US3724733A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Web infeed mechanism
Assignee: Harris Graphics Corp
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Filing: 1972-02-03
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Granted: 1973-04-03
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Expires: 1992-02-03
Abstract
Abstract An improved web infeed mechanism feeds a web of material to receiving rolls of a printing press and includes a web drive roll which is driven from the main press driveline through a chain drive assembly and harmonic drive unit. A hollow dancer roll is pivotally mounted on a pair of support arms and is pressed with a constant pressure against a bight portion of a U-shaped loop in the web by a pair of air cylinders. Upon movement of the hollow dancer roll from an initial position, a resilient member is flexed to change the resistance of a plurality of strain gauges on the resilient member. This results in a change in an output signal from a circuit containing the strain gauges and which signal is utilized to activate control apparatus to vary the peripheral speed of the web drive roll. This control apparatus includes a reversible permanent magnet control motor which is connected by a belt drive to a wave generator in the harmonic drive unit. To provide for an accurate response at different press speeds, the control apparatus also includes a tachometer which provides a signal which is directly proportional to the speed of rotation of the receiving rolls. This signal is multiplied by the signal from the strain gauges to provide an output signal which is utilized to energize the permanent magnet motor and vary the peripheral speed of the web drive roll upon movement of the dancer roll or a change in press speed.
Inventors
- 👤 R Schaffer
- 👤 J Crum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:17
CPC Classifications
B; B65; B65H; B65H23/00; B65H23/04; B65H23/18; B65H23/188; B65H23/1888; B65H2301/00; B65H2301/30; B65H2301/31; B65H2301/311; B65H2301/3112
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
395 words
An apparatus for feeding a web of material from a source to receiving rollers driven at a predetermined speed by a main drive mechanism, said apparatus comprising a web drive roll, a harmonic drive unit drivingly connected with said web drive roll, said harmonic drive unit including an input member driven by the main drive mechanism at a speed which is a direct function of the speed of the receiving rolls, an output member connected with said web drive roll and driven at a speed which is a function of the speed of said input member, and wave generator means drivingly connected with said output member and operable to vary the speed of said output member and web drive roll relative to said input member and receiving rolls, said apparatus further including motor means energizable in either a forward or a reverse direction to effect operation of said wave generator means to either increase or decrease the speed of said web drive roll relative to said receiving rolls to adjust the length of a variable length loop in the web, drive means for transmitting drive forces from said motor means to said wave generator means upon energization of said motor means in either the forward or reverse directions, dancer roll means disposed in engagement with a bight portion of the variable length loop at a location downstream of said drive roll and upsteam of the receiving rolls, arm means connected with said dancer roll means and extending transversely to a longitudinal axis of the variable length loop for supporting said dancer roll means for pivotal movement relative to said drive roll upon a change in the length of the loop, means for pressing said dancer roll means against the bight portion of the loop with a constant pressure to maintain a substantially constant tension in the web with variations in the length of the loop, sensor means connected with said arm means and said motor means for sensing changes in the position of said dancer roll means with variations in the length of the loop, and control means for effecting operation of said motor means to operate said wave generator means and vary the speed of said web drive roll relative to said receiving rolls in response to a sensing by said sensor means of a change in the position of said dancer roll means.
Claim 2
Independent Claim
395 words
An apparatus for feeding a web of material from a source to receiving rollers driven at a predetermined speed by a main drive mechanism, said apparatus comprising a web drive roll, a harmonic drive unit drivingly connected with said web drive roll, said harmonic drive unit including an input member driven by the main drive mechanism at a speed which is a direct function of the speed of the receiving rolls, an output member connected with said web drive roll and driven at a speed which is a function of the speed of said input member, and wave generator means drivingly connected with said output member and operable to vary the speed of said output member and web drive roll relative to said input member and receiving rolls, said apparatus further including motor means energizable in either a forward or a reverse direction to effect operation of said wave generator means to either increase or decrease the speed of said web drive roll relative to said receiving rolls to adjust the length of a variable length loop in the web, drive means for transmitting drive forces from said motor means to said wave generator means upon energization of said motor means in either the forward or reverse directions, dancer roll means disposed in engagement with a bight portion of the variable length loop at a location downstream of said drive roll and upsteam of the receiving rolls, arm means connected with said dancer roll means and extending transversely to a longitudinal axis of the variable length loop for supporting said dancer roll means for pivotal movement relative to said drive roll upon a change in the length of the loop, means for pressing said dancer roll means against the bight portion of the loop with a constant pressure to maintain a substantially constant tension in the web with variations in the length of the loop, sensor means connected with said arm means and said motor means for sensing changes in the position of said dancer roll means with variations in the length of the loop, and control means for effecting operation of said motor means to operate said wave generator means and vary the speed of said web drive roll relative to said receiving rolls in response to a sensing by said sensor means of a change in the position of said dancer roll means.
Claim 3
Dependent Claim
41 words
An apparatus as set forth in claim 1 wherein said dancer roll means includes a hollow cylinder and axially extending support means connected with said cylinder and said arm means for supporting said cylinder for rotation relative to said arm means.
Claim 4
Dependent Claim
142 words
An apparatus as set forth in claim 2 wherein said support means includes a shaft extending axially through said cylinder and bearing means for supporting said cylinder for rotation relative to said shaft, said arm means including first and second pivotally mounted arm members connected to opposite end portions of said shaft to support said cylinder for pivotal movement upon a change in the length of the loop, said means for pressing said dancer roll means against the bight portion of the loop including a first air cylinder connected with said first arm and a second air cylinder connected with said second arm and means for equalizing forces applied by said first and second air cylinders against said first and second arms to maintain said hollow cylinder in a predetermined orientation relative to the web as the length of the loop varies.
Claim 5
Dependent Claim
105 words
An apparatus as set forth in claim 1 wherein said control means includes first signal generator means for supplying a first signal which varies as a function of variations in the speed of the receiving rolls, said sensor means including second signal generator means for supplying a second signal which varies as a function of variations in the length of the loop, said control means being connected with said first and second signal generator means and said motor means for effecting operation of said motor means at a speed which varies as a function of variations in a multiple of said first and second signals.
Claim 6
Dependent Claim
75 words
An apparatus as set forth in claim 1 wherein said sensor means includes a resiliently yieldable member, means for flexing said yieldable member to an extent which varies with pivotal movement of said dancer roll means, and strain gauge means connected with said yieldable member for providing an output signal which varies as a function of the extent to which said yieldable member is flexed in response to pivotal movement of said dancer roll means.
Claim 7
Dependent Claim
37 words
An apparatus as set forth in claim 1 further including chain drive means operatively connected with said main drive mechanism and said input member for driving said input member at the same speed as said receiving rollers.
Claim 8
Dependent Claim
44 words
An apparatus as set forth in claim 1 wherein said drive means includes first pulley means connected to said motor means, second pulley meAns connected to said wave generator means, and belt means for transmitting drive forces between said first and second pulley means.
Claim 9
Dependent Claim
39 words
An apparatus as set forth in claim 1 wherein said motor means includes a permanent magnet field winding and armature coil means for receiving a signal which varies as a function of variations in the length of the loop.
Claim 10
Independent Claim
359 words
An apparatus for feeding a web of material from a source to receiving rollers driven at a predetermined speed by a main drive mechanism, said apparatus comprising a web drive roll, a harmonic drive unit drivingly connected with said web drive roll, said harmonic drive unit including an input member driven by the main drive mechanism at a speed which is a direct function of the speed of the receiving rolls, an output member connected with said web drive roll and driven at a speed which is a function of the speed of said input member, and wave generator means drivingly connected with said output member and operable to vary the speed of said output member and web drive roll relative to said input member and receiving rolls, said apparatus further including motor means for effecting operation of said wave generator means to either increase or decrease the speed of said web drive roll relative to said receiving rolls to adjust the length of a variable length loop in the web, drive means for transmitting drive forces from said motor means to said wave generator means, dancer roll means disposed in engagement with a bight portion of the variable length loop at a location downstream of said drive roll and upstream of the receiving rolls, said dancer roll means including a hollow cylinder disposed in engagement with the bight portion of the loop, a shaft extending axially through said hollow cylinder, and bearing means for rotatably supporting said hollow cylinder on said shaft, said apparatus further including means for pressing said hollow cylinder against the bight portion of the loop with a constant pressure to maintain a substantially constant tension in the web with variations in the length of the loop, sensor means for sensing changes in the position of said hollow cylinder with variations in the length of the loop, and control means for effecting operation of said motor means to operate said wave generator means and vary the speed of said web drive roll relative to said receiving rolls in response to a sensing by said sensor means of a change in position of said hollow cylinder.
Claim 11
Independent Claim
359 words
An apparatus for feeding a web of material from a source to receiving rollers driven at a predetermined speed by a main drive mechanism, said apparatus comprising a web drive roll, a harmonic drive unit drivingly connected with said web drive roll, said harmonic drive unit including an input member driven by the main drive mechanism at a speed which is a direct function of the speed of the receiving rolls, an output member connected with said web drive roll and driven at a speed which is a function of the speed of said input member, and wave generator means drivingly connected with said output member and operable to vary the speed of said output member and web drive roll relative to said input member and receiving rolls, said apparatus further including motor means for effecting operation of said wave generator means to either increase or decrease the speed of said web drive roll relative to said receiving rolls to adjust the length of a variable length loop in the web, drive means for transmitting drive forces from said motor means to said wave generator means, dancer roll means disposed in engagement with a bight portion of the variable length loop at a location downstream of said drive roll and upstream of the receiving rolls, said dancer roll means including a hollow cylinder disposed in engagement with the bight portion of the loop, a shaft extending axially through said hollow cylinder, and bearing means for rotatably supporting said hollow cylinder on said shaft, said apparatus further including means for pressing said hollow cylinder against the bight portion of the loop with a constant pressure to maintain a substantially constant tension in the web with variations in the length of the loop, sensor means for sensing changes in the position of said hollow cylinder with variations in the length of the loop, and control means for effecting operation of said motor means to operate said wave generator means and vary the speed of said web drive roll relative to said receiving rolls in response to a sensing by said sensor means of a change in position of said hollow cylinder.
Claim 12
Dependent Claim
96 words
An apparatus as set forth in claim 9 wherein said sensor means includes means for providing a signal which varies as a function of the direction of movement of said hollow cylinder from a predetermined position, said control means including means for effecting operation of said motor means in a forward direction in response to movement of said hollow cylinder in a first direction from the predetermined position and for effecting operation of said motor means in a reverse direction in response to movement of said hollow cylinder in a second direction from the predetermined position.
Claim 13
Dependent Claim
58 words
An apparatus as set forth in claim 9 wherein said sensor means includes a flexible member, means for flexing said member to an extent corresponding to the extent of movement of said hollow cylinder, and strain gauge means for providing an output signal which varies as a function of the extent to which said flexible member is flexed.
Claim 14
Dependent Claim
53 words
An apparatus as set forth in claim 9 further including first and second arm members fixedly connected with opposite end portions of said shaft and means supporting said arm members and hollow cylinder for rotation about a common axis extending parallel to and spaced apart from the longitudinal axis of said hollow cylinder.
Claim 15
Independent Claim
356 words
An apparatus for feeding a web of material from a source to receiving rollers driven at a predetermined speed by a main drive mechanism, said apparatus comprising a web drive roll, a variable speed drive unit drivingly connected with said web drive roll, motor means energizable In either a forward or a reverse direction to effect operation of said variable speed drive unit to either increase or decrease the speed of said web drive roll relative to said receiving rolls to adjust the length of a variable length loop in the web, drive means for transmitting drive forces from said motor means to said variable speed drive unit upon energization of said motor means in either the forward or reverse directions, dancer roll means disposed in engagement with a bight portion of the variable length loop at a location downstream of said drive roll and upstream of the receiving rolls, means for pressing said dancer roll means against the bight portion of the loop with a constant pressure to maintain a substantially constant tension in the web with variations in the length of the loop, sensor means operatively connected with said dancer roll means for sensing changes in the position of said dancer roll means with variations in the length of the loop, said sensor means including first signal generator means for providing a first signal which varies as a function of the extent and direction of movement of said dancer roll means from an initial position upon a variation in the length of the loop, and control means connected with said sensor means and said motor means for effecting operation of said motor means to operate said variable speed drive unit to vary the speed of said web drive roll relatife to said receiving rolls, said control means including means for providing a second signal which varies as a function of variations in the speed of the receiving rolls, multiplier means for providing a third signal which is a direct function of the product of said first and second signals, and means for effecting operation of said motor means in response to said third signal.
Claim 16
Independent Claim
356 words
An apparatus for feeding a web of material from a source to receiving rollers driven at a predetermined speed by a main drive mechanism, said apparatus comprising a web drive roll, a variable speed drive unit drivingly connected with said web drive roll, motor means energizable In either a forward or a reverse direction to effect operation of said variable speed drive unit to either increase or decrease the speed of said web drive roll relative to said receiving rolls to adjust the length of a variable length loop in the web, drive means for transmitting drive forces from said motor means to said variable speed drive unit upon energization of said motor means in either the forward or reverse directions, dancer roll means disposed in engagement with a bight portion of the variable length loop at a location downstream of said drive roll and upstream of the receiving rolls, means for pressing said dancer roll means against the bight portion of the loop with a constant pressure to maintain a substantially constant tension in the web with variations in the length of the loop, sensor means operatively connected with said dancer roll means for sensing changes in the position of said dancer roll means with variations in the length of the loop, said sensor means including first signal generator means for providing a first signal which varies as a function of the extent and direction of movement of said dancer roll means from an initial position upon a variation in the length of the loop, and control means connected with said sensor means and said motor means for effecting operation of said motor means to operate said variable speed drive unit to vary the speed of said web drive roll relatife to said receiving rolls, said control means including means for providing a second signal which varies as a function of variations in the speed of the receiving rolls, multiplier means for providing a third signal which is a direct function of the product of said first and second signals, and means for effecting operation of said motor means in response to said third signal.
Claim 17
Dependent Claim
67 words
An apparatus as set forth in claim 13 wherein said signal generator means includes a flexible member, means for flexing said flexible member to an extent which is directly proportional to the extent of movement of said dancer roll means from the initial position, and strain gauge means for providing a resistance which varies as a function of the extent to which said flexible member is flexed.
Claim 18
Dependent Claim
57 words
An apparatus as set forth in claim 14 wherein said strain gauge means includes a plurality of strain gauges, and said multiplier means includes means for connecting said strain gauges in a bridge circuit and for imposing on said bridge circuit a voltage which varies as a function of variations in the speed of said receiving rolls.
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) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |