Durkoppwerke Gmbh

Durkopp Adler Aktiengellschaft

Rolf Ellermann

Wilhelm Stapel

Gunter Droste

A knee-operated switch for a working machine, the switch including a carrier supported to the machine and a profile extending off the carrier at an angle to the profile. The profile includes first and second elongate, parallel electric contact strips that are normally separated. Sheathing over at least one of the strips is deflectable to in turn deflect the contact strips into engagement. Support strips support the contact strips normally apart until the contact strips are deflected together. A flexible elastic housing over the sheathing and the strips is deflectable to deflect the sheathing to move the contact strips together. The switch profile extends over a length so that actuation can take place at different actuating points along the profile.

Knee-operated switch for a working machine, especially a sewing machine

A servo device for a multineedle sewing machine which includes two needle bars; driving and steop devices for said needle bars; devices for engaging and disengaging the two needle bars relative to the driving and stop devices; a feed-length adjustment device associated with at least one feed dog for the transport of the material being sewn; an adjustable thread tensioning device for the needle threads; devices for locking each needle bar selectively in its highest position; a positioning drive for the multineedle sewing machine; and a device including a position indicator attached to an arm shaft of the multineedle sewing machine, for adjusting the speed of rotation and positioning of the needle bars in predetermined positions. The servo device comprises a control system including a pair of electrical switches which respectively correspond to the needle bars, for controlling the engagement and disengagement of the needle bars relative to the driving and stop devices; a first setting device associated with the control system, for selectively interrupting the transport by the feed dog of the material being sewn; and a second setting device associated with the control system, for temporarily increasing a thread tensioning force exerted on the needle thread by the thread tensioning device.

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Bielefeld, Germany

Rolf Ellermann