GB489547A - Improvements in and relating to elastic force and equipoising mechanisms - Google Patents

Abstract

489,547. Balancing-apparatus. CARWARDINE, G. Jan. 26, 1937, No. 2236. [Class 78 (ii)] [Also in Groups XXXII, XI, XIV, and XXIV] An equipoising mechanism comprises a collapsable linkage, carrying at one point the mass to be balanced and connected at another point to a support, and two springs or sets of springs, one of which is connected so as to act between the support and the linkage and which, while opposing the gravitational pull on the mass, tends to cause the distance between the said two points to change, and the other of which is connected to act between two points on the linkage so as to counteract this tendency. The springs are wound so that they exert a force proportional to the distance between the points between which they act. In one form, Fig. 4, a lamp 3 is pivoted at Z to a double lazy-tongs linkage which is pivoted at H to a member 1 rotatable on a pin carried by a support 2 secured to a wall. A pair of springs A, B support the lamp and exert a force tending to .close the linkage, this force being balanced by the springs C, D. In another form, Fig. 10, used for supporting a mirror 25, the links of the lazy-tongs are staggered to enable the mirror to be moved close to the wall 1. Other forms are described in which a parallelogram linkage is used, or in which the lazy-tongs linkage is pivoted to the support by means of a Hooke's joint. The mechanism shown in Fig. 4 may be modified to support a vertically movable easel. In a further modification, Fig. 12, the mass to be balanced or a member to which a spring is connected is fixed to a pulley 32, pivoted to the linkage, and a second pulley 31 is fixed to the support, a ribbon 34, fixed at its ends to the pulleys and passing over an intermediate pulley arrangement 35, 36, 37, being provided so that the mass or member always remains in a fixed angular relationship with the support. Specifications 404,615 and 433,617 are referred to.