A roll holder is inserted with a hollow tube of one of a first roll having a first inner diameter and a second roll having a second inner diameter greater than the first inner diameter. The roll holder includes a holder and a cam assembly that are supported by a support shaft and movable in an axial direction of the support shaft. The cam assembly includes an abutment and a cam. The abutment contacts a lateral end of the second roll in the axial direction of the support shaft. The cam presses against one of a first presser and a second presser of the holder in a radial direction of the support shaft to cause the one of the first presser and the second presser to press against and hold an inner circumferential face of the hollow tube of the one of the first roll and the second roll.

A tape applicator including a housing and an adjustment mechanism. The housing partially defines a cavity. The adjustment mechanism includes a course and an adjustment plate. The course includes a plurality of positions. The adjustment plate is movable along the course among the plurality of positions. The adjustment plate is held in a selected position of the plurality of positions by the housing based on a size of a tape roll configured to be supported in the cavity.

A thick document conveying device includes a paper pickup mechanism. The paper pickup mechanism has a pick roller base, a pick roller axle, a pick roller, a switching assembly, a first universal coupling, a driving mechanism, a second universal coupling, a bearing and a gear. The pick roller axle and the pick roller are located in the pick roller base. The switching assembly is located under the pick roller base. The first universal coupling is connected to the pick roller axle. The driving mechanism is sleeved on the first universal coupling. The second universal coupling is connected to the driving mechanism. The bearing is connected to the driving mechanism. The gear is connected to the bearing. As described above, both a thick document and a thin document can be adapted.

A tape holder allows a person to hold and dispense masking tape easily when preparing for painting or performing other tape related activities. The tape holder may include a first portion that is capable of sliding into or out of a person's pants pocket while a second portion extends out of the pocket and holds one or more rolls of tape. Embodiments of the tape holder are economically made from a single length of bent rod. The tape holder allows the user to easily and quickly remove and replace a roll of masking tape.

A print media holder device has first and second grip members. Permanent magnets are attached to the first and second grip members. An electromagnet is disposed between the first and second grip members, where when the electromagnet is selectively energized the permanent magnets attached to the first and second grip members are repelled in a manner that increases the outer dimension of the print media holder device to grip a media core.

Methods and apparatus for supporting a paper roll in a paper bucket of a printer are provided. The paper bucket may comprise a curved base portion for accepting paper rolls of varying widths, two oppositely disposed side walls movably mounted to the curved base portion, and a two-part spring-loaded spindle assembly extending through each of the side walls and adapted to support a paper roll therebetween. Each spindle assembly may comprise a first spring loaded spindle part and a second spring loaded spindle part movably connected to one another.

A tape dispenser includes a plastic injection molded frame with a resiliently flexible finger that helps prevent the free end of a roll of tape from accidentally retracting, falling back, and frustratingly sticking to the coiled portion of the tape. To avoid this problem, a distal end of the finger presses against the inner diameter of a cardboard or plastic spool about which the tape is wrapped. Friction between the finger's distal end and the spool's inner diameter inhibits reverse rotation of the spool. To avoid breaking the finger while forcefully loading the roll of tape into the dispenser during assembly, a lateral backstop surface on the dispenser prevents the spool from bending the finger too far in a laterally outward direction. To avoid breaking the finger during subsequent rough use, another backstop surface prevents the spool from bending the finger too far in a radially downward direction.

A winding and unwinding system for electrode plate includes a winding and unwinding box, a cooling unit, and a control unit. The winding and unwinding box includes a box body and a box door jointly defining a box space, an electrode plate discharge port provided on a side of the box body, a rotating shaft provided in the middle of the box space, an electrode plate cylinder connected to and driven by the rotating shaft, a first temperature sensor monitoring temperature of the electrode plate, a first gas detector monitoring oxygen concentration inside the winding and unwinding box, gas inlet and outlets located at bottom and top of the box body, respectively. The cooling unit communicates with the gas inlet. The control unit controls the cooling unit to regulate the temperature of the electrode plate and the oxygen concentration inside the winding and unwinding box.

A method of dispensing sheet material from two rolls includes dispensing a first sheet of material from a first roll of the material located at a first location, lowering the first roll from the first location as the first sheet of material is being dispensed, lowering a second roll of material onto a second location above the first location when the first roll has been lowered to a location below the first location, and dispensing a second sheet of material from the second roll. A dispenser allowing for dispensing from two rolls includes a first wall having a forward end, a second wall opposite and spaced apart from the first wall and a cam coupled to each wall.

A print media holder device has first and second grip members. Permanent magnets are attached to the first and second grip members. An electromagnet is disposed between the first and second grip members, where when the electromagnet is selectively energized the permanent magnets attached to the first and second grip members are repelled in a manner that increases the outer dimension of the print media holder device to grip a media core.