| 摘要 |
679,478. Spring mechanisms. GENERAL BRONZE CORPORATION. June 3, 1949 [June 4, 1948], No. 14945/49. Class 108(iii) [Also in Group X] A balancer for a slidable window sash comprises a coil spring 10 surrounding a tube 16 and secured at one end thereto, the other end of the coil being attached to a window sash; and a spiral actuator 17 attached to the sash extends into the tube and engages a key guide formed by protusions 18 separate from and mounted within the lower end of the tube, so that on alteration of the tension of the spring on movement of the window, the torsion of the spring alters in the opposite sense. The upper end 12 of the spring is looped over a hollow rivet 11 receiving a screw attaching the tube 16 to the window frame. A swivel pin 14 with a head 14 rotates freely in a bracket on the sash and is slotted to receive the lower part of the actuator 17, the end 15 of the spring 10 passing through a hole in the part 17 and in the pin 13. An outer tube 19 protects the spring 10. The pitch of the actuator 17 is less at one end, preferably the free end. In Fig. 2 the upper end of the coil spring 20 is free to rotate by attachment to grooves in an adapter 25 carrying the inner tube 30 with a key guide 33 at its lower end, the adapter 25 rotating freely on a shaft 26 on a swivel bracket 27 screwed at 28 to the window frame. The lower end of the spring 20 is fixed in grooves in a member 22 fixed to a ratchet pin 23 in which is also fixed the lower end of the actuator 31. The head 24 of the pin 23 has notches engaged by a spring pawl 24<SP>1</SP> mounted on a bracket 21 by which the pin 23 is fastened to the sash. The initial torsion of the spring may thus be adjusted. |
