Abstract: A percussive tool has a working tool mounted for reciprocations in a barrel. A collar is arranged between a shank and a working portion of the working tool. The shank of the working tool reciprocates in a guide bushing secured in the barrel to ensure reciprocations of the working tool. There is provide4d a member for determining the angular position of the working tool during the reciprications, the member comprising either the barrel proper in case of concrete breakers, or a hood, e.g. in chipping hammers. For positively controlling the angular position of the working tool, there is provided a spring having two portions of different cross-sectional configuration, a first portion being coupled for a combined rotation to the member determining the angular position of trhe working tool, and a second portion being of a cross-sectional configuration corresponding to the cross-sectional configuration of the working portion of the working tool.
December 7, 1978
Date of Patent:
November 10, 1981
Igor V. Nikolaev, Anatoly I. Lednikov, Boris G. Goldshtein, Leonid A. Gornik
Abstract: A knitting machine has a housing on which is displaceable a support cylinder carrying an array of parallel needle holders displaceable up and down. Two armed levers are pivoted on each of the holders and each have a forked arm formed with an actuating foot and with an anchor foot spaced by a gap from the actuating foot, and another arm that is engaged by a spring carried on the holder that normally tries to bias the lever to move from an operative position into an inoperative position. A slide cam on the housing has lobes or formations which are engageable with the actuating feet of the levers to displace the holders and engageable between the feet of the lever so as not to displace the holders. Furthermore, a tip cam is provided on the housing engageable with the other arm of each of the levers to displace it into the operative position.