Patent GB-543060-A (GB)
Title: Improvements in or relating to the heat-treatment of metal bodies
IPC: C21D9/30
Filed: 1940-07-12
Abstract: 543,060. Heat-treating metal bodies. SHORTER PROCESS CO., Ltd. (Linde Air Products Co.). July 12, 1940, No. 11618. [Class 72] In a method off heat-treating the surfaces of a plurality of integral portions of a metal body, e.g. cams on a cam shaft, said bodies having the same longitudinal extent, the body is resiliently supported at one end, a reciprocal motion of the body is produced by imparting a periodically recurring thrust to the opposite end, individual sources of heat are applied to each portion so as to heat only a portion longitudinally of the surface, and the amplitude of the reciprocal motion is controlled so that heat is not applied directly to the longitudinal edges of such surfaces, the heated surfaces being afterwards cooled. The shaft C is held between an upper assembly U Fig. 1 and a lower assembly L. The upper assembly comprises a spring-controlled centre 12 which engages the end of the shaft C and is provided with a boss 24 between which and the cap 22 of an externally-threaded housing 20 carrying an adjustable wheel is contained a spring 2'3. A protective shield 25 attached to the housing 20 extends downwardly over the upper end of the shaft C to prevent injury thereto by the blow pipes and the quenching device during the reciprocation of the shaft. The housing 20 is supported by a bracket 26 adjustably mounted on a column 14. The lower assembly L comprises a centre 13 engaging the lower end of the shaft and provided with a shoulder 30 against which is screwed tightly the internally expanding portion of a sleeve 31 which supports a skirt 29 surrounding the lower part of the shaft and is also provided with a depending skirt 34. Fitting in the lower part of the centre 13 is a bearing 34 provided with a flange 35 resting on, and secured to, a platform P which is provided with an aperture 37 through which the lower portion of the bearing 34 extends. To provide for the reciprocation of the centre 13, a motor M is secured to a bracket 38 secured to the underside of the platform and is provided with a speed reducer 39, Fig. 3, on the low speed shaft 42 of which is mounted an adjustable block 41 which carries a crank 40, a connecting rod 43 being pivotally attached at one end to the crank and at the other end by a pin 44 to a link 45 itself pivotally attached at one end to the centre 13 by a pin 46 and at the other end to a link 47 by means of a pin 48. The link 47 is pivoted on a normally fixed pin 49 so that the shaft 42 is rotated by the motor M, the lower end of the rod 43 will revolve and so through the link 41 reciprocate the centre 13, the amplitude of the reciprocation being controlled by the position of the block 41. To allow of the movement of the supporting members towards, and away from, each other the pin 49 connects the link 47 with an arm 50 attached to a shaft 51, Fig. 2, pivoted on collars 52 mounted on legs 53 of the platform P and is normally held in its initial fixed position by an arm 54 having at its outer end a pedal 55 provided with an extension '56 normally held in the downward position by a latch 57 attached to the lower end of a triangular frame 58. To place a shaft in position for treatment or to release a treated shaft the latch 57 is released allowing the pedal 55 to rise and with it the link 47 thus lowering the link 45 and with it the pin 46 and the centre 13. The blowpipes B and quenching device are adjustably supported on stanchions 11 which at their lower ends are mounted on slides S supported on the platform P. The ways 91 of the slides S are secured to the platform by bolts and are provided with slidable plates 92 secured to the stanchions 11, the other two stanchions being secured to plates 94 which pivot on studs 95 secured to the corresponding plates. To move the plates toward and away from the shaft C, they are provided with studs 95 which extend downwardly through slots 98 and are pivotally attached to links 99. which are pivotally attached to four corners of a square plate 100. Fig. 2. Rollers 101 secured to the underside of the platform P are provided with grooves slightly wider than the thickness of the plate 100, formed integrally with a handle H so that the plate will be supported by the rollers and rotate within the grooves. The oxygen and acetylene supply for the burners is turned on by the movement of a handle 102 of a rod 103 pivotally mounted in apertures in the legs 104 of the platform D and provided with a pin 105 engaging a hole 106 in a lever 81. By turning the handle H, lever 81 may be moved into any desired position e.g. in the direction of the arrow, Fig. 1, to turn on the gas supply. The handle H is movable along the upper leg of the frame 58 which is supported by brackets 107, 108, Fig. 2, and is provided with an abutment 109 which is contacted by the handle when it is moved from left to right to turn off the gas supply and turn on the quenching water. The gas supply is turned off by the engagement of a pin 110 on the plate 100 with an adjustable stop 111 attached to the'lever 8.1 and at the same time a roller 113 on a clevis 112 hinged to the plate 100 presses against a cam 88. pivoted on a pin 89 and supported by an elongated bracket 90 and turns on the water supply to the quenching device by depressing the plunger of a valve 87 in the supply pipe 85. When the heated cams have been cooled sufficiently the handle H is moved over the abutment 109 to its extreme right-hand position against the bracket 108. The slides 5 will then be moved to their extreme position and due to the shape of the cam 88 the rollers 113 will no longer depress the cam sufficiently to keep the valve 87 open. The treated cam shaft is now removed, an untreated one placed in position and the handle H moves from the right to the left to move the slides S and thus place the blowpipe in position for heating the cams on the shaft. Each blowpipe comprises a body 117 provided with valves to control the flow of oxygen and acetylene from pipes 60, 61 to a suitable mixer disposed within the body which is secured by ah adjustable clamp 118 to a stanchion 11. Attached to the forward end of the body is a tube 119. Fig. 5, connected by a pipe 120 to the burmer heads 121, 122 the perforated ends of which are parallel to the sides of the cam C. and which are cooled by water from a pipe 64 connected by an inlet 126 to the head 122 and thence by a passage to the heads 121, leaving the latter by a connection 128 to pipe 66. The quenching device Q comprises a jet directing head 130 disposed between the heads 121, 122 supported by a clamp 131 attached to the tube 119 and supplied with water from pipe 68 by an inlet 132. When the handle H is moved to the quenching position the gases will be automatically turned off and the water turned on. At the same time the heads 121, 122 and the head 130 will be moved into the dotted positions shown on Fig. 5, and the head 130 will direct the water on to the apex of the cam to spread out in two streams along each inclined surface of the apex. When the shaft C<SP>1</SP>, Fig. 9, is mounted in a horizontal position, the right centre is mounted in an assembly similar to the assembly U and the left centre in an assembly similar to the assembly L and reciprocated in similar manner. The blowpipes are supported on quadrants 15 secured to plates 16 by bolts 139 and mounted on transverse slides S<SP>1</SP> mounted on a frame F and the tubes 119 of the blowpipe are adjustably mounted on the quadrants 15 by U-shaped clamps 140 clamped by screws 141. The supply of gases to the blowpipe from the pipes 60<SP>1</SP>, 61<SP>1</SP> is controlled by a valve operated by a push-button switch. The slides S' are moved by a handle which when the cam surface has been heated to the desired temperature, is moved to the quenching position thus moving the slides S' and the burners away from the shaft C' and opening the water supply to the quenching means Q<SP>1</SP> comprising a pipe 157 leading to a plurality of branch pipe 158, the used quenching medium, which may comprise water or sodium hydroxide collecting in a trough 160. When the surface has been cooled sufficiently the handle S is moved through a right angle and thus operates a cam which slips past a roller pressing on a valve and allows this latter to close. In a further embodiment, the shaft may be mounted in a lathe bed in which front and rear slides are substituted for the usual cross slide, the tail stock centre being formed similarly to the assembly U and the head stock being utilized as a bearing and support for the reciprocating centre 13.