WO1982001921A1

WO1982001921A1 - Cast bearings and process therefor

Info

Publication number: WO1982001921A1
Application number: PCT/US1980/001636
Authority: WO
Inventors: Raymond E Reese
Original assignee: Raymond E Reese
Priority date: 1980-12-05
Filing date: 1980-12-05
Publication date: 1982-06-10
Also published as: EP0065948A1

Abstract

A bearing construction and method which involves the casting of a piston (22) or cylinder (23) where the bearings (40) or bushings (41) are formed in place. In preferred constructions, the bearings (40) or bushings (41) are solid bronze rod rings held in position on a fixture over which the construction material is poured so that only selected ring portions such as the outer or inner diameters, are exposed beyond the periphery of the construction material. After hardening, the exposed ring portions of the rods are milled or otherwise reduced until the rods are coextensive with the peripheral surface of the construction material.

Description

CAST BEARINGS AND PROCESS THEREFOR

TECHNICAL FIELD

This invention relates to bearing constructions such as bushings or journals and more particularly, to a novel bearing construction and method making the same which involves casting of a piston or cylinder with the bearing, bushing or journal in place.

BACKGROUND ART

It has been the conventional practice in the past to employ bearings and bushings to support shafts or journals from a housing between which there is relative movement. In general, the terms "bearing" and "bushing" are used synonymously by users of these products. Bearing manufacturers, however, have their own method of distinguishing one from the other. For example, a bearing is a full-round or semicircular (half bearing), cylindrical part composed of a steel, bronze, or other supporting back to which a special material or lining alloy is bonded. Bushings on the other hand are classified as full-round, cylindrical parts made of one special alloy to suit the intended use. The exception to these definitions is the monoalloy, semicylindrical part, which is usually termed a "half bearing". It is difficult to outline exactly where bushings should be used, inasmuch as applications vary widely and many materials are available with an equally wide variety of characteristics. In general, bushings are applicable where the unit load in pounds per square inch of projected area is high (up to 5,000 pounds) and speeds are very slow. With generous, full-flow lubrication, peripheral speeds of up to 400 fpm are obtainable with lesser loadings. Bearings generally are more costly than bushings, but are required in applications of high speeds and loadings. Bearings usually require fluid lubrication, preferably under pressure.

Probably, the most extensively used bearing metals are the babbitts, and several alloys are in general use at the present time. The metal is usually applied to a backing of either bronze or steel by centrifugal casting or spinning.

Problems and difficulties have been encountered with prior manufacturing of bearings and bushings, which stem largely from the fact that the usual centrifugal casting or spinning of the material requires extensive equipment and expensive molds and dies. Also, adhesion of the bearing or bushing material to the backing material is not readily controllable in all cases. Therefore, the life and dynamic carrying capacity of the bearings may be adversely affected. If a bearing is properly lubicated and protected from foreign matter and overloads, it will usually fail from a form of fatigue which is evidenced by a spalling or flaking of one of the raceways or backing material. Even under ideal operating conditions, the life of an individual bearing or bushing cannot be predicted accurately in advance because of a number of influences whose effects have not yet been fully determined.

Therefore, a long standing need has existed to provide a novel bearing or bushing construction and process therefor which avoids the above mentioned problems by casting the bearing construction such as a piston or cylinder with the bearing material in place so that the backing material surrounds the bearing material and properly adheres thereto.

The prior art searched did not disclose any patents that were directly related to the invention. However, the following U.S. patents .were considered in the investigation and evaluation of the prior art;

PATENT NUMBER INVENTOR ISSUED

3,803,956 Knapp 07/05/74

3,004,336 Timuska 17/10/61 2,984,895 Griffin 23/05/61

The Knapp patent discloses a method of constructing a piston assembly consisting of a piston rod having a stud at one end onto which a piston and a disc are mounted. The assembly is adaptable for use on equipment such as rear end loading refuse collecting vehicles. The Timuska patent discloses a method of reconditioning the surfaces of aluminum alloy parts, such as pistons and bearings. The method consists of metallizing (spraying) the worn-out surfaces of the parts with an aluminum alloy that is later ground or machined to the required surface. The Griffin patent also discloses a method for reconditioning the surfaces of worn pistons. The method consists of applying a disclosed mixture to the worn surface which is later machined to the desired diameter.

DISCLOSURE OF INVENTION

The problems and difficulties described in the Background Art Section are obviated by the present invention which provides a novel bearing or bushing construction which is formed in place simultaneously with the casting of a piston or cylinder. The bearings or bushings are composed of solid bronze rod rings secured in position with respect to one another in fixed spaced apart relationship. The rings are secured by a fixture having cavities for conducting an alloy construction material throughout the configuration of the fixture and wherein a selected ring portion is exposed from the alloy material such as the outer or inner diameters which are exposed beyond the periphery of the alloy material. The exposed selected ring portion is reduced so that the rod material is coextensive and flush with the adjacent surface of the alloy construction material. Therefore, it is among the primary objectives of the present invention to provide a novel bearing or bushing construction wherein a piston or cylinder is fabricated by casting of an alloy material with the bearing or bushing material in place.

Another objective of the present invention is to provide a novel method or process of producing a cast bearing in a piston or cylinder wherein the bearing or bushing material is held in place while the surrounding alloy material is being cast.

Still another objective of the present invention is to provide a novel piston or cylinder having bushings, journals or bearings formed in place so as to provide either internal or external bearing surfaces which are coextensive with the surrounding or backing construction alloy.

A further objective of the present invention is to provide a novel piston or cylinder construction which includes forming the bearing or bushing in place so that the piston or cylinder constructions are relatively economic to produce and which will provide longer life.

BRIEF DESCRIPTION OF DRAWINGS The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood with reference to the following description, taken in connection with the accompanying drawings, in which:

FIGURE 1 is a perspective view of a dump truck having hydraulic piston and cylinder assemblages incor¬porating the present invention; FIGURE 2 is an enlarged exploded view, in section, of a novel cast piston used in the assemblage of FIGURE 1;

FIGURE 3 is an exploded view, in section, of a novel cast bearing construction used in the assemblage Of FIGURE 1;

FIGURE 4 is an exploded, perspective view of the dies and jigs employed in the novel process of casting the piston shown in FIGURE 2; FIGURE 5 is an exploded perspective view of the dies and fixtures used in casting the bearing construction shown in FIGURE 3;

FIGURE 6 is a perspective view, partly in section, of another embodiment of a cast piston susceptible for use in the piston and cylinder assemblages of FIGURE 1;

FIGURE 7 is a perspective view of the dies and fixtures employed in making the cast piston shown in FIGURE 6 including external bushings or journals; FIGURE 8 is a fragmentary view, partly in section, of a cylinder having a ball bearing installation opening;

FIGURE 9 is a transversal cross sectional view of a novel cast cylinder having internal bushings or journals;

FIGURE 10 and 11 are perspective and sectional views respectively of the dies and fixtures employed in the process of casting a cylinder including internal bushings or journals; FIGURE 12 is a transversal cross sectional view of a cylinder having a cast bearing;

FIGURE 13 is a perspective view of a fixture construction used in the process of preparing the cast bearing in FIGURE 12; FIGURE 14 is a transversal cross sectional view of another cast bearing construction; and

FIGURE 15 is a top plan view of the cast bearing employed in the cylinder shown in FIGURE 14 BEST MODE FOR CARRYING OUT THE INVENTION

Referring to FIGURE 1, a truck is indicated in the general direction of arrow 10 which includes an elongated frame 11 carrying a driver's cab 12 at one end and a pivotal truck bed or cargo carrying platform indicated in general by numeral 13. As is the usual case, the frame 11 is rollably supported on the ground by wheel sets 14, 15, and 16 respectively. The bed or platform 13 is pivotally carried on the frame 11 by suitable and conventional mountings indicated in general by numeral 17.

In order to raise and lower the bed or platform 13, a set of hydraulic piston and cylinder assemblages 20 and 21 are illustrated. The opposite ends of each assemblage are operatively connected to the frame 11 and the bed or platform 13 respectively so that as the rods carrying the pistons move outwardly from their respective cylinders, the bed or platform 13 is raised. Conversely, when the rods carrying the pistons are permitted to retract into their respective cylinders, the bed or platform 13 is lowered to the frame 11.

The piston and cylinder assemblages 20 and 21 shown in FIGURE 1 incorporate the novel construction and process of the present invention and it is to be understood that the illustration of a truck having a moveable bed or platform actuated by the piston and cylinder assemblages is by way of illustration and is not intended to limit the application of the bearing constructions disclosed herein.

Referring now in detail to FIGURE 2, the piston and cylinder assemblage 20 is illustrated greatly enlarged and in section so as to show details of the piston. The piston is represented by numeral 22 and the cylinder by numeral 23. The rod is indicated by numeral 24 and includes a threaded stud 25 which is in threaded connection with internal threads carried in bore 26 of the piston 22. The piston 22 includes a receptacle 27 which receives the extreme end of rod 24 and includes a shoulder 28 that engages with the end 30 of the rod 24. The piston 22 further includes a recess 30 for accommodating a lock nut 31 which is threadably attached to the end portion of the threaded stud 25 when the stud is fully engaged with the threads provided in the bore 26 and the rod end 30 is in contact with the piston shoulder 28. The recess 30 includes at least a pair of shoulder keys 32 and 33 which may be employed for tightening the piston 22 onto the threaded stud 25 of the drive shaft or rod 24. A cup or seal is provided at the upper and lower ends of the piston 22 and are illustrated by numerals 34 and 35 respectively. The annular seals 34 and 35 are held in position by snap rings identified by numeral 36 and 37 respectively.

The prime feature of piston 22 resides in the fact that the construction material or alloy forming the body of the piston is poured into a mold comprising modules of jigs and fixtures so that a pair of bearings or bushings are constructed in place. The bearings and bushings are identified by numerals 40 and 41 respectively and are coaxially disposed with respect to the piston 22 and the drive shaft or rod 24. Preferably, the bearings or bushings 40 and 41 are composed of a material such as bronze and are of a solid composition so that when the liquid or molten alloy forming the body of the piston is poured around the solid material of the bearings or bushings, the body of the piston forms thereabout and when it solidifies, firm attachment and adhesive engagement or connection occurs with the external contacting surface of the solid material bearing or bushing. A feature of the invention resides in the fact that the external surface of the bearing or bushing which is exposed from the alloy construction material is milled or otherwise ground so that the exposed surface of the bearings or bushings are coextensive with the external surface of the piston 22. Therefore, it can be seen that the piston uses a casting procedure and that the bearings or bushings are cast in place. Although a pair of bearings or bushings 40 and

41 are illustrated, it is to be understood that a single bearing or bushing may be provided in the same manner or that more bearings can be so formed in place. Also, the width of each bearing is dependent on the particular design desired.

Referring now in detail to FIGURE 3, it can be seen that a selected end of the cylinder 23 is provided with a cup 42 which is threadably engaged with the end of cylinder 23 by means of threaded engagement 43 so that a shoulder 44 engages with a shoulder stop 45. Sealing is achieved by means of packing rings 46, 47, and 48 while a sealing ring 50 seals between the cup 42 and the bore of the cylinder 23. The packing material seals between the cup and the rod 24 of the drive shaft. The packing material may be readily tightened or adjusted by means of a retainer 51 that includes an annular collar 52 having an engagement surface 53 which fits between the cup 42 and the rod 24 to engage and tighten with packing 46. The retainer 51 and the cup

42 are secured to the extreme end of the cylinder by means of bolts such as bolt 54. A wiping ring or seal 55 seals between the rod 24 and the bore of the retainer 51. The inventive concept of the present invention includes the casting of a construction such as the cup 42 wherein one or more bearings or bushings such as bearings or bushings 56 and 57 may be formed in place in accordance with the process previously described with respect to the bearings or bushings 40 and 41 carried on the piston 22. In the former instance, the bearings or bushings 40 and 41 are external bearings or bushings and in the instance of the bearings or bushings 56 and 57, internal bearings or bushings are provided. Initially, the solid material such as bronze rings are held in a die while the alloy material in molten or liquid form is poured into the die and surrounds the solid, rings 56 and 57 so that a selected portion on the inner diameter of the rings is exposed so that after solidification, this exposed portion may be milled or otherwise cut to the proper dimension to form a bore for receiving the rod 24. Another feature of the present invention includes a lubricating system so that proper lubricant can be introduced into the bore of the cylinder 23 to lubricate the bore whereby the piston 22 may freely move therein. For this achievement, a passage way 58 is provided through the wall of the cylinder 23 at the selected end thereof in close proximity to the terminating end of the cup 42. It is noted that the end of cup 42 includes a plurality of downwardly depending limit stops such as indicated by numerals 60 and 61 having free ends which engage with the upper shoulder 62 of the piston 22. When such engagement occurs, a suitable space is available between the cup 42 and the piston 22 to permit the introduction of lubricant into the bore of the cylinder via the passage way 58. Therefore, it is essential that the lubrication passage way 58 be placed in the cylinder wall within the dimensional length of the limit stops 60 and 61.

Referring now in detail to FIGURE 4, a plurality of dies and fixtures are illustrated which are employed in producing the piston 22 shown in FIGURE 2.

- At one end of the assemblage of dies, is a base 63 which supports a cylinder 64 into which the molten or liquid construction alloy is poured to form the body of the piston. A die 64 is employed for casting the lower portion or end of the piston which includes the keys 32 and 33 for tightening the piston onto the threaded end of the drive shaft rod 24. Cut-outs 65 and 66 are employed for forming the keys 32 and 33 respectively. An intermediate collar 67 is placed on top of the die 64 and is coextensive with the lower end of the cylinder 64 so as to define a solid lower end of the piston 22 after the liquid has solidified. On top of the collar 67, a jig or fixture 68 is placed thereon. The fixture 68 includes a pair of bronze rods formed in the shape of rings which will serve as bearings or bushings 56 and 57 respectively. The rings are held in place by a central core 69 by means of spacers 70, 71, and 72. Therefore, the molten or liquid alloy material forming the body of the piston may flow between the core 69 and the inside diameter of the bronze rings forming bearings or bushings 56 and 57. After solidification, when the fixture 68 has been removed, the outer diameter of the rings is exposed and after milling, will be coextensive with the external surface of the piston body. A fixture 73 includes coaxial elements 74 and 75 which form the center of the piston providing receptacle 27 and bore 26 respectively.

Referring now in detail to FIGURE 5, it can be seen that the internal bearings or bushings 56 and 57 associated with cup 42 may be foarmed in place. Initially, the assemblage of molds and dies includes a base cylinder 76 which includes threaded elements 77, 78 and 79 which project through the wall thereof so as to extend into contact with the outer surface of a collartype mold 80 when it is inserted into the interior of the base mold 76. A ledge 81 serves to form the shoulder 45 while the threads immediately thereabove on the collar are formed by the threads 82 in the collar 80. A fixture 83 includes a mid-section carrying a pair of bronze rods in the form of rings which will form the bearings or bushings 56 and 57 in the collar 42. The upper end of the cup 42 is formed by the fixture 84 with the cap 85. In this manner, when the assemblage of molds are put together, and when molten or liquid construction alloy forming the body of cap 42 is poured in the center thereof, the alloy material will flow in the cavitites between opposing surfaces of the respective molds and dies. For the inventive process, it is noted that the molten or liquid alloy material will flow against the outer diameter of the rings 56 and 57 so that the inner diameter portion of each ring is exposed after solidification of the alloy material and removal of the die and mold assembly. Then, this exposed portion of the bearing or bushing material is removed by milling, broaching, or other machining process so that the bearings will be coextensive with the inside diameter of the cap 42.

Referring now in detail to FIGURE 6 , another embodiment of the present invention is shown wherein the piston and cylinder assemblage is represented by cylinder 90 and drive shaft rod 91. At the end of the rod 91, a piston 92 is cast thereon which includes a plurality of external bearings or bushings such as represented by numerals 93, 94, and 95. Also, the piston includes a cast raceway 96 which holds. a plurality of ball bearings, such as ball bearing 97. The plurality of ball bearings are rollably engaged with the bore of the cylinder 90 and the bore is indicated by numeral 98. As previously described, the bearings 93, 94, and 95 are cast in place when molten or liquid construction alloy is poured around the bearing material in a suitable die or mold.

As shown in FIGURE 7, the mold includes an elongated rod which represents rod 91 having a rod 100 carried at one end thereof which represents the bearing material. This material may be bronze or any other suitable material and the rod 100 is arranged in a spiral around the outer diameter of the drive shaft rod 91. The spiral of rod 100 is so arranged that various segments of the spiral are in fixed space relationship along the length of the rod 91 and the spiral terminates in fixed space relationship with respect to the bottom of the jig represented by numeral 101. Therefore, when the two halves of a die represented by numerals 102 and 103 are brought together about the spiral rod 100, a cavity is provided which exposes all portions of the spiral rod 100 except the extreme external or outer diameter portion which bears against the inside of the mold halves 102 and 103. Also, the mold halves include an inwardly projecting flange portion 104 which forms the race 96 on the piston. The flange 104 fits between the base 101 and the end of the spiral rod 100 so that the race 96 is formed immediately adjacent to the lower bearing or bushing 95.

After molten alloy material forming the body of the piston has been poured into the cavity between the opposing surfaces of the die halves 102 and 103 and the rod 91 and the exposed surfaces of the spiral rod 100, the alloy material solidifies and hardens after a period of time and the mold halves 102 and 103 are then removed. Upon removal, only the outer external portions of the spiral rod 100 are visible beyond the construction alloy forming the body of the piston 92. These exposed portions of the spiral rod 100 may be milled or otherwise machined to provide a smooth and coextensive surface on the piston. Also, the raceway 96 may be cleaned and smoothed preparatory to receiving the plurality of ball bearings therein. Referring to FIGURE 8, it can be seen that after preparation of the piston 92, the piston may be inserted into the bore of the cylinder 90 and the raceway 96 is placed in alignment with a hole 105 in the wall of the cylinder 90. When so aligned, the plurality of ball bearings, such as ball bearing 97, may be individually inserted through the hole 105 into the raceway 96. Thus, the plurality of ball bearings are loaded into the raceway until no further ball bearings can be inserted into the raceway. At this time, the last ball bearing which cannot be fully placed into the raceway can be removed and the hole 105 may then be closed or sealed. In this manner, the ball bearings are placed into the cast piston and the raceway is sealed to capture the ball bearings therein. Referring now to FIGURE 9, another embodiment of the present invention is illustrated wherein a plurality of bearings or bushings are cast in place so as to provide surfaces exposed through the bore of a cylinder. The cylinder is represented by numeral 110 and the plurality of bearings are illustrated by numerals 111, 112, and 113. It is noted that these bearings are embedded within the construction alloy of the cylinder and that their exposed surfaces are coextensive with the surface of the cylinder bore. With respect to FIGURE 10, it can be seen that the plurality of bearings or bushings formed in place in the cylinder wall of cylinder 110 can be made with the fixture illustrated in the general direction of arrow114 which includes a base 115 having an upright or vertical rod 116 on which a parting plate 117 is slidably mounted. Surrounding the rod 116 is a plurality of spirals indicated by numerals 117, 118, and 119. These spirals represent the solid bronze rod material forming the bearing or bushing. The entire assembly is encompassed by a cylindrical mold indicated by numeral 120. As shown in FIGURE 11, molten or liquid alloy forming the construction of the cylinder is poured into the cavity existing within the cylinder 120. The molten material is indicated by numeral 121 and completely occupies the space so defined including the outer diameter and substantially all of the solid brass rod forming the three spirals. However, none of the alloy material comes in contact with the portion of the rod forming the spiral constituting the inner diameter of each spiral.

Upon solidification of the alloy material, the cylinder 120 is parted from the structure as well as the rod 116 so that the cylinder construction is withdrawn with the spirals in place. At this time, the bore indicated by numeral 122 is milled or reamed so as to provide a smooth and coextensive surface there through. If desired, cuts can be made between the spiral rods 117, 118, and 119 so that a plurality of separate and individual cylinders having internal bearings can be provided.

Referring now to FIGURE 12, another embodiment of the present invention is illustrated wherein the cylinder 125 is formed with an internal bearing 126 so that a piston rod 127 may be moveably and slidably positioned within the cylinder. The end of the rod 127 is provided with a piston 128 which in combination with the bearing 126 stabilizes and insures proper movement of the drive rod 127. The bearing 126 is formed in place at a selected end of the cylinder as shown in FIGURE 13 wherein a die platform 129 is introduced into the bore of the cylinder 125 by means of a rod 130. Molten alloy material is poured into the cavity through the selected end of the cylinder 125 and when filled, the molten alloy is permitted to solidify. When solid, the rod 130 and the platform 129 are removed so that the bearing 126 remains. Plug holes for holding are indicated by numerals 131 and 132. After the bearing has been formed by the casting procedure just described, these holes are plugged with bearing material so as to retain the bearing in place.

Referring now to FIGURE 14, it can be seen that a similar bearing to the bearing 126 is provided and is represented by numeral 140 and it can be seen that the screws 141 and 142 are introduced through the wall of the cylinder 143 so as to retain the bearing 140 in place. To form the bearing 140, as shown in FIGURE 15 two mateable parts are indicated by numerals 144 and 145. The bearing includes internal screw passage way such as identified by numeral 146 and by providing a nut.on the screw in the die structure, nut-like apertures as indicated by numeral 147 are formed internally in the alloy material.

In view of the foregoing, it can be seen that a novel bearing construction is provided which may readily produce internal or external bearings on piston and cylinders wherein the body of the piston or cylinder is formed by casting and the bearing is cast in place. By simply using bronze rod stock as the bearing material and either by forming the material in rings or in spirals, a variety of bearing configurations can be produced, or cast. While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as they fall within the true spirit and scope of this invention.

Claims

1. A bearing construction comprising the combination of: a. at least one solid ring of bearing material having an inner diameter portion and an outer diameter portion; b. body material cast about said solid ring exposing a selected one of said diameter portions whereby a non-selected one of said diameter portions is completely encased and surrounded by said body material; and c. said selected one of said diameter portions is coextensive and flush with the adjacent surfaces of said body material so a smooth and contiguous bearing surface is provided.

2. The invention as defined in claim 1 wherein said selected diameter portion is said inner diameter portion so that an internal bearing surface is defined between adjacent body material.

3. The invention as defined in claim 1 wherein said selected diameter portion is said outer diameter portion so as to provide an external bearing surface between adjacent body material.

4. The invention as defined in claim 1 wherein said solid ring is a spiral forming a plurality of turns concentric with said body material.

5. The invention as defined in claim 4 wherein said selected diameter portion is said inner diameter portion of said spiral ring so that an internal bearing surface is defined separating adjacent portions of said body material.

6. The invention as defined in claim 4 wherein said selected diameter portion is said outer diameter portion of said spiral ring so that an external bearing surface is defined separating adjacent portions of said body material.

7. The invention as defined in claim 6 wherein: a. said body material includes a circular raceway in close proximity to said external bearing surface; b. a plurality of ball bearings disposed in said raceway; c. a cylinder slidably for carrying said body material as a piston and for retaining said ball bearings in said raceway; and d. said cylinder having a passageway therein for insertably receiving each of said plurality of ball bearings preparatory to disposition into said raceway.

8. A bearing construction comprising: a. a cylinder having a central bore extending therethrough and a pair of apertures provided in the wall thereof; b. a bearing formed in place in said cylinder bore having a central shaft bore coaxial with said cylinder central bore; and c. said bearing having lateral elements occupying said pair of apertures retaining said bearing in place in said cylinder central bore.

9. The invention as defined in claim 8 wherein, said bearing lateral elements are screws threaded through said pair of apertures into engagement with opposite sides of said bearing.

10. The process of making a bearing comprising the steps of: a. providing a mold defining a cavity between cylindrical outer body surrounding a core carrying at least one solid ring of bearing material in the defined cavity; b. mounting the solid ring in said surrounded core so as to expose either its inner or its outer diameter surface; c. pouring molten alloy into the cavity established between the cylindrical outer body and the core so as to encase the exposed inner or outer solid ring diameter; d. allowing the poured molten alloy to settle and harden after a period of time at ambient temperature so that the hardened alloy is bonded to the solid ring; e. removing the cylindrical body and core from the hardened and bonded alloy to expose the portion of the solid ring not previously exposed in said above mounting step; and f. machining the last mentioned exposed portion of the solid ring to provide a smooth and coextensive surface with adjacent hardened and bonded alloy material.

11. The process of making a bearing construction comprising: a. providing a cylindrical mold having a rod disposed along the centerline of the bore; b. providing a platform on the lower end of the rod; c. placing the platform to a desired depth in the bore of the cylinder via the rod; d. pouring molten alloy material into the space of the bore of the cylinder so as to fully occupy the space whereby the alloy material bonds to the wall of the cylinder defining the bore; and e. removing the rod and platform from the cylinder after hardening of the alloy material.

12. The invention as defined in claim 11 wherein the step of pouring includes pouring molten alloy material about stud holders so that the alloy material remains fixed to the cylinder.