Browse Prior Art Database

Ratchet Driven Paper Tractor with Magnetic Detent

IP.com Disclosure Number: IPCOM000079269D
Original Publication Date: 1973-Jun-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 2 page(s) / 45K

Publishing Venue

IBM

Related People

Chai, HD: AUTHOR [+2]

Abstract

An electromagnetic actuator for a paper tractor comprises, as shown in Fig. 1, an armature 10 actuated by a winding 12 on a magnetic core 14. A resilient drive pawl 16 of plastic is attached to the armature and engages a ratchet wheel 18 attached to a sprocket wheel 20, having pins 22 for driving a flexible belt 24 furnished with pins 26 for engaging holes in a form to be fed, and positioned about an idler pulley 28.

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Ratchet Driven Paper Tractor with Magnetic Detent

An electromagnetic actuator for a paper tractor comprises, as shown in Fig. 1, an armature 10 actuated by a winding 12 on a magnetic core 14. A resilient drive pawl 16 of plastic is attached to the armature and engages a ratchet wheel 18 attached to a sprocket wheel 20, having pins 22 for driving a flexible belt 24 furnished with pins 26 for engaging holes in a form to be fed, and positioned about an idler pulley 28.

As shown in Fig. 2, the ratchet wheel 18 may be connected to the sprocket wheel (not shown in this figure) along with the toothed rotor 30 of a detent mechanism 32, having a corresponding stator 34. In the detent state, the ratchet voltage VR applied to the winding 12 is off and the detent voltage VD applied to the detent stator winding is on, as shown in Fig. 3.

When VR is turned on VD is turned off, and the armature 10 moves to drive the ratchet wheel 18 clockwise. As the sprocket wheel 20 rotates 1/2 pitch, VR is turned off and VD is turned on. While the pawl returns to the initial position, the reluctance torque of the toothed rotor 30 accelerates the sprocket wheel 20 and moves it to the next detent position corresponding to 1 pitch motion, as shown by the curves in Fig. 3.

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