US2005495A - Bolt making machine - Google Patents

Description

June 18, 1935. w. l.. c LousE I 2,005,495

BOLT MAKING MACHINE Filed April 18. 1954 2 Sheets-Sheet 1 @MMM y VM gg/ Bnventor W/Z/A /V Z. 610055 Bg fm Cttornegs BOLT MAKING MACHINE Filed April 18. 1934 2 vSheets-Shea?. 2

/4a /0 /3 25 3/ 27a 29 275 30 27a Bnventor W/l/A M l. CZOUSE (I ttornegs Patented June 1,8, 1935 PATENT ori-icc nom: MAKING MACHINE William L. clause, Train, ohio, assigner-i The National Machinery Company,I Tiffin, Ohio, a

A corporation of Ohio Application Aprn is, 1934, serial No. 721,083

l2 Claims.

This invention relates to heading machines for heading or upsetting bolts, screws and analogous articles, and is particularly concernedwith blankejecting or knock-out mechanism `for such ma- 5 chines.

' In machines of the above type, it is highly desirable to use solidor one-piece dies, to avoid flash or fin formations at the part lines and other diiculties inherentin the use of open or divided dies, such as the added complication' and expense of mechanism for operating the dies, inaccuracies in the work resulting from spreading of the dies under the upsetting or forging pressure and the like. One-piece dies, however, require the blank to be ejected from the die opening by an axiallymoving member commonly termed a knock-'out pin or rod, and this member is subjected to considerable thrust axially, especially at the start of the ejecting operation, and'such thrust naturally tends to bend the pin if the latter is unsupported laterally, and since the pins are generally made of hardened steel, they can stand very little bending without breaking. Where the bolt to be formed is relatively short, solid dies are commonly used, since the stroke of the knock-out -is correspondingly short and the length of the pin which is unsupported' laterally is determined by the length of the stroke. As a consequenceV lateral stresses imposed on the knock-out pin or rod Vare not suicient to bend and causevfrequent breakage of the pin. However,` as the-length ofthe bolt increases'the required length of stroke of the knock-out pin proportionately increases. The pin must be smally enough to-enter the bore of the die and is normally driven by an ejecton rod of relatively large diameter. As a consequence, when the pin is retracted it is normally unsupported through a length equal to the :length of the ejecting stroke, and as this length increases the danger of breakage of the hardened pin under the thrust loads rapidly increases.

It is an object of Ithe present invention, therefore, to provide an improved-knock-outlassembly for machines of the above type embodyingmeans of a practical nature. and of a highly eicient character whereby the knock-out pin is adequately reinforced against bending strains or stresses due to thrust imposed thereon during blank work` ing operations, while at the same time 1the pin is accurately guided with respect to the die opening. v y

The foregoing and -other objects and advantages will become apparent in view of the following description taken in conjunction with the drawings, wherein:

Figure 1 is a fragmentary plan view. of a bolt heading `machine showing a. forming die and blank electing or knock-out mechanism of the type with A which the present invention is concerned associated therewith;

Figure 2 is a fragmentary View in side elevation of the rear portion of the machine of Figure l, showing a preferred type of actuating mechanism for the ejector or knock-'out pin forming part oi lo the knock-out assembly;

Figure 3 is an enlarged central longitudinal sectional View of a preferred typ'e of knock-out assembly, showing the knock-out pin in its advanced or knockout position;

Figure 3a, is a view similar to Figure 3 showing the knock-out plunger and pinin its retracted position ready to receive the thrust of a bolt blank during the workingoperation of thelatter;

Figures 4, 5 and 6 are views similar to Figures 3 and 3a of modifiedtypes of knock-out assemblies.

Referring to Figures 1 and 2, 5 indicates the frame of the machine and 6 the header slide which is mountedfto reciprocate in said frame. Suitably secured in the frame 5 is a `die i having a die opening 'Ia therein, in which the Shanks of the boltf blanks are extruded, or held while the blank is headed or otherwise acted upon by a tool 8 carried by the header slide 6.

The knock-out assembly illustrated in Figures 3 and 3a comprises a plunger 9 of any suitable type which is mounted in a'bore I0 formed in the frame 5 directly in rear of the die I and in axial alignment with the diev opening la. As illustrated the plunger 9 is formed with an annular enlargement or abutment shoulder I I which when the plunger 9 is in retracted position is adapted to abut a shoulder I2 formed by the end of a sleeve Illa ,which is threaded into the'bore and locked in position by a nut Ich.` Beyond the shoulder I I, ,the plunger 9 is formed with a reduced portion I3 arranged to abut at its forward end against the end of a knock-out pin I4. However, any desired arrangement for limiting the retracted positionl ofthe plunger may be employed. Mounted'to have a sliding t in the bore I0 is a vreinforcing and guide bushing or analogous` member I5 formed with an axial opening or bore I5a and reduced end portions ISb and lic. The rear end of the knock-out pin I4 is provided with a guide-or bearing collar I6 which has a sliding flt in the bore I5a, the latter terminating in a reduced concentric bore in the reduced end ISb in which the knock-out pin I4 55 has a sliding t. Mounted on each side of the bushing I5 and housed in the bore I0 are resilient positioning members in the form of compression springs I1 and I8 which serve to maintain bushing I5 in its most eiective reinforcing position. These springs also act to return the knock-out plunger to its retracted position, after the blank is ejected from the die. At its rear extremity, the plunger 9 is internally bored and threaded to adjustably receive a contact screw or analogous member I9 provided with a locking nut I9a. I

A preferred means of actuating thel plunger 8 is shown in Figure 2 and comprises a rocker arm or pusher 20 which is rotatably mounted on a shaft 2I carried by a bracket 22. The arm or pusher 20 is rocked by a cam 23 mounted on a shaft 24 carried by a bracket 25, the shaft 24 being driven from the main crank shaft of the machine (not shown) which reciprocates the header slide 6. The one extremity of the rocker arm I8 is provided with an adjustable contact member 26.

In operation, when the shank of a bolt blank is driven into the die opening 1a of the die 1 by the tool 8 during the advancing movement of the header slide, the knock-out pin I4 takes the thrust of the shank and transmits it to the frame 5 through the shoulder I I abutting against the shoulder I2, or through any other suitable backing means. In this position, it will be noted that the portion I5b of the reinforcing bushing I5, due to springs I1 and I8, is held approximately at the intermediate portion of the pin and adequately reinforces the latter against bending strains both while the pin is taking the upsetting thrust and at the start ofy the ejecting operation, while the rear extremity of the bushing laterally supports the rear extremity of the pin. Thus the pin is held against any tendency toward bending along the entire length thereof. When the header slide retracts, the rocker arm 20 drives the plunger 9 and knock-outpin inwardly and ejects the blank, the springs I1 and I8 being compressed and the bushing'IS moving to the position shown in Figure 3.

Figures 4, 5 and 6 show modified or alternate types of knock-out assemblies with respect to that shown in Figures 3 and 3a. Parts shown in Figures 4, 5 and 6 which are substantially similar to those shown and described in Figures 3 and 3a havev been given like reference numerals.

In Figure' 4 a plurality of reinforcing and guide members or bushings 21a, 21h and 21o are provided and are mounted in a sleeve bushing 28, the latter being inserted in the bore I Il and being adapted to receive the inner extremity I3 of the plunger 9. Interposed between thesejrespective bushingsv are a pair of positioning compression springs 29 and 30 which maintain the reinforcing bushings at the most effective bracing position along the yknock-out pin I4a when the latter takes the thrust and at the start of the ejecting action. The bushing 21a is limited in its rearward movement by an abutment shoulder 3I formed in the sleeve 28. During the ejecting stroke when the plunger 9 passes beyond this shoulder, springs 29 and 3 0 are compressed, and the bushings 21a and 21h are collapsed or moved together t0 allow the completion of the stroke. On the return stroke the springs serve to reposition the bushings in the most effective supporting position. This construction permits the guide bushing and spring assembly to remain in assembled position in sleeve 28 when the sleeve Illa and plunger 9 are withdrawn or removed for adjustment or repair.

The construction in Figure 5 is along the lines of that in Figure 4. In this instance the reinforcing bushings are indicated at 32a, 32h and 32e and the sleeve bushing at 33. In this instance, sleeve 33 is formed with spaced seats 36 and 35, which are preferably tapered, the movable bushings32a and 32h being also tapered or frusto-conical to adjust themselves to said seats. A pair of spacing and positioning springs 36 and 31 are provided and are preferably of unequal tension, the spring 36 embodying less resistance to compression than the spring 31. When the thrust loads are imposed on the pin Ida, which occurs during the heading and at the start of the knockout operation, the bushings 32a and 32h are in seated position so that the pin is effectively reinforced. When the plunger 9 is moved inwardly beyond seat 34, bushing 32a unseats first and then moves freely in sleeve 33, bushing 32b remaining seated until its tension is'overcome by the compression built up in spring 36, whereupon it unseats and bothlbushings collapse together to permit completion of the stroke. Spring 31, of greater tension than -spring 36, ensures return of both bushings to seated position, while on' the ejecting stroke, spring 36 offers less resistance to movement of plunger 9 and permits the center bushing, which serves the most effective reinforcing function and is preferably heavier, to remain seated until the bolt blank is well out of the die. In this construction, also, the plunger may be removed' without displacing the reinforcing assembly. 'Ihe tapered formation of bushings 32a and 32h reduces bearing or surface pin Ida and serve the function of reinforcingy bushings or like members. When the plunger 9 and pinV I4a are in retracted position and at the start of the ejecting stroke,the coilsA of spring 38 are distributed equally along thelength of pin Ida and effectively reinforce the latter against lateral thrust or stresses. v

When the plunger`9 moves forward to eject a blank, the springl 38 is compressed to clear the end I3 of the plunger. During this compression the coils of the spring tend to assume`a larger overall diameter which is prevented by the engagement of the spring in the sleeve 39,' and this tendency results in a slight additional winding of the spring about the pin Ida. Both ends of the spring are preferably left free to permit this movement.

It will be understood that structural changes and variations in arrangement of the several parts maybe adopted within the scope of the invention as defined by the appended claims. By bolt machine in the claims is meant any ma.- chine adapted for heading, upsetting, or 'otherwise working on bolts, screws and lanalogous formed with an annular abutment shoulder, a bushing for reinforcing the pin against bending stresses mounted to have sliding movement on the pin and plunger, and positioning springs disposed at opposite ends of said bushing between the die and bushing andbetween lsaid shoulder and bushing.

2. In a bolt machine, a bed frame, a die supported by said frame and having a die opening therein, said frame being formed with an elongated bore in axial alignment with said die opening, a plunger mounted to reciprocate in said latter opening and formed with an abutment shoulder, a knock-out pin connected to the forward end of said plunger in axial alignment with the die opening, a bushing for reinforcing'the pin against bending stresses having an axial opening therein in which the pin and the forward extremity of said plunger have movement, and positioning springs arranged at opposite endsof said bushing and arranged to abut said die and shoulder to maintain the bushing in the most effective reinforcing position when the pin is in retracted position and at the beginning of the knock-out stroke.

3. In a bolt machine, a die having a die opening therein, a bed frame supporting said die and having an opening in axial alignment with said die opening, a plunger mounted to reciprocate in the opening formed in the frame, a knock-out pin arranged at the forward end of said plunger in axial alignment with the die opening, a plurality of bushings for reinforcing the pin against lateral stresses mounted on the pin, and springs disposed between said bushings for maintaining the latter at the most4 effective bracing position when the plunger and pin are in retracted position and at the beginning of the knock-out stroke.

4. In a bolt machine, a one-piece die having a die opening therein, a bed frame supporting said die and having an elongated opening in axial alignment with said die opening, a sleeve bushing disposed in said frame opening and having an abutment shoulder along the interior bore thereof, a pin, a plurality of reinforcing bushings slidably mounted on said pin with the l outer bushing arranged to abut said shoulder, and springs arranged between said bushings for normally maintaining the latter in the most effective reinforcing position.

5. In a bolt machine, a one-piece die having a die opening therein, a frame supporting said die and formed with an elongated opening in axial alignment with said die opening, and a knock-out assembly disposed in said frame opening; said assembly comprising a plunger having a knock-out pin at the forward end thereof, a sleeve bushing formed with a series of spaced internal abutment shoulders, reinforcing bushings within said sleeve bushing formed with axial openings in which said pin has a sliding fit, and positioning springs arranged between said bushings to maintain the latter at the most effective reinforcing position when-the pin is in retracted position at the beginning of the knockout stroke.

6. In a bolt machine, a one-piece die having a die opening therein, a frame supporting said die and formed with an elongated opening in axial alignment with said die opening, and a knock-out assembly disposed in said frame opening; said assembly comprising a plunger having a knock-out pin at the forward end thereof, a sleeve formed with a series of spaced internal abutment shoulders, reinforcing bushings Within said sleeve formed with axial openings in which said pin has a sliding fit, and positioning springs arranged between said bushings to maintain the latter at the most effective reinforcing position whenthe pin is in retracted position at the beginning of the knock-out stroke, one of said springs embodying less resistance to compression than the remaining spring or springs.

7. In a 'bolt machine, a die having a die opening therein, a frame supporting said die and having an elongated bore therein in axial alignment with said opening, and a knock-out assembly arranged in said bore, said assembly comprising a plunger, a pin at the forward end of said plunger and adapted to be moved into said die opening by said plunger, a sleeve bushing fitted into said bore and having a plurality of tapered seats formed therein, reinforcing bushings mounted to have a sliding movement on said pin and arranged to abut said seats, and springs of unequal tension arranged between said bushings for maintaining the latter at the most effective reinforcing position.

8. In a bolt machine, a die having a die opening therein, a frame supporting said die and provided with an elongated bore in axial alignment with said die opening, a knock-out pin arranged in said bore in axial alignment with the die opening, and means for reinforcing said pin against bending stresses comprising a spring tted over said pin and having coils of a suflcient diameter and thickness to reinforce the latter against bending stresses.

9. In a bolt machine, a die having a die opening therein, a frame supporting said die and having an elongated bore in axial alignment with the die opening, a knock-out pin disposed in said bore in axial alignment with the die opening, a plunger backing up said pin, and a spring arranged around the pin and having coils 'of a diameter sufficient to occupy the space between the pin and the adjacent wall of the bore for reinforcing the pin. against bending stresses.

10. In a bolt machine, a frame, a die having an axial bore mounted therein, said frame being formed with an opening in alignment with, and of greater diameter than, the bore of said die, an ejector pin slidable in the bore of said die and in retracted position extending into said bore, a plunger for actuating said ejector pin, means slidably bearing on the walls of said opening and on said ejector pin for laterally supporting said pin, said means being resiliently positioned intermediate the ends of the portion of said pin extending into said opening in the retracted position of 'said pin, and being co1- lapsible between said plunger and said die when the plunger advances the pin into the die.

11. In a bolt machine, a frame, a die having an axial bore mounted therein, said frame being formed with an opening in alignment with, and of greater diameter than, the bore of said die, an ejector pin slidable in the bore of said die andv in its retracted position extending into said bore, a. plunger for actuating said ejector pin, shiftable means slidably bearing on the walls of said opening and on said ejector pin for laterally supporting said pin, said means including spring means for maintaining a lateral bearing for said pin positioned intermediate the ends of the portion thereof extending into said opening when said pin is retracted, and said opening, a knock-out pin axially aligned with said die opening and supported therein in its retracted position, means to support said knock' out pin at the end thereof remote from the die and means to Usupport said knock-out pin intermediate its ends, said last named means movable with respect to the pin and with respect to the die.

WILLIAM L. CLOUSE.

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