Abstract:
A hands-free dispenser has a body and a cover connected to the body. A sensor element is attached to the body. The cover has an opening that enables the sensor to protrude through the cover and extend beyond a plane of the cover when the cover is closed.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a hands-free dispenser for absorbent sheet products contained in roll form within a dispenser body, preferably paper towels. 
     2. Description of Related Art 
     Hands-free paper towel dispensers in which the towels are supplied in roll form are widely used in commercial establishments and have the advantage of relatively high capacity, and thus a less frequent need to replace the rolls. In addition, many users prefer these types of dispensers for hygienic reasons because the user need not touch the dispenser to obtain a quantity of paper towel. Current commercial embodiments of these paper towel housings are often made from molded plastics that are translucent or have white or off-white colors. 
     A number of prior art hands-free dispensers have a hand sensor mounted behind the front cover, which gives rise to certain limitations as will be discussed below. 
     SUMMARY OF THE INVENTION 
     The invention provides a hands-free dispenser comprising a dispenser body adapted to receive a roll of absorbent sheet products to be disposed within the dispenser; a cover secured to the dispenser body while permitting the cover to be opened for service of the dispenser or replacement of a roll of absorbent sheet products therein, the cover having an opening; and a sensor connected to the dispenser body and extending at least part way through the opening to protrude beyond a main plane of the cover when the cover is closed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other objects, features and advantages of the invention will become more apparent after reading the following detailed description of preferred embodiments of the invention, given with reference to the accompanying drawings, in which: 
         FIG. 1  is a perspective view showing an embodiment of a dispenser according to the present invention; 
         FIG. 2  is a front view showing the dispenser according to  FIG. 1  with the cover closed; 
         FIG. 3  is a side view showing the dispenser according to  FIG. 1  with the cover closed; 
         FIG. 4  is a sectional view through the line IV-IV of  FIG. 2 ; 
         FIG. 5  is an exploded view of a cassette of  FIG. 1 ; and 
         FIG. 6  is a front view of an embodiment of a sensor according to a preferred embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     In  FIG. 1 , it can be seen that the dispenser  1  comprises a cover  2  and a body portion  3 . The cover  2  in this embodiment is pivotally mounted to the body portion  3  via pivot pins  8  that pass through complementary aligned openings in the cover  2  and body portion  3 , although another hinge type or other pivotal mounting structure could also be used. The term “hinge structure” is used broadly herein to designate any structure that allows the cover to be pivotally mounted to the cover. The cooperating hinge structures could also take the form of bosses formed on the dispenser body that fit within openings formed on the cover. 
     With the cover closed as shown in  FIG. 3 , the cover  2  is held to the body portion  3  by a lock  7 , which involves a conventional key-actuated locking structure engaging with a cooperating locking structure on the body portion  3 . 
     In the presently preferred embodiment, the dispenser is a powered hands-free dispenser having an object sensor  10 . The object sensor  10  detects, for example, the presence of a user&#39;s hand, and in response to that detection automatically dispenses a predetermined or adjustable length of paper towel, which the user then tears off by pulling the towel against a cutting blade disposed inside the dispenser housing. The type of sensing is not limited in this invention, and could be for example passive or active infrared sensing, or sensing based on disruption of an electromagnetic field generated between a transmitting and receiving antenna. 
     As seen in  FIG. 1 , the body portion  3  supports the entirety of the object sensor  10 . Thus, when the cover  2  is opened, the object sensor  10  remains joined to the body portion  3  without any part of the sensor being connected to the cover  2 . Therefore, the openings in the cover  2  including dispensing opening  5 , and sensor opening  6  are distinctly defined. 
     In the presently preferred embodiment, the sensor  10  is part of a cassette  20  (see  FIGS. 1 and 5 ) that is removable from the remainder of the body portion  3 . Thus, reference to the “body portion” herein includes in this embodiment both the cassette and the remaining wall-mounted rear portion of body portion  3 . The cassette also includes a motor  40  and gearing  50  to drive a drive roller  15  for unwinding material from the roll of absorbent material R when the sensor  10  is activated. The cassette  20  may also include a cutting member  9  for cutting sheets of absorbent material that are to be dispensed through the dispensing opening  5 . 
     In the presently preferred embodiment as seen in  FIGS. 4 and 6 , the object sensor  10  includes an antenna printed circuit board (PCB)  14  having a pair of antennae  12 ,  13  thereon. The antenna PCB  14  and antennae  12 ,  13  in this embodiment remain outside a plane of the cover  2  when the cover is closed and extend through the sensor opening  6 . In greater detail, the PCB  14  preferably is disposed entirely forward of a plane containing at least part of each of the upper and lower outer edges of the opening  6 , when the cover is closed. The PCB  14  preferably projects at least partially through the opening  6 , it being understood that the area of the dispenser cover  2  surrounding opening  6  is a non-recessed region of the cover  2 . 
     A sensor lens  11  preferably surrounds the antenna PCB  14  and antennas  12 ,  13  to protect them. An advantage of this configuration of the antenna PCB  14  and antenna  12 ,  13 , is that it allows the cover  2  and/or the body portion  3  to be made from stainless steel, aluminum or other metal material, or metallized or metal-plated plastic material, without disruption of the electromagnetic field or IR radiation that might occur if the sensor were disposed behind a metallized or metal cover. Of course, the invention is nonetheless not limited to the use of a metal or metallized or metal-plated cover. A further advantage of this arrangement is that it eliminates the need for an external wiring harness to connect the sensor to a control board. 
     In alternative embodiments, cover  2  and body portion  3  may be made by injection molding of plastic. When the dispenser is plastic, cover  2  may be entirely opaque or mainly opaque or translucent, except in an area of the window  4 , which is preferably transparent. 
     Returning to  FIG. 1 , the body portion  3  comprises a rear mounting surface  30  that is generally perpendicular to the top, bottom and side surfaces. In the embodiment of  FIG. 1 , the rear mounting surface  30  includes mounting holes for mounting cassette  20  thereto. When the screws  22  holding the cassette  20  to the rear mounting surface  30  are unscrewed, the cassette may be readily slid from the body portion to, for example, enable batteries (not shown) that power the dispenser to be changed or so that the cassette can be returned to the manufacturer for repair and/or software upgrades. A replacement cassette may then be exchanged for the first cassette so that the dispenser can remain in use. Although a battery-operated dispenser is preferred, a hard-wired or plug-in or solar-powered dispenser is also within the scope of the present invention. 
     As to the roll R of absorbent sheet material to be dispensed from the dispenser, this roll may either be a continuous imperforate roll, which is detached from the roll by the user pulling the dispensed sheet against a cutting blade of the cutting member  9 , or may instead be a partially pre-cut web in which the force of the user pulling on the dispensed sheet serves to sever the tabs that connect the dispensed sheet to the next sheet to be dispensed, as is common in hands-free mechanical dispensers. Those pre-cuts can be made either during manufacturing converting of the roll, or in-situ by a blade in the dispenser that pre-cuts the tail of the sheet as it is being dispensed. 
     The term “absorbent sheet products” as used herein embraces not only paper products such as paper napkins, but also absorbent nonwoven materials not normally classed as papers or tissues. Such nonwoven materials include pure nonwovens and hybrid nonwoven/pulp webs whose properties are similar to those of tissue paper, but which are based for example on nonwoven or airlaid materials containing low amounts of synthetic fibers, binders, wet strength agents and the like. An example of such a material would be a wetlaid or foam-formed hydraulically entangled nonwoven material comprising at least 30% by weight pulp fibers and at least 20% by weight manmade fibers or filaments. 
     While the present invention has been described in connection with various preferred embodiments thereof, it is to be understood that those embodiments are provided merely to illustrate the invention, and should not be used as a pretext to limit the scope of protection conferred by the true scope and spirit of the appended claims.