GB126489A - Improvements in Appliances for Polishing Glass and the like Substances. - Google Patents

Abstract

126,489. Taylor, W. May 21, 1918. Supplying abrading-materials.-Abrading-mate rial or lubricant is supplied automatically, and as required, to the contacting surfaces in glasspolishing machines, particularly lens-polishing machines of the type described in Specification 14651/15. The actual supply of lubricant is controlled by the variation in adhesion that takes place between the polisher and the lens as the existing supply of lubricant dries up. When the lateral pull thereby created reaches a predetermined strength, a spring-controlled member is moved, and causes a fresh amount of lubricant to be supplied. A constant circulation of lubricant is maintained in the pipes o<1>, c<1>, Fig. 1, by means of a centrifugal pump (not shown). Nozzles c, arranged near to the polishing-surfaces a, b, are normally kept closed by means of air-pressure supplied from a pipe c<8> holding the needle-valve c<3>, Fig. 5, closed against the pressure of a spring c<6>. A pipe h forms part of the same air-pressure. svstem, and is fitted with a valve j<4>, Figs. 3 and 4, which is opened by the lateral pull between the contacting surfaces when the lubricant becomes sticky, thereby lowering the air-pressure in the chamber c<7>, Fig. 5, and allowing the spring c<6> to retract the needle c<3>, and a fresh supply of lubricant to be sprayed from the nozzle c, preferably at the point where momentarily the surface of the work is exposed by the movement of the polisher. The valve j<4> is operated as follows. The ballpointed finger j<2>, Figs. 1, 3, and 4, which actuates the upper contacting surfaces b is carried by a link j, which is pivoted on a pin i. This pin is carried by an arm d<1> on a tubular bar d clamped bv a screw g, Fig. 4, to an arm f, which actuates the upper member b by ordinary mechanism (not shown). At the farther end of the link j is the valve j<4> seating on a bush d<2> at the end of the bar d, to which the pipe h is connected. At the other end of the link j is a graduated arm j', against which a plunger k<5> is pressed by means of a coiled spring k contained in a tubular holder k<1> pivoted at k<2> to the bar d. The turning-moment of the spring pressure on the arm j<5>, and consequently the force with which the valve j<4> is held in its seating, can be adjusted by varying the point at which the plunger k<5> engages the graduated arm j<5>. In this manner, the point at which the drag between the two contacting-surfaces shall be sufficient to cause the finger j<1> to overcome the force of the spring k holding the valve j<4> closed can be determined, and the supply of fresh lubricant controlled accordingly. Throttle valves p<2> control the supply of air pressure from the main pipe p to the pipes c<8>, p. Vacuum may be used instead of pressure. As an alternative method, the varying pull between the contacting surfaces may be applied to a dynamometer placed between a crank carrying the polishing- member and the actuating crank-shaft, the dynamometer being adjusted to yield at a predetermined lateral pull, as the lubricant dries, and thereby actuating means for supplying a fresh quantity of lubricant.