Apparatus and methods usable in connection with dispensing flexible sheet material from a roll
View Patent ↗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.
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 structure defining a discharge chute of the dispenser downstream of said feed mechanism;
a transfer mechanism for contacting a leading segment of sheet material extending from a roll and moving said sheet material into a feed nip of said feed mechanism;
a plurality of sensors for detecting the presence and absence of sheet material in said discharge chute and outputting respective signals indicative thereof; and
a control device for receiving said respective signals, and controlling said motor to selectively drive said feed mechanism in response thereto to dispense a predetermined length of the sheet material from the point at which a leading edge portion is detected by at least one sensor of said plurality of sensors, said control device further determining, based upon said signals, a condition wherein a working roll of sheet material is either absent or depleted, and in response to said determination controlling said transfer mechanism to attempt a transfer of feed to a new roll of sheet material.
2. The dispenser according to claim 1 , wherein said control device determines a depletion or absence of a working roll based upon at least one sensor of said plurality of sensors detecting the absence of sheet material in said discharge chute for a predetermined interval of advancement of said feed mechanism by said motor.
3. The dispenser according to claim 2 , wherein said predetermined interval of advancement is set by a sheet detection timer of said control device.
4. The dispenser according to claim 1 , wherein said transfer mechanism comprises a motor, the operation of which is controlled by said control device.
5. The dispenser according to claim 4 , wherein said transfer mechanism motor drives a transfer bar of said transfer mechanism to move toward said feed nip of said feed mechanism, for contacting a leading segment of sheet material extending from a roll and moving said sheet material into said feed nip of said feed mechanism.