US2210107A - Method of making lubricant receiving fittings - Google Patents

Description

Aug. 6, 1940. G. F. THOMAS Er AL 210,107

METHOD 0F MAKING LUBRICANT RECEIVING FITTINGS Filed April 16, 1937 3 ShBevtS-Sheet l www Aug 5 1940- G. F. 'rHoMAs Er m. 2,210,107

METHOD OF MAKING LUBRICANT RECEIVING FITTINGS Filed April` 16, 1937 3 Sheets-Sheet 2 g'. 7 7047102 9J Jaa 22a jj /22Jy/1.////

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METHOD 0F MAKING LUBRICANT- RECEIVING FITTINGS Filed April 16,' 1957 3 Sheets-Sheet 3 lli fil-i PafenieaAug. e, i940 UNITED STATES] PATENT oFFicE METHOD or MAKING lL'UlsRroiiN'r 1"* RECEIVING FITTINGS n George F. Thomas, Riverside, Frank'A. Ross, Lake f i Bluff, v'and Joseph Bystricky, Chicago, Ill.; assignors to Stewart-Warner Corporation, Chicagc,vIll., a corporation of Virginia Application AprilklG, 1937, Serial No. 137,220"

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relatively expensive with respect to the tool maintenance cost'and the labor cost of the automatic screw machine operators, and fittings of the drive type made in this manner have not beenv as satisfactory asy fittings made by the method of the present invention.

According to our present invention, the fitting blanks are formed vby a cold-heading machine. The Y`rincipal advantages of this method of making the fitting blanks are the greater speed with which the blanks may be produced, thev decreased van'iount of scrap metal, the decreased labor cost, and the great superiority of the finished product.

In manufacturing fittings of the drive type, that is', fittings which may be driven into the uritapped 'oil hole of a bearing and are capable of forming a rthread in the bearing, it is desirable that the threads on the shank of the fitting beI of the maximum feasible hardness and toughness, and these properties of the metal `in the threads are enhanced by the improvement in the grain structure as a result of the compacting of the metal in the cold-heading machine. l

it is thus an object of our inventionto provide an improved lubricant receiving` fitting in which the grain structure of the metal is improved during the operation of manufacturing the fitting.

A further object is to provide an improved m'ethed of manufacturing lubricant receiving littingswfor high pressure lubricating systems by which the cost of manufacture may be reduced and the quality of the'fittings improved.

A further object isy to provide improved tools and dies usable in the manufacture of headed lubricant receiving fittings by means of a cold `heading machine. u

Other objects will appear `from the following description, reference being had 'to the accompanying drawings, in which:

Fig. l is, a vertical sectional view of the cutting die and shear blade by which the first step of the operation of making the fitting is accomplished; Fig 2 shows apiece of round bar stock illustrating the stock after the completion of the first operation; Y Y y I Fig. 3 is a vertical cross-sectional view of the punch and die utilized in the cold heading. machine for performing the second step in the operation ofl forming the fitting;

Fig. l shows apiece of stock after the second I Fig. 5 is a vertical sectional view ofthe die and plunger of the cold-heading machine utilized in performing theth'ird step of forming the tting; Fig. 6 is a view partlyin section illustrating the stock after the third 4stepuof the cold heading operation has been performed upon it;

Fig. `'Z is a vertical sectionalview of the plunger step in the operation has beenperformed upon and die of thecold-hea'ding machine utilized in` performing the fourth step of the operation of forming the iitting blank;

Fig. 8 is an elevational view of the blank after the fourth operation has been performed upon it;

Fig. 9 is a central vertical sectional view of the die and plunger used inthe `cold heading machine for performing the fifth step of the operation'of forming the fitting blank; y l

Fig. l0 is a View similar to Fig. 9 showing the position of the parts of the die and plunger during the return stroke of the latter;

Fig. ill is la transverse sectonal'view of 'the y,

die shownf in Fig. 9 taken on the line II-IVI' thereof; 1 Fig. 12 is Va sectional view, and Fig. 13 is an elevational view v.of the fitting blank after the fifthV step of the operation of forming the blank hasr been performed upon the stock;

Fig. 14 is a perspective view diagrammatically illustrating a machine for rolling threads upon the operation of forming the fitting;

.Figl 15'is an elevational view of the fitting blank after the-sixth operation. has been performed upon it; -1 y Y y Fig'. 16 illustratesy the succession of drilling operations by which the bores and counterbores are y formedin the fitting;

Fig. l'l is a central' longitudinal `.sectional View n of the fitting after the drilling operations have Fig. 20 is a central longitudinal sectional View4 `the fitting blank constituting the sixth step in f of the completed fitting showing the check valve and spring assembly therein; and

Figs. 21 and 22 are views illustrating the manner of securing the fitting to a bearing.

Generally speaking, the method of our invention comprisesy twelve steps;

1. Cutting olf a suitable length of steel rod stock;

2. Extruding one end of the stock to reduce the diameter thereof;

3. Further reducing the diameter of the previously reduced end of the stock and upsetting the central portion to Aincrease its diameter;

4. Further extruding the reduced end portion of the stock and further upsetting the central portion to form the hexagon-shaped wrench-engaging part of the fitting;

5. Upsetting the reduced diameter end.' portion of the tting to form the head of the nished fitting;

6. Tumbling the tting to polish and remove slight burrs;

7.Rolling a thread upon the shank of the fitting;` f

8. Drilling the bore through the fitting-usually in several steps;

9. Crimping the spring supporting ange;

10. Heat treating the fitting;

1l. Plating the fitting; and

12. Assembling the ball check valve and sprlng in the fitting.

The above enumerated operations are preferably performed in the order named, but some variation in the order may be made without departingfrom the general method of our invention.

`The iirst operation performed upon the stock is illustrated in Fig. 1 wherein the steel rod stock 20 (which is preferably supplied in large coils) is advanced through a die 22 until itabuts against a xed stop 24. Thereafter, a shear blade 26 is moved inthe direction indicated by the arrow in Fig. 1 to shear the required length of stock to form the blank 28 shown to a slightly enlarged scale in Fig. 2. The die 22 is preferably mounted in the cold-heading machine and the shear blade 26 is reciprocated by means of a suitable cam as the reciprocating head of the machine approaches the bed which carries the die 22.

The blank 28 shown in Fig. 2 is next transferred to a die 30 which is mounted in a suitable holder 32 mounted upon the cold-heading machine. Thedie 30 has a tapering neck portion 34 into which the end portion of the blank 28 is pressed by means of a plunger 36 secured in a plunger carrier 38 mounted on the reciprocating head of the machine. A knock-out pin 48 is suitably secured in a holder 42 by means of a stud 44, the holder 42 Ahaving a head 46 secured thereto by a force t. A compression coil spring 48 surrounds the holder 42 serving as a cushion for the head 46. The piece of stock is thus formed by means of the extruding die 30 into the blank 50 shown to slightly enlarged scale in Fig. 4.

The blank 50 is then automatically transferred from the extruding die 30 to a die 52 molihted in a suitable holder 54. The neck 56 formed in the die 52 is of slightly lesser diameter than the neck 34on the die 30 so that the reduced diameter end portion 58 of the blank 50 is further reduced in diameter and lengthened by being forced past the throat 56 of the die 52. The die 52 has a liar-ing mouth 60 leading to the throat 56, and a substantially cylindrical recess 62 is provided to 'permit upsetting the central portion of the blank. The punch 64 has a frusto-conical recess 66 formed therein which is effective to form the shank of the tting.

A knock-out pin 68 is mounted for sliding movement in a bore 'l0 formed in the punch and is further guided by a head I2 secured to the knock-out pin 68, the head being reciprocable in a cylindrical bore 14 formed in the punch 64. The knock-out pin 68 is retractable against the compression of a coil spring 16 which engages the rear face of the head 'I2 and serves to move the knock-out pin outwardly upon completion of this step in the operation. The die 54 is likewise provided with a knock-out pin 18 which is carried by a holder 80 into which a holding stud 32 is threaded, and over which a head 8l! is secured. A compression spring 86 acts as a cushion for the leftward (Fig. 5) movement of the knock-out pin 18. In addition to extruding the end portion 88 of the fitting blank and upsetting the central portion 90 thereof by means of the die 52, during this operation, the knock-out pin 68 which has a central conical tip- 92 for this purpose, makes a central conical indentation 94 in the base of the shank portion 96 of the fitting blank.

Fig. 6 shows the fitting blank to a slightly enlarged scale, showing its form after completion of the operation upon it of the punch and die shown in Fig. 5.

The blank of Fig. 6 is then automatically transferred to a die 98 (Fig. 7) secured in a die holder |00. This die has a smoothly aring throat |02 into which the fitting blank is pressed further to extrude and extend the reduced diameter portion of the blank and has a hexagonal shaped recess |04 and a very narrow cylindrical recess |06 which form the hexagonal wrench engaging portion |08 and the slight rib ||0 respectively on the blank as shown in Fig. 8. The punch ill has a stepped recess ||2 which further upsets the shank portion 96 of the blank of Fig. 6 to form a tapered shank portion H4, a pilot portion H6, and a lip portion ||8 on the blank as shown in Fig. 8. The die is provided with a suitable knock-out pin |20 and the punch with a knockout pin |22 which are mounted in the die and punch respectively in a manner similar to that shown in Fig. 5 and previously described.

The blank shown in Fig. 8 is then automatically transferred to the heading die and punch shown in Figs. 9 and 10. Thisdie comprises a sleeve |24 having a bore |26 within which a die holder |28 is reciprocable. A plurality (here illustrated as four) of collapsible die elements |30 are mounted for sliding movement within the tapering bore |32 formed within the diey holder |28. Set screws |34 threaded in the die holder |28 have their ends |36 projecting into suitable grooves |38 formed in the external tapered edges of the die elements |30. It will be noted that the grooves |38 are formed one half in each of two adjacent die elements |30. The ends |38 of the set screws |34 thus prevent the die elements |30 from being pushed out of the die holder |28 and serve to guide these elements in their reciprocatory movement. The set screws |34 are locked in place by a ring |40 which passes around thev periphery of the die holder |28.

The die holder |28 is pressed outwardly by a relatively heavy compression coil spring |42 which is' compressed between a guide |44 pressed in the sleeve |24 and a seat |46 which pushes against the die holder |28. The knock-out pin |48 for the die is secured in a plunger |50. The

plunger |50 is slidable in a bore |52 formed in 75 acidic? the knock-out pin'actuator |56, which in turn is guided foi` sliding movement in bores |58 and |60 formed in the guide |44; The plunger |50 is normally urged outwardly by a compression coil spring |62 which is seated in a cup' |64 which may be adjusted by means of a set screw |66, the latter being locked in position by a socket set screw |68. The inner end of the knock-out pin actuator |56 `has a beveled cam face |'|0 which may be engaged bya suitable cooperating cam to force the knock-out pin Vactuator |56 outwardly (tof the left, Figs. 9 and 1.0).- The punch i12-Which is illustrated in Figs. 9 and 10 has a recess |14 which is similar in shape to the recess ||2 formed in the punch (Fig. 7). The punch is provided vwith a knock-out pin |16 which may be generally similar to the knock-out pin |22 used With-the punch illustrated in Fig. '7. Y

It will be noted that the punch and die of Fig. 9 will rst cause the reduced diameter end portion of the fitting to force the knock-out pin |48 rearwardly from the'position in which itis shown in Fig. 1() tothe position in which it is shown in Fig. 9. During the latter portion of this movement of the fitting to the right (Fig. 9)

the hexagonal portion |08 of the fitting blank will engage in the complemental hexagonal recess |78 formed collectively by the die elements |30, and, since the inward movement of the knock-out pin |438 is limited by the engagement of the inner end of the plunger |50 with the cup |65, further pressure exerted upon the fitting` blank by the punch will cause the die elements |30 to be forced inwardly. As a result of this inward movement,`the die elements |30`are con-v tracted about the fitting blank thereby forming the head |90 thereon, which head is formed by upsetting the reduced diameter portion of the Upon separation of the punch and die as illustrated in Fig. l0, the knock-out pin |19 in the punch will press theA shank portion `of the fitting from the recess |14 in the punch |`|2 and the spring will press the die holder |20 to the left. At the same time, spring |62 will force the knock-out pin |48 outwardly, and the latter, by exerting an outwardly directed force (to the left Fig. l0) first upon the fitting and later upon the die elements |30, will cause the latter to move outwardly both longitudinally and'radially to permit the head of the fitting to escape from the recess |82 formed by the die elements. As soon as the die elements |305 have been moved to the left (Fig. 10)-suiciently to permit escape from the head of the fitting, the knock-out pin actuated by its spring |62 will eject the fitting 'from the die elements |38, thereby completing the coldheading and extruding operations formed upon the cold-heading machine. The resultant fitting shown in Figs. 12 and 13 will thus be formed with a head |89, a hexagonal portion |08, a rib ||`0, a tapered shank portion i 4a generally cylindrical pilot portion i6, and a lip portion H8.

All of these forming operations are preferably successively'performed upon a singlecold-heading machine equipped with automatic means for transferring the blanks from one'punch and die set to the next set. Thus, one formed blank (Figs. 12and '13) will be produced for each forward and return stroke'cycle of the reciprocating head of the machine; All of these operations are performed without the application of eX- ternalfheat.y Of course some heat is developed in the metal due to the Working of it, but the metal never exceeds its critical temperature or becomes sufficiently hot to form a scale upon its surface. VIf it. were attempted to heat the blanks', the forming operations might be performed more easily, but the formation of scale upon the' surface of the fitting blank would result in irregularities After the operations performedv upon the stock of the cold-heading machine, the fitting blanks of Figs. 12 and 1E are put in a tumbling barrel to remove any slight burrs or iins which may have resultedfrom the cold-heading operations. f

After the tumbling operation, the fitting blanks are inserted in the hopper of a thread rolling machine, from which they are fed one at a time to a position between a pair of dies |90 and |92. In Fig. 14, the die |92 is represented as fixed and the die |90-as movable relative thereto. As the die |99 movesv to the end of the die |92, the fitting is rotated and Suiiicient pressure brought to vbear upon itby the dies |90 and |92 to roll a thread |94 (Fig. 15) upon the shank of the fitthe fitting will drop from between the two dies and the die |90 will return to receive another fitting. The threading surfaces of the dies |90 and |92 are provided with a plurality of serrations |95, |96 respectively. These serrations are of particular forni to produce a certain desired thread form, as is more particularly disclosed in the copending application of George F. Thomas and Joseph Bystricky, Serial No. 42,746, 1iled September 30, 1935.

After the thread |94 has been rolled upon the fitting blank, the fitting is subjected tol successive drilling operations as shown in Fig. 1.6, wherein the drill |98 drills a counterbore 200 oflargest diameter in the shank portion of the' fitting, -drill'202 drills an intermediate bore 204, drill 266 drills a second intermediate bore 208 in the fitting blank, vdrill 2|0 drills a third intermediate bore 2|2, and drill 2|@ forms the inlet hole 2|6 in the head of the tting. The fitting, after the completion of the drilling operations, is illustrated in Fig. 17. n

After thev drilling operations, the lip 2|8 is crimped over to form the spring seat as indicated inl Figs. 18' and 19, wherein a die 220 is suitably conformed to receive the fitting, head end first,

and a punch 222, having a recess 226` formed therein, will bend the lip 2|8 inwardly to form a flange. Thereafter, a punch 226y having a point 228 and an annular recess 230 surrounding in the surface of the fitting and interfere with the operation of the dies.

ting. As the die |99 completes its forward' stroke, v

the point 228 is brought down upon the flanged brittle, and especially the thread will retain'the .w

strength acquired during the coldworking operations.

After the heat-treating operation, the fitting blanks are suitably plated with cadmium or other suitable plating metal and then the manufacture of the fitting is completed by assembling a ball check valve 236 and the spring 232 in the fitting. Due to the fact that the lip 234 is curled inwardly, it is possible to insert the conical compression coil spring 232 by pressing it into the opening in the lip 234, preferably turning it slightly so as to aid the spring in passing the reduced diameter opening in the lip. After the spring has passed the lip, its outermost turns will eX- pand and snap into the annular groove 23|, generally V-shaped in cross-section, which is formed by the lip 232 as best shown in Fig. 20.

The fitting thus produced is adapted to be driven into an untapped oil hole of a bearing in the manner indicated in Figs. 21 and 22, wherein the bearing 24E! for shaft 2132 is provided with a drilled oil hole 2M. The lowermost turn of the thread ml on the fitting forms a pilot to aid in guiding the fitting coaxially into the oil hole 244. A suitable drive tool 246 may be conveniently utilized in applying the fitting to the oil hole. This drive tool has a recess 248 to receive the head of the fitting, a flaring surface 252 complemental to the curved tapering surface on the body of the fitting, and a cylindrical counterbore 252 which is of slightly larger diameter than the maximum diameter of the hexagonal wrench-engaging portion m8 of the fitting. The driving tool 266 is provided with a spring 254 which acts as a resilient grip beneath the head of the fitting to hold the fitting within the drive tool. Having positioned the drive tool and fitting, as shown in Fig. 2l, the end of the drive tool is struck with a hammer 25E, whereupon the fitting will be driven into the oil hole 2M. During this driving operation, the tting will swage threads complemental to the threads |92 of the fitting upon the internal surface of the bearing oil hole 24d, as is more particularly disclosed in the aforesaid copending application,

Serial No. 42,746, filed September 30, 1935.

The fitting may, with excellent results, be driven into bearings of various metals, such as cast iron, Wrought iron, brass, cold rolled steel, cast steel, and forged steel. The threads |94 on the fitting are rendered so tough by the compacting of the metal during the operations of making the fitting that they will not be deformed or break when the fitting is driven into such hard and tough metals as steel forgings.

By theY method of manufacture herein described, the toughness of the metal is materially increased, as compared with a fitting made from the same stock which is formed by screw machine operations.

The thread Hifi of the fitting is preferably of standard pipe thread pitch so that a drive type fitting as herein disclosed may be unscrewed from a bearing into which it has been driven and replaced by a fitting having a standard pipe thread.

The small recess formed in the die 98 (Fig. '7) by which the rib l l0 (Fig. 8) is formed, serves as relief means for receiving excess metal. Without providing this space into which excess metal may flow, the dies might frequently be broken because the weight of metal in the blank 28 (Fig. 2) may vary slightly due to slight variations in the diameter of the stock and possibly also to very minor variations in the length of the blank 28. The ribs IID thus formed adja cent the flat surfaces of the hexagonal portions |08 of the fitting serve several useful purposes. These `ribs make it easy to distinguish a drive type fitting from the usual fittings which are otherwise generally similar in appearance. They also serve as a means to prevent a socket or other wrench from sliding down and away from the hexagonal portion of the fitting.

As previously stated, We have found that lubri cant receiving fittings produced by the above described method are far superior to similar fittings produced by machining operations. parently, the cold-Working of the metal increases its density by compacting the metal. Furthermore, it appears that the grain structure is altered and the fibers or fiow lines are made to conform to the shape of the fitting. 'Ihis effect is particularly advantageous in the threaded shank of the fitting where the great increase in tensile strength of the metal, due to the coldworking operations, makes it possible for the thread to maintain its shape even when driven into the oil hole of a bearing made of a very had and tough metal.

The heat treatment of thel tting is such that the so-called fibrous grain structure of the metal is not greatly altered except at the surface where it is case-hardened. The fitting may be considered as comprising a shell or skin which is extremely hard, `but in which any tendency to brittleness is overcome because this hard shell is backed by compacted metal of high density in which the flow lines or bers extend generally parallel to the surface.

The method of the present invention results in a fitting which is superior to one which might be made out of much more expensive high-grade steel. While such high-grade steel, by heattreating, might be given the desirable hardness, such hardness would o-rdinarily be accompanied by undesirable brittleness. By cold-Working a relatively inexpensive low-grade steel in the manner herein set forth, a fitting having the desired surface hardness and interior strength and toughness may be uniformly and cheaply produced.

While the construction of the dies may be varied somewhat from the forms disclosed herein, these forms have been found to be highly satisfactory after extended `experimentation and use. The fiact that the fitting is relatively small, the stock which is used is very tough, and that the fitting must have two portions of increased diameter separated by a neck portion, presented diicult problems in the design of the necessary dies. For example, in the die of Figs. 9 and 10, it was found that it was very desirable to utilize four sliding elements I3@ instead of two or three, as is customarily done in die construction, in order to make it possible to Withdraw the fitting from these die elements Without requiring too great reciprocatory travel of the die elements.

While we have shown a particular product and a particular form of apparatus utilized in performing the method of our invention and have described a method as constituting operations performed in definite order, it will be understood by those skilled in the art that the method, apparatus, and the product may be varied, and the various operations modified or' performed in different order without departing from the salient features of our invention. In the accompanying claims, We therefore intend to include all such equivalent apparatus and methods and products wherein substantially the same results are obtained by substantially the same means or methods.

We claim: 1. The method. of making a headed drive type tting which comprises extruding a portion of a cylindrical bar of steel to reduce its diameter, s y

upsetting the remaining portion of the bar' to form the shank and hexagonal wrench-engaging part of the fitting, andv upsetting the extruded portion to form the headv of the fitting.

2. The method of making a headed drive type tting which comprises extruding a portion of a cylindrical bar of steel to r'educe its diameter, upsetting the remaining portion of the bar to form the shank and hexagonal Wrench-engaging part of the tting, upsetting the extruded portion to form the head of the fitting, and rolling a thread upon thevshank of the tting.

3. The method of making headed lubricant receiving fittings from steel rod of less diameter than the greatest diameter of the tting which comprises, severing a short length from a supply of rod stock, extruding a portion of said rod to form an extension thereon of less diameter than the rod, increasing the diameter of the remain-- ing part of the short length of rod by longitudinal compression, forming said increased diam-eter part to the external shape of the shank portion of the nished fitting by cold-heading operations,

and upsetting the extension portion to form a head part while retaining a part of said extension portion as a neck joining the head with the shank portion of the tting.

4. The method of making headed lubricant receiving fittings from steel rod of less diameter than the greatest diameter` of the fitting which comprises, severing a short length from a supply of rod stock, extruding va portion of said rod to form an extension thereon of less diameter than the rod, increasing the diameter of the remaining part of the short length of rod by longitudinal compression, forming said increased diameter part to. theA external shape of the shank portion of the finished fitting by cold-heading operations, and upsetting the extension portion to form a head part while retaining a part of said extension portion as a neck joining the head with a shank portion of the fitting, all of said operations being performed without applying external heat to the rod stock.

' GEORGEI F. THOMAS.

FRANK A. RO'SS. JOSEPH BYSTRICKY.

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