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Paper Feed Motor

IP.com Disclosure Number: IPCOM000089140D
Original Publication Date: 1977-Sep-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 3 page(s) / 52K

Publishing Venue

IBM

Related People

McQuade, DJ: AUTHOR [+3]

Abstract

A paper feed motor is shown in Fig. 2. This motor is of an improved form which eliminates potentially unreliable operation and high noises and severe wear that may accompany use of a design using a single coil spring output drive and an electromagnet input drive. The improvement is to utilize linear springs to follow the magnetic input force curve more exactly so that a higher output load force is provided. Lower noises and wear are achieved by a more efficient mechanical design.

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Paper Feed Motor

A paper feed motor is shown in Fig. 2. This motor is of an improved form which eliminates potentially unreliable operation and high noises and severe wear that may accompany use of a design using a single coil spring output drive and an electromagnet input drive. The improvement is to utilize linear springs to follow the magnetic input force curve more exactly so that a higher output load force is provided. Lower noises and wear are achieved by a more efficient mechanical design.

In Fig. 1 the electromagnetic force available at the output end of an armature attracted to an electromagnetic coil is shown versus the gap between the armature and the stationary pole pieces. This is curve 1 in Fig. 1. The present design motor uses only a coil spring to drive the feed wheel, and this wastes all of the energy above the dotted line in region 1 of Fig. 1, since the coil spring is linear in its output force in this region. In regions 2 and 3 the amount of energy wasted is less, but other problems can occur. In regions 2 and 3 the gap is growing larger, and the coil spring is releasing its force to drive the motor. If greater force can be exerted, potential unreliable operation in the motor can be alleviated.

Turning to Fig. 2, the mechanical design for the present motor is shown. A paper frictional feed wheel 5 is attached through a shaft to a ratchet wheel 6 which is driven by pawl 7. Pawl 7 is oscillated in the vertical direction by the forces of a coil spring 8 and a moving armature 9. Armature 9 is driven by electromagnetic core 10, which is energized by magnet coil 11. Pole piece 12 operates to confine the magnetic flux path to strongly attract armature 9. A flat spring 13 has been attached to the underside of armature 9, as shown, and a cantilever leaf spring 15, which is adjusted by positioning a slider...