US3747690A

US3747690A - Jack hammer

Info

Publication number: US3747690A
Application number: US00163696A
Authority: US
Inventors: R Deike
Original assignee: Individual
Current assignee: CONSTRUCTION ROBOTICS Inc (AUST) PTY Ltd
Priority date: 1973-07-19
Filing date: 1973-07-19
Publication date: 1973-07-24
Anticipated expiration: 1990-07-24

Abstract

An improved manually actuated self-energizing jack hammer or driver useful as a demolition tool, a compactor, a post or pile driver, a digging tool and the like, composed of an inner anvil tube or barrel receiving a post or pile therein or mounting a tamper, a breaker, a cutter, a digger or the like tools and a tubular ram or hammer telescoped over and guided on the barrel with a recoil spring between the anvil and hammer for lifting the ram after it delivers a hammer blow to the anvil barrel. The inner tube or anvile barrel separates and insulates the driver member such as a fence post or tool from contact with the hammer ram and at the same time guides the ram to insure maximum direct delivery of force from the ram to the tool or post. Handles are provided on the ram for convenient grasping by a single operator to impart a rhythmic reciprocation to the ram aided by the recoil spring to deliver maximum impact blows through the anvil barrel to the tool or post with minimum manual effort. The telescoped barrel tube and ram tube are preferably non-circular in crosssection to prevent relative rotation of the tubes and a heavy hard steel hammer head is secured in the open top of the ram tube preferably in non-mating relation to provide an air vent. The guide tube or barrel also preferably has a heavy hard steel head on the top end thereof providing an anvil receiving the blows from the hammer head. A lock bolt is provided to selectively hold the tubes in telescoped relation.

Description

United States Patent 1 Deike JACK HAMMER [75] Inventor: Robert F. Deike, Cheyenne, Wyo.

[73] Assignees: William H. Chamberlain; Anna B.

Chamberlain, Cheyenne, Wyo. part interest to each [22] Filed: July 19, 1973 [21] Appl. No.: 163,696

Related U.S. Application Data, [63] Continuation-impart of Ser. No. 123,787, March 12,

Primary Examiner-James A. Leppink Attorney-Carltonl-lill, .1. Arthur Gross et al.

57 j ABSTRACT An improved manually actuated self-energizing jack [11] 3,747,690 [451 July 24,1973

hammer or driver useful as a demolition tool, a compactor, a post or pile driver, a digging tool and the like, composed of an inner anvil tube or barrel receiving a post or pile therein or mounting a tamper, a breaker, a cutter, a digger or the like tools and a tubular ram or hammer telescoped over and guided on the barrel with a recoil spring between the anvil and hammer for lifting the ram after it delivers a hammer blow to the anvil barrel. The inner tube or anvile barrel separates and insulates the driver member such as a fence post or tool from contact with the hammer ram and at the same time guides the ram to insure maximum direct delivery of force from the ram to the tool or post. Handles are provided on the ram for convenient grasping by a single operator to impart a rhythmic reciprocation to the ram aided by the recoil spring to deliver maximum impact blows through the anvil barrel to the tool or post with minimum manual effort. The telescoped barrel tube and ram tube are preferably non-circular in crosssection to prevent relative rotation of the tubes and a heavy hard steel hammer head is secured in the open top of the ram tube preferably in non-mating relation to provide an air vent. The guide tube or barrel also preferably has a heavy hard steel head on the top end thereof providing an anvil receiving the blows from the hammer head. A lock bolt is provided to selectively hold the tubes in telescoped relation.

14 Claims, 11 Drawing Figures PAIENTED SHEU 2 OF 2 INVENTOR. E054??? E DtV/(f JACK HAMMER RELATED APPLICATION This application is a continuation-in-part of my U.S. Pat. application, Ser. No. 123,787 filed Mar. 12, 1971 entitled Manually Actuated Jack Hammer.

BACKGROUND OF THE INVENTION Field of the Invention This invention relates to improvements in jack hammers disclosed in my aforesaid parent application, Ser. No. 123,787 filed Mar. 12, 1971, dealing with guide barrel and ram configurations, a lock for the barrel and ram, and a reinforced shock absorbing handle arrangement. More specifically this invention provides a jack hammer composed of telescoped oval metal tubes with the inner tube having an anvil head receiving blows from a hammer head secured to the outer tube, with a spring expanding to separate the head and anvil and elongated handles secured at their top and bottom ends to opposite sides of the outer tube.

SUMMARY OF THE INVENTION The improved driver or jack hammer provided by this invention has telescoped flattened cylindrical or oval metal tubes in sliding relation with an anvil head bottom end or guide means for receiving a post or pile projecting through the inner. tube to engage the anvil head thereof. Additional guides may be provided adjacent the head to center the post in the tube.

The handles extend verticallyin spaced relation from the opposite flat faces of the outer or ram tube and are turned inwardly at their top and bottom ends to be attached to these faces. To further rigidify the handles with minimum transfer of shock from the'ram tube and to also provide a carrier for the locking bolt, gusset plates are welded to the ram tube between the top and bottom ends of the handles and carry metal channels along their top edges which receive cylindrical tubes or pipes welded at their outer ends to the handles and extending into spaced relation from the ram tube. Bolts connect these pipes or tubes to the angle strips. One of the pipes receives a slide bolt and has a bayonet slot in its top'face for a bolt pin. The bolt is spring urged to project through a hole in the ram tube and engage a hole or recess in the guide barrel or tube. The end of the bolt is bevelled in a downward direction so that the guide barrel when pushed into the ram tube will depress the'bo lt until its aperture orrecess registers therewithflwhereupon the spring will urge the bolt into locked relation with the inner tube thus holding the two tubes in a desired telescoped position.

The spacing of the pipes from the ram tube and the connection of the pipes to the ram tube through bolts provides a shock absorbing mounting between the ram tube and the central portions of the handles. The inwardly bent end portions of the handles also provide shock absorbing connections between the handles and ram tube. To further insulate the operator from shock, the handles can be surrounded by resilient rubber or plastic grips.

The driver head is preferably in the form of a heavy elongated cylinder with a closed end providing a recess for the recoil spring. This cylinder is welded along its length in the top end of the ram tube and air relief chambers are thus provided on opposite sides of the head between the elongated ends of the flattened or oval ram tube and the outer cylindrical wall of the driver head.

It is therefore an object of this invention to provide improvement on the manually actuated jack hammer disclosed and claimed in my aforesaid parent application, Ser. No. 123,787 filed Mar. 12, 1971.

Another object of the invention is to provide a jack hammer with telescoped oval anvil and ram tubes.

A further object of the invention is to provide a jack hammer which has an inner guide tube with an anvil block on its top end and a tool carrying chuck or post guide at its bottom end surrounded by and guiding a ram tube having a hammer head at its top end impacting against the anvil together with a compression recoil spring between the anvil and hammer head.

A further object of the invention is to provide an improved shock absorbing handle construction for jack hammers.

A still further object of this invention is to provide a lock for the telescoped tubes of jack hammers to maintain the same in telescoped position during periods of non-use.

A still further object of the invention is to provide an improved hammer head and ram tube arrangement for a jack hammer which will vent air from the tube.

Other and further objects of this invention will be apparent to those skilled in this art from the following detailed description of the annexed sheets of drawings which, by way of preferred examples, illustrate several embodiments of the invention.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a verticalcross-sectional view, with parts in elevation, of a jack hammer according to this invention showing the parts in lowered striking position;

FIG. 2 is a view similar to FIG. I but showing the .parts in raised or recoiled position;

FIG. 3 is a cross-sectional view taken along the line III-III of FIG. 1;

FIG. 4 is a crosssectional view taken along the line IVIV of FIG. 1;

FIG. 5 is a cross-sectional view taken along'the line V--V of FIG. 1;

FIG. 6 is a cross-sectional view taken along the line Vl-Vl of FIG. 1 with the bolt separated from the tube;

FIG. 7 is a cross-sectional view taken along the line VII-VII of FIG. 5;

FIG. 8 is an enlarged longitudinal cross-sectional view of the bottom end of the guide or anvil tube equipped with a removable chuck carrying a tool according to this invention; A

FIG. 9 is a transverse cross-sectional view taken along the line IXIX of FIG. 8;

FIG. 10 is an elevational view of a modified jack hammer having cylindrical ram and anvil tubes held in nomrotatable telescoped relation by lugs on the anvil tube riding in slots in the ram tube; and

FIG. 11 is a transverse cross-sectional view taken along the line XI-XI of FIG. 10.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The jack hammer of FIGS. 1 and 2 includes an elongated metal ram tube 11 telescoped over and guided on an elongated anvil post or tool receiving tube 12. The ram tube 11 has a heavy driver head tube or hammer l3 welded in the upper end thereof. The top end of the driver head or hammer is closed by a heavy disk 14 welded in the tube 13.

A heavy anvil head is welded in the upper end of the tube 12.

A helical compression spring 16 extends through the driverhead 13 and has its top end coil secured to the disk 14 by a nut and bolt assembly 17. In its free state the bottom end of the spring 16 projects beyond the hammer 13 for a number of turns and the bottom end coil of the spring overlies the anvil head 15 without being secured to the head. As shown in FIG. 1, the spring 16 is compressed completely within the driver head 13 when this head delivers the impact blow to the anvil head 15. In this compressed condition, of course, the spring is loaded to recoil the ram tube upwardly to the FIG. 2 position after it delivers its impact blow so that the next impact blow is delivered to the anvil head l5upon applicationof downward force to the ram tube by the operator.

As shown in FIG. 3, the tubes 11 and 12 are flattened cylinders or oval shaped and are infree sliding mated relation so that they cannot rotate relative to each other. The ram tube 11 has flat opposite side faces 11a and the anvil tube 12 has mating flat side faces 12a.

As shown in FIG. 4 the cylindrical driver or hammer head 13 is welded to the side faces 11a of the ram tube 11 along weld bonds 18. Since the head 13 is cylindrical and the tube 11 is oval, air vent passages 19 are provided through the top of the tube 11 on both sides of the head 13. I

As shown in FIGS. 1 to 3, the anvil head 15 is reinforced by bevelled curved gusset plates 20 welded to the underface of the head 15 and to the inner side walls 12a of the tube 12. These plates 20 converge from the flat side walls of the tube 12 to the head, 15 and surround a central area 21 of the head (FIG. 3) to guide a fence post F.P. to the center of the tube 12, as will be more fully hereinafter described.

The opposite flat side faces 11a, 11a of the ram tube 1 1 each have a handle 22 secured thereon. Each handle 22 has an' elongated vertical portion 22a spaced outwardly from and parelleling the side faces 11a, 11a of the tube 11 with inturned top and bottom end portions 22b bolted to brackets 23 which are welded to the side faces Illa, 11a and diverge at about a 45 angle outwardly, therefrom. Bolts 24 extend through the ends of the handle portions 22b and through the brackets 23 receiving nuts on the inner ends thereof to unite the handles to the tube 11."

As shown in FIGS. 1 and 2, the top end portions 22b of the handles are about level with the top end of the tube 11 while the bottom end portions 22b of the bandles are'adjacent the bottom end of the tube 11. In this manner, the vertical portions 22a of the handles extend substantially the entire length of the tube 11, but it should be understood that the handle length may be shortened if desired. Long handles are preferred so that the flat side walls 11a of the tube 11. These pipes 26 I rest in horizontal channels 27 carried by gusset plates 28 welded to the flat faces 1 la of the tube 1 1 and to the divergent sides of the channels, thereby providing a rigid trough projecting laterally from the tube and receiving the pipes 26. Bolts 28a extend through the pipes and slots in the channels. Nuts on these bolts are tightened against the channels to provide a shock absorbing connection between the pipes and channels.

One of the pipes 26 slidably supports a lock bolt 29 spring pressed by a spring 30 out of the inner end of the pipe. The flat face 11a of the tube 1 1 adjacent this pipe has a hole 11b therethrough into which the pipe freely projects in spaced relation from the face wall. The anvil or tool receiving tube 12 has a hole 12b adapted to register with the open end of the pipe and receives the lock bolt 29 therein to hold the tubes 11 and 12 in telescoped position..

The forward end of the lock bolt 29 is downwardly bevelled at 29a to provide a latch that will ride on the tube 12 to depress the bolt into the pipe 29 until the hole 12b can receive the bolt.

The top face of the pipe 26 receiving the bolt 29 has a bayonet slot 26a therein and a bolt pin 31 projects from the bolt 29 through this slot so that the operator may retract the bolt and lock it in the notch of the bayonet slot to hold it in retracted position or may release the pin from the notch so that the bolt will lock the tube 12in the tube 11.

As shown in FIGS. 8 and 9, the bottom end of the anvil or tool receiver tube 12 may receive a tool chuck 32 or, as shown in FIGS. 1 and 2, may receive a post guide 33.

The tool chuck 32 is a heavy hard steel block with an oval recess 34 in the top face thereof receiving the bottom end of the tube 12. Wing bolts 35 are threaded through the block and through holes 126 in the end of the tube 12 to lock the chuck to the bottom of the tube. The chuck has a hexagonal hole 36 therethrough and an enlarged cylindrical bottom recess 37 with a fragmental spherical shoulder 37a converging to the hexagonal hole 35.

A tube 38 extends at a steep angle through the side wall of the chuck block 32 to open into the recess 37 below the shoulder 37a. A pair of vsteel balls 30 separated by and connected to a spacer rod 39a are slidably mounted in the tube 38. A stop pin 40 projects into the tube 37 between the steel balls 38 to limit the extent of movement of the balls in the tube.

A tool 41 such as a concrete breaking chisel is releasably retained in the chuck 32 and has a hexagonal top pin end 42 fitting in the hole 36 thereby holding the tool against rotation relative to the chuck. A head 43 on the tool fits freely in the cylindrical recess 37 and seats against the shoulder 37a. This head 43 has a bottom face 44 engaged by the leading steel ball 39 in the tube 38 thereby retaining the tool in the chuck. The shank 45 of the tool depends beyond the bottom end of the chuck to terminate in a cutting point or chisel edge 46 below the chuck.

To mount the tool 41 in the chuck, it is only necessary to insert the hexagonal pin end 43 in the hole 36 causing the head 43 to depress the projecting steel ball 39 back into the tube 38 until the head clears the ball, whereupon the ball will drop underneath the face 44 to lock the tool in the chuck. When it is desired to remove the tool from the chuck, it is only necessary to retract the ball 39 from under the face 44 of'the tool head 43.

The chuck 32 may be easily replaced with the post guide 33 of FIGS. 1 and 2 which has a recess 33a to receive the end of the tube 12 and the same wing bolts 35 to lock the chuck to the tube. The chuck 33, however, has a through hole 47 shaped .to slidably and snugly receive the fence post RP. therethrough for guiding the post centrally in the tube 12. As also shown in FIG. 1, the upper end of the fence post is guided to the central area 21 of the anvil head 15 by the bevelled gussets 20.

in the modified jack hammer 50 of FIGS. and 11 a cylindrical ram tube 51 is telescoped over a cylindrical anvil tube 52. The tube 51 has elongated slots 53 in diametrically opposite sides thereof extending from adjacent the top of the tube to adjacent the bottom thereof. The tube 52 has lugs 54 near the top end thereof projecting laterally therefrom into these slots and freely slidable therein. The two tubes are thus slidably keyed together and the outer tube 51 can be lifted to pull the inner tube 52 therewith when the lugs 54 engage the bottoms of the slots 53. The lugs 54 can be integrally welded to the sides of the tube 52 so as not to obstruct the tube interior for receiving a fence post.

Alternatively, when the jack hammer 50 is to be used as a breaking tool or digger where the tube 52 does not receive a post or pile, holes 55 can be provided at spaced intervals along the length of the tube to selectively receive pins 56 which extend into the slots 53 to limit or control the length of the working stroke of the ram 51 as desired. Thus if it is desired to limit the amount the tube 52 can project from the tube 51, a pin 56 can be positioned closer to the bottom of the tube 52 so that it will contact the bottom of the slots 53 when the tube 52 extends from the tube 51 a desired amount. Two spaced pins could be simultaneously used to limit the extent of both the lifting and lowering stroke of the ram tube 51 with'one pin contacting the tops of the slots 53 at the end of the lifting stroke and the other contacting the bottoms of the slots after the impact blow to facilitate lifting of the tool 41' carried by the chuck 32.

The modified hammer 50 can otherwise have the same construction and components as the hammer 10.

To operate the jack hammers of this invention, it is only necessary to mount the desired tool 41 in a chuck such as 32 or to drop the

anvil guide tube

12 or 52 over a fence post guided into the tube by a chuck such as 33. Then, asingle operator merely grasps the handles 22 at a convenientlevel, raises the ram tube 11 or 51 to a convenient height and drops it with a downward thrust force whereupon the spring 16 will initially compress and then the driver head 13 will strike the anvil 15 to deliver a hammer blow to the

anvil guide tube

12 or 52 which in turn transfers this blow either to the tool or to a the fence post. The compressed spring then expands to recoil the tube 11 or 51 upwardly on the tube 12 or $2 positioning it for thenext downward thrust by the operator. A rhythm is soon built up enabling the operator to exert maximum impact blows on the tool or fence post with minimum manual effort.

It will be understood that the tool, fence post or other work piece being acted upon is never directly engaged by the hammer head since the blow from the hammer head is always transmitted to the anvil and the anvil tube isolates the hammer head from the tool or work piece. It will also be understood that the anvil tube acts as a guide insuring the application of the full impact blow on the tool or work piece on eachstroke of the ram tube. Thus, there can be no canting or misalignment of the ram tube relative to the tool or work piece.

cl claim as my invention: h I i l. A driver tool which comprises a hollow guide tube having an anvil head secured to the top end thereof and a chuck secured to the bottom end thereof, a hollow driving ram tube telescoped over said guide tube in non-rotatable relation therewith having a hammer head adapted to impact against the anvil head of said guide tube, a compression spring between the hammer head and anvil'head effective to recoil the hammer head away from the anvil head after each blow of the hammer head against the ram head, said spring having a free extended length substantially less than the stroke of the ram tube on the guide tube, and elongated handles secured to the ram tube and extending in laterally spaced relation from opposite sides of the ram tube for a substantial portion of the length of the ram tube.

2. The driver tool of claim 1 wherein the guide tube and the ram tube have non-circular cross-section configurations in mating relation preventing relative rotation of the tubes.

3. The driver tool of claim 1 wherein the guide tube and the ram tube have oval cross-sectional shapes in mated non-rotating engagement.

4. The driver tool of claim 1 wherein the chuck is removable.

5. The driver tool of claim 1 wherein the guide tube has post guide means therein directing a post to engage the central portion of the anvil head.

6. A jack hammer which comprises telescoped tubes in non-rotating mated engagement, an anvil head secured to the inner tube, a hammerhead secured to the outer tube, a coil spring between said heads effective to recoil the hammer head away from the anvil head after each blow of the hammer head against the anvil head, said spring having a free extended length less than the stroke of the outer tube on the inner tube, and elongated handle means secured to the outer tube having gripping portions in laterally spaced relation from opposite sides of the outer tube.

7. The jack hammer of claim 6 wherein said tubes are oval shaped.

8 The jack hammer of claim 8 wherein the outer tube is oval shaped, the hammer head is cylindrical and extends into the upper end of the outer tube and air vent passages are provided through the top end of the outer tube between the cylindrical hammer head and the oval tube.

9. The jack hammer of claim 8 wherein the tubes are cylindrical with cooperating lug and slots holding the tubes against relative rotation.

10. The jack hammer of claim 8 wherein the outer tube has elongated slots terminating adjacent the ends thereof and the inner tubehasprojections riding in the' slots.

11. The jack hammer of claim 10 wherein the projections are the ends of a removable pin traversing the inner tube.

12. A driver tool which comprises a hollow guide tube having an anvil head secured to the top end thereof and a chuck secured to the bottom end thereof, a hollow driving ram tube telescoped over said guide tube in non-rotatable relation therewith having a hammer head adapted to impact against the anvil head of said guide tube, a compression spring between the hammer head and anvil head effective to recoil the hammer head away from the anvil head after each blow of the hammer head against the ram head, elongated handles secured to the ram tube and extending in laterally spaced relation from opposite sides of the ram tube for substantial portion of the length of the ram tube, and shock absorbing means connecting the handles to the ram tube.

13. A driver tool which comprises a hollow guide tube having an anvil head secured to the top end thereof and a chuck secured to the bottom end thereof, a hollow driving ram tube telescoped over said guide tube in non-rotatable relation therewith having a hammer head adapted to impact against the anvil head of said guide tube, a compression spring between the hammer head and anvil head effective to recoil the hammer head away from the anvil head after each blow of the hammer head against the ram head, elongated handles secured to the ram tube and extending in laterally spaced relation from opposite sides of the ram tube for a substantial portion of the length of the ram tube, a lock bolt carried by a handle, said ram tube having an aperture freely receiving said lock bolt, and said guide tube having a recess receiving the lock bolt when the recess is aligned with the ram tube aperture whereby the ram tube and guide tube are locked together in telescoped relation.

14. A jack hammer which comprises telescoped tubes in non-rotating mated engagement, an anvil head secured to the inner tube, a cylindrical hammer head secured to the outer tube, a'coil spring between said heads extending into the hollow interior of the cylindrical head effective to recoil the hammer head away from the anvil head after each blow of the hammer head against the anvil head, and elongated handle means secured to the outer tube having gripping portions in laterally spaced relation from opposite sides of the outer tube.

Claims

1. A driver tool which comprises a hollow guide tube having an anvil head secured to the top end thereof and a chuck secured to the bottom end thereof, a hollow driving ram tube telescoped over said guide tube in non-rotatable relation therewith having a hammer head Adapted to impact against the anvil head of said guide tube, a compression spring between the hammer head and anvil head effective to recoil the hammer head away from the anvil head after each blow of the hammer head against the ram head, said spring having a free extended length substantially less than the stroke of the ram tube on the guide tube, and elongated handles secured to the ram tube and extending in laterally spaced relation from opposite sides of the ram tube for a substantial portion of the length of the ram tube.

4. The driver tool of claim 1 wherein the chuck is removable.

6. A jack hammer which comprises telescoped tubes in non-rotating mated engagement, an anvil head secured to the inner tube, a hammer head secured to the outer tube, a coil spring between said heads effective to recoil the hammer head away from the anvil head after each blow of the hammer head against the anvil head, said spring having a free extended length less than the stroke of the outer tube on the inner tube, and elongated handle means secured to the outer tube having gripping portions in laterally spaced relation from opposite sides of the outer tube.

7. The jack hammer of claim 6 wherein said tubes are oval shaped.

8. The jack hammer of claim 8 wherein the outer tube is oval shaped, the hammer head is cylindrical and extends into the upper end of the outer tube and air vent passages are provided through the top end of the outer tube between the cylindrical hammer head and the oval tube.

10. The jack hammer of claim 8 wherein the outer tube has elongated slots terminating adjacent the ends thereof and the inner tube has projections riding in the slots.

14. A jack hammer which comprises telescoped tubes in non-rotating mated engagement, an anvil head secured to the inner tube, a cylindrical hammer head secured to the outer tube, a coil spring between said heads extending into the hollow interior of the cylindrical head effective to recoil the hammer head away from the anvil head after each blow of the hammer head against the anvil head, and elongated handle means secured to the outer tube having gripping portions in laterally spaced relation from opposite sides of the outer tube.