CA2152699A1 - Rotary hammer - Google Patents
Rotary hammerInfo
- Publication number
- CA2152699A1 CA2152699A1 CA002152699A CA2152699A CA2152699A1 CA 2152699 A1 CA2152699 A1 CA 2152699A1 CA 002152699 A CA002152699 A CA 002152699A CA 2152699 A CA2152699 A CA 2152699A CA 2152699 A1 CA2152699 A1 CA 2152699A1
- Authority
- CA
- Canada
- Prior art keywords
- casing
- hammer
- tool
- roller
- rollers
- 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.)
- Abandoned
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
- B25B21/02—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
- B25B21/026—Impact clutches
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25D—PERCUSSIVE TOOLS
- B25D16/00—Portable percussive machines with superimposed rotation, the rotational movement of the output shaft of a motor being modified to generate axial impacts on the tool bit
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25D—PERCUSSIVE TOOLS
- B25D2250/00—General details of portable percussive tools; Components used in portable percussive tools
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Earth Drilling (AREA)
Abstract
Rotary impact hammers, which are primarily used for breaking up concrete, asphalt or frozen ground, include a rotating shaft with impacting members mounted thereon for repeatedly engaging a hammer to reciprocate the latter. The present invention includes rollers mounted on pivot arms which are urged by centrifugal forces into engagement with the inner wall of a casing. A reciprocating hammer is mounted on the casing with an anvil end extending into the casing for engagement by the rollers. In order to reduce wear on the rollers and on the inner surface of the casing, the hammer is tilted into the direction of travel of the rollers, so that the rollers engage a ramp on the inner or top end of the hammer. A reduced diameter area of the rollers engages the anvil end of the hammer, to reduce wear on the inner surface of the casing, particularly around the hole for the hammer.
Description
- 21~2699 This invention relates to a rotary hammer and in particular to a rotary impact hammer utilizing rollers urged into contact with a reciprocating tool by centrifugal force.
Rotary hammers have a variety of applications including rock drilling and pile driving but are most often used for breaking up hard materials such as concrete, asphalt or frozen ground. The use of centrifugally urged impact members to reduce the forces transmitted back to the body of the hammer is well known in the prior art. Examples of such prior art devices are disclosed in Canadian Patent No. 439,702 issued February 18, 1947 to Ernest Craig, and United Stated Patents Nos. 3,262,506, issued July 26, 1966 to Herbert Hoffman and 5,002,134, issued March 26, 1991 to Sakuji Yamada. However, the patented devices provide for partial absorption only of the rebounding force, and generally the component of the force in the radial direction only. Moreover, rotary hammers including impact rollers which engage the inner surface of the hammer casing (Canadian Patent 439,702 - Craig) are subject to excessive wear, particularly on the inner surface of the hammer casing around the hole for receiving the tool.
An object of the present invention is to overcome the shortcomings of the prior art apparatuses by providing a rotary impact hammer including rollers rotatably mounted on pivoting arms, which enable most of the rebound impact force to be absorbed by the centrifugal force induced in the arms and rollers.
Another object of the invention is to reduce wear on the rollers by mounting the impact tool slightly tilted rearwardly of the direction of roller travel, forming a ramp at the leading edge of the tool for the rollers to engage.
By leading edge is meant the edge of the tool first encountered by the roller.
Yet another object of the invention is to reduce the amount of wear on the inner surface of the hammer casing by providing a recess in the rollers in the area where they engage the upper end of the tool.
Accordingly, the present invention relates to a rotary hammer comprising cylindrical casing means having an inner and an outer wall; axle means mounted in said casing means for rotation on the longitudinal axis therof; first arm means in said casing means fixed at one end to said axle means; second arm means pivotally mounted on the other end of said first arm means; roller means rotatable on said second arm means for engaging the inner wall of said casing means; tool means mounted in said casing means, said tool means including an inner anvil end for engagement by said roller means and an outer work engaging end; and stop means for limiting movement of said tool means in said casing means, whereby, when said axle means is rotated, centrifugal force causes said roller means to engage the inner wall of said casing means and repeatedly impact the anvil end of said tool means, resulting in reciprocation of said tool means.
The invention will be described in greater detail with reference to the accompanying drawings, which illustrate a preferred embodiment of the present invention, wherein:
Figure 1 and 2 are perspective views taken from opposite sides of the rotary hammer of the present invention;
Figure 3 is a cross-sectional view of the casing of the rotary hammer of Figs. 1 and 2;
Figure 4 is a perspective view of a tool mounting assembly used in the rotary hammer of Figs. 1 and 2;
Figure 5 is a longitudinal-sectional view of the assembly of Fig. 4;
Figure 6 is a perspective view of a roller assembly used in the hammer of Figs. 1 and 2; and Figure 7 is an exploded, perspective view of the bottom of the casing of the hammer of Figs. 1 and 2.
With reference to Figure 1, the rotary hammer, which is generally indicated at 1, includes a drum or casing 2 defined by a cylindrical side wall 3 and a pair of disc-shaped end walls 4 and 5. The casing 2 is mounted on the arm 6 of a vehicle such as a backhoe (not shown) equipped with a hydraulic system, which is used to operate the rotary hammer. For this purpose, arcuate flanges 7 and . 25 mounting plates 8 are provided on the casing side wall 3.
The plates 8 are interconnected by rods 10 and a plate 11.
A shaft 13 is rotatably mounted in bearings 14 for rotation on the longitudinal axis of the casing 2. The shaft 13 is rotated by a hydraulic motor 16 which is connected to the hydraulic system of the vehicle by lines 17. The shaft 13 rotates a roller assembly generally indicated at 18 (Fig. 3) which in turn drives a reciprocating hammer 19. The tool or hammer 19 in this case is defined by a cylindrical body 20 with a pointed outer free end and a flat inner or top end 22.
The hammer 19 is mounted in the drum 2 by means of a mounting block 23 supported by the mounting plates 8. The block 23 is connected to the plates 8 by bolts 24 and nuts 25. As best shown in Figs. 4 and 5, the hammer 19 is slidably mounted in the block 23 and in a stop block 26. An annular flange 28 on the hammer 19 engages the top end of an annular recess or shoulder 29 in the block 23 to limit upward movement of the hammer in the blocks 23 and 26. The pin 30 extends through a recess 32 in one side of the hammer body 20 near the top end thereof. The pin 30 is held in place by a bolt 33.
The upper or anvil end of the hammer 19 slides in a sleeve or bushing 35, which is mounted in the drum or casing 2. The bushing 35 is basically cylindrical, including a small diameter top end 36 for sliding into an opening 37 (Fig. 6) in the casing 2, and a larger diameter bottom end 38, with a shoulder 39 therebetween for limiting movement of the bushing into the casing 2. The shoulder 39 of the bushing 35 is machined to match the curvature of the outer surface of the casing 2. As best shown in Fig. 5, the inner or top end 36 of the bushing 35 terminates at or short of the inner surface 40 of the casing side wall 3.
Referring to Figs. 3 and 7, the roller assembly 18 includes a pair of arms 42 fixedly mounted on the shaft 13.
The arms 42 are interconnected by a pair of rods 43, which are parallel to the shaft 13. Thus, the arms 42 and the rods 43 form a rectangular frame, which is fixed on, i.e.
does not rotate with respect to the shaft 13. A pair of pivot arms 45 are rotatably mounted on the outer end of each rod 43. The arms 45 are held on the rods 43 by C-clips 46.
Because the arms 45 rotate during use, a sleeve 47 is provided on the bearings 14 to prevent damage to the bearings by the ends 48 of the arms. A shaft 50 is mounted in bearings 51 in the outer end of each arm 45. A roller 52 is mounted on each shaft 50 for rotation around the longitudinal of the shaft. A recess 54 is provided in the center of the roller 50, i.e. in the area of the roller which contacts the hammer 19. Because the casing 2 is weakened by the opening 37, it is best not to run the roller 52 across the area of the opening. Otherwise, cracks are likely to occur in the area of the opening 37.
The rods 43 and the shafts 50 are lubricated by grease from manifolds 56 and lines 57. The manifolds 56 are mounted on the fixed arms 42. Grease is introduced into the manifolds 42 via a longitudinally extending passage 59 in the axle 13 and radially extending passages (not shown) intersecting the passage 59 at the points of attachment or the inlets, of the manifolds 56.
In use, the hydraulic motor 16 is actuated to cause rotation of the shaft 13 and of the fixed arms 42.
Centrifugal force acting on the pivot arms 45 and on the rollers 52 causes the latter to engage the inner wall 40 of the casing. During rotation of the roller 52, a line through the longitudinal axes of the rods 43 and the shafts 50 intersects the longitudinal axes of the arms 42 to define an angle of 10 to 15, i.e. the pivot arms 45 follow the fixed arm 42 in the direction of rotation. In Fig. 3, the arms 45 are positioned as they would be for clockwise rotation of the shaft 13. As shown in phantom outline in Fig. 5, upward movement of the hammer 19 is limited to a position in which the leading edge of the top end 22 of the hammer 19 is more or less flush with the inner surface of the casing 2 while the trailing surface is raised slightly with respect to such surface. Thus, the top end 22 of the hammer 19 defines a ramp for the rollers 52. Each time a roller 52 runs across the ramp defined by the top end 22 of the hammer 19, the latter is moved rapidly downwardly. Upon striking a hard surface, the hammer 19 rebounds and is again driven downwardly by one of the rollers 52.
Rotary hammers have a variety of applications including rock drilling and pile driving but are most often used for breaking up hard materials such as concrete, asphalt or frozen ground. The use of centrifugally urged impact members to reduce the forces transmitted back to the body of the hammer is well known in the prior art. Examples of such prior art devices are disclosed in Canadian Patent No. 439,702 issued February 18, 1947 to Ernest Craig, and United Stated Patents Nos. 3,262,506, issued July 26, 1966 to Herbert Hoffman and 5,002,134, issued March 26, 1991 to Sakuji Yamada. However, the patented devices provide for partial absorption only of the rebounding force, and generally the component of the force in the radial direction only. Moreover, rotary hammers including impact rollers which engage the inner surface of the hammer casing (Canadian Patent 439,702 - Craig) are subject to excessive wear, particularly on the inner surface of the hammer casing around the hole for receiving the tool.
An object of the present invention is to overcome the shortcomings of the prior art apparatuses by providing a rotary impact hammer including rollers rotatably mounted on pivoting arms, which enable most of the rebound impact force to be absorbed by the centrifugal force induced in the arms and rollers.
Another object of the invention is to reduce wear on the rollers by mounting the impact tool slightly tilted rearwardly of the direction of roller travel, forming a ramp at the leading edge of the tool for the rollers to engage.
By leading edge is meant the edge of the tool first encountered by the roller.
Yet another object of the invention is to reduce the amount of wear on the inner surface of the hammer casing by providing a recess in the rollers in the area where they engage the upper end of the tool.
Accordingly, the present invention relates to a rotary hammer comprising cylindrical casing means having an inner and an outer wall; axle means mounted in said casing means for rotation on the longitudinal axis therof; first arm means in said casing means fixed at one end to said axle means; second arm means pivotally mounted on the other end of said first arm means; roller means rotatable on said second arm means for engaging the inner wall of said casing means; tool means mounted in said casing means, said tool means including an inner anvil end for engagement by said roller means and an outer work engaging end; and stop means for limiting movement of said tool means in said casing means, whereby, when said axle means is rotated, centrifugal force causes said roller means to engage the inner wall of said casing means and repeatedly impact the anvil end of said tool means, resulting in reciprocation of said tool means.
The invention will be described in greater detail with reference to the accompanying drawings, which illustrate a preferred embodiment of the present invention, wherein:
Figure 1 and 2 are perspective views taken from opposite sides of the rotary hammer of the present invention;
Figure 3 is a cross-sectional view of the casing of the rotary hammer of Figs. 1 and 2;
Figure 4 is a perspective view of a tool mounting assembly used in the rotary hammer of Figs. 1 and 2;
Figure 5 is a longitudinal-sectional view of the assembly of Fig. 4;
Figure 6 is a perspective view of a roller assembly used in the hammer of Figs. 1 and 2; and Figure 7 is an exploded, perspective view of the bottom of the casing of the hammer of Figs. 1 and 2.
With reference to Figure 1, the rotary hammer, which is generally indicated at 1, includes a drum or casing 2 defined by a cylindrical side wall 3 and a pair of disc-shaped end walls 4 and 5. The casing 2 is mounted on the arm 6 of a vehicle such as a backhoe (not shown) equipped with a hydraulic system, which is used to operate the rotary hammer. For this purpose, arcuate flanges 7 and . 25 mounting plates 8 are provided on the casing side wall 3.
The plates 8 are interconnected by rods 10 and a plate 11.
A shaft 13 is rotatably mounted in bearings 14 for rotation on the longitudinal axis of the casing 2. The shaft 13 is rotated by a hydraulic motor 16 which is connected to the hydraulic system of the vehicle by lines 17. The shaft 13 rotates a roller assembly generally indicated at 18 (Fig. 3) which in turn drives a reciprocating hammer 19. The tool or hammer 19 in this case is defined by a cylindrical body 20 with a pointed outer free end and a flat inner or top end 22.
The hammer 19 is mounted in the drum 2 by means of a mounting block 23 supported by the mounting plates 8. The block 23 is connected to the plates 8 by bolts 24 and nuts 25. As best shown in Figs. 4 and 5, the hammer 19 is slidably mounted in the block 23 and in a stop block 26. An annular flange 28 on the hammer 19 engages the top end of an annular recess or shoulder 29 in the block 23 to limit upward movement of the hammer in the blocks 23 and 26. The pin 30 extends through a recess 32 in one side of the hammer body 20 near the top end thereof. The pin 30 is held in place by a bolt 33.
The upper or anvil end of the hammer 19 slides in a sleeve or bushing 35, which is mounted in the drum or casing 2. The bushing 35 is basically cylindrical, including a small diameter top end 36 for sliding into an opening 37 (Fig. 6) in the casing 2, and a larger diameter bottom end 38, with a shoulder 39 therebetween for limiting movement of the bushing into the casing 2. The shoulder 39 of the bushing 35 is machined to match the curvature of the outer surface of the casing 2. As best shown in Fig. 5, the inner or top end 36 of the bushing 35 terminates at or short of the inner surface 40 of the casing side wall 3.
Referring to Figs. 3 and 7, the roller assembly 18 includes a pair of arms 42 fixedly mounted on the shaft 13.
The arms 42 are interconnected by a pair of rods 43, which are parallel to the shaft 13. Thus, the arms 42 and the rods 43 form a rectangular frame, which is fixed on, i.e.
does not rotate with respect to the shaft 13. A pair of pivot arms 45 are rotatably mounted on the outer end of each rod 43. The arms 45 are held on the rods 43 by C-clips 46.
Because the arms 45 rotate during use, a sleeve 47 is provided on the bearings 14 to prevent damage to the bearings by the ends 48 of the arms. A shaft 50 is mounted in bearings 51 in the outer end of each arm 45. A roller 52 is mounted on each shaft 50 for rotation around the longitudinal of the shaft. A recess 54 is provided in the center of the roller 50, i.e. in the area of the roller which contacts the hammer 19. Because the casing 2 is weakened by the opening 37, it is best not to run the roller 52 across the area of the opening. Otherwise, cracks are likely to occur in the area of the opening 37.
The rods 43 and the shafts 50 are lubricated by grease from manifolds 56 and lines 57. The manifolds 56 are mounted on the fixed arms 42. Grease is introduced into the manifolds 42 via a longitudinally extending passage 59 in the axle 13 and radially extending passages (not shown) intersecting the passage 59 at the points of attachment or the inlets, of the manifolds 56.
In use, the hydraulic motor 16 is actuated to cause rotation of the shaft 13 and of the fixed arms 42.
Centrifugal force acting on the pivot arms 45 and on the rollers 52 causes the latter to engage the inner wall 40 of the casing. During rotation of the roller 52, a line through the longitudinal axes of the rods 43 and the shafts 50 intersects the longitudinal axes of the arms 42 to define an angle of 10 to 15, i.e. the pivot arms 45 follow the fixed arm 42 in the direction of rotation. In Fig. 3, the arms 45 are positioned as they would be for clockwise rotation of the shaft 13. As shown in phantom outline in Fig. 5, upward movement of the hammer 19 is limited to a position in which the leading edge of the top end 22 of the hammer 19 is more or less flush with the inner surface of the casing 2 while the trailing surface is raised slightly with respect to such surface. Thus, the top end 22 of the hammer 19 defines a ramp for the rollers 52. Each time a roller 52 runs across the ramp defined by the top end 22 of the hammer 19, the latter is moved rapidly downwardly. Upon striking a hard surface, the hammer 19 rebounds and is again driven downwardly by one of the rollers 52.
Claims (4)
EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS
FOLLOWS:
1. A rotary hammer comprising cylindrical casing means having an inner and an outer wall; axle means mounted in said casing means for rotation on the longitudinal axis therof; first arm means in said casing means fixed at one end to said axle means; second arm means pivotally mounted on the other end of said first arm means; roller means rotatable on said second arm means for engaging the inner wall of said casing means; tool means mounted in said casing means, said tool means including an inner anvil end for engagement by said roller means and an outer work engaging end; and stop means for limiting movement of said tool means in said casing means, whereby, when said axle means is rotated, centrifugal force causes said roller means to engage the inner wall of said casing means and repeatedly impact the anvil end of said tool means, resulting in reciprocation of said tool means.
2. A rotary hammer according to claim 1, wherein the anvil end of said tool means is inclined with respect to the inner wall of said casing means defining a ramp for engagement by said roller means.
3. A rotary hammer according to claim 1 or 2, wherein said roller means follows a circular path of travel in said casing means, and the longitudinal axis of said tool means is inclined with respect to a line extending diametrically of the path of travel through said longitudinal axis of the tool means.
4. A rotary hammer according to claim 1, wherein said roller means includes an annular recess for contacting said anvil end of said tool means without contacting the inner wall of said casing means for limiting wear on said casing means in the area of said tool means.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002152699A CA2152699A1 (en) | 1995-06-27 | 1995-06-27 | Rotary hammer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002152699A CA2152699A1 (en) | 1995-06-27 | 1995-06-27 | Rotary hammer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2152699A1 true CA2152699A1 (en) | 1996-12-28 |
Family
ID=4156129
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002152699A Abandoned CA2152699A1 (en) | 1995-06-27 | 1995-06-27 | Rotary hammer |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2152699A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103388474A (en) * | 2012-05-12 | 2013-11-13 | 刘素华 | High-efficiency non-clamping impact-blanking digging method and high-efficiency non-clamping impact-blanking digger |
| CN103510954A (en) * | 2012-06-24 | 2014-01-15 | 刘素华 | Method used for reciprocating impact excavation by arranging discharge port for discharging, and reciprocating impact excavator used for implementing method by arranging discharge pot for discharging |
-
1995
- 1995-06-27 CA CA002152699A patent/CA2152699A1/en not_active Abandoned
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103388474A (en) * | 2012-05-12 | 2013-11-13 | 刘素华 | High-efficiency non-clamping impact-blanking digging method and high-efficiency non-clamping impact-blanking digger |
| WO2013170629A1 (en) * | 2012-05-12 | 2013-11-21 | Liu Suhua | High-efficiency mining method for percussing falling-materials without trapping materials and high-efficiency mining machine for percussing falling-materials without trapping materials |
| AU2013262356B2 (en) * | 2012-05-12 | 2016-07-07 | Suhua LIU | High-efficiency mining method for percussing falling-materials without trapping materials and high-efficiency mining machine for percussing falling-materials without trapping materials |
| CN103388474B (en) * | 2012-05-12 | 2016-12-28 | 刘素华 | The system of attack of a kind of efficiently not material folding impact blanking and efficient not material folding impact blanking digger |
| CN103510954A (en) * | 2012-06-24 | 2014-01-15 | 刘素华 | Method used for reciprocating impact excavation by arranging discharge port for discharging, and reciprocating impact excavator used for implementing method by arranging discharge pot for discharging |
| CN103510954B (en) * | 2012-06-24 | 2016-12-28 | 刘素华 | Arrange the reciprocating impact system of attack of discharging hole discharging and realize the method discharging reciprocating impact digger in discharging hole is set |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4978258A (en) | Cutting tool | |
| US6491111B1 (en) | Rotary impact tool having a twin hammer mechanism | |
| KR20000069148A (en) | Rotary impact tool with involute profile hammer | |
| US3605914A (en) | Rotary impact wrench mechanism | |
| AU2007202967A1 (en) | A tool holder for a pavement breaker | |
| KR920004683B1 (en) | Rotary impacting apparatus | |
| JP2021032074A (en) | Asphalt crusher | |
| US4082151A (en) | Cam mounting for an impact tool | |
| AU2007202970A1 (en) | Beat piece support structure for a hammer drill | |
| CA2152699A1 (en) | Rotary hammer | |
| JP2002192482A (en) | Crushing device and tool | |
| CN116427854B (en) | Highway bridge pile foundation digs device soon | |
| US6203113B1 (en) | Cutting drum with percussive bits | |
| JP2006505728A (en) | Improved device | |
| US4247149A (en) | Mechanically actuated impact mechanism | |
| US4593767A (en) | Impact device | |
| US4867251A (en) | Impact device | |
| US4783123A (en) | Tool bit for impact ripping of a mine face | |
| AU2004222834A1 (en) | Rotary hammerdrill bit | |
| JPH08226237A (en) | Crashing device | |
| CN210659927U (en) | Disc connecting mechanism supported by multi-shaft sleeve and rotary drilling rig | |
| CN112921755A (en) | Open type non-impact eccentric excitation mechanism and vibration wheel | |
| CN213573874U (en) | Screw drill transmission shaft assembly with vibration reduction function | |
| CN220780478U (en) | Stone crushing device for mining machinery | |
| JPH09217316A (en) | Cutter device for surface cutting civil engineering work |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |