US2586943A - Machine for sizing bushings - Google Patents

Description

Feb. 26, 1952 J. HALLAl-:R MACHINE FOR sIziNG BUsHINGs 2 SHEETS-SHEET Al Filed April 25. 1947 MQ mm. mm. NQ

Feb. 26, 1952 J ':||A| LER MACHINE FOR SIZING BUSHINGS 2 SHEETS-Smm 2 Filed April 25. 194'?V n wa N ww W A z ff/ZI,

fw -I Patented Feb. 26, 1952 UNITED STATES PATENT OFFICE MACHINE FOR SIZIN G BUSHINGS John Haller, Northville, Mich.

Application April 25, 1947, Serial No. 743,875

s claims..

This invention relates to fluid-operated presses,

and in particular to presses for shaping articles to their proper sizes.

One objectof this invention is to provide a sizing press to overcome dimensional variations arising in the manufacture of bushings prepared by powder metallurgy so as to bring the bushings to their intended dimensions after they have been subjected' to the sintering operation.

Another object is to provide a sizing press for bushings prepared by powder metallurg-y, as set forth in the preceding object, wherein the various elements of the press `operate automatically in timed relationship to carry out the various steps in the bushing sizing cycle of operations.

Another object is to provide a sizing press for bushings prepared by powder metallurgy, as set forth in the preceding objects, wherein the motions of the various elements of the press are started and stopped according to a predetermined sequence of operations by means of limit switches and a pressure-operated switch, so that the machine is substantially automatic in its operation after it has once been started.

Another object is to provide a sizing press for bushings prepared by powder metallurgy, as set forth in the preceding objects, wherein the bushings are fed automatically to the press, forced automatically into a sizing die, sized for ther internal and external dimensions, and automatically ejected from the die, after which the various elements of the press are then returned automatically to their start positions preparatory to.

carrying out a new sizing operation upon the next bushing.

In the drawings:

Figure 1 is a central vertical section, partly in side elevation, through a fluid pressure press for sizing bushings, together with the electric and hydraulic circuits therefor according to a preferred form of the invention;

Figure 2 is a central longitudinal section through one of the four-way valves used in the hydraulic circuit shown in Figure l;

Figure 3 is a vertical cross-section taken along the line 3 3 in Figure 1, showing the bushingfeeding chute and sizing die;

Figure 4 is a diagrammatic longitudinal section through the principal Working elements of the press of Figure 1 in their startingI position;

Figure 5 is a longitudinal section similar to Figure 4, but showing the positions of the parts after the abutment plunger has moved into engagement with the sizing die;

Figure 8 is a longitudinal section, similar to Figures 4 and 5, but showing the positions of theY parts after the bushing has been forced into theA sizing die to properly size the outer dimensionA thereof;

Figure 7 is a view similar to Figures 4, 5 and 6, but showing the positions of the parts after the internal sizing plunger has been moved through the bushing to properly size the internal bore thereof;

Figure 8 is a View similar to Figures 4 to 7 inelusive, but showing the positions of the parts after the abutment plunger has been retracted c and the bushing pushed out of the sizing die; and

Figure 9 is a View similar to Figures 4 to 8 inclusive, but showing the positions of the parts after the internal sizing plunger has been retracted and the nished .bushing is being ejected.

Hitherto, the making of .bushings by powder metallurgy has been subject to considerable difculty because of the great deviationsfrom their intended dimensions during manufacture. Even though the formation -of the bushings is verycarefully controlled, after the sintering operation has been carried out, such bushings are frequently found to deviate very Widely from their desired dimensions. In order to use such bushings properly for bearing purposes, it is, of course, necessarythat they should very accurately t the shafts which they are used to support and at the same time provide very accurate clearances. rlhe purpose of the present machine is to restore such bushings to their proper dimensions, since these bushings by reason of their material and pecularities of construction are capable of deformation into their proper dimensions.

Mechanical construction of press Referring to the drawings in detail, Figure l'l shows diagrammatically a bushing sizing press, generally designated Il), in longitudinal vertical section, together with the hydraulic circuit for and i6 therein for receiving a tubular die IT.'

The die Il has an internal bore I8 which is of precisely the desired outside diameter for thel iinished bushings. The die I'I is held in position within the bore I5 by a retainingring I 9= secured thereto as at 20, and fitting into anI annular external recess 2 I vin the die I8.

The bushings 22 to be sized by the press of the4 present invention are, 'as previously stated, made by powder metallurgy and, after sintering, are

placed in an inclined feed chute 23 (Figure 3) mounted on a bracket 24 secured as at 25 to the die holder I2. The chute 23 is provided with a oor 26 which is extended downward below the lower end 21 of the chute and terminates in a curved rest 28 which has a flared forward edge 29.

Likewise mounted on the base or bed and bolted thereto as at 3| is an abutment cylinder 32 having a bore 33 in which is reciprocably mounted a plunger 34 having a head 35 (Figure l) The plunger 34 passes through a bore 36 in the end wall of the cylinder 32 and carries on its outer end an enlargement 31 with a socket 38 therein.

Mounted in the socket 38 and secured to the enlargement 31 by the bolt 39 is an annular abutment 40 having a tubular recess 4| therein and an annular abutment portion 42 thereon.

The cylinder 32 in its side wall is provided with spaced fluid ports 43 and 44 which are hydraulically connected, as set forth below. A cylinder head 45 is bolted as at 46 to the abutment cylinder 32.

Mounted on the base or bed |I on the opposite side of the die holder I2 from the abutment cylinder 32 and bolted thereto as at 41, is a sizing cylinder 48. The sizing cylinder 43 is provided with a bore 49 within which a hollow outer plunger 50 reciprocates, access to the cylinder bore 49 being provided by ports 5| and 52 (Figure 1) connected to the hydraulic system as described below. The outer cylinder 48 is closed at its outer end by a cylinder head 53 bolted thereto as at 54 and containing the central axial bore 55. Similarly, the opposite end wall of the cylinder 48 is provided with an axial bore 55.

The plunger 5|) is provided with a hollow head 51 having an annular recess 58 in one end wall thereof into which the enlarged end of the hollow plunger rod 59 snugly ts and is held in position by a retaining ring 60 bolted as at 6I to the head 51. The hollow rod 50 in turn is provided with an annular recess 62 in which is secured the enlarged end of an outer sizing plunger 63 of tubular form, and held in position by a retaining ring 64 bolted thereto as at 65. The outer sizing plunger 63 is provided with an annular abutment face or end 56 of approximately the same size as the ends of the bushings 22 to be sized. The

provision of the recess 62 and retaining ring 64 enables the outer sizing plunger 63 to be removed and other plungers of dii-ferent sizes inserted, according to the diferent sizes of bushings 22 to be sized.

The outer sizing plunger 63 is provided with a longitudinal bore 61 (Figure l) of substantially the same size as the inner bore of the bushing 22 to be sized and containing an inner sizing plunger 68 of the same outer diameter as the inner diameter intended for the bushings 22. The plunger 68 passes through a bore 69 in the end of the hollow plunger rod 59 and is seated in a recess 10 in the end of a screw plug 1|, to which it is secured by a fastener 12 threaded into the end thereof. The screw plug 1| in turn is threaded into a recess 13 in the end of an inner plunger 14 which is reciprocably mounted in the bore 15 within the hollow plunger rod 59 and which is provided with a head 16 which is in turn reciprocable in the enlarged bore 11 within the hollow head 51. Y

The head 16 and plunger 14 are provided with an axial bore 18 and a passageway 19 leading therefrom (Figure l) to the bore 11. Mounted in the bore 18 is a tubular stem 89 having a longitudinal passageway 8| leading therethrough to a port 82. The stem 89 is provided with a thread enlargement 83 which is threaded into the outer end of a hollow plunger 84. The inner end of the plunger 84 is enlarged as at 85 and is threaded into the outer end of the bore 'l1 so as to form a closure therefor. The hollow plungers 84 and 59 reciprocate to and fro within the bores 55 and 56 respectively. The annular passageway 86 within the hollow plunger 34 and outside the tubular stem 89 leads to a port 81 (Figure l).

Hydraulic system In order to reciprocate the various plungers, the cylinders containing these plungers are connected to three conventional solenoidally operated four-way valves, generally designated 83, 39 and 90V respectively. Each of these valves is of any suitable type, and may consist of the type shown for purposes of illustration in Figure 2. The valve 88, for example, may consist of a valve casing 9| (Figure 2) containing a longitudinal bore 92 with annular enlargements 93 and 94 near the opposite ends thereof and interconnected by a passageway in the wall thereof. The passageway 95 terminates in an exhaust port 91 leading to a fluid supply tank, as described below. Diametrically opposite the exhaust port 91 is a pressure fluid supply port 99. On either side of the pressure fluid supply port 96 are ports 99 and 99 which are customarily piped to the opposite ends of the cylinder containing a plunger which it is desired to reciprocate in opposite directions. These ports 98, 99 alternately serve as pressure and suction ports respectively as the plunger is reciprocated in opposite directions.

Reciprocably mounted in the bore 92 is a valve spool lili] having three spaced heads 59|, |92 and |93 separated by neck portions |94 and |05. The valve spool |99 is also provided with a longitudinal passageway |06 having transverse central and end passageways |01. The valve spool |98 is connected at its opposite ends to operating rods |98 and |09 around which are cciled compression springs ||0 adapted to urge the valve spool |99 into its neutral position (Figure 2) when neither of the rods |98 or |99 is pushed or pulled.

The operation of the conventional four-way valve shown in Figure 2 depends on the setting of the valve spool |09 as determined by the operating rods |98 or |09. These are sometimes operated manually, but in the present circuit are preferably operated by solenoids, as described in connection with the electrical circuit. When the valve spool is shifted to the left, pressure iiuid passes from the port 96 into the port 98 and thence to the cylinder to be operated. Meanwhile, the fluid discharged from the opposite end of that cylinder passes through the port 99 and passageways |01, |86 and 95 out through the discharge port 91 to the tank.

When the spool |83 is shifted toward the righthand end of the bore 92 (Figure 2) the reverse distribution of uid occurs. Under these circumstances, pressure fiuid is supplied from the port 96 through the neck portion |95 into the port 99 and thence to the cylinder being operated. The fluid displaced by the plunger thereof returns through the port 98 the passageways |91, |96 and 95 and the port 91 and returns to the fluid supply tank.

The ports 43 and 44 of the abutment cylinder 32 are connected by conduits ||8 and to the four-way valve 88, whereas the ports 5| and 52 of the outer bore 49 of the sizing cylinder 48 are connected by conduits ||2 and ||3 to the four-1v way valve 89 (Figure 1). The ports 82 and 81 connected to the hollow plungers or stem passageways 8| and 88 respectively are connected by conduits ||4 and I I5 to the four-way valve l9|). The conduits just described are connected to ports in the four- way valves 88, 89 and 90 corresponding to the ports 99 and 98 in Figure 2. The pressure uid for actuating the machine is sup` plied by a hydraulic pump IIB. the pressure side or outlet of which is connected by the conduit I I 1 to the ports in the four- way valves 88, 89 and 98 corresponding to the ports 96 in Figure 2. The suction port of the pump ||6 is connected. by a conduit I I8 to the fluid tank I I9 upon which the pump I I6 is conveniently mounted. An electric motor coupled to the drive shaft |2| of the pump I I6 operates the latter. ports of the four- way valves 88, 89 and 99 corresponding to the port 91 of Figure 2 are connected to the conduit |22 leading back to the luidvtank II9. The latter is lled with a suitable operating fluid, such as oil or water. The conduit I I5 is connected by a branch conduit |23 to a pres-l sure-responsive switch, generally designated |24 the discharge of which is connected by the conduit |25 tothe conduit |22.

Electrical control system In order to actuate the four- way valves 88, 89 and 90, each of these is provided with solenoid windings. The four-way valve v88 has solenoid: windings |26 and |21 (Figure l) adapted to shift solenoid armatures |28 and |29 on the endsV oi the control rods |08 and |99 respectively (Figure 2). Similarly, the four-way valve 89 is provided with solenoid windings I 3|) and |3| adapted to actuate the control rod armatures |32 and` |33 and the four-way valve 90 has solenoid windings |34 and |35 operating the control rod armatures I 36 and |31. trolled by a manual switch |48, limit switches |4I, |42, |43 and |44, and by the pressure switch |24, as described hereinafter in connection with the operation of the invention. The limitY switches |4I, |42, |43 and I 44 are supported respectively on brackets |45, |46, |41 and |48 mounted respectively upon the cylinder 32, .die holder I2 and cylinder 48. The limit switch I4| is tripped by a projection 49 upon an arm |59 mounted upon an upright |5| which in turn is mounted upon the enlargement 31 of the plunger 34. The arm |58 also has'an end portion |53 which actuates the limit switch |42. The limit switches |43 and |44 are actuated by a projection. |53 and an end portion |54 on an arm |55 supported by an upright |56 mounted upon the hollow plunger rod 59.

The limit switches |4| and |42 are singlethrow normally open switches whereas the limit switches |43 and |44 are double-throw switches. All of the switches |4| and |44 are inter-connected by wiring which is energized from asuitable source of electric current. In order to simplify the wiring diagram, the points indicated by the black dots I 51 to |66 inclusive are assumed to be interconnected and in turn to be connected to a source of electric current.

Operation In the operation of the invention, let it be assumed that the various parts of the machine are in the position shown in Figures l and 4. Let it also be assumed that a supply of bushings 22 The discharge The solenoid windings are con# to be sized has been placed in the chute 23, as shown in Figures 1 and 3, with the lower-most bushing 22 supported upon the rest 28. The manual switch |48 is now closed by the operator, energizing-the forward solenoid coil |21 of the four-way valve 88 by way of the left-hand contacts of the limit switch |44, which at this time are -bridged by the switch bar. This action shifts the four-way valve 88 to its forward stroke po sition, so as to admit pressure fluid from the line ||1 to the line III and port 44 at the left-hand end of the cylinder bore 33. This pressure uid pushes the plunger head 35, rod 34 and annular abutment 48 to the right until the annular abutment surface 42 engages the left-hand end oi the die I1. The iiuid escaping from the righthand end of the cylinder 32 escapes through the port 43, conduit ||0, valve 88 and conduit |22 back to the tank H9. The parts have now reached the positions shown in Figure 5. Mean# while, the switch bar of the limit switch |4| has.

rolled ofi the projection |49 as the arm |50 has moved to the right, opening its contacts and deenergizing the switch |4I.

When the annular abutment 4|J has reachedA the end of its travel, the end |52 of the arm |50 trips the limit switch |42, closing its contacts and thereby energizing the solenoid I3I of the four-way Valve 89. This causes pressure uid to flow from the conduit |I1 into the conduit ||2 and port 5| into the space immediately adjacent the cylinder head 53 of the cylinder 48. This pressure -forces the outer plunger 58 to the left, causing the outer sizing plunger 63 to engage the lowermost bushing 22 and lpush it into'the bore I8 of the sizing die I1. Meanwhile, the uid escaping from the forward end of the cylinder bore 49 returns to the tank I I9 by way of the port 52, conduit ||3, valve 89 and conduitV II2.

The parts have now reached the positions shown' switch |44 as the end |54 of the arin |55 travels leftward.

The bridging of the right-hand contacts of the limit switch |43 energizes the solenoid winding |35 of the four-way valve 99, shifting it to forward stroke. Pressure fluid is then delivered through the conduit II5 to the right hand end of the cylinder bore 11, shifting the plunger head 16 and inner sizing plunger 68 to the left, causing the latter to enter the bore of the bushing 22. Meanwhile, the fluid displaced from the left-hand side of the head 16 escapes back to the tank ||9 f by way of the stem 86, conduit II4, valve 90 and.

conduit |22. The parts have now reached the positions shown in Figure '1.

With the various plungers halted in engage-l ment with the bushing 22, the pump |15 conltinues to deliver pressure fluid thereto and the pressure rises in the hydraulic circuitl until it closesl the normally open pressure switch |24. This energizes the return solenoid winding I 26 of the four-way valve 88, shifting it upon return stroke and causing the flow-of pressureluid to accesar the cylinder bore 33 to be reversed, thereby retracting the abutment plunger 34. At. the same time the closing. of the pressure switch. |24 also bridges. its left-hand pair of contacts so as to re-energize the forward solenoid winding I3I. of the four-way switch 39, shifting this to forward stroke. This delivers pressure fluid through. the conduit H2 to cause the plunger head 85 and plunger rods 59 and 53 to move to the left, expelling the bushing 22 from the sizing die as the abutment plunger 34 is retracted. The parts'- have now reached the positions shown in Figure 8.

As the abutment plunger 34 is retracted to the position shown in Figure l, the-,projection |49 on the arm, I5i| closes thenormally-open limit switch MI, thereby energizing the return solenoid windings |3ll and |34 ofthe four-way valves 89 and 90., shifting these valves to return stroke positions. This causes pressure fluid to be delivered through the conduits 3 and i4, retracting the outer and inner plungers. 59 and 14 and also the sizing plungers 63 and til.v The parts have now reached the posiitons shown in Figure 9, and the bushing.. thus ejected by the retraction of the plungers 63 and 68, drops into a suitable receiver. Meanwhile,l another bushing 22 drops from the chute 23 onto the rest 28.

The retraction of the plunger 59 causes the. end |54 of the arm |55 to trip the limit switch |44 so as to unbridge its right-hand contacts and bridge itsleft-hand contacts, as shown in Figure l. This cle-energizes the. return solenoid windings. |30 and |34 of the four-Way valves 89 and. S0, shifting them to their neutral positions and halting the retraction of the plungers 58 and '14. The bridging of the left-hand, contacts ofA the. limit switch |44, however, starts the. cycle of opera-` tions anew by re-energizing the forward solenoid winding |21 of the. four-way valve 88 shifting it to forward stroke position. Assuming that the manual switch |40 is still closed, the. above described cycle of operations repeats itself indefinitely as long as bushings 22 are supplied. to thechute 23 to be sized.

What I claim is:

l. In combination in a bushing sizing: appara.- tus, an external bushing sizingY member having a sizing bore therein open at both ends withA its in-- ternal` diameter slightly smaller than the external, diameter of the, bushing to be sized fory receivingA said bushing, a movable abutment mem ber engageable with one end of said external sizing member, a bushing feeding member of smaller diameter than said bore engageable with one end of said bushing to feed said bushing into.` said sizing bore, an internal bushing. sizing member of the internal diameter desired for said bushing, engageable with the interior of saidbushing, fluid pressure motors connected to said abutmentmember and to said feeding member and to said internal sizing member, a source of pressureiuid1 connected to said motors, av duid pressure control circuitv including a conduit system. connecting said motors to said fluid pressure source and containing control valves operable in timed relation ship to move said abutment member into. engagement with one end of said sizingA member and to move said feeding member toward the. other end of said external sizing member to. feed said bushing into said bore, and tozmove saidY internal sizing member into said bushing and a. pressure-responsive. device operableto retract' said abutment member and. to further advance said feeding member through said bore to eject 8,-. said bushing from said bore in response to the attainment. of a predetermined pressure in said circuit.

2. In combination in a. bushing sizing apparatus, an external bushing sizing member having a sizing bore therein open at both ends with its internal` diameter slightly smaller than the external diameter of the bushing to be sized` for receiving said bushing, a movable abutment member engageable with one end of said external sizing member, a bushing feeding member of smaller diameter than said bore engageable with one end of said bushing to feed said bushing into said sizing bore, an internal bushing sizing member of the internal diameter desired for said bushing engageable with the interior ofl said bushing, fluid pressure motors connected to said abutment member and to said feeding member and to said internal sizing member, a source of pressure fluid connected to said motors, a uid pressure control circuit including a conduit system connecting said motors to said fluid pressure source and containing control valves operable in timed relationship to move said abutment member into engagement with one end of said sizing member and to move said feeding member toward the other end of said external sizing member to.` feeding said bushing into said bore, and to move said internal sizing member into said bushing and a pressure-responsive device operable to retract said abutment member and to further advance said feeding member through said bore to eject,

said bushing from said bore and withdraw said internal sizing member from said bushing in response to the attainment of a predetermined pressure in said circuit.

3. 1n combination in a bushing sizing apparatus, an external bushing sizing member having a sizing bore therein open at both ends with its. internal diameter slightly smaller than they external diameter of the bushing tol be sized for receiving said bushings a movable abutment member engageable with one end of said external sizing member, a, bushing feeding member of smaller diameter than said bore engageable with one. end of said bushing to feed said bushing; into. said sizing bore, an internal bushing sizing member of the internal diameter desired for said bushing engageable with the interior of said bushing, fluid, pressure motors connected to. said abutment member and to said feeding member and to said internal sizing member. a source. of pressure. fluid connected to said motors, and aV fluid pressure control circuit including a conduit system connecting said motors to said fluid pressure source and 'containingcontrol valves operable. in timed relationship to move said abutment member into engagement with one end of said sizing member and to move said feeding member toward the other end of said external sizing member to feed said bushing into saidbore, and to move said internal sizing member into said bushing and thereafter to retract said abutment member and to further advance said feeding member through said bore to eject saidbushing from said bore.

4. In combination in a bushing sizingapparatus, a sizing die having a sizing bore therein open at both ends with its internal diameter slightly smaller than the external diameter of the bushing to be sized forA receiving said bushing, a. iiuid-pressure-operated abutment plunger movable into engagement with one end ofA said die, a uid-pressure-operated feeding plunger of: smaller diameter than saidbore engageable with one end of said bushing to feed said bushing into said bore, a huid-pressure-operated internal sizing plunger of the internal diameter desired for said bushing movable into the interior of said bushing, a source of pressure iiuid, a fluid pressure circuit connecting said source of pressure fluid to said plungers, a fluid pressure control circuit including a conduit system connecting said motors to said fluid pressure source and containcontrol valves operable in timed relationship to move said abutment plunger into engagement with one end of said die and also to move said feeding plunger toward said die to feed said bushing into said bore and iinally to move said internal sizing plunger into said bushing vand a pressure responsive device operable in response to the attainment of a predetermined pressure in said iiuid pressure circuit to retract said abutment plunger and to further advance said feeding plunger through said bore to eject said bushing from said bore.

5. In combination in a bushing sizing apparatus, a sizing die having a sizing bore therein open at both ends with its internal diameter slightly smaller than the external diameter of the bushing to be sized for receiving said bushing, a -luid-pressure-operated abutment plunger movable into engagement with one end of said die, a fiuid-pressure-operated feeding plunger of smaller diameter than said bore engageable with one end of said bushing to feed said bushing into said bore, a uid-pressure-operated internal sizing plunger of the internal diameter desired for said bushing movable into the interior of said bushing, a source of pressure iiuid, a uid pressure circuit including a conduit system connecting said source of pressure iiuid to said plungers, a pressure fluid control valve in said conduit system connected between said source and 'each of said plungers, an electrical valve operator connected to each valve, and an electrical control circuit interconnecting said operators, said electrical control circuit including a pressure responsive switch operable in response to the attainment of a predetermined pressure in said fluid pressure circuit to energize certain of said operators to retract said abutment plunger and to further advance said feeding plunger through said bore to eject said bushing from said die.

6. A bushing sizing press comprising a supporting structure, a die holder mounted on said structure, an external bushing sizing die mounted on said die holder and having a bore therethrough open at both ends with its internal diameter slightly smaller than the external diameter o1' the bushing to be sized and adapted to receive said bushing, a plurality of iiuid pressure motors mounted on said structure on opposite sides of said die holder, an annular abutment member mounted on one motor and having a bushing feeding member receiving socket, said abutment 1' member being disposed in alignment with said die and movable into and out of closing engagement with one end of said bore, a bushing feeding member of smaller diameter than said bore mounted on one-motor and movable through said bore from the opposite end thereof and an internal bushing sizing member of the internal diameter desired for said bushing mounted upon one motor and movableinto and out of said bushing.

7. A bushing sizing press comprising a supporting structure, a die holder mounted on said structure, an external bushing sizing die mounted on said die holder and having a bore therethrough open at both ends with its internal diameter slightly smaller than the external diameter of the bushing to be sized and adapted to receive said bushing, a plurality of iluid pressure motors mounted on said structure on opposite sides of said die holder, an annular abutment member mounted on one Imotor and having a bushing feeding member receiving socket, said abutment member being disposed in alignment with said die and movable into and out of closing engagement with one end oi said bore, a bushing feeding member of smaller diameter than said bore mounted on one motor and 'movable through said bore from the opposite end thereof, an internal bushing sizing member of the internal diameter desired for said bushing mounted upon one motor and movable into and out of said bushing and a. bushing holder adapted to contain a multiplicity of bushings and having a bushing rest at its outlet mounted adjacent said die and positioned to hold a bushing in alignment with said bore and said feeding member.

8, A bushing sizing press comprising a supporting structure, a die holder lmounted on said structure, an external bushing sizing die mounted on said die holder and having a sizing bore therethrough open at both ends with its internal diameter slightly smaller than the external diameter of the bushing to be sized and adapted to receive said bushing, a fluid-pressure-operated annular abutment plunger having a sizing plunger receiving socket therein, said abutment plunger being movable into and out of engagement with one end of said die, and telescoping feeding and internal sizing plungers movable toward and away from said die and into engagement with said bushing to push said bushing into said die and insert said sizing plunger in said bushing, said feeding plunger having an external diameter smaller than the minimum internal diameter oi' said sizing bore.

JOHN HALLER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STA-TES PATENTS

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