US2860421A

US2860421A - Self-centering transfer punch

Info

Publication number: US2860421A
Application number: US524391A
Authority: US
Inventors: Joseph J Smith
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-07-26
Filing date: 1955-07-26
Publication date: 1958-11-18
Anticipated expiration: 1975-11-18

Description

NOV. 18, 1958 J, J, SMH-H SELF-CENTERING TRANSFER PUNCH Filed July 26, 1955 ATTD RN EYS p as at 27 for engagement with United States l Patent Otlice 2,860,421 -SELF-CENTERING TRANSFER PUNCH Joseph J. Smith, East Hartford, Conn. .Application July 26, 1955, Serial No. 524,391 3 Claims. (Cl. 33-191) and more particularly centering transfer punch which inexpensive to manufacture.

Other objects and advantages Will be apparent during the course of the following description.

In the accompanying drawings, forming a part of this application, and in which like numerals are used to designate like parts throughout the same:

Figure l is an elevational View of the transfer punch, constructed according to the present invention.

Figure 2 is a sectional view taken on the line 2 2 of Figure 1 and illustrating the punch in use.

Figure 3 is an elevational View showing the punch removed from the support and body members.

Figure 4 is an elevational view illustrating the body member.

Figure 5 is a bottom plan view of the device.

Figure 6 is a longitudinal sectional view taken through the support member.

Figure 7 is atop plan view of the device.

Referring in detail to the drawings, there is shown a self-centering transfer punch which includes a body member 10, a cylindrical punch 11, and a support member 12.

The body member 10 may be made of any suitable material such as hardened metal, and the body member 10 includes an upper enlarged portion 14 that may be knurled exteriorly as at so as to facilitate the gripping thereof. The body member 10 further includes a reduced diameter portion 16 and there is provided in the body member 10 a longitudinally extending bore 17. There is provided on the reduced diameter portion 16 a threaded section 19 for a purpose to be later described, and the lower edge of the reduced diameter portion 16 is tapered or beveled as at 18, Figure 4.

The punch 11 extends through the bore 17 in the body member il), and the punch 11 includes a major cylindrical portion 2t) which has a lower pointed end 21. The pointed end 2l of the punch 11 is adapted to engage or form an indentation 22 in a work piece 23, and a template 24 having a plurality of openings 25 therein may be used in conjunction with the work piece 23.

The construction of the support member 12 is shown in detail in Figure 6. Thus, the support member 12 includes an upper enlarged shoulder 26 which is threaded interiorly the threaded section 19 of the body member 10. The support member 12 further includes a lower enlarged annular collar 28, and there is provided an intermediate section or portion 31. Arranged in the' collar 28 and in the intermediate section 31 is a plurality of spaced radially disposed slits or slots 29 for a purpose to be later described. The inner portion of the collar 28 may be tapered for engagement with the tapered sur face 18 of the body member 10. The exterior surface of the shoulder 26 may be knurled as shown in Figure l.

From the foregoing, it is apparent that there has been provided a self-centering transfer punch and in use, with the parts arranged as shown in the drawings, the template 24 is arranged on the work piece 23. Then the lower portion or collar 28 of the support member 12 is arranged in engagement with the desired opening or hole 25 in the template 24. By manuallygripping the knurled shoulder 26, the support member 12 can be section 19 of the body member 10 and also due to the provision of the slots 29, the effective diameter of the collar 28 can be varied so that it can be made to snugly fit openings 25 of different diameters or sizes. The tapered surface 30 on the interior of the support member 12 engages the tapered surface 18 on the bottom of the body member 10 so as to maintain the parts in their proper position.

with the collar 28 snugly in the work piece 23.

The present invention can cover a wide range of material stock thicknesses or different diameters. Also, the device can be used in establishing a center mark or datum point on various sizes of holes.

As an example of how the present invention may be used, a tool maker or sheet metal worker may be provided with a master template that may have as many as fifteen holes of several decimal sizes in various locations which range from approximately .250 inch in diameter up to and including .350 inch in diameter. The tool maker might be asked to take the master template with the various size holes in it and with the use of a sharp pointed steel scriber, proceed to mark the outline of the various hole sizes above mentioned, onto possibly twenty pieces of at plate sheet metal for the purpose of proscribed separately from the above mentioned master template. Previously, no fast or accurate method has been devised to pick up the positive center of the fifteen above mentioned various sized holes that he has to locate and provide a center mark for the purpose of drilling these holes to the certain diameters as provided in the master template above mentioned and to'tolerances of .003 diameter of positive location. In the above mentioned example, the mechanic doing the job would take the transfer punch of the present invention and screw the support member 12 onto the body member 10. Then, the spring collet or collar 28 would be set down in one of the holes 25, the template being on top of the material 23. Then, the punch 11 is inserted in the bore 17 and the top of the punch can be struck with a mallet or hammer. This will make a center mark or prick punch mark for a positive starting point for vthe mechanic to drill the hole to a desired diameter hole. Thus, there will be a very large amount of time saved in layout n transferring holes. Previously, it was necessary to make up individual transfer punches for each hole size required.

I claim:

l. In a self-centering transfer punch, a body member including an enlarged cylindrical portion, said body member including a reduced diameter cylindrical portion hav- Patented Nov. 1s, 195sy ing an upper threaded section, there being a longitudinally extending bore in said body member, the lower edge of said body member being tapered, a punch extending through said bore and having a lower pointed end, a support member arranged over the reduced diameter portion of said body member and including an intermediate cylindrical section, an enlarged shoulder arranged in threaded engagement with the threaded section of the reduced diameter portion of said body member, there being an annular collar on the lower end of said support member, there being a plurality of spaced radially disposed slots in said collar and in the intermediate section of said support member, the inner portion of the support member adjacent the collar being tapered for engagement with the tapered lower end of said body member and the lower edge of said support member being concave in cross section.

2. The structure as dened in claim 1, wherein said shoulder and wherein the enlarged cylindrical portion of said body member are knurled exteriorly. l

3. In a self-centering transfer punch, a body member including an upper enlarged cylindrical portion7 said body member including a reduced diameter cylindrical portion having an upper threaded section, there being a longitudinally extending bore in said body member, the lower edge of said body member being tapered, a punch extending through said bore and including a major cylindrical portion, a lower pointed end, a support member arranged over the reduced diameter portion of said body member and including an intermediate cylindrical section, an upper enlarged shoulder having a threaded interior arranged in threaded engagement with the threaded section of the reduced diameter portion of said body member, there being an annular enlarged collar on the lower end of said support member, there being a plurality of spaced radially A' disposed slots in said collar and in the intermediate section of said supportl member, the exterior surface of said shoulder and the exterior surface of said enlarged cylin- .drical portion being knurled exteriorly and the lower end of said support member adjacent the collar being concave in cross section, said support member including an inner longitudinally extending passageway including a lower tapered surface for engagement with the tapered lower edge of said body member so as to maintain the parts in their proper positions.

References Cited in the le of this patent UNITED STATES PATENTS 953,282 Nash Mar. 29, 1910 1,259,335 Acton Mar. 12, 1918 2,255,361: -Mueller Sept. 9, 1941 2,519,908 Howard Aug. 22, 1950 l FOREIGN PATENTS 6,816 Great Britain Feb. 8, 1896, of 1895