US3339644A - Hydraulic hammer - Google Patents
Hydraulic hammer Download PDFInfo
- Publication number
- US3339644A US3339644A US444742A US44474265A US3339644A US 3339644 A US3339644 A US 3339644A US 444742 A US444742 A US 444742A US 44474265 A US44474265 A US 44474265A US 3339644 A US3339644 A US 3339644A
- Authority
- US
- United States
- Prior art keywords
- piston
- bore
- spool valve
- hammer
- annular
- 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
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25D—PERCUSSIVE TOOLS
- B25D9/00—Portable percussive tools with fluid-pressure drive, i.e. driven directly by fluids, e.g. having several percussive tool bits operated simultaneously
- B25D9/14—Control devices for the reciprocating piston
- B25D9/145—Control devices for the reciprocating piston for hydraulically actuated hammers having an accumulator
Definitions
- a fluid actuated hammer including a casing having a bore, a piston reciprocally mounted within the bore, the piston having first valve means formed thereon, a hammer movable with the piston to strike a tool, second valve means reciprocally mounted within the bore and operative in conjunction with the first valve means to control passage of fluid to the piston to drive the hammer against the tool and to relieve fluid pressure on the piston to allow the hammer to be returned to a starting position, a means including the first valve means for reciprocating the second valve means and a means for relieving excessive pressures within the casing when the second valve means is switching from a position wherein the hammer is driven and a position wherein the piston is returned to its original starting position.
- the principal object of this invention is to provide a new and improved hydraulic hammer.
- Another object of the invention is to provide a hydraulic hammer wherein the control valving does not require a special, separate, mechanical actuator.
- Another object of the invention is to provide a hydraulic hammer wherein the control valving does not require a special, separate, mechanical actuator, and wherein the valving is arranged with respect to the piston so as to substantially reduce the number of fluid passages within the housing.
- Another object of the invention is the provision in a hydraulic hammer of a new and improved bumper mechanism for cushioning the return of the piston actuated hammer.
- Another object of the invention is the provision in a hydraulic hammer of a new and improved resilient tool mounting wherein spring mean-s are confined within the hammer casing to preclude interference therewith by objects in the environment in which the hydraulic hammer is operated, thereby resulting in a hydraulic hammer that may be used with greater safety.
- Another object of the invention is to provide a control valve for a hydraulic hammer that is arranged concentrically about the piston so as to minimize the space requirements for the control valve.
- Another object of the invention is the provision in a control valve for a hydraulic hammer of means for shifting the control valve to various positions through the use of surfaces of differing areas.
- FIGURE 3 is a fragmentary vertical section of the hydraulic hammer, and showing another stage in a cycle of the operation of the device;
- FIGURE 4 is yet another fragmentary vertical section of the hydraulic hammer, and showing still another stage in a cycle of the operation of the device;
- FIGURE 5 is still another fragmentary vertical section of the hydraulic hammer, and showing a further stage in a cycle of the operation of the device;
- FIGURE 6 is a vertical section taken approximately along the line 66 of FIGURE 4, and showing a portion of the duct work in a device made according to themvention;
- FIGURE 7 is a fragmentary horizontal section taken approximately along the line 7-7 of FIGURE 5, and showing a portion of a control valve operator of a device made according to the invention
- FIGURE 8 is a fragmentary horizontal section taken approximately along the line 8-8 of FIGURE 5, and showing another portion of a control valve operator in a device made according to the invention.
- FIGURE 9 is a fragmentary horizontal section taken approximately along the line 9-9 of FIGURE 2, and showing a portion of a manual control valve for a hydraulic hammer made according to the invention.
- the hydraulic hammer comprises an upper casing section 22 having a flange 24 on its lower end.
- a lower casing section 26 has an inturncd end 27 on its lower extremity, and a flange 28 on its upper end.
- the flange 28 is suitably constructed so as to mate with the upper casing flange 24.
- the two casing sections are secured together by suitable fastening means, such as bolts 30 and nuts 32.
- the lower casing section 26 further comprises a bore 34.
- a sleeve 36 within which an impacting hammer is received for reciprocating movement relative thereto, as will be seen hereinafter.
- a second sleeve Abutting the lower end of the sleeve 36 is a second sleeve, generally designated 38, which is of stepped construction.
- the sleeve 38 comprises a pair of sections, the largest section 40, having a dimension substantially equal to that of the bore 34, while the smaller section 42 has a diameter substantially less than that of the bore 34.
- the smaller section 42 of the sleeve 38 additionally carries a keyway 44 in which is received a key 46 which is mounted in a threaded aperture 48 in the inturncd section 27 of the lower casing 26.
- Suitable springs 50 are interposed between the inturncd end portion 27 and the enlarged section 40 of the sleeve 38 so as to bias the latter against the lower edge of the sleeve 36.
- the springs 50 are about the smaller section 42 of the sleeve 38 and are contained only within the lower casing section 26. This feature is extremely desirable as it lends an added safety factor to the device. It will be appreciated that during operation of the hammer, the springs 50 will, on occasion, be subject to flexing, as when the hammer is withdrawn from the work. In prior art devices, comparable springs are externally exposed and thus subject to interference by objects within the environment in which the hammer is being used. Such interference could cause the interfering object to be propelled by the springs against the operator of the hammer or other workmen and bystanders and possibly result in injury to such persons.
- the sleeve 38 is also provided with an irregularly shaped bore 52 for reception of the complementary shaped end 54 of a tool 56. Intermediate the ends of the tool 56 is provided a collar 58 to limit movement of the tool within the bore 52 in one direction.
- a latch 60 which is pivotally mounted at 62 to the inturned end 27 of the casing 26.
- the latch 60 includes an extension portion 64 arranged in the path of the tool collar 58.
- a manually operable lever 66 is mounted on the latch 60, such that the latter may be selectively manipulated to move the extension 64 out of the path of the tool collar 58, so that the tool may be removed from the hammer mechanism.
- a plunger 68 is mounted in a bore 70 in the casing 26 and is biased by a spring 72, also received in the bore 70, against the latch 60 so as to normally maintain the extension 64 in the path of the collar 58.
- the upper casing section 22 is provided with an inlet 74 for hydraulic fluid and an outlet 76 for the same (see FIGURES 1 and 2).
- a gastype pressure accumulator 78 which may be of conventional construction, communicates with the inlet 74, while a similar accumulator 80 communicates with the outlet 76.
- the accumulators 78 and 80 serve to smooth pressure pulses within the hydraulic fluid.
- the inlet 74 includes a threaded bore 82 (see FIGURE 2) which may receive a suitable hose and fitting 84 connected to a source of hydraulic oil under pressure.
- the threaded bore 82 terminates in a chamber 86 having a pair of branch conduits 88 and 90.
- Aligned with the conduit 90 is a bore 91 in which is disposed a tubular valve 92.
- On the end of the tubular valve 92 remote from the conduit 90 is a plurality of gear teeth 94 which are meshed with a spur gear 96 disposed within a bore 98.
- the spur gear 96 is mounted on a shaft 100 which is journalled in a plug 102 for the bore 98 (see FIGURE 9).
- the plug 102 is maintained in a sealing relation with the bore 98 by securing means such a screws 103. Additionally, suitable sealing means 104 are disposed between the bore 98 and the plug 102 for reasons that will be seen hereinafter.
- a handle, or manual operator, 106 is mounted on the end of the shaft 100 and may be rotated to cause rotation of the spur gear 96 and thus reciprocal movement of the tubular valve 92 within the bore 91 and the conduit 90.
- a spring 108 is interposed between the upper end of the tubular valve 92 and a plug 110 which seals the upper end of the bore 91.
- the tubular valve 92 is provided with a hollow center 112 to permit passage of pressurized fluid therethrough to the upper end of the tubular valve member 92.
- Such a construction is desirable as the pressurized fluid within the chamber 86 exerts a substantial force on the bottom of the tubular valve 92, which tends to force the tubular valve 92 upwardly.
- the hollow center 112 permits the fluid to pass to the upper end of the valve 92 to exert an equalizing downward force on the upper end of the tubular valve member 92.
- the upper casing 22 is provided with a stepped bore 113 in which a piston 114 is received for reciprocation relative thereto as seen in FIGURE 2.
- An upper section 116 of the bore 113 is slightly enlarged to receive an enlarged piston head 118.
- the piston head 118 has a pair of operating surfaces 120 and 122 oppositely disposed thereon.
- the uppermost surface 120 has a significantly larger size or surface area than does the lower operating surface 122.
- An annular port 124 is formed in the enlarged section 116 of the bore 113 and is in communication with the inlet conduit 88.
- a channel 126 which is periodically placed in communication with the inlet 74 terminates in an annular port 127 in the bore 113 above the large piston operating surface 120.
- a bumper 128 having an outwardly flared upper portion 130 (see FIGURES 2 and 6).
- the outwardly flared portion 130 is seated on an appropriate recess 132 in the upper end of the bore 113.
- a spring 134 is interposed between the bumper 128 and a sealing plug 136 threaded into the upper end of the bore 113.
- an annular port 138 is placed in the upper end of the bore 113 between the bumper 128 and the plug 136.
- a conduit 140 connects the ports 138 to the port 124 and ultimately to the inlet 74, thus providing a path for pressurized fluid to the space in the bore 113 between the bumper 128 and the plug 136, to bias the bumper 128 downwardly.
- the lower end of the bumper 128 is positioned within the bore 113 so as to abut the end of the piston 114 when the latter is in its uppermost position.
- the purpose of this construction is twofold. Firstly, by virtue of its hydraulic and spring biasing, the bumper 128 will tend to dissipate the kinetic energy of the piston 114 imposed thereon by a positive contact therewith if such should occur.
- the nature of the operation of a hydraulic hammer is such that extremely high pressure pulses may exist within the fluid above the piston during such times as the channel 126 is not in communication with the inlet 74 or the outlet 76. The pressure of such pulses may be greater than the inlet pressure and are relieved by movement of the bumper 128.
- the lower end of the bore 113 is provided with a greatly enlarged section 142 [for reception of a reciprocal spool valve 144 (see FIGURE 2).
- a reciprocal spool valve 144 see FIGURE 2.
- Within the enlarged bore section 142 are three annular outlet ports 146, 148 and 150, the ports 146 and 150 serving to equalize pressure on the opposite ends of the spool valve 144, which communicate with each other, with the outlet accumulator 80 and with the outlet 76 by means of a channel 151.
- the inlet port 152 also communicates with the inlet accumulator 78 by virtue of the connection of the latter to the chamber 153.
- first annular groove 156 Formed on and extending about the outer periphery of the spool valve 144, is a first annular groove 156 arranged such that for one position of the spool valve 144 within the enlarged bore section 142, the inlet port 152 will communicate with the port :154 to direct pressurized fluid into the channel 126 and to the piston head 118. Additionally, the first annular groove 156 is arranged to be in continuous communication with the inlet port 152, and thus the inlet '74.
- a second annular groove 158 which is placed on the spool valve 144 such that for another position of the spool valve 144 within the enlarged bore 142, the second annular groove 158 will permit communication between the port 154, and thus the channel 126, and the outlet port 148 to relieve the pressure exerted on the piston head 118.
- the spool valve 144 includes a central bore 160 through which the piston 114 extends.
- the spool valve bore 160 together with the piston 114 defines a first annular duct 162 which is separated by a land 163 (FIGURE 3) from a second annular duct 164, which in turn is separated by a land 165 from a third annular duct 166.
- Apertures 167 permit fluid communication between the first annular passage 162 and the first annular groove 156 for purposes as will be seen hereinafter, while, by virtue of its location on the lower end of the spool valve 144, the third annular duct 166 is substantially continuously in communication with the outlet port 146.
- a pair of groups of opposed bores 168 and 172 there are provided in opposite ends of the spool valve 144, a pair of groups of opposed bores 168 and 172.
- the group of bores 168 comprise two bores
- the group of bores 172 comprise four such bores, as is seen in FIGURE 8.
- Pin 170 are placed within the group of bores 168 while pins 174 are placed within the group of bores 172. In the case of both the pin 170 and the pins 174, one end of each pin abuts a stationary portion of the casing, or the like.
- the group of bores 168 communicate directly with the first annular groove 156 while the group of bores 172 communicate with the second annular duct 164 in the spool valve 144 by means of a relieved portion 173 in the bore 160 of the spool valve 144.
- the spool valve 144 will be forced upwardly as seen in the various figures.
- first annular passage 176 on the piston 114 which is separated by a land 177 [from a second annular passage 178.
- the passages 176 and 178 on the piston 114 are arranged with respect to the ducts 162, 164 and 166 in the bore 160 of the spool valve 144 such that for one position (see FIGURE 3) of the piston 114 with respect to the spool valve 144, the first annular passage 176 permits fluid communication between the first annular duct 162 and the second annular duct 164, and thus the group of bores 172; while for another position (see FIGURE 5) of the piston with respect to the spool valve 144, the second annular passage 178 will permit fluid communication between the second annular duct 164, and thus the group of bores 172, and the third annular duct 166.
- first annular duct 162 is in continuous communication with the inlet 74, it will be apparent that whenever the position of the annular passage 176 is such as to permit communication between the first annular duct 162, the second annular duct 164, and the group of bores 172, the spool valve 144 will be moved upwardly to be there maintained until the pressure is relieved. Furthermore, since the third annular duct 166 is in substantially continuous communication with the outlet, it will be apparent that whenever the second annular passage 178 permits communication between the second annular duct 164 and the third annular duct 166, the pressure exerted in the group of bores 172 will be relieved thus permitting the pressure exerted within the group of bores 168 to force the spool valve 144 downwardly.
- the lower end of the enlarged bore section 142 is closed by a plug 180 held in place by suitable securing means such as bolts 182, as shown in FIGURE 3.
- the plug 180 is provided with a 'bore 184 through which the piston 114 extends.
- an annular port 186 Near the lower end of the plug bore 184 is placed an annular port 186 which communicates by means of a conduit 188 with the outlet port 146.
- the annular port 186 collects the major portion of the fluid 1eak age between the piston 114and the plug 180 and directs such fluid to the outlet port 146 and ultimately to the out let 76.
- suitable sealing means 192 between the plug 180 and the piston 114. Additional-1y, sealing means 190 are placed along the interface of the plug 180 and the upper casing member 22 to preclude leakage there'between.
- the plug 180 is attached to the lower end of the upper casing member 22. Accordingly, that portion of the piston 114 that projects through the plug 180, etxends into'the lower casing section 26 and has attached thereto a hammer 194. As best seen in FIGURE 2, the piston 114 terminates in a conical end 196 which is received in a mating recess 198 within the hammer 194. To secure the hammer 194 to the piston 114, there is provided a threaded nut member 200 which is received in a threaded recess 202 within the hammer 194.
- the lower end of the nut 200 bears against a locking ring 204 which is seated in an annular groove 206 in the piston 114.
- pressurized fluid will flow through the conduit 88, the port 124, and the enlarged bore section 116 to the small operating surface 122 of the piston head 118, thus forcing the latter upwardly until it abuts the bumper 128.
- the piston will be maintained in this position until the valve 92 is opened.
- the second annular passage 178 on the piston 114 will permit any pressurized oil in the group of bores 172 to flow to the outlet 146 through the relieved portion 173, the second annular duct 164, the second annular passage 178 and the third annular duct 166.
- the spool valve 144 will drop to its lowest position within the enlarged bore section 142 under the influence of gravity or will be driven to such position when the valve 92 is open by the admission of pressurized oil to the group of bores 168.
- the spool valve 144 at a point about midway between its etxreme lower and upper positions (see FIGURES 3 and 4, respectively), will not permit communication between the channel 126 and the inlet port 152 or the outlet port 148. In other words, channel 126 is temporarily blocked. Any pressure pulses in the hydraulic fluid above the piston 114 and within the channel 126 caused by the impact of the hammer 194 on the tool 56 will, however, be reduced to acceptable level of a magnitude approaching that of the inlet pressure by the yielding action of the movable bumper 128 and its communication with the inlet 74 via port 138, conduit 140, port 124, conduit 88 and chamber 86. Additionally, during the return of the piston 118 to its upper position, when the channel 126 is blocked, the pressure created by displacement of fluid by the surface 120 is dissipated by the yielding of the bumper 128.
- the piston 118 is thereby caused to decelerate to a stop at about the time it contacts the bumper 128, first by the pressure increase above the large operating surface 120 due to the blocking of the channel 126 by the spool valve 144 in the course of its movement, and secondly, by the subjection of the large operating surface 124 to inlet pressure when the spool valve 144 has substantially completed its movement prior to the time at which the pitson 118 reaches its upper position. Should the spool valve 144 stick slightly, the bumper mechanism will stop the piston and dissipate its kinetic energy without damage to the casing.
- valve 92 by selective adjustment of the valve 92, the pressure exerted on the enlarged operating surface 120 of the piston 114 can be regulated thus regulating the rapidity of reciprocation of the piston 114 and the hammer 194. Accordingly, the number of cycles through which the device progresses in any given period of time can be selectively adjusted.
- a hydraulic hammer made according to the invention will be an extremely compact device by virtue of the arrangement of the valving with respect to the piston.
- This same construction provides a distinct advantage over various prior art devices by the elimination of a number of fluid paths within the hammer casing thereby eliminating costly boring in the casing to provide such fluid paths.
- the means for shifting the valve member in a hydraulic hammer according to the invention to control the action of the hammer does not require any special mechanical operators and accompanying linkages, thereby resulting in a simpler construction.
- conduit While such terms as conduit, channel, passage, duct and port have been used in the foregoing description in relation to the various elements, which use was necessitated by a desire to provide clarity in the foregoing description, it is intended that they be substantially synonymous and commonly definitive of any structure capable of passing a fluid, and not be limited to the specific illustrated structure with which they are associated.
- a hydraulic hammer comprising (a) a casing having a bore, an inlet port, a pair of connected outlet ports, and a channel,
- annular spool valve within said casing and mounted about the passage bearing portion of said piston for reciprocating movement relative to both said casing and said piston, said spool valve having first and second annular grooves about its outer surface and positioned such that for one position of said spool valve within said casing, said first annular groove will connect said inlet port and the other end of said channel for fluid passage therethrough, and for another position of said spool valve within said casing said second annular groove will connect said other end of said channel to one of said outlet ports for fluid passage therebetween; said first annular groove further being positioned to be in communication with said inlet port for all positions of said spool valve within said housing; said spool valve further including first, second and third separate ducts formed in its inner surface, said first duct being in continuous communication with said first annular groove and thus said inlet port; said third duct being positioned to be in substantially continuous communication with the other of said pair of outlet ports; said first and second passages on said piston and said first, second and third ducts being
- spool valve positioning means including a pair of opposed surface means of differing size on said spool valve, the largest of said pair of surface means being in communication with said second duct, the smallest of said pair of surface means being in communication with said first annular groove, whereby when said inlet port is connected to a source of fluid under pressure, said hammer will be cyclically reciprocatcd.
- a fluid actuated hammer comprising (a) a casing having a bore, an inlet, an outlet and a channel,
- annular valve means about said piston and movable to a first position for connecting said channel to said inlet to supply fluid under pressure to said piston to move the latter from said return position to said impact position and movable to a position to connect said channel to said outlet whereby said piston may be moved to said return position
- annular valve means comprises a spool valve reciprocally mounted within said casing and wherein said connecting means comprises a pair of annular grooves on said spool valve.
- the fluid actuated hammer of claim 2 including bumper means in said bore adjacent said piston, said bumper means including an element having a portion positioned to abut said piston when the latter is in said return position, spring means resiliently biasing said element into said position, and means for directing fluid under pressure against said element to urge said element into said position.
- a fluid actuated hammer comprising:
- said piston including first valve means formed thereon,
- said first valve means includes a first passage for periodically supplying fluid under pressure to said one of said surface means and a second passage for periodically relieving fluid pressure on said one of said surface means.
- said second valve means includes first duct means for continuously supplying fluid under pressure to said first passage and second duct means for connecting said one of said surface means alternatively to said first passage and to said second passage.
- valve means movable between a first position wherein said inlet is in fluid communication with said operating surface to apply hydraulic fluid under pressure to said operating surface to move said piston in a first direction, and a second position wherein said operating surface is in fluid communication with said outlet to relieve fluid pressure on sad operating surface whereby said piston may be moved in a second direction opposite said first direction;
- valve means comprises a reciprocal valve and said yieldable means comprises a movable element biased into an end of said bore adjacent said opertaing surface having a first surface in fluid communication with said bore and a second surface in continuous fluid communication with said inlet whereby when fluid pressure within said bore exceeds a predetermined level, said element will move against the bias and fluid pressure applied thereto from said inlet to relieve excessive pressure within said bore with said excessive pressure being transmitted by said element to said inlet.
- a single channel provides for fluid communication between said operating surface and said valve means, said valve means comprising a single valve member for alternately connecting said inlet and said channel and said outlet and said channel.
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- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Percussive Tools And Related Accessories (AREA)
Description
Claims (1)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US444742A US3339644A (en) | 1965-04-01 | 1965-04-01 | Hydraulic hammer |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US444742A US3339644A (en) | 1965-04-01 | 1965-04-01 | Hydraulic hammer |
Publications (1)
Publication Number | Publication Date |
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US3339644A true US3339644A (en) | 1967-09-05 |
Family
ID=23766158
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US444742A Expired - Lifetime US3339644A (en) | 1965-04-01 | 1965-04-01 | Hydraulic hammer |
Country Status (1)
Country | Link |
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US (1) | US3339644A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3857448A (en) * | 1971-11-15 | 1974-12-31 | Proline Ind Pty Ltd | Hydraulically operated tamper |
US5893419A (en) * | 1997-01-08 | 1999-04-13 | Fm Industries, Inc. | Hydraulic impact tool |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US919035A (en) * | 1908-04-11 | 1909-04-20 | Victor Edward Lane | Pneumatic hammer. |
US1807787A (en) * | 1931-06-02 | Pluid actuated percussive tool | ||
US1827647A (en) * | 1928-11-09 | 1931-10-13 | Galaz Juan | Attachment for pneumatic hammers |
US2180034A (en) * | 1937-03-15 | 1939-11-14 | Gas Tool Patents Corp | Internal combustion hammer |
US2672847A (en) * | 1950-06-10 | 1954-03-23 | Le Roi Company | Reciprocable hydraulic impact motor |
US3204534A (en) * | 1963-01-24 | 1965-09-07 | Raymond Int Inc | Drawbar multiplier |
-
1965
- 1965-04-01 US US444742A patent/US3339644A/en not_active Expired - Lifetime
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1807787A (en) * | 1931-06-02 | Pluid actuated percussive tool | ||
US919035A (en) * | 1908-04-11 | 1909-04-20 | Victor Edward Lane | Pneumatic hammer. |
US1827647A (en) * | 1928-11-09 | 1931-10-13 | Galaz Juan | Attachment for pneumatic hammers |
US2180034A (en) * | 1937-03-15 | 1939-11-14 | Gas Tool Patents Corp | Internal combustion hammer |
US2672847A (en) * | 1950-06-10 | 1954-03-23 | Le Roi Company | Reciprocable hydraulic impact motor |
US3204534A (en) * | 1963-01-24 | 1965-09-07 | Raymond Int Inc | Drawbar multiplier |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3857448A (en) * | 1971-11-15 | 1974-12-31 | Proline Ind Pty Ltd | Hydraulically operated tamper |
US5893419A (en) * | 1997-01-08 | 1999-04-13 | Fm Industries, Inc. | Hydraulic impact tool |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: DANA CORPORATION, TOLEDO, OHIO, A VA CORP. Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:REXNORD INC., A CORP. OF WI;REEL/FRAME:004864/0624 Effective date: 19821101 Owner name: DANA CORPORATION,OHIO Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:REXNORD INC., A CORP. OF WI;REEL/FRAME:004864/0624 Effective date: 19821101 |
|
AS | Assignment |
Owner name: RACINE FLUID POWER INC., C/O ROBERT BOSCH CORPORAT Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:DANA CORPORATION;REEL/FRAME:004924/0873 Effective date: 19880512 Owner name: RACINE FLUID POWER INC., C/O ROBERT BOSCH CORPORAT Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:DANA CORPORATION;REEL/FRAME:004924/0873 Effective date: 19880512 |