Patent GB-190429200-A (GB)
Title: Improvements in or relating to the Manufacture of Cast Chain, and Apparatus therefor.
Inventor: HART HENRY
Filed: 1904-12-31
Granted: 1906-01-31
Abstract: 29,200. Hart, H. Dec. 31. Making chains ; casting ; milling ; sawing ; castings. - Chains, particutarly those made of aluminium or aluminium alloys, are cast by the use of a plurality of link-forming chill moulds combined with means for successively filling with molten metal, for removing the links thus produced from the moulds and transferring them to other moulds, where they are united by newly-cast links to the end of the growing chain, and for removing the gits from the cast links. The link moulds each comprise four parts 37, 37<a>, 38, 38<a>, Fig. 6, provided with registration projections and grooves and mounted in frames 39 having lugs by which they are linked together to form a chain 2, Fig. 1. Rollers on the pins of the chain run on tracks carried by the main frames. The parts 37, 37<a> are separated by springs 49 and closed by rollers 52 engaging cam-surfaces 53. The parts 38, 38<a> have motions away from the parts 37 and from each other, each motion being controlled by separate guides, springs, and cam-surfaces, the guides being universally arranged and all the springs being adjustably strained. The mould parts are recessed to receive links through which a new link is to be cast. The chain 2 passes round a driving-wheel 4; Fig. 2, and a tension wheel 3 with sliding spring bearings 6 controlled by screws 11 and worm gearing 13. The shaft of the wheel 4 carries two oppositely-set ratchet-wheels 17, 18. The wheel 17 has a spring detent 19 and a camactuated pawl 20. A pawl 29 on the other ratchetwheel acts as a locking-detent, prevents overrunning of the chain, and is lifted out of action by a cam just prior to the stroke of the pawl 20. The camsurfaces 53 have movable extensions 241 adapted to slide parallel to the directionof travel of the chain and controlled by.links and a cam. When a link has been cast at 238, the upper parts of the mould are opened, leaving the link partly exposed and held by the parts 37 ready to be gripped at the git by a transferring-device 134, Fig. 4. When the link is so gripped, the extensions 241 are withdrawn, allowing the spring 49 to separate the mould parts and release the link. The gripping-head of the device 134 is mounted on a carriage 128 sliding on guide-shafts 91, 92. rotatable in crossheads 89 connected to a system of bars and slides so as to have a vertical movement and a horizontal movement across the chain 2. The shaft 91 operates to rotate the gripping-head about the axis 143, Fig. 6, by a lug 133 and rod 132, Fig. 4, and the shaft 92 carries a pinion geared to a pinion on the shaft of the crank 142 by a sliding rack-bar 145, for operating a toggle 138 to open the grips 137, which are closed when free by a spring 139. The shafts are universally coupled through telescopic shafts 95, Fig. 2, to shafts 96, 97 controlled by a cam shaft 104 mitre-geared to the main driving and cam shaft 25. When the link is grasped, the head 134 is raised and rotated through 90 degrees, and the carriage is traversed towards the right of Fig. 4 and simultaneously or immediately after towards the left of Fig. 1. The transferred link is then situated equally over two adjacent moulds, and the head is lowered to deposit and release it. The carriage and head are then returned to their initial positions. The transverse and vertical movements are provided with antifriction rollers running on track bars. A compound roller bearing surface for the carriage 128 consists of a divided horizontal roller 147, Fig. 2, contacting with vertical rollers 148, 149, Figs. 2 and 4, set one on each side of the rollers 147 at such a distance apart that no one section of the roller 147 can contact with both of the vertical rollers at the same time. The longitudinal traverse of the carriage is effected by a rack-bar 153 geared at 154, 155 to a sector 156 on a shaft 157 which is oscillated by an arm 162 and a cam rod 165 working on an adjustable crank-pin. Adjustment of this pin is obtained by means of a screw provided with a bevel-wheel meshing with teeth on a sector 171 which is loose on the shaft and retains the arm 162 between an adjustable abutment 172 and a spring stop 173. Variation in length of the chain 2 causes the bearings 6 to be traversed by the springs, and correspondingly displaces a lever linked at 178 to a slidable wedge 177, adapted to contact with a pin 176 carried by the sector 171 and thereby to arrest the latter ; the spring 173 is thus compressed and the bevel-wheel rotated to cause the crank-pin to be set nearer the centre and to increase the oscillation of the shaft 157 and the sector 156. Motion of the wedge 177 in either direction affects the amount of this extra oscillation and automatically adjusts the travel of the link-transferring device to suit the altered length of the chain 2. Feelers 182, Fig. 3, pivoted on a slide and geared together at 186 test whether a link has been transferred by engaging the git. If the link is absent, the feelers rotate past one another, raising the tail 195 to the position shown in dotted lines in Fig. 3. A rod 198 is allowed to rise at this time under the influence of a spring by a cam 200, and, its end being no longer restrained at 195, it rises and displaces a lever 200<a> linked to a knock-off arm 203 for the clutch lever 206, thereby stopping the machine. The feelers are normally held apart by a spring 194. The feeler carriage moves on ways 229 and is controlled by a cam 189. Motion on the ways 229 is effected as required from the automatic compensating-link 178. The driving-pulley 211 is loose on the shaft, and is clutched by friction shoes 214 sliding in guides on a boss 212 keyed to the shaft and splined to the sleeve 216, which is grooved to receive it, and is rotatable in a ring 217 connected by a toggle 226 and link 227 to the operating- handle. Arms on the sleeve 216 are connected by toggle-levers to the shoes 214. The shaft end is bored to receive a headed stud 222 connected to the sleeve by a pin passing through slots in the shaft and boss, and outwardly impelled to maintain the clutch in the off' position by a spring abutting against the shaft end. Metal is introduced to the moulds at 238 and 239 from nozzle chambers 274 closed by conical-ended valve-rods 260, Fig. 5, weighted and cam-controlled. The chambers 274 are in open connection with containers 251 pivotally mounted on carriages resting on rails and traversable by screw and bevel gearing actuated by a rack-bar 260 on the link 178. The container is tilted by a cam to make tight contact between the nozzle and mould just prior to the raising of the rod 260. Heating- means are provided at 275. The cast chain is conducted from the moulds over a guide-pulley 276, and through guides past saws and milling or grinding discs which cut off the gits and smooth the link sides at the points of removal. These discs are independently driven as indicated diagrammatically in Fig. 2. Means may be provided for heating or cooling the moulds before or after casting, and for applying plumbago, asbestos, or like material to the mould surfaces, and a pump may be added to cast under pressure. The links may be transferred by way of an intermediate magazine, and the chain of moulds is removable and interchangeable.