US3889342A

US3889342A - Apparatus for assembling piston ring end guides

Info

Publication number: US3889342A
Application number: US396500A
Authority: US
Inventors: Jack E Mulligan
Original assignee: Ramsey Corp
Current assignee: Sealed Power Technologies LP; Kodiak Partners Corp
Priority date: 1973-09-12
Filing date: 1973-09-12
Publication date: 1975-06-17
Anticipated expiration: 1992-06-17

Abstract

Apparatus for assembling with split expansion rings, end guides which carry integral self retaining frictional elements engageable with the ring at opposite sides of the ring gap. In sequence, an end guide unit is fed into position across the ring gap and is then pushed into position within the ring across the gap, the frictional retaining elements being forced into position between the spaced wall flange segments defining the channel within the ring in which the end guide is received.

Description

United States Patent Mulligan APPARATUS FOR ASSEMBLING PISTON RING END GUIDES [75] Inventor: Jack E. Mulligan, Ferguson, Mo.

{73] Assignee: Ramsey Corporation, St. Louis, Mo.

[22] Filed: Sept. 12, 1973 [21] Appl. No.: 396,500

[52} US. Cl 29/211 D [51] Int. Cl B23q 7/10 [58] Field of Search 29/211 D, 222, 200 P, 211 R [56] References Cited UNITED STATES PATENTS 3,681,837 8/1972 Franklin 29/211 D 5,3 T 51 3.7 46 5,2 X 46 F Fl, 8/ a s; 17.,

. 79, j J9 I, i iv /90 1 1 June 17, 1975 Primary Examiner-Thomas H. Eager Attorney, Agent, or Firm-Hill, Gross, Simpson, Van Santen, Steadman, Chiara & Simpson [57] ABSTRACT Apparatus for assembling with split expansion rings, end guides which carry integral self retaining frictional elements engageable with the ring at opposite sides of the ring gap. In sequence, an end guide unit is fed into position across the ring gap and is then pushed into position within the ring across the gap, the frictional retaining elements being forced into position between the spaced wall flange segments defining the channel within the ring in which the end guide is received.

16 Claims, I4 Drawing Figures PATENTEDJUN 1 1 ms 3 8 89,342

SHEET 2 F ig. 14

1 APPARATUS FOR ASSEMBLING PISTON RING END GUIDES This invention relates to apparatus for assembling piston ring end guides or latches with the piston rings, and is more particularly concerned with apparatus which is especially efficient in assembling self-retaining end guides with the piston rings.

In a common type of split piston ring employed as an expander or spacer expander ring, normally used as part of an oil control ring assembly, two flat rail rings are maintained in axially separated position and expanded radially outwardly by the spacer-expander ring. During installation of these rings into a piston groove and insertion of the piston into the cylinder, the end portions of the split rings must be held against overlapping and in proper endwise abutment. For this purpose end guides or latches are employed to assure that the ends of the split ring will properly abut.

Inasmuch as the sole function of the end guides or latches is to maintain the end alignment of the rings, the end guides or latches must be low cost and every effort must be made to maintain the cost of assembling the end guides or latches with the rings to the barest minimum. To this end, a new and improved end guide has been devised which comprises a single piece molded plastic unit having an elongated lance portion projecting from a self-retaining head to extend across the gap in a ring within a radially outwardly opening channel of which the unit is received. In addition to a retaining head at one end, the unit also carries integrally therewith a separable retaining element spaced from the head and engageable with the ring at the opposite side of the gap therein from the head end retaining element. A further economy has been to mold a plurality of the end guides in a generally seriate ladderform arrangement for seriatim detachment from the ladder and assembly with respective piston rings.

It is to the provision of new and improved apparatus for efficient assembly of the end guide units with the piston rings that the present invention is directed.

An important object of the present invention is to provide a new and improved appartus for installing selfretaining end guides or latch units with piston rings.

Another object of the invention is to provide a new and improved apparatus which is especially suitable for feeding end guides from a supply into position for assembly with piston rings.

A further object of the invention is to provide new and improved apparatus which efficiently directs end guides from a supply into position for assembly with piston rings and sequentially assembles the end guides with the piston rings.

Still another object of the invention is to provide a new and improved apparatus for assembling end guides with piston rings and which will automatically operate in a complete sequential cycle including feeding an end guide into position for assembly with a piston ring and then effecting actual assembly of the end guides with the piston rings, rapidly and efficiently.

Other objects, features and advantages of the invention will be readily apparent from the following description of certain preferred embodiments thereof, taken in conjunction with the accompanying drawings although variations and modifications may be effected without departing from the spirit and scope of the novel concepts embodied in the disclosure, and in which:

FIG. 1 is a fragmentary elevational view, partially in section, of a piston and cylinder assembly demonstrating utility of a piston ring of the type with which the present invention is concerned.

FIG. 2 is a fragmentary enlarged cross-sectional view of an oil control piston ring assembly received in a groove in the piston of FIG. 1.

FIG. 3 is a plan view of an expander-spacer ring equipped with an end guide or latch of the type with which the present invention is concerned.

FIG. 4 is a fragmentary elevational view taken substantially along the line IV-IV of FIG. 3.

FIG. 5 is a fragmentary longitudinal sectional elevational view taken substantially along the line VV of FIG. 4.

FIG. 6 is an enlarged sectional detail view taken substantially along the line VI-VI of FIG. 5.

FIG. 7 is an enlarged fragmentary sectional detail view taken substantially along the line VIIVII of FIG. 5.

FIG. 8 is a fragmentary elevational view of an end guide unit supply ladder provided as a unitary plastic molding.

FIG. 9 is a front elevational view of apparatus for assembling the end guides with piston rings.

FIG. 10 is a top plan view of the apparatus of FIG. 9, taken substantially in the plane of line X-X in FIG. 9.

FIG. 11 is an enlarged fragmentary sectional view taken substantially along the line XI-Xl of FIG. 9.

FIG. 12 is a fragmentary enlarged sectional detail view taken substantially along the line XII-XII of FIG. 9.

FIG. 13 is an enlarged fragmentary sectional elevational view taken substantially along the line XIII-XIII of FIG. 10.

FIG. 14 is a schematic illustration of an operating electropneumatic circuit for cyclical operation of the apparatus.

By way of background, there is shown in FIG. 1 a representative piston 15 and cylinder 17 of an internal combustion engine wherein the piston has a plurality of ring assemblies mounted in its perimeter adjacent to its head end, including compression rings 18 and 19 and an oil ring assembly 20.

Referring now to FIG. 2, the oil ring assembly 20 includes an expander-spacer ring 21 and two rail rings 22 and 27, the assembly being received in a complementary ring groove 28 in the piston 10.

As best illustrated in FIGS. 2,3 and 4, the expanderspacer ring 21 is of generally U-shape cross section providing a radially outwardly opening channel 29 defined by a top row 30 and a bottom row 31 of circumferentially spaced flange segments which project radially in spaced parallel relation and are connected together at their radially inner edges by vertically extending web sections 32 integral therewith through axially extending respective reverse bend formations 33 against which the radially inner edges of the rail rings 22 and 27 seat and are thrust radially outwardly to engage the wall of the cylinder 17. For this purpose the ring 21 is compressed from a normal expanded condition wherein the flange segments 22 and 27 and the connecting sections 32 act as springs to generate a circumferential expanding force against the rail rings 22 and 27.

In order for the expander-spacer ring 21 to function satisfactorily, split ends 34 at a gap 35 must not overlap but must abut in substantially perfect alignment in the compressed condition of the ring wherein the gap 35 is closed. In order to avoid misalignment of the ends there has been provided a new and improved form of gap latch or end guide 37 comprising a guide shaft 38 of a length to extend to a substantial distance each side of the gap 35 when received within the channel 29 and of a width only slightly smaller than the space between the wall segments 30 and 31. Means for retaining the end guide 37 in place in the assembly comprise retaining elements which are respectively frictionally anchored to the ring at opposite sides of the gap 35 and prevent escape of the guide 37 after assembly with the ring.

In this instance one of the retaining elements comprises a head block 39, integral at one end of the shaft 38, having lateral friction bosses 40 on its sides to facilitate frictional retaining gripping engagement with the confronting inner faces of the segments 30 and 31 at one side of the gap 35 with the shaft 38 extending from the head 39 across the gap and to a substantial extent beyond the opposite end of the ring between the segments 30 and 31.

To retain the end guide 37 and more particularly the shaft portion 38 against radially outward displacement from the channel 29 or endwise escape during expansion of the ring 21 in fitting it over the piston 15, a second frictionally anchored retaining element 41 is provided which engages in firm frictional relation with and between the segments 30 and 31 adjacent the end 34 of the ring which is opposite to the end 34 adjacent to which the head retaining element 39 is positioned. For this purpose the element 41 is provided with respective side projecting friction bosses 42 (FIGS. 4,5 and 7) which retain this element in overlying relation to the shaft 38. A chamfered end edge 43 is directed toward a barb-like shouldered tip 44 on the distal end of the shaft 38 which faces generally toward the latch element 41.

In a preferred arrangement, the retaining element 41 is provided as an originally integral part of the end guide 37 so as to avoid the need for handling separate parts, with the frictional resistance upon engagement of the bosses 42 with the segments 30 and 31 during assembly causing the element 41 to detach from the shaft 38 so that after assembly the shaft can move relative to the fixed latch element 41. For this purpose, the element 41 is, as initially made, attached to the shaft 38 by a frangible neck 45 (FIG. 8). By molding the end guide 37 from suitable plastic material, the unitary structure of the shaft 38 and the

retaining elements

39 and 41 can be readily effected according to any preferred molding technique.

In order to facilitate supply and assembly operations, a plurality of the end connectors or guides 37 are preferably molded in a convenient spaced seriate, ladderlike arrangement 45 providing a suitable plurality of the guides connected as by means of frangible connections 47 to a common bar 48 at the head retaining elements 39, and by means of frangible connections 49 to a common bar 50 at the terminals of the tips 44. Thereby the individual guides 37 can be readily broken from the spaced

parallel bars

48 and 50 by rupturing the respective

frangible connections

47 and 49, to supply the end guides seriatim to piston rings as required. There may be as many of the guide units 37 in the supply ladder 46 as desirable or as may be conveniently handled in automatic or semi-automatic assembly apparatus.

According to the present invention, new and improved apparatus for semi-automatic assembling of the end guides or latches 37 with piston rings 21 has been provided as exemplified in FIGS. 9-14. More particularly, the apparatus is provided with means for receiv ing the end guides 37 in the ladder 46 supply arrangement, stripping the end guide units 37 successively from the supply ladder 46, feeding each successively stripped end guide 37 into position for assembly with a respective one of the piston rings 21, and completing the assembly by press fitting the retaining element head 47 within the ring at one side of the gap 35, and separating and press fitting the retaining element 41 of the end guide into the ring at the opposite side of the gap over the shank 38 of the assembled end guide. For this purpose the apparatus includes a magazine structure (FIGS. 9,10,11 and 13), which in this instance is equipped to handle the ladder-form supply of end guides, one ladder at a time, although it will be apparent that by suitable extension of the magazine structure a series of the ladders could be accommodated. In this instance, vertical guide track means are provided for receiving the

ladder bars

48 and 50, comprising a vertical track groove 52 for the bar 48 and a vertical track groove 53 for the bar 50. The

track grooves

52 and 53 guide the ladder 46 downwardly so that the lowermost of the end guides 37 rests upon a complementary feed surface 54 extending in a front to rear direction and having a transverse curvature formed on a radius substantially complementary to the radius of curvature of the outer diameter of the piston ring 21 and to which curvature the end connector shafts 38 are also desirably formed to facilitate assembly of the end connectors with the rings. In the present instance, the feed surface 54 is provided on a member 55 providing at each side of the feed surface at least in line with the

track grooves

52 and 53 escape clearances for discard of the bars 48 and as the end guides 37 are progressively stripped therefrom. Support for the member is provided by body member in the form of a vertical plate 57 which also supports the magazine 51 and is mounted on a base provided by a horizontal base plate 58 carried by a machine frame 59. Drop-out holes 60 in the base plate 58 are provided in line with the

track grooves

52 and 53 for discard of the separated

ladder posts

48 and 50 to a suitable scrap receptacle thereunder.

Each of the end guides 37 is successively stripped from the supply ladder and moved into position for assembly with one of the rings 21 by means of a reciprocable feed plunger 61 which is formed in complementary shape to engage slidably with the feed surface 54 and is of a thickness and a width to engage with substantially the entire length at the rear side of the end guide shaft 38 which lies upon the feed surface, as best seen in FIGS. 11 and 13. Feeding stroke and return reciprocations of the plunger 61 are effected by means of a motor 62 desirably in the form of a fluid operated, such as pneumatic, cylinder having a piston 63 suitably attached as through the medium of a yoke bar 64 to the rear end of the plunger 61. Means such as mounting box 65 support the motor 62 over the base plate 58. To assist in reciprocably guiding the plunger 61, means comprising a fixed guide rod 67, projecting forwardly from the top of the block 65 in spaced parallel relation to the piston rod 63, extends through a complementary guide aperture 68 in the yoke bar 64.

In a feeding stroke, the plunger 61 moves from a retracted position as shown in full line in FIG. 11, forwardly into engagement with the end guide 37 resting on the feed surface 54, stripping such end guide from the ladder bars 48 and 50 by breaking the

respective connections

47 and 49. Continued forward thrusting of the thus detached end guide 37 moves it through a clearance aperture 69 in the mounting plate 57 and finally into assembly position aligned with the channel 29 of one of the rings 21 supported on a stepped mandrel 70 desirably comprising a forward extension from the member 55 and offset concentrically relative to the feed surface 54 equal to the radial dimension of the ring so that the free edges of the flange segments 30 and 31 lie within the curved plane of the feed surface. Feed thrust of the plunger 61 is controlled to drive the end guide forwardly beyond the front end of the feed surface 54 and into position directly over the channel 29 of the ring 21. Just as the end guide 38 reaches the assembly position over the ring 21, it is restrained against overshooting and is pressed down into the channel 29 by means comprising a biasing leaf spring finger 71. In addition to its guide press-in function, the finger 71 desirably also serves as an aid to positioning the ring 21 and holding the ring in the proper assembly position on the mandrel 70. For this purpose, the spring finger 71 has an attachment terminal flange 72 received in a suitable complementary recess 73 in the back face of the mounting panel 57 and above the clearance opening 69, means comprising the screws 74 securing the flange in place and to position the spring finger in a downwardly and forwardly oblique biasing position normally pressing downwardly and with a slight rearward component of biasing pressure against the ring segment flanges 31 whereby the ring is held down against the mandrel 70 and against a rear locating shoulder 75 providing a drop-off from the feed surface 54. For best results. the biasing spring finger 71 is centered, as best seen in FIGS. 9, and 13, in the opening 69, and a longitudinal central clearance notch 77 is provided in the plunger 61 to clear the spring finger. To

facilitate moving the ring 21 into position under the spring finger 71, the front terminal end portion of the finger is turned up to provide a cam lip 78. Thereby even though the normal spring bias of the finger 71 causes it to be pressed below the radial width dimension of the ring 21, the ring can be pressed rearwardly into the assembly position under the finger by camming the ring against the lip 78. Also the turned up curved lip 78 facilitates smooth release of the ring 21 after assembly of the selected end guide 37 has been completed.

1n the present instance, mounting of the rings 21 on the mandrel 70 is effected manually, although it will be readily apparent that suitable mechanical means may be provided for mounting the rings 21 successively in position for assembly of the ring guides therewith and then removal after the assembly, automatically coordinated with other operations of the apparatus. To facilitate mounting of the rings in proper position to facilitate assembly of the end guides therewith, the mandrel 70 is in the form of a segment of a cylinder which is wide enough to support the ring 21 equally at each side of the ring gap 35 within which is received a fixed locating key 79 (FIGS. 9, 10, 12 and 13) so located with respect to the feed opening 69 as to position the ring gap 35 in alignment with the space between the retaining

elements

39 and 41 of the end guides 37 as they are fed to the ring with which to be assembled. Desirably the key 79 is carried fixedly by the mandrel 70. Thereby, on mounting one of the rings 21 on the mandrel 70, its gap 35 must be properly located to receive the key 79 therein between the ends 34 of the ring (FIG. 13). This properly locates the gap for reception of the retaining

elements

39 and 41 of the end guide within the respective end portions of the ring.

Means for driving the retaining

elements

39 and 41 into their generally press fit frictional retaining engagement within the end portions of the ring 21 comprise an insertion plunger 80 (FIGS. 9, 12 and 13) which is guided reciprocably by a guide plate or bracket 81 mounted on the forward face of the supporting panel 57 in a position to engage and drive the retaining

elements

79 and 41 into the channel of the ring 21. Reciprocal cyclical driving and return strokes of the plunger 80 are effected by suitable means comprising a motor 82 such as a fluid operated, i.e. pneumatic, cylinder mounted on a suitable supporting bracket 83 (FIGS. 9 and 10) carried by the mounting plate 57. A piston rod 84 of the motor 82 is suitably connected to the upper end of the plunger 80.

Means are provided for assuring proper alignment of the ring 21 on the mandrel against the shoulder when the plunger is driven in an inserting stroke. To this end, the lower front end portion of the plunger 80 carries fixedly therewith a downwardly extending alignment finger 85 having a longitudinal downwardly opening notch 87 to clear the key 79 and providing a pair of spaced finger projections 88 for alignment engagement with each of the end portions of the ring 21 so that if there is any misalignment due to warpage or any other reason of the end portions or if the ring has not been quite fully pushed toward the shoulder 75 during mounting of the ring, the alignment fingers 88 will, in advance of engagement with the end guide by the plunger 80 properly align the end portions of the ring. To facilitate this function, the finger projections 88 extend beyond the driving end of the plunger 80 and are provided with lead-end oblique cam surfaces 89 facing toward the ring. To accommodate the finger projections 88, the mandrel 70 is provided with respective clearance holes 90 at the respective opposite sides of the key 79.

In order to drive the retaining

elements

39 and 41 into position within the ring 21 in proper sequence in the insertion stroke of the plunger 80, its driving tip is properly profiled as best seen in FIG. 13, being provided with stepped driving

shoulders

91 and 92 for the

elements

39 and 41, respectively, with the driving shoulder 91 projecting a desirable distance in advance of the shoulder 92. The stepped differential between the

shoulders

91 and 92 is such that although the shoulder 92 engages the taper 43 of the element 41 and swings the element 41 from its normal oblique projection from the shaft 38 toward the shaft, the shoulder 91 will engage and start thrusting the retaining element 39 into press fit engagement within the ring channel before the shoulder 92 so presses against the retaining element 41 as to possibly break it free from the shaft 38. Thereby, in the continuing insertion thrust of the plunger 80, the shoulder 91 first begins the press fit drive of the element 39 into the ring channel followed by the shoulder 92 pressing the element 41 into position in the channel at the opposite side of the gap 35,

and in the final continuing thrust of the plunger 80 the element 41 enters into press fit with the respective ring wall segments 30 and 31 and being fully press fitted in place detaches from the shaft 38 while the shoulder 91 moves the element 39 into its fully driven position wherein the shaft 38 underlies the element 41, substantially as depicted in FIG. 5. As soon as this operation has been completed, the plunger 80 is backed off and the ring 21 loaded with the end guide 37 assembled therewith is removed from the mandrel 70 and another ring placed in position to have one of the end guides 37 assembled therewith in a repeat cycle. Such assembly cycles can be continued as long as there are end guides 37 in the ladder 46, the next succeeding of the end guides 37 falling into position automatically as each preceding end guide is stripped from the ladder. It may be noted that the magazine tracks 52 and 53 are of sufficient length so that when the operator observes that the upper end of the ladder has descended significantly below the top of the mounting plate 57, another ladder 46 can be inserted to continue descending with the preceding ladder as one after the other of the end guides 37 is stripped therefrom in the operation of the machine.

Means are provided for coordinating operations of the plungers and effecting the feeding and assembling functions in proper automatic sequence. In a semiautomatic operating sequence, the operator mounts one of the rings 21 in position and then manually operates a device for initiating a cycle of operation, such as pressing a starting button 93 (FIG. 14) of an operating circuit functioning through means for maintaining the cycle of operation to completion comprising a relay 94 which initially actuates an electrical device 95 to operate a valve 97 to direct air from a source 98 to the feed slide motor 62, thereby energizing it to feed one of the end guides 37 into position over the ring to receive the same. As the feed plunger 61 reaches the end of its feeding stroke, a trip head 99 (FIG. carried by an arm 100 on the yoke 64 strikes and moves a trip arm 101 ofa limit switch 102, thereby signaling the relay 94 to effect actuation of the electrical control 95 to actuate the valve 97 to reverse the motor 62 and in sequence activate the insertion plunger motor 82 in a driving stroke which is terminated when a trip head 103 (FIG. 9) on a trip arm 104 carried by the plunger 80 strikes and moves an actuating arm 105 of a limit switch 107 to signal the relay for activating the electrical actuator 95 to reverse the plunger motor 82 and return the plunger 80 to its starting position, whereupon the cycle terminates until the starting button 93 is again pressed.

It will be understood that variations and modifications may be effected without departing from the spirit and scope of the novel concepts of this invention.

I claim as my invention:

1. Apparatus for assembling end guides with split piston rings of channel shape, comprising:

means for mounting a split piston ring in position to receive an end guide in assembly therewith and including means for properly locating the gap between ends of the ring at the ring gap;

means for positioning an end guide adjacent to the ring across the gap and aligned with the ring channel; and

inserting means for thrusting the end guide laterally into the ring channel across the gap.

2. Apparatus according to claim I, wherein said means for supporting the ring comprises a mandrel and said gap aligning means comprises a key carried by the mandrel.

3. Apparatus according to claim 1, including means cooperative with said inserting means for assuring alignment of the ends of the ring with one another and alignment of the end portions of the ring with said insertion means.

4. Apparatus according to claim 1, wherein said insertion means comprises a plunger having stepped thrusting shoulders for successively driving retaining elements of the end guide into engagement with the respective opposite end portions of the ring.

5. Apparatus according to claim 4, wherein said stepped shoulders comprise a first shoulder for driving a terminal head element into press fit within the ring channel up one side of the gap and a second shoulder for driving a latch retaining element of the end guide into press fit engagement with the opposite end portion of the ring.

6. Apparatus according to claim 1, wherein said feeding means include a feed surface, and a feed plunger for driving the end guide from a supply into position with respect to the ring which will receive the end guide.

7. Apparatus according to claim 6, including a magazine for receiving a ladder of seriate end guides, and said feeding means comprising a feed surface on which the end guides of the ladder are successively received. and a plunger for stripping the end guides successively from the ladder and thrusting them along said feed surface into position for assembly with the ring by said inserting means.

8. Apparatus according to claim 1, including means for cyclically coordinating operation of said feeding means and said inserting means.

9. Apparatus according to claim 8, wherein said feeding means includes a feeding plunger and a driving motor, said inserting means comprises an inserting plunger and a drive motor, and means for cyclically operating said motors comprising a manually operable device for initiating the cycle and means for maintaining the cycle of operation to completion including sequential operation of said feeding means and said inserting means.

10. An apparatus for assembling elongated end guides with piston rings, comprising:

a feed surface;

a magazine for supplying end guides seriatim to said feed surface;

means for supporting a channeled piston ring with its channel aligned with said surface to receive an end guide; and

a plunger for driving the end guide which is an engagement with said surface into position for insertion into the channel of the ring.

11. Apparatus according to claim 10, wherein said means for supporting a ring comprises a stepped mandrel supporting the ring with its outer perimeter aligned with said surface, and means for holding the ring in position relative to said surface to receive the end guide.

12. Apparatus according to claim 11, wherein said means for holding the ring include a shoulder between said mandrel and said surface and a biasing element having components of biasing thrust toward said mandrel and toward said shoulder.

13. Apparatus according to claim 12, wherein said biasing means comprises a spring finger functioning means for inserting the end guides into the ring channel includes a plunger. respective motors for driving said plungers, and means for coordinating operation of said motors.

16. Apparatus according to claim 15, said means for coordinating operation of said motors including a circuit having respective limit switches activated by means connected with said plungers.

Claims

1. Apparatus for assembling end guides with split piston rings of channel shape, comprising: means for mounting a split piston ring in position to receive an end guide in assembly therewith and including means for properly locating the gap between ends of the ring at the ring gap; means for positioning an end guide adjacent to the ring across the gap and aligned with the ring channel; and inserting means for thrusting the end guide laterally into the ring channel across the gap.

2. Apparatus according to claim 1, wherein said means for supporting the ring comprises a mandrel and said gap aligning means comprises a key carried by the mandrel.

7. Apparatus according to claim 6, including a magazine for receiving a ladder of seriate end guides, and said feeding means comprising a feed surface on which the end guides of the ladder are successively received, and a plunger for stripping the end guides successively from the ladder and thrusting them along said feed surface into position for assembly with the ring by said inserting means.

10. An apparatus for assembling elongated end guides with piston rings, comprising: a feed surface; a magazine for supplying end guides seriatim to said feed surface; means for supporting a channeled piston ring with its channel aligned with said surface to receive an end guide; and a plunger for driving the end guide which is an engagement with said surface into position for insertion into the channel of the ring.

13. Apparatus according to claim 12, wherein said biasing means comprises a spring finger functioning also to press the end guide into the channel of the ring as delivered by said plunger.

14. Apparatus according to claim 10, wherein said magazine has spaced guide tracks for receiving side bars of a supply ladder of the end guides, wherein the end guides are attached at opposite ends to the bars in seriate relation, said plunger being operative to strip the end guides successively from the ladder.

15. Apparatus according to claim 10, wherein said means for inserting the end guides into the ring channel includes a plunger, respective motors for driving said plungers, and means for coordinating operation of said motors.