Patent GB-978232-A (GB)
Title: Improvements in or relating to the manufacture of pipe jointing sleeves and the like
Inventor: SKINNER EDWARD JUDGE
IPC: B21D39/04
Filed: 1961-07-20
Abstract: 978,232. Making pipe connections, stamping, soldering, shearing, bending, corrugating, tube expanding. WEDNESBURY TUBE CO. Ltd. Oct. 22, 1962 [July 20, 1961], No. 26259/61. Headings B3A, B3E, B3J, B3Q, B3R and B3W. A method of forming a pipe-jointing member having a pipe receiving circular section portion of ductile material, the wall of which is locally expanded to provide an internal annular recess and which is partially filled with solder, comprises circumferentially confining the pipereceiving portion externally except in the annular zone in which the recess is to be formed, locating a loop of solder internally of the pipe receiving portion at that zone and squeezing the loop by pressure under opposed axially directed forces while constraining it against inward radial displacement so that the solder expands radially to form the recess wherein it is thereafter retained. A thin-walled cylindrical copper sleeve 1 for joining the end of two copper or brass pipes 2 comprises an internal annular abutment 3, and internal annular recesses 4 filled with solder 6 which when heated is melted and defuses by capillary action between the surfaces of pipes and sleeves to form on cooling a liquid-tight joint between the members. A sleeve blank is positioned between a pair of annular abutments 11 in a split die 7 having an annular projection 12 and annular recesses 13. In alignment with the die opening 8 is a mandrel 14 connected to a reciprocal spigot 15. The mandrel comprises a head portion 16 having a diameter slightly greater than that of the internal diameter of the sleeve blank. A sleeve 18 slidable over the mandrel and supported in a block 19 attached to an impeller 20 comprises a leading diameter equal to that of the mandrel head and a main diameter slidable in the die opening 8. The impeller 20 forms part of a yoke member comprising a box 29 supported by a pair of supporting spindles 30, 31 rotatably mounted in bearings 81, 82 on a main slide 77 reciprocable in main guideways 78 mounted on a machine frame 79. Operation of a fluid motor 86 via a lost motion sub-guideway assembly 83, 84 moves the yoke forward on its slide to engage the mandrel midway in the sleeve blank and into contact with a similar mandrel head inserted from the other end of the sleeve and a stop 24 to abut the die face and arrest the movement of the mandrel 14, continued movement of the yoke moves the sleeve 18 along the mandrel to compress a ring of solder 26 against the rear face of the head 16 and squeeze it radially outwards to expand the sleeve locally into the recesses 13 to form the recesses 4 which are filled with the solder. This latter movement of the yoke compresses a multi-disc spring 52 located about the rear end of an inner liner 40 and at the same time draws fluid from a reservoir 53 past a non-return valve 58 via passageways 74, 75, 77 into the increasing annular recess 37a produced by the relative movement of the annular portion 38 of a liner 34 moving away from the enlarged portion 41 of the liner 40. Upon completion of the operation the yoke is retracted and rotated through 90 degrees to a charging position, during the rotation, a ball contact 70 is depressed by engagement with a cam 71 to release the non-return valve and allow the oil to return to the reservoir, the spring to expand and return the mandrel and sleeve to their starting positions. A quadrant 97 mounted on the slide 77 and engageable with a pinion 95 attached to the end of the spindle 31 is actuated by a roller 99 which engages with a cam 100 attached to the machine frame. During the initial movement of the sub-slide assembly 843 the yoke remains in the charging position, during the second movement, i.e. when the slides 77 and 83 are moving together, the roller 99 moves off the cam to cause the yoke to rotate into the operative position. A spring 103 connected to a plate 96 keyed to the spindle 31 and the quadrant pivot 98 serves to hold the roller 99 out of engagement with the cam 100 when the yoke is in the operative position. A radius arm 104 having an adjusting screw 105 is mounted on the spindle 30 and engages an abutment 106 on the main slide to limit the angular movement of the yoke. A strip feed and shaping device 108 comprises two pairs of peripherally grooved edge guiding rollers 109 and two pairs of driven shaping rolls 110, 111 which impart a corrugated cross-sectional form to a continuous strip of solder 94. The shaping rolls are driven via a shaft 114, gears 115, 116, 117, an Oldham coupling 120, bevel gears 122, 123, a one-way coupling 125, a shaft 126 and dog and friction clutches 127, 138. A roller 141 at the lower end of a spring 139 biased lever 133 is engaged by an adjustable stud mounted on the main slide 71, as the slide moves through the last part of its working stroke it rotates the lever 133 against the spring 139 to rotate the shaft and drive the rolls until the leading edge of the strip 94 abuts a stop plate 143 at which point the friction clutch slips to prevent distortion of the strip against the stop. The lever 133 is returned to its starting position by the spring 139. The forming roll may be manually operated via an extension shaft 121 or after disengagement of the dog clutch 127. A severing device comprises a reciprocable slide 162 driven by a rack-and-pinion 150, 151 carried on the sub-slide 83 via a cam and crank 153, 155, a tool carrier 165 pivotally mounted on the slide 162 comprising a shaped cutter 166 and a forming tool 167, and a cutter bar 169. Forward movment of the cutter severs a piece of solder from the strip and continued forward movement displaces the piece adjacent a recess 170 in the stop plate 143. The gap 144 above the plate 143 may be slightly tapered in the direction of displacement of the piece so that when the cutter is retracted by a spring 158 the piece of solder will be frictionally retained. During the return stroke of the slide 162 a pneumatic relay is operated to rotate the carrier 165, via a worm-and-wheel assembly, to position the forming tool 167 which is then driven forward during the next rotation of the cam 153 to deform the piece of solder about the mandrel 14 which is located in the charging position in the recess 170 of the plate 143. The forming operation is carried out during the forward movement of sub-slide 83, movement of the main slide 77 thereafter turns the mandrel 14 into its operative position, during the return motion of the slides 83, 77 severing of the solder strip and rotation of the mandrel into the charging position respectively is effected. An alternative method of forming the loop of solder about the mandrel 14 comprises feeding a length of solder 178 through a guide block 180 and deflecting it by means of an arcuate guide 181 around the mandrel when in its charging position. A reciprocating cutter bar 184 severs the strip and deforms the severed end, about the mandrel. The feed and severing drive means may be similar to those described above.