GB878597A - Improvements in and relating to adjustable beds and the like - Google Patents

Abstract

878,597. Adjustable beds. DURA CORPORATION. Feb. 3, 1960, No. 3787/60. Class 52(2). [Also in Group XXIX] Two bed-operating double-acting hydraulic motors are interconnected by solenoid operated valves and a reversible pump that, by the operation of electrical switches alone, a single reversible electric motor can be used to operate either hydraulic motor separately or both motors together. As shown, a double-acting hydraulic ram 44 is pivoted at 46 to a stationary frame 10 and controls the angle of inclination of a U- shaped back-rest frame 20 pivoted at 26. The piston rod 42 of the ram acts on bell-crank lever 40 to turn shaft 32 and rotate frame 20 by means of connecting links 38. A second hydraulic ram 76 operates a foot section 56, Fig. 2, through a similar bell-crank lever 72 and links 82. The part 58 of the section is connected by pivots 88 and links 64 are constrained to lift the end 24 to about the level of the pivots 88. The rams 44 and 76 are operated by power unit 48 which consists of a reservoir, reversible pump and electric motor. In one direction of rotation of the motor the pump output enters lines 50 and 78 and in the other direction, the output enters lines 52 and 80. Solenoid operated valves are mounted in the cylinder heads of rams 44 and 76 (see Group XXIX) and the fluid cannot enter the cylinder to operate the ram piston until the appropriate solenoid or both solenoids are energized. A pushbutton switch control assembly, 142. Fig. 8, is connected with the forward and reverse field coils 178 and 176 of the motor and the solenoids of the valves in rams 44 and 76. The four buttons, when depressed, hold the switches 212, 214, 216 and 218 in the dotted line position. The circuit through the motor field coil 178, established by depressing switch 216 or 212, is broken if either switch 218 or 214 is simultaneously depressed. Neither can field coil 176 be energized by switches 218 and 214 while either switch 216 or 212 remains depressed. Depression of each switch operates a valve solenoid through lines 162, 202 and 210, 160.