US 3788537 A
A pin chuck comprising a spring pin holder and punch for inserting the spring pin in a cooperating hole in a workpiece. The construction of the tool permits ready substitution of different sized pin holders and punches whereby a range of pin sizes may be inserted through the use of the same basic tool. The tool includes means for accurately controlling the extent of the pin insertion into the hole.
Description (OCR text may contain errors)
United States Patent [191 Fox [ HAND-LOADED PIN CHUCK  Inventor: William P. Fox, c/o Mechanical Application lnc., Edgecomb, Maine 04578  Filed: July 31,1972
 Appl. No.: 276,845
I52] U.S. Cl. 227/142, 227/147  Int. Cl. 1325c 1/00  Field of Search 227/142, 147, 149
 References Cited UNITED STATES PATENTS 2,430,532 '11 1947 Rayburn 227/142 2,543,942 3/1951 Shaff 227/147 1,699,519 1/1929 Brown, 227/147 [451 Jan. 29, 1974 3,219,248 11/1965 Krewson, Jr. ..227/147 Primary Examiner-Granville Y. Custer, Jr. Attorney, Agent, or Firm-Charles E. Pfund, Esq.; Chittick, Thompson & Pfund  ABSTRACT A pin chuck comprising a spring pin holder and punch for inserting the spring pin in a cooperating hole in a workpiece. The construction of the tool permits ready substitution of different sized pin holders and punches whereby a range of pin sizes may be inserted through the use of the same basic tool. The tool includes means for accurately controlling the extent of the pin insertion into the hole.
7 Claims, 6 Drawing Figures HAND-LOADED PIN CHUCK BACKGROUND OF THE INVENTION The use of so-called spring pins is extensive. A spring pin is a small cylinder (usually of metal) of selected length and slit longitudinally so that it is circumferentially compressible whereby it may be forced into a slightly smaller cylindrical hole.
Spring pins serve many permanent and temporary uses such as for example, the anchoring of two or more workpieces against relative transverse movement or, when, partially inserted so as to extend above the surface of the workpiece','acting as locating means for other elements. 7
Since a spring pin is usually quite a small element, it is somewhat difficult to hold it in the fingers while at the same time tapping it with a hammer to start its insertion into an undersized hole. Accordingly, numerous tools have been invented to accomplish the insertion of spring pins in a more convenient manner. Some tools have means for automatically feeding a succession of pins to the inserting means, while others require preliminary manual insertion of each individual spring pin into the chuck or pin holding device preparatory to the inserting operation.
SUMMARY OF THE INVENTION dividually loaded by hand into a nose piece. This operation is easily and quickly performed at the position of the tool which will ordinarily be mounted in an arbor press or some other means for applying downward pressure such as a drill press. Then downward movement of the hand operated press will force the spring pin into the cooperating hole in the workpiece. The
tool is so constructed that the pin may be positively inserted a predetermined distance, that is, to a position below the workpiece surface, flush with the surface or extending above the surface.
BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, FIG. 1 shows the spring pin placed manually in the nose piece and ready for insertion in the hole in the workpiece.
FIG. 2 shows the pin partially inserted along with a corresponding change in the position of the elements of the tool.
FIG. 3 shows the pin completely inserted to the determined depth.
FIG. 4 shows the tool with a substituted punch assembly designed to accommodate larger spring pins.
FIG. 5 shows an alternative arrangement of the parts whereby the pin. at the completion of the punch stroke is only partially inserted in the hole.
FIG. 6 is a greatly enlarged section taken on line 66 of FIG. 1.
DESCRIPTION OF A PREFERRED EMBODIMENT Referring to the several figures in the drawings, the
tool comprises a short cylindrical shank 2 having a flat 4 adapted to be secured in an arbor press. The shank terminates at its lower end at 6 and a short distance thereabove has a circumferential groove 8 extending thereabout. A tubular body 10 which preferably is cylindrical, has a threaded hole 12 near its upper end into which is threaded a set screw 14 whose inner end 16 resides in groove 8. In this manner, the shank is effectively connected to the body 10.
Located within the remaining lower portion of the body 10 is a punch assembly. This comprises a punch holder 18 the upper end 20 of which rests against the lower end 6 of shank 2. The punch holder 18 has a circumferential groove 22 thereabout whereby it may be held in position within the body 10 by another set screw 24 the inner end of which resides in the groove 22. Punch holder 18 has an axial bore therethrough as at 26 to receive therein in tight relation a punch 28 whose length will be determined by the operative conditions that have to be met.
The lower end of punch holder 18 is of reduced diameter at 30 to receive loosely thereabout a coil spring 32 which is in tight frictional engagement with the punch holder 18 at an intermediate section 34 of slightly enlarged diameter.
Slidably fitting within the lower end of body 10 is a nose piece 36 having an axial bore 38 therethrough adapted to receive therein in free relation the lower end of punch 28. The upper portion of the nose piece 36 is of reduced diameter as at 40 to receive loosely thereabout spring 32 and there is an intermediate section 42 of slightly greater diameter adapted to be in tight frictional engagement with the lower end of spring 32. Thus, the spring 32 which is frictionally attached to the punch holder 18 at the section 34 and to the nose piece 36 at the section 42 acts to hold the nose piece in a determinable normal position within the body 10 as illustrated in FIG. 1.
The diameter of bore 38 in nose piece 36 is such that a spring pin 44 may be freely inserted therein through the bottom end. When spring pin 44 is so inserted, it is retained therein by means of a U-shaped spring 46 which resides in two opposite horizontal slots 48 and 50 which slots penetrate the wall of bore 38 so that the spring 46 can grip the pin 44. This construction is shown in enlarged detail in FIG. 6. Preferably, the ends of the spring pins 44 are beveled as illustrated in the drawings.
The lower end surface 52 of punch holder 18 and the upper end surface 54 of nose piece 36 together act as stops to limit the descent of punch 28 with respect to nose piece 36.
The operation of the device is as follows: With the shank 2 of the tool mounted in a conventional arbor press (not shown) and with the lower end of nose piece 36 a few inches above the workpieces 56 and 57 which are'to be joined, a spring pin 44 is manually positioned in bore 38 and held in this position by the light pressure of U-shaped spring 46. A conventional elastic O-ring may be substituted for spring 46.
The workpieces 56 and S7 with the aligned holes 58 are placed on the base of the arbor press directly below pin 44. Entranceof the spring pin into aligned holes 58 is facilitated by the beveled end of the spring pin and/or by chamfering the ends of the holes as at 60. The arbor press is then manually actuated to lower the tool first to the position shown in FIG. 1 and then on downward until the lower end of the pin 44 is in engagement with,
movement of body and punch 28 can continue as the spring 32 is compressed. Thus, in FIG. 2, it will be noted that the lower end of body 10 has moved downwardly with respect to nose piece 36 and the stop surfaces 52 and 54 are approaching each other.
Downward motion of the tool is continued until as shown in FIG. 3 the stop surfaces 52 and 54 come into engagement thereby to stop downward movement of punch 28 and body 10. The depth to which the pin 44 is inserted in hole 58 is controlled by the length of the punch 28. In FIG. 3, the punch 28 is of such length that the pin 44 will be inserted to a depth just below the surface 64 of workpiece 56. On the other hand, if the length of the punch is shortened, as illustratedin FIG. 5, so that at the time the stop surfaces 52 and 54 come together the lower end of the punch is above the surface 64 of the workpiece, then the pin 44 will be only partially inserted in hole 58.
Another way of controlling the extent of the insertion of pin 44 into hole 58 would be to vary the initial distance between the stop surfaces 52 and 54. Small washers surrounding punch 28 could be placed between the stop surfaces thereby to diminish the distance the punch could descend before the stops came together. Washers such as those just referred to, for limiting the downward movement of the punch are shown in dotted lines in FIG. 4 at 66.
Another way of controlling the depth of insertion'of the spring pin 44 into holes 58 would be by the use of conventional adjustable stop means (not shown) associated directly with the arbor press.
The tool of the present invention is also readily adapted to insert pins of different diameters. A common range of sizes of spring pins runs in 1/16 inch increments from l/16 to M1 of an inch. A series of punch assemblies may be supplied with each tool so that by the simple expedient of replacing one assembly with another, different sized pins may be accommodated.
To change from one punch assembly to another the set screw 24 is removed which permits the entire punch assembly consisting of the punch holder 18, punch 28, spring 32 and nose piece 36 to be removed from body 10. Then as illustrated in FIG. 4 a different punch assembly may be inserted in the same body 10 and locked in place by the repositioning of set screw 24. The new assembly consists of a punch holder 18' of the same size as punch holder 18 but mounting therein a larger punch 28'. The lower end of the punch fits within a nose piece 36' of the same outside diameter as nose piece 36 but having a larger bore to receive the larger 4 size punch 28'. The spring 32 may be the same as that shown in FIGS. 1, 2 and 3.
While the tool herein described and claimed has been used principally in connection with the insertion of spring pins, it will be understood that it is equally useful in the insertion of any other type of small pin, tubular or solid, in a suitably sized hole.
It is intended to cover all changes and modifications of the examples of the invention herein chosen for purposes of the disclosure which do not constitute departures from the spirit and scope of the invention.
1. Means for inserting a spring pin in a hole of cooperating size in a workpiece, said means comprising:
a tubular supporting body;
a pin punch fixed to a punch holder removably secured within said body and paralleling the long dimension of said body;
a nose piece slidably located in the lower end of said body and having a bore therethrough in which is located the lower end of said punch;
a compressible spring within said body, said spring fixed at its upper end to said removable punch holder and attached at its lower end to said nose piece thereby to normally hold said nose piece in a position in which the lower end of said punch is above the lower end of said nose piece bore and the lower end of said nose piece is below the lower end of said body;
means associated with the lower end of said nose piece bore for holding a spring pin therein; and,
stop means for limiting inward movement of said nose piece with respect to said body.
2. The construction set forth in claim 1 and a shank attached to said tubular supporting body adapted to connect said body to axial force applying means.
3. The construction set forth in claim I, said punch holder, punch, spring and nose piece being removable as a unit from said body.
4. The construction set forth in claim 1, said stop means arranged to limit movement of said nose piece inwardly of said body to a position in which the lower end of said nose piece is below the lower end of said body.
5. The construction set forth in claim 1, said punch holder having a depression in its outer surface and removable means extending through said body into said depression to hold said punch holder said removable relation to said body.
6. The construction set forth in claim 1, said stop means comprising the lower end of said punch holder and the upper end of said nose piece.
7. The construction set forth in claim 1, said means for holding the spring pin in the nose piece comprising a slot through the wall of said nose piece intersecting said bore and resilient means extending into said slot to engage said spring pin.