the percussion drive is combined with a rotating drive, then a complicated miter gear unit is needed.
To eliminate these disadvantages, it has been suggested to use a swash-plate in tead of the crank drive for reciprocating `~
the actuating piston. As compared to a cran~ drive, a swash-~` plate Xas the advantage that the driving mechanism can be constructed much more compactly.
Known percussion mechanisms have the common disadvant-~` age that the percussiv~ ~orce is not continuously variable. This failing applies to percussion mechanisms with a crank drive as well as to those using a swash-plate.
Therefore, it is the primary object of the present invention to provide a pexcussion mechanism where the percussive force can be regulated.
?6~ `
In accordance with the present invention, the per-cussive force is regulated by pivotally supporting a driving disk for the actuating piston on a drive shaft. A control member secured to the drive shaft so that it rotates with i-t, is axially movable on -the shaft and regulates the extent to which the disk is pivoted relative to the axis of the shaft.
With the aid of the control member the dis~ can be displaced from a neutral position into a working position.
In the neutral position the plane of the disk extends per-pendicularly to the axis of the driving shaft so that no reciprocating movement is transmitted to the actuating piston.
In the working position, the disk can be pivoted to a positio~
where it effects the maximum reciprocating movement of the actuating piston. Intermediate posit:ions of the disk can be established between the neutral posit:ion and the maximum pivotally displaced position of the d:isk. In the neutral position where the actuating piston experiences no reciprocating movement, the total o~tput of the driving motor of the device is available for the rotation of the tool mounted in the device.
With the exception of a position parallel to the axis of the driving shaft, theoretically, the pivot axle of the disk can be ~n any position. For optimum adjustabili.ty of the disk, however, it is practical to arrange the pivot axle extending normally to the axis of the driving shaft. With such an arrange-ment of the pivot axle depending on the axial movement of the control member it is possible to achieve an optimum pivotal deflection of the disk.
In the operation o~ the device capable of use as a hammer drill or a chipping hammer, it is advantageous to be able to operate the device in a range from a minimum to a maximum percussive force. To afford such variable percussion operation, it is advantageous if a spring element acts to return the disk to its neutral position from a pivoted working position. The restoring force produced by the spring element is supported by the centrifugal force acting on the disk. The spring element can be a compression spring arranged around and coaxially to the driving shaft. A compression spring requires little space and can be easily replaced~
Various embodiments can be provided for the control member. In an especially practical embodiment, the control element is shaped as a drum with its surface facing the disk extending obliquely of a plane normal to the axis of the driving shaft. Such an embodiment makes it very simple to produce the control member. The inclination of the surface of the control member facing the disk is established relative to the pivot axle of the disk. Accordingly, for the maximum deElection of the disk, it is possible that the facing surfaces of the control mem~er and the disk are in contact.
~Yial movement of the control member can be effected in different ways from the exterior ~f the device. In a particularly practical embodiment, however, the movement of the control~ember is achieved by supporting the working cylinder so that it is axially movable. The working cylinder is moved by pressing one end of the cylinder against another surface so that it is moved in its axial direction against the orce of a spring. When the force displacing the working cylinder is removed, the spring effects the return of the working cylinder.
Normally, the displacement is effected by pressing the device including the working cylinder against a workpiece. When the device is lifted off the wor~piece, the spring biased displacement ~2~Z
of the working cylinder assures that further percussive action is prevented. In this arrangement, the working cylinder is in operative contact with the control member.
Hammer drills are often used for work involving purely rotational movement. To prevent any percussive force in the device when only rotational movement is desired, it is advantageous if an adjustable stop for the working cylinder is provided. The stop is arranged so tha-t in one position it prevents any axial movement of the working cylinder while in another position it permits axial movement of the woxking cylinder for axial displacement of the control member along the driving shaft. Therefore, the stop assures the operation of the device in two operating conditions, "rotation only" and "rotation-percussion".
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodi~ents of the invention.
IN THE DRAWING5~
Fig. 1 is a side view of a device useful as a hammer drill or a chipping hammer, partly in section, with the device illustrated in the "rotation only" operating condition; and, Fig. 2 is a side view, partly in section, of the same device as shown in Fig. 1, however, ilIustrated in the "rotation-percussion" operating condition.
The device shown in Fig. 1, capable of being used as a ~2~ 1Z
.
hammer drill or a chipping hammer, includes a housing 1 having a handle 2 at its right-hand end as viewed in the drawing. A
trigger-like switch 3 and an electrical connection line 4 are provided in the handle 2. As viewed in Fig. 1, the left-hand end of the device is its front end and its right-hand end is its . .
rear end. In the rear portion of the housing 1 an electric motor 5 is located. A shaft 5a extends from the electric motor 5 toward the front end of the housing and the front end of the shaft i5 constructed as a pinion 6. Pinion 6 is in meshed engagement with a gear 7 secured on a driving shaft 8, with the axis of the shaft 8 extending in the rear end-front end direction `~
of the housing parallel to and offset from shaft 5a. Consequently, the driving shaft 8 is driven via the pinion 6 and the gear 7.
On the shaft 8, forwardly of the gear 7 is an annular disk 9 having an oversize central opening 9a. Disk 9 is pivotally mounted on the driving shaft 8 about a pin at axle pin 10 extending perpendicularly of the axis oE rotation of the driving shaft 8.
The size of opening 9a ensures that the disk 9 is pivotally displaceable about the pivot axle 10 between a neutr~l position ie perpendicular to shaft 8 and a number of working po~itions at varying angles to shaft 8. In Fig. 1 the disk 9 is shown in the neutral position and it is normally biased into this position by a compression spring 11 coaxial with and laterally surround-ing the shaft 8 and extending between gear 7 and disc 9. Located on the opposite side of the disk 9 from the spring 11 is a control member 12 which is axially movable along the driving shaft 8.
The control member 12 is drivingly connected to the driving shaft 8 by a wedge drive key 13 so that it rotates with the shaft 8 but can slide axially along it. The front end of the driving shaft 8 is provided with an elongated tooth or splined arrangement ~z~
8a extending around the circumference of the shaft, and ex-tending axially therealong a prede-termined distance. Each end of shaft 8 is suitably carried in bearings 8b and 8c located in -the housing.
Control member 12 has a control surface 12 lying in a plane having a longitudinal axis angled relative to shaft 8, and a lateral axis para~llel to a~le pin 10. A working cylinder 14 is located wi-thin the housing above the driving shaft 8 and coaxial with shaft Sa. The axes of the working cylinder 14 and the driving shaft 8 are disposed in parallel relation. The working cylinder has a front end F (at the lef-t hand of the drawing) projecting from the front end of the housing 1 and a rear end R loca-ted within the housing forwardly of the electric motor 5. An actua-ting piston 15 is positioned in the rear part of the working cylinder and a percussion piston 16 is located within the working cylinder forwardly oE the actuating piston.
The adjacent facing surfaces of the actuating piston 15 and the percussion piston 16 are spaced apart forming an air cushion therebetween. Air cushion 17 transfers the reciprocating motion of the actuating piston 15 to the percussion piston 16 so that the percussion piston 16 can transmit percussive force. On the outside sur~ace of the working cylinder 14 near its rear end R, an outwardly projecting toothed rim 14a is provided which forms a pinion and this rim is in meshed engagement with the elongated toothed surface or spline 8a on the front end portion of the driving shaft 8. Consequently, the rotation of the driving shaft 8 causes the working cylinder 14 to be rotated due to the meshed engagement of the toothed surface 8a and the toothed rim or pinion 14a. Working cylinder 14 is mounted in the housing 1 so that it can be moved to and fro for a limited -- 6 ~
., ~
distance in its axial direction.
For this purpose it is supported in a roller ~earing 21 and a ball bearing 22 spaced apart from one another. Bearing 21 engages an elongated cylindrical raceway 23 on cylinder 14 so that on axial displacement of cylinder 14 the raceway 23 will remain in engagement with bearing 21.
searing 22 is fastened around a forwar~ portion of cylinder 14 and is secured against shoulder 24 by means of circlip 25. Bearing 22 is slideably supported in a cylindrical portion 26 of housing 1, and is axial displaceable therein in unison with cylinder 14. In the neutral position of the device illustrated in Figure 1, the working cylinder 14 is kept in a forward position by means of a compression spring 18 encircling the working cylinder and pressing on bearing 22, and circlip 25.
An adjustable stop member 19 is rotatably mounted in ~he housing.
Stop 19 has a projection l9a extending into the axial path of movement of the working cylinder. ~rojection l9a i9 mounted of~set on disc l9b which is part of stop 19. ~y rotation of stop 19 it is possible to move projection l9a into and out of ; 20 engagement with the rear end of cylinder 14 and thus to secure cylinder 14 in the position shown in Figure 1. In this position, which is called the neutral position, there will be no reciprocation of the piston 15. The cylinder 14 will simply rotate, thus causing rotation of a tool bit (not shown) secured in the tool carrier 14b. In this position, the disc 9, ~eing urged by spring 11 into its forward position perpendicular to shaft 8, also urges control member 1~ forwardly on shaft 8, and control member 1 2 is free to move forwardly until it reaches the rear end of cylinder 14. In this position therefore disc 9 will simply rotate in groove I5a of piston 15, without causing any ~7~6~32 reciprocation. `~
In Figure 2, the device illustrated in Figure 1 is shown in the "rotation-percussion" position. Movement into this second position is achieved by changing the position of the stop 19, as well as by pressing the device against a surface, such as a workpiece. By noting the different positions of the stop 19 in Figures l-and 2, it can be appreciated that in Figure,2 it is possible to displace the working cylinder 14 axially rearwardly from the position shown in Figure 1. In Figure 2, a tool 20 is shown inserted into the tool carrier 14b.
With the stop 19 positioned as in Figure 2 the projection l9a is swung rearwardly. When the tool 20 extending from the front end of the working cylinder 14, is pressed against a surface r the working cylinder moves axially inwardly into the housing until its rear end contacts the downwardly extending pro,jection l9a on the stop 19. As the working cylinder moves inwardly into the housing, the rear end of the working cylinder in contact with the forwardly facing surface of the control member 12 moves the control mem~er axially rearwardly relative : ~ to the drlving sha~t 8. The surface 12a of the control member facing the disk 9 is i ~lined obliquely to a plane extending normally of the axis of the driving shaft 8. As the surface 12a contacts~the aisk 9, the disk pivots about its pivot axle 10 , oversize opening 9a permits this pivoting or tilting action, relative to shaft 8. Since the disk 9 and the control member 12 rotate in this position in unison with the driving shaft 8, the disk performs a wobbling movement. As it rotates, the disk 9 engages a groove 15a in the lateral surface of the actuating piston 15. Due to the wobbling movement of the disk 9 as it rotates, a reciprocating movement is transmitted to the ~2~
actuating piston 15. Accordingly, in the "rotation-percussion"
position shown in Figure 2, the disk 9 is displaced about the pivot axle 10 to a maximum extent and the reciprocating strokes of the actuating piston are also at a maximum. Between this maximum `'rotation-percussion" position and the neutral or "ro-tation only" position shown in Figure 1, the angular deflection of the disk 9 and consequently, the percussion stroke, can be varied by changing the contact pressure or the extent to which the disk is angularly deflected. When the device is lifted - 10 off the surface, the working cylinder 14 is displaced axially outwardly by the compression spring 18 to the position shown in Figure 1. Further, the centrifugal force acting on the disk 9 and the effect of the compression spring 11 also act on the disk and through it on the control member, cause the return of the disk 9 to the perpendicular neutral position of Figure 1. Therefore, this embodiment of the present invention permits a continuous adjustment of the degree of percussive force acting on the material being processed by the device.
Having described what is believed to be the best mode by which the invention may be performed, it will be seen that the i~vention may be particularly defined as follows:
A device for use as a hammer drill or chipping hammer including a ~ousing, an axially elongated working cylinder positioned within said housing and having a front end and a rear end, a percussion mechanism located within said working cylinder, means for operating said percussion mechanism, said percussion mechanism comprising an actuating piston mounted and reciprocally movable within said working cylinder, a percussion piston located within said working cylinder between said actuating piston and the front end of said working cylinder, ~iL?d~3i'2 said percussion piston being s~ ced axially from said actuating piston forming an air cushion therebe-tween so that the .reciprocating action of said actuating piston is -transmitted via the air cushion to said percussion piston, said operating means comprising a driving shaft spaced laterally from said working cylinder, and a disk mounted on said driving shaft and disposed in contact with said actuating piston, wherein the improvement comprises that said disk extends transversely of said driving shaft and includes an axle pivotally connecting said disk to said driving shaft so that the plane of said disk relative to the axis of said driving shaf-t can be angularly displaced for effeeting variable axial displacement of said ae-tuating piston within said working cylinder, and a eon~rol member positioned on and rotatable with said driving shaEt, and said eontrol member being displaeeable in the axial direetion of said drivin~ shaft for movement into contact with said disk for pivotally displacing said disk .relativ0 to the axis of said driv.ng shaft.
While speeifie embodiments of the invention have been shown and described in detail to illustrate the application of the inventive prineiples, it will be understood that the inventi~on may be embodied o~herwise without departing from sueh prine~ples.
Claims (11)
1. A device for use as a hammer drill or chipping hammer including a housing, an axially elongated working Cylinder positioned within said housing and having a front end and a rear end, a percussion mechanism located within said working cylinder, means for operating said percussion mechanism, said percussion mechanism comprising an actuating piston mounted and reciprocally movable within said working cylinder, a percussion piston located within said working cylinder between said actuating piston and the front end of said working cylinder, said percussion piston being spaced axially from said actuating piston forming an air cushion therebetween so that the reciprocating action of said actuating piston is transmitted via the air cushion to said percussion piston, said operating means comprising a driving shaft spaced laterally from said working cylinder, and a disk mounted on said driving shaft and disposed in contact with said actuating piston, wherein the improvement comprises that said disk extends transversely of said driving shaft and includes an axle pivotally connecting said disk to said driving shaft so that the plane of said disk relative to the axis of said driving shaft can be angularly displaced for effecting variable axial displacement of said actuating piston within said working cylinder, and a control member positioned on and rotatable with said driving shaft, and said control member being displaceable in the axial direction of said driving shaft for movement into contact with said disk for pivotally displacing said disk relative to the axis of said driving shaft.
2. Device, as set forth in claim 1, wherein said pivot axle of said disk extends perpendicularly of the axis of said driving shaft.
3. Device, as set forth in claims 1 or 2, wherein a spring element acts on said disk for returning said disk to a position where it is in a plane extending perpendicularly of the axis of said driving shaft.
4. Device, as set forth in claim 1, wherein said control member comprises a drum-like member having a first surface facing said disk and said first surface extending obliquely of the axis of said driving shaft.
5. Device, as set forth in claim 1, wherein said working cylinder is axially displaceable within said housing, said working cylinder having a surface thereon in contact with said control member for axially displacing said control member along said driving shaft when said working cylinder is moved relative to said housing.
6. Device, as set forth in claim 5, including an adjustable stop mounted on said housing and extending into the path of axial movement of said working cylinder for selectively limiting the extent to which said working cylinder is axially movable within said housing.
7. Device, as set forth in claim 1, wherein the axis of said working cylinder and the axis of said driving shaft are disposed in parallel relation, said actuating piston having an annular groove in the outer circumferential surface thereof, said disk extending outwardly from said driving shaft into contact with said actuating piston within the annular groove therein, and said actuating piston having a neutral position wherein it does not experience any reciprocating movement when said disk extends perpendicularly of the axis of said driving.
shaft.
shaft.
8. Device, as set forth in claim 7, including means located on said driving shaft for biasing said disk into the position where it contacts said actuating piston in the neutral position, said control member being located on the opposite side of said disk from said biasing means, and the surface of said control member facing the adjacent surface of said disk being disposed at an oblique angle to the adjacent surface of said disk when said disk secures said actuating piston in the neutral position.
9. Device, as set forth in claim 8, wherein said working cylinder forms a tool holder at the front end thereof, said percussion piston being axially displaceable through said working cylinder into the range of said tool holder, and spring means in contact with said working cylinder for biasing said working cylinder in the direction outwardly from said housing.
10. Device as set for in claims 4 or 8 wherein said oblique surface of said control member has a longitudinal axis lying at said oblique angle, and a lateral axis lying parallel to said axle of said disc.
11. Device as set forth in claims 1,4 or 7 wherein said disc has an oversize opening receiving said drive shaft therethrough.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19792917475 DE2917475A1 (en) | 1979-04-30 | 1979-04-30 | DRILLING OR CHISEL HAMMER |
| DEP2917475.2 | 1979-04-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1129682A true CA1129682A (en) | 1982-08-17 |
Family
ID=6069620
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA350,874A Expired CA1129682A (en) | 1979-04-30 | 1980-04-29 | Hammer drill or chipping hammer device |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS55144914A (en) |
| CA (1) | CA1129682A (en) |
| CH (1) | CH646900A5 (en) |
| DE (1) | DE2917475A1 (en) |
| FR (1) | FR2455496A1 (en) |
| GB (1) | GB2048753B (en) |
Families Citing this family (31)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3132450A1 (en) * | 1981-08-17 | 1983-02-24 | Hilti AG, 9494 Schaan | DRILLING HAMMER WITH GUIDE CYLINDER FOR THE STRIKE |
| US5238537A (en) * | 1981-09-15 | 1993-08-24 | Dutt William H | Extended nip press belt having an interwoven base fabric and an impervious impregnant |
| US5234551A (en) * | 1981-09-24 | 1993-08-10 | Dutt William H | Extended nip press belt having an interwoven base fabric and an impervious impregnant |
| DE3205141A1 (en) * | 1982-02-13 | 1983-08-18 | Robert Bosch Gmbh, 7000 Stuttgart | DRILLING HAMMER |
| DE3215198A1 (en) * | 1982-04-23 | 1983-10-27 | Friedrich Duss Maschinenfabrik GmbH & Co, 7265 Neubulach | Electro-pneumatic drilling and/or chipping hammer |
| DE3224050A1 (en) * | 1982-06-28 | 1983-12-29 | Black & Decker, Inc. (eine Gesellschaft n.d.Ges.d. Staates Delaware), 19711 Newark, Del. | Drive device for the striking mechanism of an impact or drilling hammer |
| DE3237616A1 (en) * | 1982-10-11 | 1984-04-12 | Hilti AG, 9494 Schaan | DRIVING DEVICE FOR NAILS AND THE LIKE FASTENING ELEMENTS |
| DE3311265A1 (en) * | 1983-03-28 | 1984-10-11 | Hilti Ag, Schaan | ELECTROPNEUMATIC DRILL AND CHISEL HAMMER |
| NL8304043A (en) * | 1983-11-24 | 1985-06-17 | Skil Nederland Nv | DEVICE FOR DRIVING A DRILL AND / OR IMPACT TOOL. |
| DE3405922A1 (en) * | 1984-02-18 | 1985-08-22 | Robert Bosch Gmbh, 7000 Stuttgart | HAND MACHINE, ESPECIALLY DRILLING HAMMER |
| JPS6120208U (en) * | 1984-07-06 | 1986-02-05 | 丸善工業株式会社 | engine impact drill |
| DE3429140A1 (en) * | 1984-08-08 | 1986-02-20 | Black & Decker Inc., Newark, Del. | DRILLING HAMMER WITH A PNEUMATIC STRIKE |
| DE3504650C2 (en) * | 1985-02-12 | 1994-01-20 | Bosch Gmbh Robert | Hammer drill with increased actuation force for the coupling of the impact drive |
| DE3506695A1 (en) * | 1985-02-26 | 1986-08-28 | Robert Bosch Gmbh, 7000 Stuttgart | DRILLING HAMMER |
| DE3523100A1 (en) * | 1985-06-28 | 1987-01-08 | Metabowerke Kg | Hammer drill |
| DE3537254A1 (en) * | 1985-10-19 | 1987-04-23 | Licentia Gmbh | Electropneumatic rotary percussion hammer drill for working rock, concrete and similar materials |
| JPS62199312A (en) * | 1986-02-25 | 1987-09-03 | Matsushita Electric Works Ltd | Vibrating drill |
| NL8801466A (en) * | 1988-06-07 | 1990-01-02 | Emerson Electric Co | DEVICE FOR DRIVING A DRILL AND / OR IMPACT TOOL. |
| DE3829683A1 (en) * | 1988-09-01 | 1990-03-15 | Black & Decker Inc | DRILLING HAMMER |
| DE4020242C2 (en) * | 1990-06-26 | 1996-09-26 | Helmut Loebel | Drilling machine, in particular for creating recesses in walls, for housing electrical installation boxes |
| DE4207295A1 (en) * | 1992-03-07 | 1993-09-09 | Black & Decker Inc | DRILLING HAMMER |
| WO1995021039A1 (en) * | 1994-02-04 | 1995-08-10 | Dumitru Panu Misailescu | Portable hand-held machine |
| AT403670B (en) * | 1994-12-20 | 1998-04-27 | Reiter Anton | Attachment for portable drills |
| DE19851888C1 (en) * | 1998-11-11 | 2000-07-13 | Metabowerke Kg | Hammer drill |
| DE10160864A1 (en) * | 2001-12-12 | 2003-06-26 | Hilti Ag | Axial striking electric hand tool device |
| DE102004018084B3 (en) * | 2004-04-08 | 2005-11-17 | Hilti Ag | hammer drill |
| DE102005061399A1 (en) * | 2005-12-22 | 2007-07-05 | Robert Bosch Gmbh | Hand power tool e.g. drill hammer or chipping hammer, has driven element of axial drive unit which is mounted directly on torque transmission wheel |
| JP4794306B2 (en) * | 2006-01-27 | 2011-10-19 | 株式会社マキタ | Impact tool |
| DE102007000391A1 (en) * | 2007-07-19 | 2009-01-22 | Hilti Aktiengesellschaft | Hand tool with percussion |
| EP3028818A1 (en) * | 2014-12-03 | 2016-06-08 | HILTI Aktiengesellschaft | Power tool |
| CN108677629B (en) * | 2018-07-14 | 2023-11-03 | 徐瀛 | Electric tamping tool |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2136523C3 (en) * | 1971-07-21 | 1983-11-03 | Hilti AG, 9494 Schaan | Electric hammer |
| CH559089A5 (en) * | 1973-05-22 | 1975-02-28 | Ruettimann Geiger Ernst | |
| DE2364344A1 (en) * | 1973-12-22 | 1975-06-26 | Impex Essen Vertrieb | Jackhammer with striker hammer damping system - compression chamber and choke outlet controlled by hammer tip piston |
| DE2438490C2 (en) * | 1974-08-10 | 1985-09-26 | C. & E. Fein Gmbh & Co, 7000 Stuttgart | Gear for an electric motor-driven portable hammer drill |
| DE2449191C2 (en) * | 1974-10-16 | 1988-03-24 | Robert Bosch Gmbh, 7000 Stuttgart | hammer |
| CH588632A5 (en) * | 1975-03-04 | 1977-06-15 | Bosch Gmbh Robert | Impact drill with swashplate - has spring loaded pneumatic impact piston reciprocating inside tool drive sleeve |
| DE2655899A1 (en) * | 1976-12-09 | 1978-06-22 | Bosch Gmbh Robert | CRAFT MACHINE |
| DE2738057A1 (en) * | 1977-06-29 | 1979-02-15 | Bosch Gmbh Robert | CRAFT MACHINE |
-
1979
- 1979-04-30 DE DE19792917475 patent/DE2917475A1/en active Granted
-
1980
- 1980-03-05 GB GB8007517A patent/GB2048753B/en not_active Expired
- 1980-04-22 JP JP5244680A patent/JPS55144914A/en active Granted
- 1980-04-23 FR FR8009073A patent/FR2455496A1/en active Granted
- 1980-04-28 CH CH327280A patent/CH646900A5/en not_active IP Right Cessation
- 1980-04-29 CA CA350,874A patent/CA1129682A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| FR2455496A1 (en) | 1980-11-28 |
| JPS639924B2 (en) | 1988-03-03 |
| GB2048753B (en) | 1982-12-15 |
| DE2917475C2 (en) | 1988-09-01 |
| CH646900A5 (en) | 1984-12-28 |
| FR2455496B1 (en) | 1984-01-20 |
| GB2048753A (en) | 1980-12-17 |
| DE2917475A1 (en) | 1980-11-13 |
| JPS55144914A (en) | 1980-11-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1129682A (en) | Hammer drill or chipping hammer device | |
| US4325436A (en) | Hammer drill or chipping hammer device | |
| EP0358978B1 (en) | Rotary hammer | |
| US9114514B2 (en) | Rotary power tool operable in either an impact mode or a drill mode | |
| US5435397A (en) | Rotary hammer with a pneumatic hammer mechanism | |
| EP0345896B1 (en) | Device for driving a drilling and/or percussion tool | |
| US5711380A (en) | Rotate percussion hammer/drill shift device | |
| US5337835A (en) | Drill and/or impact hammer | |
| US6234255B1 (en) | Adjustable stroke for a reciprocating saw | |
| GB2190870A (en) | Rotary hammer driving mechanism | |
| GB2170746A (en) | Hammer drill | |
| US5186685A (en) | Flange mounting arrangement | |
| US11318596B2 (en) | Power tool having hammer mechanism | |
| GB2399615A (en) | A vibration reduction apparatus for a power tool and a power tool incorporating such apparatus | |
| EP1432552B1 (en) | A percussion device | |
| US4612999A (en) | Percussion tool | |
| US20230118960A1 (en) | Power tool | |
| JP3491054B2 (en) | Cutting device with rotating head | |
| CN115199739A (en) | Gear adjusting device | |
| EP0560512B1 (en) | Rotary hammer | |
| EP0012438B1 (en) | Percussive tools | |
| GB2160810A (en) | Hammer drill | |
| US4617760A (en) | Table reciprocating apparatus | |
| JP3238639B2 (en) | Silent clutch for electric screwdriver | |
| EP3812097B1 (en) | Rotary hammer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |