GB611138A - Improvements in or relating to electrical reciprocating tools - Google Patents

Abstract

611,138. Vibratory tools. BURGESS BATTERY CO. April 23, 1946, No. 12233. Convention date, May 18, 1945. [Class 124] [Also in Groups XV, XVI, XXII and XXXV] In an electrical vibratory tool suitable for use as a dental hammer or for tamping, the tool proper 28 is carried at the forward end of a drive rod 25 which is guided axially during its reciprocation and is normally maintained out of the sphere of influence of an armature 16 which is intermittently urged forward upon energization of an electromagnet 13- 15, the drive rod being movable rearwardly into said influence. In the. form shown, the armature 16 is held at one end by a flange 17 on the magnet shell 12 and its other end projects through an opening 11 in the tubular tool stem 10, the shell 12 and stem 10 being enclosed in a two-part synthetic resin casing 18. Turning of the tool 28 is prevented by projections 31 on the drive rod engaging slots 30 in a bushing 23, adjustably screwed on to the stem 10. Similar projections 33 maintain a second rod 32 aligned with the rod 25, and sleeves 34, 35 slidable on the two rods are separated by a loose compression spring 36. The normal position of the end of the rod 32 in relation to the coil 13 is adjusted by means of the bushing 23, movement of which is limited by a shoulder 37. The stroke of the armature 16 is regulated by means of a spring- urged bolt 38, and the strength of the impulses is regulated by controlling the pressure of the tool 28 on the work. The tool may be operated by alternating current or by pulsating direct current. In one modification, the rods 25, 32 are replaced by a single rod, in a second the electromagnet is located at the extreme end of the tool, and in a third a slidable sleeve-shaped handle surrounds the tool stem.