US3921043A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for maintaining substantially constant torque in a web transport apparatus
Assignee: Xerox Corp
•
Filing: 1973-12-14
•
Granted: 1975-11-18
•
Expires: 1993-12-14
Abstract
Abstract Method and apparatus for maintaining substantially constant the torque output from a first motor coupled to drive a first reel. A second motor is mechanically coupled to a second reel, the motors effecting a direct reel-to-reel drive whereby a web is transported therebetween. In normal directional mode of operation, current drawn by the armature of the first motor, proportional to the torque generated thereby, is monitored and applied to the armature of the second motor as a reverse biasing current therefor to provide a reverse torque to the second motor whereby the rotation of the first motor is opposed. The reverse torque adjusts the web tension in a manner to maintain the torque output of the first motor substantially constant.
Inventors
- 👤 Guillermo F Luzio
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:31
CPC Classifications
B; B65; B65H; B65H23/00; B65H23/04; B65H23/18; B65H23/1806; G; G11; G11B; G11B15/00; G11B15/18; G11B15/43
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
141 words
A method of maintaining substantially constant the torque output of a first motor driving a first reel, a web being transported between a second reel and said first reel comprising the steps of: driving said web from said second reel to said first reel, generating a voltage signal directly proportional to the current drawn by said first motor, comparing said voltage signal with a reference voltage and generating a signal representing the difference therebetween, said reference voltage corresponding to a predetermined torque output produced by said first motor, converting said difference signal to a reverse biasing current, and applying said reverse biasing current to a second motor mechanically coupled to said second reel to thereby provide a reverse torque To said second motor whereby tension is exerted on said web to maintain the torque output of said first motor substantially constant.
Claim 2
Independent Claim
141 words
A method of maintaining substantially constant the torque output of a first motor driving a first reel, a web being transported between a second reel and said first reel comprising the steps of: driving said web from said second reel to said first reel, generating a voltage signal directly proportional to the current drawn by said first motor, comparing said voltage signal with a reference voltage and generating a signal representing the difference therebetween, said reference voltage corresponding to a predetermined torque output produced by said first motor, converting said difference signal to a reverse biasing current, and applying said reverse biasing current to a second motor mechanically coupled to said second reel to thereby provide a reverse torque To said second motor whereby tension is exerted on said web to maintain the torque output of said first motor substantially constant.
Claim 3
Dependent Claim
20 words
The method as defined in claim 1 wherein the tension exerted on said web by said second motor is adjustable.
Claim 4
Dependent Claim
34 words
The method as defined in claim 1 wherein said reverse biasing current is of a polarity to cause said second reel to rotate in a direction to oppose the rotation of said first reel.
Claim 5
Dependent Claim
149 words
In a web transport control system wherein said web is transported between first and second reels, the combination comprising: a first motor operatively coupled to said first reel for driving said web in a first direction, a second motor operatively coupled to said second reel, means for generating a voltage signal which is directly proportional to the current drawn by said first motor, means for comparing said voltage signal with a reference voltage and generating a signal representing the difference therebetween, said reference voltage corresponding to a predetermined torque output produced by said first motor, means for converting said difference signal to a reverse biasing current, and means for applying said reverse biasing current to said second motor to thereby provide a reverse torque to said second motor whereby tension is exerted on said web to maintain the torque output of said first motor at a substantially constant value.
Claim 6
Dependent Claim
149 words
In a web transport control system wherein said web is transported between first and second reels, the combination comprising: a first motor operatively coupled to said first reel for driving said web in a first direction, a second motor operatively coupled to said second reel, means for generating a voltage signal which is directly proportional to the current drawn by said first motor, means for comparing said voltage signal with a reference voltage and generating a signal representing the difference therebetween, said reference voltage corresponding to a predetermined torque output produced by said first motor, means for converting said difference signal to a reverse biasing current, and means for applying said reverse biasing current to said second motor to thereby provide a reverse torque to said second motor whereby tension is exerted on said web to maintain the torque output of said first motor at a substantially constant value.
Claim 7
Dependent Claim
21 words
The combination as set forth in claim 4 wherein the tension exerted on said web by said second motor is adjustable.
Claim 8
Dependent Claim
34 words
The combination as defined in claim 4 wherein said reverse biasing current is of a polarity to cause said second reel to rotate in a direction to oppose the rotation of said first reel.
Claim 9
Dependent Claim
12 words
The combination as defined in claim 6 wherein said web comprises microfilm.
Claim 10
Dependent Claim
171 words
In a web transport control system wherein said web is transportable between first and second reels, the combination comprising: a first motor operatively coupled to said first reel for driving said web in a first direction, a second motor operatively coupled to said second reel, speed control means coupled to said first motor for supplying a control current to said first motor to control the operating speed of said first motor, means for generating a voltage signal which is directly proportional to said control current, means for comparing said voltage signal with a reference voltage and generating a signal representing the difference therebetween, said reference voltage corresponding to a predetermined torque output produced by said first motor, means for converting said difference signal to a reverse biasing current, and means for applying said reverse biasing current to said second motor to thereby provide a reverse torque to said second motor whereby tension is exerted on said web to maintain the torque output of said first motor at a substantially constant value.
Claim 11
Dependent Claim
171 words
In a web transport control system wherein said web is transportable between first and second reels, the combination comprising: a first motor operatively coupled to said first reel for driving said web in a first direction, a second motor operatively coupled to said second reel, speed control means coupled to said first motor for supplying a control current to said first motor to control the operating speed of said first motor, means for generating a voltage signal which is directly proportional to said control current, means for comparing said voltage signal with a reference voltage and generating a signal representing the difference therebetween, said reference voltage corresponding to a predetermined torque output produced by said first motor, means for converting said difference signal to a reverse biasing current, and means for applying said reverse biasing current to said second motor to thereby provide a reverse torque to said second motor whereby tension is exerted on said web to maintain the torque output of said first motor at a substantially constant value.
Claim 12
Dependent Claim
20 words
The combination as defined in claim 8 wherein the tension exerted on said web by said second motor is adjustable.
Claim 13
Dependent Claim
34 words
The combination as defined in claim 8 wherein said reverse biasing current is of a polarity to cause said second reel to rotate in a direction to oppose the rotation of said first reel.
Claim 14
Dependent Claim
12 words
The combination as defined in claim 10 wherein said web comprises microfilm.
Claim 15
Dependent Claim
72 words
The combination as defined in claim 8 wherein said speed control means comprises: means for generating a first signal which is representative of the velocity of the web, means for producing a second signal which is representative of a desired web velocity, means for comparing said first and second signals and generating a third signal which represents the difference therebetween, and means responsive to said third signal for generating said control current.
Claim 16
Dependent Claim
24 words
The combination as defined in claim 12 wherein said first signal generating means comprises a shaft encoder which is directly responsive to web velocity.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-17 | 1979-05-19 | 1979-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-17 | 1983-05-19 | 1983-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-17 | 1987-05-19 | 1987-11-18 | $7700.00 | Window Closed / Lapsed |