Abstract: A device for engaging in and disengaging printed circuit cards from the associated card holding frame is provided, which comprises at least an operating lever and at least a card guide element having at each of its ends a head portion, the guide element head portion facing the outside of the card holding frame being provided with means for receiving by snap action said operating lever, said operating lever having a means for engagement with the card so that the rotation of the operating lever causes the card to be engaged in or disengaged from the card guide element.

Abstract: Disclosed is a device for adjusting the length of a rod, which comprises in combination a cylindrical body provided with an internally embedded nut for allowing the external male screw formed on the peripheral surface of a rod to be driven therethrough and adapted to be freely moved in the direction of the length of the rod by the rotation thereof around its axis, a pair of freely swingable pawls disposed in an opposed relationship and extended via constrictions serving as hinges therefor from the upper edge of the cavity of said cylindrical body, an annular operating member encircling the upper edge of the cavity of said cylindrical body and having the outer ends of said pawls connected thereto, whereby a vertical movement imparted to said annular operating member causes the inner free ends of said pawls to plunge into or emerge from said cavity and consequently come into or out of engagement with a flattened portion formed above said male screw on said rod and enable the movement of said cylindrical body to

Abstract: Disclosed is a plastic cord clamp which comprises a pair of opposed arcuate holding members having the lower ends thereof connected with each other through an intervening thin-walled hinge portion to form a roundly bent main clamp body, said hinges portion being flexible to the extent of allowing said opposed holding members to diverge or converge freely about said hinge portion as the fulcrum, mutually engageable pawls formed one each at the upper ends of said pair of holding members and a pair of leg members formed one each at the lower ends of said pair of holding members and adapted to protrude outwardly therefrom tangentially to the clamp body in opposite directions, whereby said two leg members converge when said upper ends of holding members are opened to admit a cord between the two holding members and the leg members diverge and come into fast engagement with the edges of matching perforations bored in a holder plate when said engaging pawls are closed in on the admitted cord and brought into mutual