US3922902A

US3922902A - Dent removal device

Info

Publication number: US3922902A
Application number: US422187A
Authority: US
Inventors: Davis R Jarman
Original assignee: Individual
Current assignee: GRABBER MANUFACTURING Co A GA CORP
Priority date: 1973-12-06
Filing date: 1973-12-06
Publication date: 1975-12-02
Anticipated expiration: 1992-12-02

Abstract

An elongated cylinder incorporating a forwardly projecting workpiece engaging screw member manipulable by an enlarged handwheel. A hammer is slidably positioned within the cylinder and, through a valve controlled fluid system, is moved forward into a releasable mounted position at the forward end of the cylinder and rearward, under increased pressure, so as to deliver a substantial impact blow on a rearwardly located anvil or abutment.

Description

'United States Patent 1191 Jarman Dec. 2, 1975 1 1 DENT REMOVAL DEVICE [75] Inventor: Davis R. Jarman, Brunswick, Ga.

[73] Assignee: Virgil l-linson, Brunswick, Ga. a

part interest 122] Filed: Dec. 6, I973 [21] Appl. No.: 422,187

3,137,483 6/1964 Zinkiewicz 173/91 X 3,269,223 8/1966 Pawloski.... 91/466 X 3.323.346 6/1967 Spangler.... 1 72/407 3.326.304 6/1967 Johnson..... 173/170 X 3,476,015 11/1969 Ackley.... 91/446 X 3,570,289 3/1971 Smyers 72/705 3,657,917 4/1972 Chelminski 72/453 3,744,291 7/1973 Hagcrty Ct 2117 72/705 X 3,777,621 12/1973 Blok Ct 31. 1. 91/446 X Primary Examiner-C. W. Lanham Assistant Examiner-D. M. Gurley Attorney, Agent, or FirmClarence A. OBrien; Harvey B. Jacobson [57] ABSTRACT [56] References Cited An elongated cylinder incorporating a forwardly pro- UNITED STATES PATENTS jecting workpiece engaging screw member manipula- 152391 6/1874 Manson 173/132 x eniarged f A hammer Shdably 1 292 429 1/1919 Bull 1 173/132 x Posltloned Wlthm the cylmder n hrough a valve- 1,313.353 2/1920 Nurnberger... 91/446 Controlled fluid System is moved forward into a 1,604,958 11/1926 Bayles.. 173/132 x leasable mounted Position at the forward end of the 2,396,562 3/1946 Forss 1 72/407 cylinder and rearward, under increased pressure, so as 2,457,930 1/1949 Smith..... 29/252 X to deliver a substantial impact blow on a rearwardly 2,715,913 Taylor located anvil or abutn1ent 2,933,068 4/1960 Johnson et a1... 173/133 2,934,984 5/1960 Woodman 81/5235 X 4 Claims, 4 Drawing Figures m Ill/ll/l/ll/I/l/l/l/l/ll, 40 36 k h 66 I 6 32 5 74 64 42 70 IR .Wl/RCE DENT REMOVAL DEVICE The present invention relates to new and useful improvements in powered dent removal devices.

It is a primary object of the present invention to provide a dent removing tool which utilizes a pressure moved sliding weight to develop the force required to reform the metal sheet or the like to effect the desired straightening thereof. While the basic idea of using a sliding weight for this purpose is known, the known devices in most cases are of cumbersome construction both difficult to attach to the workpiece and inherently unsafe in that the weight is exposed and hand manipulated. Such known devices are also frequently difficult to operate, particularly in other than a horizontal position.

The dent removal device of the present invention is unique in overcoming the deficiencies of the known de vices. More particularly, the attachment of the device to the workpiece is simply effected through an enlarged handwheel which enables an attachment of the forward or workpiece gripping portion of the device without an awkward manipulation of the entire device. Once attached, the tool can be, through the use of air pressure, operated by a single hand and, in connection therewith, can be utilized in any position, including a vertical position wherein a downward pull is desired. As indicated, the device uses a sliding weight or hammer. However, as opposed to conventional dent removal tools, the weight herein is completely concealed within a housing or air cylinder whereby any danger of the moving weight contacting the hand or hands of the user of the tool is completely avoided.

The device itself is of a compact and relatively simple, although highly unique, construction and utilizes a structural arrangement which will provide trouble-free service.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.

FIG. 1 is a perspective view of the tool of the present invention;

FIG. 2 is an enlarged cross-sectional detail through the tool illustrating the control valve in a neutral position;

FIG. 3 is a cross-sectional view similar to FIG. 2 wherein the valve is shifted to an initial position which moves the hammer to its starting or cocked position; and

FIG. 4 is a similar view wherein the valve has been further shifted to the hammer driving position.

Referring now more specifically to the drawings, reference numeral is used to generally designate the dent removing tool or device comprising the present invention. This tool 10 includes an elongated hollow body or cylinder 12 having an enlarged gripping and manipulating handle 14 mounted at one end thereof and a workpiece engaging member 16 mounted at the second end thereof.

The opposed ends of the cylinder 12 are internally threaded with the handle mounting end, designated by reference numeral 18, constituting the rear end of the cylinder and with the workpiece mounting end, designated by reference numeral 20, constituting the forward end of the cylinder.

The workpiece engaging member 16 is in the nature of a tapered threaded metal screw which includes an enlarged head portion 22 having a rearwardly projecting enlarged key or rib 24 seated within a transverse slot defined within the forward end of an elongated threaded shaft 26. The shaft 26 projects integrally from an enlarged block 28 rotatably retained within the forward end portion of the cylinder 12 by a combined end plate and bearing 30 threaded within the internally threaded end portion 20 of the cylinder 12. This bearing 30 includes a peripheral flange which seats against the extreme end of the cylinder 12 and an internal seat or socket which rotatably receives the block 28. An instepped portion 32 is provided between the block 28 and the externally threaded shaft 26 so as to define a seating shoulder 36 slightly forward of the combined end plate and bearing 30. An enlarged handwheel 38 is threaded or otherwise locked to the shaft 26 against the shoulder 36 with this handwheel 38 and the workpiece engaging screw 16 being fixed to the shaft 26 by an internally threaded cap 40 which clamps the handwheel 38 against the shoulder 36 and similarly locks the enlarged ribbed head 22 of the screw 16 to the end of the shaft 26. As will be appreciated, the end of the cap 40 is of course apertured so as to allow the tapered screw 16 to project forwardly therebeyond for engagement with the workpiece. Constructed in this manner, it will be appreciated that the screw 16 can be affixed to the workpiece, generally designated by reference numeral 42, through merely a manipulation of the handwheel 38 without requiring a manipulation of the entire tool 10. Basically, in attaching the screw 16, a small hole will be drilled through the workpiece 42, this normally constituting the dent which is to be removed. Then, through a manipulation of the handwheel 38, the tapered screw 16 is screwed into the formed hole, this screw being self-tapping in nature so as to provide for a positive interlocking with the workpiece 42.

Alternatively, the screw 16 can be made with a sharpened point so that when the tool was cocked, the weight of the piston will drive the point through the sheet metal whereby the screw can be screwed into the metal without having to perform the additional step of drilling a hole in the sheet metal. Likewise, the tool can be used to pull bearings and seals in addition to its dent removal functions by utilizing an appropriate work engaging head thereon.

The force necessary to outwardly draw the dent is achieved by a sliding weight or hammer 44 provided within the cylinder 12. Manipulation of the hammer 44 is effected by a valve controlled air pressure system. This system is incorporated within the handle 14 which includes an elongated valve chamber 46 orientated transversely across the rear end 18 of the cylinder 12, a handgrip portion 48 rearwardly thereof, and an integral externally threaded forwardly projecting anvil or abutment defining portion 50 which threads within the rear portion 18 of the cylinder 12 for effecting a locked mounting of the handle 14 on the cylinder 12 in conjunction with a closing of the rear portion of the cylinder. The abutment 50 includes an air port 52 centrally therethrough. The chamber 46 includes an upper bleed port 54 in generally aligned relation with the abutment port 52 and a second smaller bleed port 56 located below the cylinder 12. Aligned with this second smaller bleed port 56 is an elongated air line 58 which extends from communication with the valve chamber 46 forwardly and into communication with the forward end of the cylinder 12 immediately inward of the block 28 and cylinder end closing bearing 30. The lower end of the chamber 46 is provided with an enlarged inlet 60 and is adapted to threadedly mount a line 62 extending from an appropriate source of pressurized air.

Provided within the valve chamber 46 is an elongated valve or valve member 64 mounted for controlled longitudinal reciprocation therein through the combined action of an expanded coiled compression spring 66 engaged between the upper end of the chamber and the top of the valve 64 and a pivoted trigger 68 also engaging the upper end of the valve 64. As will be appreciated, an outward swinging of the trigger 64 toward the handgrip portion 48 of the handle 14 will effect an upward sliding of the valve 64 against the biasing force of the spring 66 with a relaxing of the force on the trigger 68 causing a downward or opposite movement of the valve 64 under the influence of the spring 66.

An axial bore extends inwardly through the lower end of the valve 64 at the inlet end of the chamber 60 and terminates short of the inner end of the valve in a laterally directed passage 68 which, in the lowermost or neutral position of the valve 64, as illustrated in FIG. 2, is orientated below the abutment port 52 with the abutment closing the outer end of the passage 68. A second passage 70 extends laterally from the axial bore 66 at a point just inward of the inlet end thereof. A first annular passage 72 surrounds the valve 64 below the lateral passage 68 and a second annular passage 74 surrounds the valve 64 immediately above the passage 70 and, in the position of FIG. 2, below the bleed port 56.

In operation, the spring 66 in its fully expanded position retains the valve in the position of FIG. 2 wherein the bleed ports, abutment port 52 and air line 58 are respectively sealed off from the valve passages and hence the air supply.

With reference to FIG. 3, an initial movement of the trigger 68 raises the valve 64 so as to align the passage 68 with the abutment port 52 and simultaneously align the annular valve passage 74 with the adjoining end of the air line 58 and the small bleed port 56 aligned therewith. In this position, the pressurized air is introduced into the rear of the cylinder behind the hammer 44 resulting in a forward driving of the hammer 44 with the relatively small bleed port 56 providing for a comparatively soft movement of the hammer 44. At the forwardmost position of the hammer 44, the hammer releasably interlocks with a rearwardly extending ball 76 integrally formed with the block 28 and rearwardly spaced therefrom. The hammer 44 includes a ball conforming socket 78, the entrance to which is resiliently restricted by an appropriate seal, O-ring, or the like 80 whereby a releasable snap-locking of the hammer 44 to the forward end of the cylinder is effected. In this manner, the hammer is retained at the forward end of the cylinder regardless of the orientation of the tool 10. Incidentally, it will be noted that this interengagement of the hammer 44 and the ball 76 positions the hammer 44 slightly from the block 28 with the forward end of the air line 58 communicating with the cylinder between the hammer 44 and the block 28.

With reference to FIG. 4, when the powered rearward driving of the hammer 44 is desired so as to effect a pull on the workpiece engaged screw 16, the pull on the trigger 68 is continued so as to further upwardly shift the valve 64 with the lower air passage 70 aligning with the air line 58 for the introduction of a flow of pressurized air into the forward portion of the cylinder 12 between the hammer 44 and the block 28. At the same time, the upper annular passage 72 communicates the abutment port 52 directly with the upper bleed port 54 for an exhausting of the air between the hammer 44'and the abutment or anvil 50. The releasable interlocking of the hammer 44 and ball 76, in addition to facilitating a use of the tool in any desired orientation, also provides a means for allowing a small buildup of pressure forward of the hammer 44 prior to a snap-release of the hammer 44 which tends to increase the force of the impact against the abutment or anvil 50. The hammer, upon striking the abutment 50, causes a rearward jerk on the tool and a corresponding outward pulling of the workpiece 42, normally a dent which is to e straightened.

Upon release of the trigger, the valve 64 will move past the position of FIG. 3 tending to reposition the hammer 44 in its forward ball locked position preparatory to another rearward power driving of the hammer. It will be appreciated that the ball 76 and mating pocket 78 are spherical whereby a rotation of the ball 76, such as will occur upon a setting of the screw 16 through a manipulation of the handwheel 38 will not affect the alignment of the ball and socket. In fact, depending upon the particular tolerances involved, the ball 76 may rotate within the socket 78 or the hammer 44, if locked to the ball 76, rotate with the screw 16 upon manipulation of the handwheel 38.

From the foregoing, it should be appreciated that a highly unique dent removing device has been defined. This device incorporates an air driven hammer which is completely concealed and which exerts a pulling force through a separately manipulable workpiece engaging member. The tool is usable in any position with the hammer being stabilized in a cocked or ready position at the forward end of the device through a releasable interlock. Operation of the device is effected through a simple trigger control which shifts a valve progressively through a series of steps which initially position the hammer at the forward end of the device adjacent the workpiece engaged member and subsequently forcibly rearwardly drives the hammer to effect a rearward forcing of the entire tool and attached workpiece.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scop of the invention.

What is claimed as new is as follows:

1. A fluid actuated hand tool for dent removal and the like comprising an elongated cylinder including forward and rear ends, a workpiece engaging element mounted on and projecting forwardly from the forward end of the cylinder, a longitudinally slidable hammer positioned within, said cylinder, a first fluid port through the cylinder at the rear end thereof, a second fluid port through the forward end, of said cylinder, a source of pressurized fluid, valve means selectively communicating the source of pressurized fluid with said first fluid port for a forward positioning of said hammer within the cylinder and with said second fluid port for a rearward driving of said hammer, abutment means at the rear of said cylinder receiving the impact of the rearwardly driven hammer, and lock means at the forward end of the cylinder for automatically engaging and releasably securing said hammer upon a forward positioning of the hammer, said second fluid port being located forward of said lock means with release of said lock means being effected in response to communication of the source of pressurized fluid with the second fluid port and a small buildup of pressure forward of the hammer, said workpiece engaging element comprising a threaded member for rotational driving into a workpiece aperture, and means for rotatably driving said threaded member independently of the remainder of the tool, the means for rotatably driving said threaded member comprising mounting means rotatably locking the threaded member to the forward end of the cylinder for rotation of the threaded member relative to the cylinder, and an enlarged handwheel locked to the mounting means for a rotational manipulation thereof.

2. The tool of claim 1 wherein said lock means comprises an enlarged ball rigid with and projecting internally of the forward end of the cylinder, said hammer having an internal socket receiving said ball upon a forward movement of the hammer and resilient means releasably retaining the socket about said ball.

3. The tool of claim 2 wherein said valve means includes an elongated valve chamber, an elongated valve longitudinally shiftable within said chamber, said first and second fluid ports communicating with said chamber at spaced points therealong, said chamber including a bleed port generally coplanar with and angularly spaced from each fluid port, air passage means within said valve, a fluid inlet in said chamber communicating said chamber with said source of pressurized fluid, and means for selectively shifting said valve within said chamber for a selective communication of the air passage means with one of said fluid ports while the second of said fluid ports is communicated with its associated bleed port.

4. The tool of claim 3 including a handle mounted on the rear of said cylinder, said handle incorporating said valve chamber and including a hand grip spaced from said valve chamber and a trigger control for the valve

Claims

1. A fluid actuated hand tool for dent removal and the like comprising an elongated cylinder including forward and rear ends, a workpiece engaging element mounted on and projecting forwardly from the forward end of the cylinder, a longitudinally slidable hammer positioned within said cylinder, a first fluid port through the cylinder at the rear end thereof, a second fluid port through the forward end of said cylinder, a source of pressurized fluid, valve means selectively communicating the source of pressurized fluid with said first fluid port for a forward positioning of said hammer within the cylinder and with said second fluid port for a rearward driving of said hammer, abutment means at the rear of said cylinder receiving the impact of the rearwardly driven hammer, and lock means at the forward end of the cylinder for automatically engaging and releasably securing said hammer upon a forward positioning of the hammer, said second fluid port being located forward of said lock means with release of said lock means being effected in response to communication of the source of pressurized fluid with the second fluid port and a small buildup of pressure forward of the hammer, said workpiece engaging element comprising a threaded member for rotatioNal driving into a workpiece aperture, and means for rotatably driving said threaded member independently of the remainder of the tool, the means for rotatably driving said threaded member comprising mounting means rotatably locking the threaded member to the forward end of the cylinder for rotation of the threaded member relative to the cylinder, and an enlarged handwheel locked to the mounting means for a rotational manipulation thereof.

4. The tool of claim 3 including a handle mounted on the rear of said cylinder, said handle incorporating said valve chamber and including a hand grip spaced from said valve chamber and a trigger control for the valve means.