This invention relates to apparatus operable to dispense paper toweling or other paper sheet material from a roll. More particularly, the invention relates to paper sheet material dispensers employing electric motors to advance the sheet material during the dispensing operation.
Electro-mechanical dispensers employing an electric motor to transport toweling during a dispensing operation are well known. Such arrangements include both dispensers which are manually actuated, as by means of a push button, and those employing a sensor, such as a sensor sensing proximity of a user's hand, to initiate operation.
U.S. Pat. No. 6,820,785 issued Nov. 23, 2004, discloses an electro-mechanical roll towel dispenser including a housing with a roll carrier disposed therein to rotatably support a roll of towel material. An electro-mechanical feed mechanism is disposed in the housing to dispense measured sheets of the towel material. The feed mechanism operates in a first mechanical operational mode wherein the towel sheets are dispensed by a user grasping and pulling on a tail of the towel material extending from the housing, and a second electrical operational mode wherein a measured length of a next sheet is automatically fed from the housing to define the tail for the next user.
The dispenser of U.S. Pat. No. 6,820,785 includes a sensor for detecting a parameter that is changed by an initial pull exerted on a tail of a web of material extending from the opening of the dispenser. The sensor also generates a signal sent from the sensor to a control circuit or circuitry causing the motor employed in the apparatus to drive the feed mechanism until a measured length of web material that includes the tail of web material has been fed from the dispenser in the form of a measured sheet for subsequent removal by the user.
Similar devices are disclosed in U.S. Pat. No. 3,730,409 and Patent Publication Document WO 00/63100. The devices of these latter two documents have sensors for detecting movement of a tail end of web material such that the feed mechanism is activated in response to detecting the movement.
U.S. Pat. No. 8,382,026, issued Feb. 23, 2013, relates to a multi-function paper towel dispenser selectively operable to dispense paper toweling from a roll of paper toweling employing a plurality of alternative operational modes. The desired mode of operation can be selected utilizing control switches associated with sensor structure and electronic control circuitry of the dispenser. The multi-function paper towel dispenser is characterized not only by its versatility, but by its relative simplicity, ease of use and reliability in any of the operational modes selected. Two of the modes are a paper hidden mode and a paper exposed mode, each of which utilizes sensor structure in combination with electronic control circuitry to operate an electric motor driven rotatable toweling support roller to partially cut and dispense the paper toweling. The electric motor is also utilized to rotate the paper toweling support roller when not employing the sensor structure, the motor essentially operating in a hybrid mode wherein a pull force exerted on the toweling tail initiates rotation of the toweling support roller, the electric motor then being energized to reduce the pull force required by a user to effect final dispensing of a towel. Furthermore, a user can manually rotate the paper toweling support roller to effect dispensing of a towel in any of the modes.
The sensor structure of the multi-function paper towel dispenser is operatively associated with the electric motor to energize the electric motor and cause rotation of the toweling support roller to transport the paper toweling for dispensing from the dispenser in either a first mode of operation wherein the electric motor is energized responsive to the sensor structure sensing positioning of a user's hand at a predetermined location external of the housing or in a second mode of operation wherein the electric motor is energized responsive to the sensor structure sensing the removal of a toweling tail from a location external of the housing.
U.S. Pat. No. 8,555,761 discloses another type of “hybrid” mode wherein an electric motor provides a tail if needed. The term “hybrid” encompasses either motor assist type, which could be used in one dispenser, if desired, using a selector switch.
A common feature of electro-mechanical paper toweling material dispensers is an electric motor which is operatively associated with a rotatable paper sheet support roller and which starts and stops to deliver the leading end of the toweling to a desired position (which may be either within the dispenser housing in certain types of dispenser operations or outside the dispenser housing in other types of dispenser operations).
It is important to provide consistent length of the towel portion to be dispensed and thus uniform placement of the leading end of the towel portion. This is true regardless of cutter blade type employed in a dispenser, whether fixed or toweling support roller mounted. Consistent towel portion length is especially useful in certain dispenser types allowing a motor assist mode wherein an overrun can trigger a second sheet to dispense.
As will be described below, the present invention utilizes dynamic braking in a unique combination with certain other paper sheet material dispenser apparatus components. While dynamic braking structures are known, use of such structures with paper sheet dispenser apparatus as disclosed herein is novel.
With the invention disclosed herein the tail remains consistent whether the batteries powering the DC motor employed have full voltage or are drained.
The tail also remains consistent as the roll diameter is consumed from a full roll (large diameter) to consumed roll (small diameter).
Another advantage is that a manufacturer can have a larger manufacturing tolerance for its mechanisms. That is, tail length consistency is less affected by tight or loose mechanisms.
The present invention relates to paper sheet material dispenser apparatus for dispensing paper sheet material from a roll of paper sheet material having an existing tail portion with a leading end.
The apparatus includes a housing having a housing interior and defining an opening communicating with said housing interior.
A roll support is within said housing interior for rotatably supporting the roll of paper sheet material, the sheet material support roller having a cylindrically-shaped outer peripheral surface.
The apparatus also includes a DC motor for receiving DC power from a DC power source, the DC motor operatively associated with the sheet material support roller for rotating the sheet material support roller to move the tail portion relative to the opening to a preselected position with the leading end thereof disposed either within the housing interior or externally of the housing.
Dynamic braking structure is operatively associated with the DC motor responsive to termination of DC power from the DC power source to the DC motor to brake the DC motor and place the tail portion at said preselected position.
Other features, advantages and objects of the present invention will become apparent with reference to the following description and accompanying drawings.
Referring now to the drawings, a multi-function paper towel dispenser constructed in accordance with the teachings of the present invention is illustrated. As explained and disclosed in greater detail below, the dispenser is selectively operable to dispense paper toweling from a roll of paper toweling employing a plurality of alternative operational mode, one of the modes being a “hybrid” mode wherein an electric motor assists user to reduce pull force or provide a tail.
The paper towel dispenser disclosed in U.S. Pat. No. 8,382,026 and incorporated herein by reference includes a housing 10 (shown in
Mounted in the interior of the housing 10 is an assembly 14 (see
A rotatable toweling support roller 18 has a cylindrically-shaped outer peripheral surface and is rotatable in a predetermined direction of rotation. A cutter blade 20 (see
A cam follower 22 and cam system 24 (
Rotation of toweling support roller 18 will cause the cam followers to move along the cam surfaces defining the channels. This, in turn, will cause the cutter blade 20 to pivot relative to the toweling support roller 18.
The cutter blade is movable between an inactive position wherein the cutter will not sever the toweling and a severing position wherein the cutter blade is positioned outwardly of the toweling support roller to at least partially sever the toweling on the toweling support roller.
An electric motor 30 is operatively associated with the toweling support roller for selectively rotating the toweling support roller. A mechanical electric switch 32 is operatively associated with the electric motor and with the toweling support roller. The electric switch is electrically connected to the electric motor through a microprocessor of circuit board 62.
The electric switch 32 is responsive to rotation of the toweling support roller 18 by a user of the dispenser from a rest or inactive position to a first position to energize the electric motor when the toweling support roller reaches the first position and cause rotation of the toweling support roller by the electric motor from the first position to a second position and reducing the pull force required by a user pulling the paper toweling during rotation of the toweling support roller between the first position and the second position. Further, the mechanical electrical switch 32 is responsive to rotation of the toweling support roller beyond the second position to deenergize the electric motor. This mode of operation, sometimes hereinafter referred by as a hybrid or third mode of operation, is described in more detail below.
Mechanical electric switch 32 includes a switch actuator element 34 having a roller 36 at the end thereof which is biased into engagement with a circular end 38 of the toweling support roller 18. The switch actuator element 32 alternatively opens or closes the switch during rotation of the toweling support roller.
Located at circular end 38 of the toweling support roller and engaged by the switch actuator element roller during rotation of the toweling support roller is an arcuate projection 40. The projection extends only part way along the periphery of the toweling support roller and has two tapered projection ends 42. Extending completely about circular end 38 and disposed outwardly of the arcuate projection is a toweling support roller gear 44 having teeth. Meshing with the teeth of the toweling support roller gear are teeth of a drive gear 46 which is driven by electric motor 30, the latter suitably being in the form of a DC gear motor. A one-way clutch needle bearing 48 connects the drive gear to the electric motor to allow the performance of certain functions indicated below. Electric wiring connects the switch 32 to the electric motor through a microprocessor.
The multi-function paper towel dispenser incorporates sensor structure operatively associated with the electric motor to energize the electric motor and cause rotation of the toweling support roller to transport the paper toweling for dispensing. This sensor structure is utilized in conjunction with electronic control circuitry in a manner which will now be described.
The sensor structure is identified by reference numeral 60 and employs a “bouncing” technology in the infrared spectrum that bounces a wave off a hand or paper to activate the unit. That is, the sensor structure is operatively associated with the electric motor to energize the electric motor and cause rotation of the toweling support roller to transport the paper toweling for dispensing from the multi-function paper toweling dispenser in either first mode of operation wherein the electric motor is energized responsive to the sensor structure sensing positioning of a user's hand or other object at a predetermined location external of the housing or in a second mode of operation wherein the electric motor is energized responsive to the sensor structure sensing the removal of a toweling tail from a location external of the housing.
The control switch panel 64 and control switches shown in
A second mechanical electric switch 76 is employed when the multi-function paper towel dispenser operates in either the paper hidden mode or paper exposed mode to stop rotation of the toweling support roller when the dispensing cycle is completed. Switch 76 is fixedly mounted adjacent to toweling support roller gear 44 and is engageable during rotation of the toweling support roller by a projection 78 extending from the gear 44. Once the first and second mode mechanical electrical switch 76 is engaged by the projection 78, rotation of the toweling support roller and transport of the toweling will come to a stop.
Switches 32 and 76 may be incorporated in a manually operated knob such as that disclosed in co-pending U.S. patent application Ser. No. 13/317,492, filed Oct. 19, 2011.
During rotation of the toweling support roller the blade associated with the toweling support roller will cut the sheet, the amount of which is controlled by the position of the actuator of mechanical electric switch 76. In a preferred actuator position, the sheet is cut more than ninety percent. This allows the user to easily remove the sheet with a very light pull force. When the sheet is removed by the user, the dispenser will not dispense another sheet until the user puts a hand under the sensor.
When the control circuit receives a signal to turn off the motor it removes power at the relay. This removes the power to the motor and connects the motor terminals together (NC position).
When powered, the windings/coils of the DC motor 30 store electro-magnetic energy by means of an electrical field. When the power to the motor is disconnected this energy field collapses and supplies electrical energy that further sustains the motor rotation. With dynamic braking, as this field collapses this electro-magnetic energy is applied back to the motor by using the relay 104 (or H-Bridge as shown in
A diode 102 is employed in the circuit to protect the circuit from reverse EMF (Electro Motive Force) developed at the motor. That is, EMF refers to the voltage generated by a spinning motor. Reference numeral 106 depicts Magnetic Field at the motor.
Every time the DC motor 30 turns off it brakes, regardless of the dispensing mode. The DC motor 30 is operatively associated with the sheet material support roller of the dispenser for rotating the sheet material support roller and moving the tail portion relative to the housing exit opening to a preselected position with the leading end thereof either within the housing interior or externally of the housing, depending upon which dispensing operation employing a DC motor is being carried out.
Use of an H-Bridge is preferred because it consumes less electricity than a mechanical relay and costs less.