Patent ES-341333-A1 (ES)
Title: Method and Apparatus for Making Thin Wall Flexible Bearing Liners
IPC: F16C33/14
Filed: 1967-06-02
Abstract: A method of making thin wall flexible bearing liners comprises subjecting a strip of bearing material, at each of a number of locations along the length thereof, to a succession of different operations to bring it to the required degree of finish, including rendering the strip arcuate across its width and in a subsequent operation successively severing from the arcuate strip portions of the required dimensions for the liners and upon which certain or all of the other operations have been carried out. A strip 12 comprises a steel backing supporting a layer of lead-bronze, aluminium-tin or other alloy and a bearing layer of a tin or lead alloy. Alternatively the bearing layer may be of PTFE and lead or a single layer strip may be used. The strip is fed with the steel backing uppermost by rollers 8, step by step, to a press mechanism or capsule where the upper surface is indented by a tool 16 at 9, as a platen 10 descends. Subsequently the bearing surface is indented by a tool 19 and a tool 20 stamps a trade mark and/or part number at 21. One or more steps in the movement brings the strip to a pair of cutters 22 having right-angled cutting edges 23, 24 to form shoulders 26. The next movement step of the strip brings the shoulders 26 into engagement with stops 27 to hold the strip stationary while a preceding part has marginal portions cut away thereby enabling the next movement to be effected to bring the reduced portion between die parts 28, 29. The female die 28 is part cylindrical and its outer portions are inclined to the cylindrical portion, the leading edges of the inclined portions being shearing edges arranged to co-operate with shearing faces 32. As the die 28 descends, the strip portion is bent and sheared part way across its width from either edge. The next step movement brings the strip portion to co-operating die halves, the female 34 being equivalent in length to three step movements, and the male 35 being mounted on a spring loaded pin 36. The die 34, 35 forms the strip portion to a semi-cylindrical section and the ends of the strip enter a cut away portion 37a as spring discs 39 are compressed. As the strip portion is advanced it is raised by the male die half 35 so that its ends are above the grooved portions of a part 37 and the next downward movement of the female die forces the parting faces of the now formed liner into the grooves and curved faces 42 thereof form curved corners 87 to the parting faces 82. As this forming operation is performed axial spread of the strip is avoided since a preceding part of the strip is also being pressed in the right-hand portion of the dies 34, 35. A member 43 prevents the strips curling upwards during the pressing steps and is provided with a passage 44 through which compressed air may be passed to blow away any loose particles present between the die members 34, 35. The strip then passes to a capsule 45 wherein blocks (48) are mounted between arcuate portions 47. Each block (48) contains a plunger (49) which is actuated by a rocker pivotably mounted on the block, Fig. 3 (not shown). As the platen 10 rises washers 57 on rods 56 engage portions 55 of the rockers thereby driving the plungers downwardly to pierce oil holes 86 in the liners. Die inserts (51a) on the plungers form depressions 85 around the holes or they may only form the depressions without the holes if a punch is not provided. The strip then passes to another capsule where a cutting edge 64 and a shearing member 65 on parts 59, 60 sever the liner from the strip. During the severing operation, the liner is carried on a spring loaded support on a plate 77 and a shearing and bending member 79 engages an edge of the liner as the die part continues to descend to form a locating projection 62. The liner is pushed by spring loaded pads (69) against a shoulder 68 to locate it axially as the projection is formed, Fig. 7 (not shown). As the die part 63 moves upwardly the liner is stripped therefrom by a part 81. The next step movement pushes the bearing liner out of the apparatus. The internal surface of the liner may be finished in separate apparatus by machining.