GB434070A - Improvements in and relating to dovetailing machines - Google Patents

Abstract

434,070. Dovetailing - machines. DRAPAK, O., DRAPAK, A., and DRAPAK, J., R÷chlitz, near Reichenberg, Czecho Slovakia. Dec. 13, 1934, Nos. 35854 and 35855. Convention dates, Dec. 14, 1933 and April 18, 1934. [Class 145 (i)] The movements of a dovetailing - cutter are controlled by a pin moving around a template the profile of which corresponds to one notch between two dovetails, the required number of dovetails being cut by repeated traversals of the pin around the template. In a dovetailing- machine, Fig. 1, the rotary cutter 7 and its driving motor 8 are mounted in a frame 9 which can move longitudinally on bars 19 mounted in a transverse slide 21. A bar 4 provided with a handle 5 passes through a guide 6 on the machine frame and through the cutter frame 9 ; by means of a wire 11 actuated by a lever 10 on the handle 5, a lever 13, Fig. 4, mounted in the frame 9 is rotated against the action of a spring 14 to force the bar 4 against a toothed rack 15 mounted in the frame 9, which is thus clamped to the bar 4 to move therewith. A pin 3<1> carried by the bar 4 engages the edge of a template 1, Fig. 2, removably secured to the machine frame, and having a single notch 2<1> corresponding to the space between two dovetails. Transverse movement of the cutter frame 9 is effected by a two-armed lever pivoted on the bar 19, one arm of this lever being formed as a handle 18, the other arm being connected by a link with the machine frame. By means of the handles 5, 18 the pin 3<1> is caused to trace out the outline of the notch 2<1>, the frame 9 being clamped to the bar 4 so as to move forwardly therewith; the clamping device 13, 15 is then released so that the bar 4 can be moved back to its initial position while the frame 9 remains stationary. In this manner a number of dovetails are cut by repeated passages of the pin 31 around the profile of the single-notched template 1. Two boards 2, 3 are clamped together at right-angles by clamping beams moved by screws against spring pressure. A member 25 ensures the positioning of the vertical board 2 with its lower edge level with the lower face of the horizontal board 3 ; the member 25 is then retracted by linkwork actuated by a handle 32. The machine may be portable so as to be mounted on a bench ; the cutter may be driven by an electric motor, compressed air or by a flexible shaft.