Abstract:
A cam holder system is described. A cam mechanism allows the holder to accept sheet material and be closed easily, while still maintaining strong holding power. The holder is formed by two or more separate pieces of extruded rigid material that slide together. End caps can be used to hold the pieces in alignment with each other so that they do not slide apart when the holder is opened. The cam is located near the middle of the assembly so that the user has leverage when opening and closing the holder. The holder can be squeezed in one direction to open the holder, and in the other direction to close the holder. A lever arm for closure is located above the cam, and a lever arm for opening is located below the cam. The receiving slot is located on-center so that the holder and the sheet material remain aligned with each other during use.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a cam holder system. More particularly, the present invention relates to a cam holder system for clasping sheet material. 
         [0003]    2. Description of Related Art 
         [0004]    In general, display holders are used for suspending replaceable sheet material, such as posters, pictures, signs, and advertisements. They are traditionally placed in public areas, such as storefronts, buses, taxicabs, stands, and the like. In retail locations, signs are hung in windows or inside the store to draw customers and passersby into the store, and/or to advertise a special item or promotion. These retail locations may be standalone big box stores or specialty shops, or may be located within shopping or strip malls. Display holders may also used in private areas, such as offices and homes, for displays, presentations, or decorations. 
         [0005]    Traditional devices for gripping and suspending sheet material are either suspended from the ceiling or affixed to a wall. The devices are designed to receive and engage the material easily, while bearing the weight of the suspension. However, many traditional devices fail to adequately meet this objective. 
         [0006]    One traditional suspension device uses a two-piece aluminum construction. The two rails come together on the side, forming a gap that is used to insert the sheet material. The holder is easy to close, but requires a tool to open. A more recent system allows the two halves of the holder to come together at the top of the holder so that the user can pry it open by hand. However, the halves are very close together, making opening difficult. Other holders have hinged clips with limited ranges of motion, while still others use basic clips that are sometimes unable to support the weight of the sheet material. 
       SUMMARY OF THE INVENTION 
       [0007]    Thus, there is a need in the art for a system for clasping sheet material that is designed to readily and easily receive and engage sheet material such that the sheet material can be changed as frequently as desired. Furthermore, there is a need in the art for a system that provides sufficient clamping engagement to support the weight of the sheet material. 
         [0008]    A cam holder system is described that meets these and other needs. A cam mechanism allows the holder to accept sheet material and be closed easily, while still maintaining strong holding power. The holder is formed by two or more separate pieces of rigid material that slide together. The material may be extruded aluminum, stainless steel, plastic, and the like. The surface of these outer pieces can be any shape. In one embodiment, the pieces have a concave curve shape that assists in opening and closing the cam holder by hand. The pieces may be shaped to create a funnel-shaped slot when the two halves are in an open position, allowing for easy introduction of sheet material into the receiving slot. End caps can be used to hold the pieces in alignment with each other so that they do not slide apart when the holder is opened. 
         [0009]    Sheet material may be any material capable of being clasped, such as, for example, posters, pictures, signs, and advertisements, made of a wide variety of stock, such as paper, metal, plastic, rubber, glass, etc. The stock may be coated, laminated, or plain, and may be flexible or rigid. Furthermore, the stock may be soft or hard, and have a high or low coefficient of friction. 
         [0010]    The cam is located near the middle of the assembly so that the user has leverage when opening and closing the holder. The outer pieces can be squeezed in one direction to open the holder, and squeezed in the other direction to close the holder. A lever arm frame member for closure is located above the cam, and a lever arm for opening the holder is located below the cam. The receiving slot is located on-center so that the cam holder system hangs straight in alignment with the received sheet material. 
         [0011]    In one embodiment, a cam holder system for clasping sheet materials between a pair of cam surfaces is provided that comprises: a first elongated frame member having a first cam surface defined thereon; a second elongated frame member having a second cam surface defined thereon; a hinge element coupled to the first elongated frame member and the second elongated frame member to pivotally attach the first elongated frame member to the second elongated frame member with the first cam surface and the second cam surface opposing one another and to define an axis of rotation substantially in the longitudinal center of the first elongated frame member and the second elongated frame member about which the first elongated frame member and the second elongated frame member rotate relatively; wherein the first cam surface and the second cam surface are on the same side of the axis of rotation in a latitudinal direction of the first elongated frame member and the second elongated frame member to allow the first cam surface to move relatively toward the second cam surface when the first elongated frame member and the second elongated frame member rotate relatively about the axis of rotation. 
         [0012]    In one example, the first elongated frame member includes a first leg and a second leg and the hinge element is coupled to the first elongated frame member by the first leg. In another example, the second elongated frame member includes an outer closing arm positioned substantially above the longitudinal center, an outer opening arm positioned substantially below the longitudinal center, and an inner arm, and wherein the hinge element is coupled to the second elongated frame member by the inner arm. 
         [0013]    In another example, the outer closing arm of the second elongated frame member rotates about the axis of rotation toward the first elongated frame member to move the second cam surface toward the first cam surface to clasp sheet material. In this example, the first earn surface and the second cam surface may further oppose one another substantially in the longitudinal center of the first elongated frame member and the second elongated frame member when the outer closing arm of the second elongated frame member is rotated about the axis of rotation toward the first elongated frame member. 
         [0014]    In another example, the inner opening arm of the second elongated frame member rotates about the axis of rotation toward the first elongated frame member to move the second cam surface away from the first cam surface to un-clasp sheet material. In still another example, the first elongated frame member and the second elongated frame member form a receiving slot to receive the sheet material. In a further example, the hinge element is a rod and channel element. In another example, at least one of the first elongated frame member and the second elongated frame member comprise extruded aluminum. 
         [0015]    In one example, the first elongated frame member includes an end cap leg. In that same example, the first elongated frame member and the end cap leg may further form an end cap channel configured to engage one or more end caps. 
         [0016]    In another example, the cam holder system further comprises an end cap. 
         [0017]    In still another example, at least one of the first elongated frame member and the second elongated frame member includes a clip channel. In that same example, the clip channel may further be configured to engage one or more clips. 
         [0018]    Still other aspects, features and advantages of the present invention are readily apparent from the following detailed description, simply by illustrating a number of exemplary embodiments and implementations, including the best mode contemplated for carrying out the present invention. The present invention also is capable of other and different embodiments, and its several details can be modified in various respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The present invention will be understood more fully from the detailed description given below and from the accompanying drawings of various embodiments of the invention, which, however, should not be taken to limit the invention to the specific embodiments, but are for explanation and understanding only. 
           [0020]      FIG. 1A  is an end view of a cam holder system in an open position according to an embodiment of the present invention; 
           [0021]      FIG. 1B  is an end view of a cam holder system in a closed position according to an embodiment of the present invention; 
           [0022]      FIG. 2A  is a perspective view of a cam holder system according to an embodiment of the present invention; 
           [0023]      FIG. 2B  is a perspective view of a cam holder system with end caps according to an embodiment of the present invention; 
           [0024]      FIG. 3A  is an end view of a cam holder system in an open position with sheet material positioned between the frame member and the lever arm member according to an embodiment of the present invention; 
           [0025]      FIG. 3B  is an end view of a cam holder system in an open position with sheet material positioned within the receiving slot according to an embodiment of the present invention; 
           [0026]      FIG. 3C  is an end view of a cam holder system in a closed position with sheet material positioned within the receiving slot according to an embodiment of the present invention; 
           [0027]      FIG. 4A  is an end view of a cam holder system with wide grip in a closed position according to an embodiment of the present invention; 
           [0028]      FIG. 4B  is an end view of a cam holder system with wide grip in an open position according to an embodiment of the present invention; and 
           [0029]      FIG. 5  is a perspective view of two cam holder systems clasping sheet material according to an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0030]    A cam holder system for clasping sheet material is described. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the exemplary embodiments. It is apparent to one skilled in the art, however, that the present invention can be practiced without these specific details or with an equivalent arrangement. 
         [0031]    Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views,  FIGS. 1A and 1B  show an end view of a cam holder system according to an embodiment of the present invention in an open and closed position, respectively. Cam holder system  101  is formed by two pieces that slide together, a first elongated frame member  65  and a second elongated frame member  55 , made of a rigid material. The rigid material may be extruded aluminum, stainless steel, plastic, and the like. 
         [0032]    First elongated frame member  65  includes hinge element  10 , which is shown as circular in shape, but may also be any other rotatable shape. First elongated frame member  65  also includes elongated handle  30  and inner wall  20 . In one embodiment, first elongated frame member  65  also has angled leg  70 , which can be configured to engage one or more end caps (not shown) that can be used to hold first elongated frame member  65  and second elongated frame member  55  in alignment with each other so that they do not slide apart when holder system  101  is opened. 
         [0033]    Second elongated frame member  55  of cam holder system  101  has outer arm  40  and inner arm  50 . Inner arm  50  has second cam surface  155 . A gap is formed between outer arm  40  and inner arm  50 , which pivotally houses hinge element  10  of first elongated frame member  65 . Hinge element  10  is shown as a rod and channel configuration, but it is contemplated that it can be any other connectable configuration, such as a pivot joint, a glide joint, a hinge, and the like. 
         [0034]    Elongated handle  30  and outer arm  40  extend both above and below the axis of rotation A R , which is located substantially in the longitudinal center of the first elongated frame member  65  and the second elongated frame member  55 , near the middle of cam holder system  101  so that a user has substantially equal leverage when both opening and closing system  101 . 
         [0035]    In one embodiment, cam holder system  101  has been opened, as shown in  FIG. 1A , by applying lateral opening pressure P o  on outer arm  40  below longitudinal center L C , of the second elongated frame member  55 . The applied lateral opening pressure P o  causes second elongated frame member  55  to rotate about the axis of rotation A R , and move second cam surface  155  away from first cam surface  165 . 
         [0036]    The cam holder system  101  has been closed, as shown in  FIG. 1B , by applying lateral closing pressure P c  on outer arm  40  above longitudinal center L C  of the second elongated frame member  55 . The applied lateral closing pressure P c  causes second elongated frame member  55  to rotate about the axis of rotation A R , and move second cam surface  155  toward first cam surface  165 , to clasp sheet material between first cam surface  165  and second cam surface  155 . 
         [0037]    As shown in  FIG. 1A , when cam holder system  101  is in an open position, receiving slot  60  is created between inner arm  50  and inner wall  20 . As shown in  FIG. 1B , when the cam holder system  101  is closed, the distal end of outer arm  40  located below the axis of rotation A R  is pushed toward first elongated frame member  65  and receiving slot  60  no longer exists, as second cam surface  155  rotates directly opposing first cam surface  165 . 
         [0038]    First cam surface  165  and second cam surface  155  are on the same side of the axis of rotation A R  in a latitudinal direction Lat of first elongated frame member  65  and second elongated frame member  55 . This allows second cam surface  155  to move relatively toward first cam surface  165  when first elongated frame member  65  and second elongated frame member  55  rotate relatively about the axis of rotation A R . Similarly, if the opening and closing lateral pressures were applied to first elongated frame member  65  instead of to second elongated frame member  55 , then first elongated frame member  65  would rotate toward and away from second elongated frame member  55 . In that example, first cam surface  165  would move relatively toward and away, respectively, from second cam surface  155 . 
         [0039]    Receiving slot  60  is located on-center of system  101  so that cam holder system  101  hangs straight in alignment with the clasped sheet material. In one example, in order to increase holding strength of cam holder system  101 , first cam surface  165  and/or second cam surface  155  may be grooved, scored, coated, scratched, or otherwise altered to increase the friction between inserted sheet material and first cam surface  165  and/or second cam surface  155 . 
         [0040]    Hinge element  10  is coupled to second elongated frame member  55  by inner arm  50 . In one embodiment, clip channel  80  is also coupled to first elongated frame member  65 . Clip channel  80  is configured to engage one or more clips for hanging the cam holder system  101 , as shown in  FIG. 5  and described herein. Clip channel  80  is shown as trapezoidal in shape, but may also be any other shape, including circular or rectangular. 
         [0041]    Elongated handle  30  and outer arm  40  may be positioned such that a funnel shape is created between them when cam holder system  101  is in an open position of  FIG. 1A , allowing for easy introduction of sheet material into receiving slot  60 . In this embodiment, elongated handle  30  and outer arm  40  are of a mirrored concave curve shape to assist in opening and closing cam holder system  101  comfortably and easily by hand. However, elongated handle  30  and outer arm  40  may be of any shape, and do not necessarily have to be of the same or mirrored shape, and do not necessarily have to create a funnel between them. 
         [0042]      FIGS. 2A and 2B  are three-dimensional perspective views of cam holder system  101  according to an embodiment of the present invention, without and with an end cap, respectively. As described previously, the first elongated frame member  65  and the second elongated frame member  55  are pivotally connected via hinge element  10 . In order to ensure that second elongated frame member  55  and first elongated frame member  65  do not disconnect by sliding apart, end caps  100  may be removably or permanently affixed on either end of cam holder system  101 , as shown in  FIG. 2B . End caps  100  are configured to be slid into cam holder system  101  between elongated handle  30  and angled leg  70 . In this instance, end caps  100  have an elongated triangular insertion leg (not shown) that slides into the triangular channel formed between elongated handle  30  and angled leg  70 . Angled leg  70  extends along the entire length of cam holder system  101  in order to accommodate a plurality of lengths of the insertion leg of end caps  100 . In this example, end caps  100  are shaped to accommodate clip channel  80 , so that clip channel  80  may be accessed even after end caps  100  have been affixed. 
         [0043]      FIGS. 3A-3C  illustrate a step-by-step end view as sheet material  110  is being inserted into the cam holder system  101  between the first elongated frame member  65  and the second elongated frame member  55 . In  FIG. 3A , the cam holder system  101  is in an open position with sheet material  110  approaching receiving slot  60 . As discussed previously, cam holder system  101  has been opened by applying pressure on a proximal end of outer arm  40  below hinge element  10 , and causing the lever arm member to pivot open. 
         [0044]    In  FIG. 3B , sheet material  110  is positioned within receiving slot  60 . Finally, in  FIG. 3C , cam holder system  101  has been closed by applying force F C  on the distal end  41  of outer arm  40  above hinge element  10  in the direction indicated, and causing the lever arm member to pivot closed. Inner arm  50  is positioned directly against sheet material  110 , which is positioned directly against inner wall  20 . As discussed previously, receiving slot  60  is located on-center so that the cam holder system  101  hangs straight in alignment with the clasped sheet material  110 . 
         [0045]      FIGS. 4A and 4B  show an end view of a cam holder system  501  with wide grip according to an embodiment of the present invention in a closed and open position, respectively. In this embodiment, hinge element  510  is positioned further from inner wall  520  in order to create wide receiving slot  560 . Wide receiving slot  560  is positioned between inner wall  520  and inner arm  550  regardless of whether the cam holder system  501  is in an open or closed position. This embodiment allows the system  501  to accommodate larger, thicker, and/or softer sheet material without puncturing, perforating, flattening, or otherwise damaging the sheet material between inner wall  520  and inner arm  550  when the system  501  is in a closed position ( FIG. 4A ). 
         [0046]      FIG. 5  is a perspective view of cam holder systems  200  and  300  attached to sign  210 . Sign  210  is positioned between the inner wall and inner wall of cam holder systems  200  and  300  on both ends, and was inserted into systems  200  and  300  by the method illustrated in  FIGS. 3A-C . Cam holder system  200  has clips  120  attached via clip channel  80 , and cords  130  attached to clips  120  by which to suspend the system. In this embodiment, clips  120  are slid into an end of clip channel  80  and moved parallel within the channel until they reach desirable positions. Clips  120  may also be positioned into clip channel  80  by squeezing the clips and applying pressure to them perpendicularly to clip channel  80  until they are positioned within the channel. In another embodiment, clips  120  may be permanently affixed to clip channel  80 . 
         [0047]    Although clip channel  80  of cam holder system  300  does not have clips  120 , it is possible for clip channel  80  to have clips  120  and cords  130  that attach cam holder system  300  to another cam holder system and sign via another set of clips, and so forth. 
         [0048]    Cam holder systems  200  and  300  have end pieces  100  positioned at both ends of each system. As discussed previously, end pieces  100  may be removably or permanently affixed on either or both ends of cam holder systems  200  and  300  in order to ensure that the systems do not disconnect by sliding apart. 
         [0049]    Other implementations of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. Various aspects and/or components of the described embodiments may be used singly or in any combination. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.