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Publication numberUS3038360 A
Publication typeGrant
Publication dateJun 12, 1962
Filing dateMar 24, 1960
Priority dateMar 24, 1960
Publication numberUS 3038360 A, US 3038360A, US-A-3038360, US3038360 A, US3038360A
InventorsLawrence J Mormann
Original AssigneeLawrence J Mormann
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Sheet metal working tools
US 3038360 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

June 12, 1962 1 J. MORMANN SHEET METAL WORKING TOOLS Filed March 24, 1960 /HVEN /b/T United States Patent @thee `Patented June l2, 1962 3,038,360 SHEET METAL WORKING TOOLS Lawrence J. Mormann, 601 2nd St. N., La Crescent, Minn. Filed Mar. 24, 1960, Ser. No. 17,372 3 Claims. (Cl. 81-15) 'I'his invention relates to new and useful improvements in sheet metal working tools, and the principal object of the invention is to provide a tool lwhich may be easily and conveniently used for delivering impacts on sheet metal for purposes of straightening, forming, deforming, or otherwise working the same.

As such, the tool in accordance with the invention is particularly well suited for automobile body work, `although the use thereof is by no means restricted to this environment. An important feature of the invention resides in providing a tool of this type which may be effectively utilized in poorly accessible locations and which, being manually actuated, is fully self-contained and does not require connection to external sources of energy such as electricity, compressed lair or hydraulic fluid.

Some of the advantages of theinvention reside in its simplicity of construction, ease of operation, lightness of weight, durability Iand in its adaptability t-o economical manufacture.

With the above more important objects and features in view and such other objects and features as may become apparent as this specication proceeds, the invention will be understood from the following description taken in conjunction with the accompanying drawings, wherein like characters of reference are used to designate like parts, and wherein:

FIGURE l is a side elevational view of the invention;

FIGURE 2 is a fragmentary longitudinal sectional view thereof on an enlarged scale and showing the plunger in its projected position;

FIGURE 3 is a fragmentary sectional view, similar to that shown in the left-hand portion 'of FIGURE 2, but illustrating the plunger in its retracted position;

FIGURE 4 is a fragmentary sectional view, similar t0 that shown in FIGURE 2 but illustrating the cam member in a position where it is about to re-engage the cam surfaces of the plunger after the latter has been retracted and returned to its projected position; and

FIGURE 5 is a fragmentary sectional view, taken substantially in the plane of the line 5-5 in FIGURE 2.

Referring now to the 'accompanying drawings in detail, the sheet metal impact tool in accordance with the invention is designated generally by the reference numeral and embodies in its construction a frame 11 including a tubular member 12 provided at one end thereof with a hollow head or housing 13 extending at right angles from the axis of the member 12, as shown. An elongated bar member 14 has one end portion 14a thereof suitably secured to the member 12, while the other end portion 14b of the member 14 is spaced away from the member 12 and disposed adjacent the housing 13, as illustrated.

The housing 13 is equipped with an end plug 15 having an `axial bore 16 therein which slidably receives a reciprocable plunger 17, the latter having a work engaging point or extremity 17a movable toward and away from the bar member portion 14h. The lmem-ber portion 14b constitutes a work abutting or backing pad while the plunger delivers impacts against the work, as will ybe hereinafter described.

The lower end portion of the plunger, indicated at 17b, is rectangular in crosssection and slidable in a rectangular aperture formed in a transverse partition 1S in the housing 13, whereby the plunger is prevented from rotating. rl `he intermediate portion of the plunger is provided with a collar or shoulder 19 anda compression spring 20 is interposed between this shoulder and the partition 18, so as to Cil urge the plunger outwardly, that is, toward the pad 14h, to the position shown in FIGURE 2.

The lopposite sides of the plunger portion 17b are pro` vided with inclined grooves forming c-am surfaces 21 and the lower end of the portion 17b is also inclined so as to provide a cam surface 22. A cam member 23, suitably mounted at one end of an Vactuating rod 24, has a forked portion 23a which, as is -best shown in FIGURE 5, straddles the plunger portion 17b and terminates in a pair of inclined cam elements 25 which are slidably receivable in the cam grooves of the plunger. The rod 24 extends longitudinally through the frame member 12 and is connected at its other end lby a pivot pin 26 to the lower end of and actuating arm or lever 27, the upper end of the latter being fulcrumed vby a pivot pin 28 between a pair of transversely spaced, upstanding supports 29 which lare provided rigidly on the frame member 12 adjacent the frame portion 14a. It is to be noted that the diameter of the frame member 12 is substantially larger than that of the rod 24 and that the portion of the member 12 adjacent the lever 27 is provided with bearings 3d which slida-bly receives the rod Kand retain the same substantially centralized in the frame member. However, the other end portion of the rod 24, adjacent the plunger 17 is movable downwardly or depressible from its centralized position in the frame member 12, it Ibeing understood that the rod 24 is suieiently rigid, yet exible enough to permit such downward deflection or depression to occur. Nevertheless, the inherent resiliency of the rod `2d returns the rod, after deilection, to its initial centralized position in the member 12, in which position the cam member 23 engages the underside `of kan `abutment 31 `which is formed in the frame member 12 adjacent the housing 13.

When the tool is placed in use, it is applied to the work so that the area of the work to ybe operated upon is disposed between the abutment pad 14b and the extremity 17a of the plunger 17. Thereupon, while holding the supports 29 in the palm of the hand, finger pressure is exerted on the lever 27 in the direction `of the arrow 32, thus causing the rod 24 to slide inside the member 12 in the direction of the arrow 33, and `also causing the elements 25 of the cam member 23 to slide along the inclined cam surfaces 21, and retracting the plunger 17 against the resilient action of the spring 20, and also compressing a tapered, spiral compression spring 34 which is interposed `between the cam member 23 and an yannular shoulder 35 provided in the frame member 12. When the cam member 23 reaches the position shown in FIGURE 3, the plunger is fully retracted and further sliding movement of the rod 24 in the direction 33 causes the cam elements 25 to become disengaged from the cam surface 21 of the plunger, thus permitting the plunger to be forcibly projected by the spring 20 to deliver 4a positive impact against the work in abutment with the pad 14b.

When pressure on the lever `27 is relaxed, the spring 3'4 urges the rod 24 and the cam member 23 to their initial position, but by that time the plunger 17 will have returned to its initial position so that it is not possible for the cam element-s 25 to re-enter the cam grooves from the direction in which they left them. However, during such return movement, the cam elements 25 will come into engagement with the cam surface `22 of the plunger, with the result that the cam member 23 will -be forced downwardly and the yadjacent end portion yof the rod 24 will lbe deflected accordingly. In so doing, the cam member 23 will pass under the lower end of the plunger to the position shown in FIGURE 4, at which point the cam elements 25 will clear the cam surface 22 of the plunger and will permit the cam member 23 to resume its initial, centralized position, with the cam elements 25 re-entering the cam grooves in the plunger from the left-hand side, as viewed in the drawings. The device will then be ready for the next cycle 3 of operation. Thus, by alternately pressing and releasing the lever 27, 'the plunger 1.7 may be caused to deliver a series of impacts against the work to perform whatever operation may be intended.

While in the foregoing there has been shown and described the preferred embodiment of the invention, various modifications may become apparent to those skilled in the art to which the invention relates. Accordingly, it is not desired to limit the invention to this disclosure and various modifications may be resorted to, such `as may lie within the spirit `and scope of the appended claims.

What is claimed as new is:

1. In a sheet metal impact tool, the combination of a frame including an elongated hollow main frame member and an elongated hollow head connected to one end of said frame member in perpendicular relation therewith, a projeotable and retractable work engaging plunger reciprocable longitudinally in said head, and means for actuating said plunger, said actuating means comprising resilient means in the head for urging said plunger to its projected position, a reciprocable actuating rod extending longitudinally in said frame member `and having inner and outer ends, means lat lthe outer end of said rod for reciprocating t-he same, a fork provided at the inner end of the rod and straddling said plunger, said plunger being provided at opposite sides thereof with a pair of inclined grooves offset by an acute angle from` the axis of reciproca tion of said rod, and la pair of inturned cam elements provided on the furcations of said fork and slid-ably engaging said grooves whereby to retract the plunger against the action of said resilient means when the rod is moved outwardly in the frame member, ysaid `cam elements being disengaged from said grooves at the youter end of the rod movement whereby to release the plunger for projection by said resilient means.

2. The device as dened in claim 1 wherein said plunger is provided with an inclined end surface adjacent and substantially parallel to said grooves, said cam elements of said fork being engageable with said inclined end surface during inward movement of said rod in said frame member and the inner end portion lof the -rod being laterally deiiectable in the plane of said plunger during such move-l ment whereby said fork may by-pass said plunger end for re-engagement of said cam elements with said grooves while the plunger `remains relatively stationary.

3. The device as defined in claim Z together with resilient means provided in said main frame member in engagement with said fork for urging the latter toward said plunger.

Cox Aug. 30, 1932 Ristow Mar. 17, 1959

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1874460 *Jun 27, 1930Aug 30, 1932Cox John E PPrick punch
US2877820 *Dec 17, 1956Mar 17, 1959Milwaukee Electric Tool CorpPower hammer
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4751970 *Oct 28, 1985Jun 21, 1988Robert Bosch GmbhAngular attachment for transmitting and deviating output power of a machine
US5479804 *Sep 28, 1994Jan 2, 1996Clay L. CookTools for paintless dent repair
U.S. Classification72/437, 72/452.8, 72/444, 72/705, 72/412
International ClassificationB21D1/06
Cooperative ClassificationY10S72/705, B21D1/06
European ClassificationB21D1/06