Patent GB-553033-A (GB)
Title: Improvements in or relating to typographical slug casting machines
IPC: B41B11/52
Filed: 1941-11-03
Abstract: 553,033. Pumps for molten metals. TURNER, H. K. (Mergenthaler Linotype Co.). Nov. 3, 1941, No. 14176. [Class 102 (i)] [Also in Group XVI] In a pump for molten metals the stroke of the pumpplunger is effected in three separate stages, the first two being produced by cam action and the third by pneumatic action. Air is expelled from the throat of the metal-pot during the first stages, and the metal is injected. into the mould during the third stage. After the casting, the level of the metal in the pot is restored by a dipper, which supplies metal from a reservoir. A wiper, which cleans the mouthpiece before it engages the mould, is yieldingly mounted so as to avoid interference with the mouldcarrier. The action of the pump is prevented if the line is not clamped by the lefthand vice-jaw, or if the mould does not move forward into contact with the matrices, or the metal-pot does not make contact with the mould. (1) The metal-pot O<SP>1</SP>, Fig. 4, is divided by a partition O<SP>2</SP> into a main compartment O<SP>3</SP> and a reservoir O<SP>4</SP>, the upper edge of the partition determining the level of the metal in the main compartment. The pot is mounted on a carriage K, which is moved horizontally on rollers into casting position by the action of toggle-levers and a cam. The pump plunger P is given a constant stroke and is operated for the actual injection of the metal by a piston working in a double-acting air cylinder S, the admission of air to which is controlled by a cam-operated valve. The downward movement of the piston is reinforced by a spring. The rod S<SP>17</SP> of the piston is attached at its lower end to a hollow block S<SP>16</SP>, in which is mounted to slide a headed rod Z, Fig. 6, supported by a spring Z<SP>1</SP>. The rod Z is connected through a block Z<SP>2</SP> and a releasable latch to the upper end of the plunger-rod P<SP>1</SP>. The action of the piston is at first prevented by a cam-controlled dog L, which projects beneath the block S<SP>15</SP> on the piston-rod. The first downward movements of the plunger are effected by a cam-operated lever J, which acts on a lug on the block Z<SP>2</SP>, the spring Z<SP>1</SP> being thereby compressed. In the first stage, the lever J depresses the plunger far enough to close the admission port o of the pump - well O<SP>7</SP>. This prevents the metal in the well and throat from being disturbed and spilt during the forward movement of the pot. After the movement of the pot to casting position, the lever J effects a further downward movement of the plunger, which raises the metal to the top of the throat and drives out the air. The dog L is then retracted by a cam, and the air pressure on the piston causes the metal to be injected into the mould. After the casting, the plunger is raised by the piston, the air supply to which has been reversed. The ascent of the plunger is arrested by the lever J in a position in which the admission-port o is still covered, so that splashing of the metal is prevented during the backward movement of the pot. The yielding of the spring Z<SP>1</SP> permits the piston to return to its uppermost position, in which it is then locked by the dog L. The lever J is then permitted to rise by its cam, so that the plunger is fully raised by the spring Z<SP>1</SP>. (2) Metal is supplied to the main compartment O<SP>3</SP>, Fig. 4, of the pot from the reservoir O<SP>4</SP> by a vertically moving dipper N operated by a rod N<SP>1</SP> from the plunger-rod, the metal flowing from the dipper over the edge of the partition O<SP>2</SP> The descent of the dipper is cushioned by a spring N<SP>4</SP> to prevent splashing, and its temperature is maintained by a skirt N<SP>10</SP>, which depends into the metal. (3) A wiper Q for the pot mouthpiece is carried by arms Q<SP>1</SP> pivoted on the pot and depressed by a spring under the control of a cam. The wiper is pivoted to plates q<SP>13</SP>, which can yield rearwardly against the pull of a spring q<SP>16</SP> in the event of obstruction. The wiper is held up to the mouthpiece by a spring q<SP>17</SP>. (4) The pump is locked out of action by pivoted stops R, R<SP>1</SP>, Fig. 6, which obstruct the movement of the dog L and the lever J unless moved into inoperative position by an aircylinder R<SP>4</SP>. Air is admitted to the cylinder by a spring-closed valve, which is opened when a rod Y<SP>8</SP>, Fig. 16, slidable lengthways through the left-hand jaw G, is pushed back by contact of the jaw with the matrices M or with the opposite jaw. The supply-pipe to the spring-closed valve also contains two-bleeder-valves, both of which must be closed before the pump is unlocked. One Y<SP>3</SP> of these is closed by a plate a<SP>5</SP>, mounted on the mould-carrier A<SP>1</SP>, when the mould A makes contact with the matrices. If the carrier does not contain a mould, the plate a<SP>5</SP> moves endways, so that it does not close the valve Y<SP>3</SP>. The other bleedervalve is closed when the pot mouthpiece makes contact with the mould. Specifications 551,161, 551,171 and 551,185, [all in Group XVI], are referred to.