Apparatus and Methods Usable in Connection With Dispensing Flexible Sheet Material From a Roll

• US 20080087758A1
• Filed: 12/10/2007
• Published: 04/17/2008
• Est. Priority Date: 03/07/2002
• Status: Active Grant

• Current Assignee: GPCP IP Holdings LLC
• Original Assignee: Georgia Pacific Consumer Operations LLC (KOCH Industries Incorporated)
• Inventors: Formon, John, Morris, Andrew, Gahris, David, Susi, Michael
• Granted Patent: US 7,845,593 B2
• Time in Patent Office: Days
• US Class Current: 242/563
• CPC Class Codes: A47K 10/36 with mechanical dispensing, roll switching or cutting devices
• CPC Class Codes: A47K 10/3612 with drive and pinch rollers
• CPC Class Codes: A47K 10/3625 with electronic control means
• CPC Class Codes: A47K 2010/3668 Detection of the presence of a user
• CPC Class Codes: A47K 2010/3881 with tearing edges having movable parts
• CPC Class Codes: B65H 35/10 from or with devices for breaking partially-cut or perforated webs, e.g. bursters
• CPC Class Codes: H03K 2017/9606 using one electrode only per touch switch
• CPC Class Codes: Y10T 225/12 With preliminary weakening
• CPC Class Codes: Y10T 225/205 With feed-out of predetermined length from work supply
• CPC Class Codes: Y10T 225/209 With feed-out of lead-end to aid initial grasping
• CPC Class Codes: Y10T 225/232 Plural supply sources
• CPC Class Codes: Y10T 225/238 With housing for work supply
• CPC Class Codes: Y10T 225/268 By resiliently engaging package ends or interior of core
• CPC Class Codes: Y10T 225/30 Breaking or tearing apparatus
• CPC Class Codes: Y10T 83/541 Actuation of tool controlled in response to work-sensing means
• CPC Class Codes: Y10T 83/8822 Edge-to-edge of sheet or web [e.g., traveling cutter]
• CPC Class Codes: Y10T 83/889 Tool with either work holder or means to hold work supply
• CPC Class Codes: Y10T 83/896 Rotatable wound package supply

Abstract

A powered dispenser for dispensing individual sheet segments from a continuous roll of sheet material provided with spaced tear lines comprises a powered feed mechanism, a releasable, powered drive mechanism, a powered transfer mechanism, a pair of web sensing sensors, a capacitive sensing system providing automatic sensitivity adjustment, and control circuitry. A dual power supply system provides a mechanical lock-out functionality, and the control system is protected from electrostatic build-up on the surface of the feed roller. The web sensor, and an antenna plate of the capacitive sensing system, are provided on respective printed circuit boards mounted in overlying relation. Utilizing signals received from the pair of web sensors and the capacitive sensing system, the control circuitry senses the presence of a user to activate the powered drive mechanism, and prevents further dispensing of the sheet material until a previously dispensed segment is separated from the roll. The web sensors detection of a leading edge of the sheet material initiates a predetermined interval of sheet material advancement providing a proper placement of successive tear lines. Various approaches may be utilized to accommodate inadvertent sheet “tabbing” scenarios. The web sensors, together with the control circuitry, are also used to detect the depletion, or absence, of a working roll of sheet material, whereupon the control circuitry controls the powered transfer mechanism to automatically transfer the web feed supply from a depleted working roll to a reserve roll. The powered transfer mechanism may include a motor driven transfer bar, or provide motor driven release of a spring biased transfer bar. Another arrangement allows for ready release of a roll core, and drop of the same into an open dispenser cover for removal.

Claims

1. A dispenser for dispensing flexible sheet material, comprising:

a support for rotatably supporting a roll of sheet material;

a feed mechanism for advancing the sheet material from said roll;

a motor for driving the feed mechanism;

a plurality of sensors spaced along a width of said sheet material for detecting respective leading edge portions of said sheet material and outputting respective signals indicative thereof, and

a control device for receiving said respective signals and controlling said motor to drive said feed mechanism to dispense a predetermined length of the sheet material from the point at which a leading edge portion is first detected by one of said plurality of sensors.

2. The dispenser of claim 1, further comprising a structure defining a discharge chute downstream of said feed mechanism, and wherein said plurality of sensors are mounted on said structure to detect the presence and absence of sheet material within said discharge chute.

3. The dispenser of claim 2, wherein said plurality of sensors comprise a plurality of optical sensors.

4. The dispenser according to claim 3, wherein said optical sensors are mounted in spaced relation on a printed circuit board extending along a width of said discharge chute.

5. The dispenser according to claim 4, wherein said printed circuit board is snap-fit within a slot providing a passageway through said structure to said discharge chute.

6. A dispenser for dispensing flexible sheet material, comprising:

a support for rotatably supporting a roll of sheet material;

a feed mechanism for advancing the sheet material from said roll;

a motor for driving the feed mechanism;

a sensor for detecting a leading edge portion of said sheet material and outputting a signal indicative thereof,

a measurement device for measuring a first interval of advancement of said feed mechanism terminating with a detection of a leading edge portion by said sensor; and

a control device for receiving signals from said sensor and said measurement device and for controlling said motor to drive said feed mechanism to dispense a predetermined length of the sheet material from a determined initialization point, said control device comprising;

a storage device for storing a nominal measure of said first interval of advancement;

a comparator for comparing a measurement of said measurement device with said nominal value; and

determination means for determining said initialization point for a given dispense cycle based upon an output of said comparator.

7. The dispenser according to claim 6, wherein for a current dispense cycle said determination means selects as said initialization point the point at which said sensor detects a said leading edge, if a difference between a measurement of said measurement device for the current dispense cycle and said nominal value does not exceed a predetermined amount, and selects as said initialization point a point corresponding to said nominal value if said difference exceeds said predetermined value.

8. The dispenser according to claim 7, wherein the nominal value stored in said storage device is calculated based upon measurements made by said measurement device.

9. The dispenser according to claim 8, wherein the nominal value is a moving average of measurements made by said measurement device for past dispense cycles.

10. The dispenser according to claim 6, wherein said measurement device comprises a shaft encoder that counts intervals of displacement of a feed roller of the feed mechanism.

11. A dispenser comprising:

a housing having a discharge opening;

a support within the housing for supporting a continuous strip of sheet material having a plurality of spaced tear lines defining leading and trailing edges of individual removable segments, with an outer segment having a free leading edge and inner segments which in turn become outer segments as adjoining outer segments are removed;

a feed mechanism for repeatedly moving the sheet material in advancement and retraction intervals, said advancement intervals serving to advance successive outer ones of said segments through the discharge opening and out of the housing, said retraction interval serving to initialize the sheet material for said advancement interval;

a sensor for repeatedly detecting arrival of a said leading edge of retracting sheet material at a first position defining the end of said retraction interval and the beginning of said advancement interval, as sheet material is repeatedly retracted back into the discharge opening; and

a control device for receiving a signal from the sensor indicating a said arrival of a said leading edge at said first position, and for initiating said advancement interval from said first position, said advancement interval terminating when said leading edge of the sheet material has advanced from said first position a predetermined amount, to repeatedly place said spaced tear lines at a second position that is variable downstream of said first position in relation to variations in the lengths of said segments, said second position defining the beginning of a said retraction interval for a next adjacent segment, when it is in turn initialized for said advancement interval.