Browse Prior Art Database

Nonstick Capstan Pinch Rolls

IP.com Disclosure Number: IPCOM000088698D
Original Publication Date: 1977-Jul-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 2 page(s) / 14K

Publishing Venue

IBM

Related People

Denson, RL: AUTHOR [+3]

Abstract

This article describes a means for producing nonsticking, nonwetting capstan pinch rolls.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 52% of the total text.

Page 1 of 2

Nonstick Capstan Pinch Rolls

This article describes a means for producing nonsticking, nonwetting capstan pinch rolls.

Conventional friction magnetic tape drives, such as those used in low cost audio tape players, consist of a driven capstan to which the tape is pinched by an idler roll. The idler roll is (made of an easily deformed elastomeric material which conforms to the capstan and produces relatively uniform forces normal to it. This increases the wrap of the magnetic tape about the capstan to produce sufficient contact area for generating the required drive force on the tape. The viscoelastic properties which allow elastomeric materials to work well in these applications also lead, upon prolonged static engagement under pressure, to contact wetting of the contacted tape which then follows the idler roll on start-up to produce a wrap about the idler roll and consequent breakage of the tape.

It would be desirable to use inexpensive audio tape players to read digital information in operating as a storage for initial program loading in data processing machines. Due to the aforementioned contact wetting problem of the conventional pinch rolls on audio tape, these devices cannot be left engaged to a tape during static conditions. This requires the operator to engage the drive initially and to disengage it after use. If contact wetting could be avoided, the device could be used more conveniently with a remote control without operator intervention by leaving the drive engaged and starting the device with automatic equipment.

It is well known that low energy surfaces, such as those produced by fluorocarbons, reduce the tendency of contact wetting against other surfaces. At the same time, surface friction and traction characteristics are drastically reduced. Elastomeric materials under static loads conform to the loading surface and, in the case of capstans in tape drive mechanisms, this conformance or "set" is so great that high initial traction force by the capstan is necessary t...