Abstract:
A clamping device comprises a clamping base and a cam mechanism. The clamping base has an opening for receiving at least a part of an object to be clamped and a cavity for receiving the cam mechanism. The cam mechanism is rotatable with respect to the clamping base between a first position, in which the clamping device completely locks the object to be clamped, and a second position, in which the clamping device completely releases from the object. The clamping device can achieve clamping/locking of an object without use of additional tools. In some cases, the clamping device can operated among three different positions, i.e., completely released position, pre-locked position, and completely locked position, facilitating the control and handling of the object.

Description:
CROSS-REFERENCE TO RELATED DOCUMENT 
       [0001]    This application claims priority benefit from Chinese utility model application No. 201320337395.5 filed on Jun. 13, 2013, the disclosure of which is incorporated herein by reference. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates to a clamping device, especially to a clamping device suitable for use with fragile products such as glass. 
       BACKGROUND OF THE INVENTION 
       [0003]    The mounting and movement of fragile products, such as glass, are normally carried out by means of special tools. For instance, when a glass shower door is mounted, a level and a glass clamper are always needed to fix and move the glass door. However, the coupling of conventional glass clampers with glass requires additional fasteners such as screws or bolts. This causes the mounting operation to be time-consuming and it requires additional tools to complete the mounting operation. In addition, conventional glass clamper can only be operated between completely released position and completely locked position, which is inconvenient for the mounting operation. 
       SUMMARY OF THE INVENTION 
       [0004]    An object of the invention is to provide a clamping device which does not need any additional tool to achieve clamping. 
         [0005]    Another object of the invention is to provide a clamping device which can be operated among complete released position, pre-locked position and completely locked position, facilitating mounting operation. 
         [0006]    To achieve the one or more objects of the present invention, a clamping device is provided comprising a clamping base and a cam mechanism. The clamping base has an opening for receiving at least a part of an object to be clamped and a cavity for receiving the cam mechanism. The cam mechanism is rotatable in relation to the clamping base between a first position, in which the clamping device completely locks the object to be clamped, and a second position, in which the clamping device completely releases the object. 
         [0007]    In one preferable embodiment, the clamping device further comprises a flexible cushion located within the opening and when in use between the clamping base and the object to be clamped. The flexible cushion is provided to enhance clamping of the object by increase of friction force between the object and the cushion. The cushion preferably is provided with teeth on one or both sidewalls toward to the object. 
         [0008]    In one preferable embodiment, the clamping device further comprises a rigid cushion located in one sidewall of the flexible cushion and when in use abutted against the cam mechanism. Preferably, the rigid cushion has a lateral wing to increase contact area so as to prevent the rigid cushion from displacement. 
         [0009]    According to one embodiment, the clamping base further comprises a linkage used for linking the clamping device and the object to other elements. The linkage is preferably laterally extended from the clamping base. 
         [0010]    According to one embodiment, the clamping device comprises two sidewalls and one top wall connecting the two sidewalls, defining the opening. The top wall has a first recess and one of the two sidewalls has a second recess, and the first and second recesses jointly define the cavity for receiving the cam mechanism. 
         [0011]    According to one embodiment, the cam mechanism comprises a rod, a cam portion and a linkage portion connecting the rod with the cam portion . The cam portion is substantially in form of a cylinder and has a protruded surface on at least a part of an outer surface of the cylinder. 
         [0012]    In a preferable embodiment, the cam mechanism comprises a rod, a cam portion and a linkage portion connecting the rod with the cam portion. The cam portion is substantially in form of a cylinder and has a first protruded surface and a second protruded surface on at least apart of an outer surface of the cylinder. The first protruded surface has a height with respect to the outer surface smaller than that of the second protruded surface. The protruded surfaces having different heights enable to achieve pre-locking and complete locking of the object. In pre-locking position, the object is not able to freely move but still movable when an external force is applied thereon. In complete locking position, the object is completely not movable. 
         [0013]    Preferably, the first and second protruded surfaces are non-continuous. The first protruded surface preferably has a substantially rectangular section and the second protruded surface preferably has a substantially arched section. 
         [0014]    According to one embodiment, the object to be clamped is glass, wood or other suitable materials, preferably glass. 
         [0015]    The clamping device provided by the present invention can achieve clamping/locking of an object without use of additional tools. In preferable case, the clamping device can operated among three different positions, i.e., completely released position, pre-locked position, and completely locked position, facilitating the control and handling of the object. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0016]      FIG. 1  shows a clamping device according to one example of the invention. 
           [0017]      FIG. 2  shows an exemplary cam mechanism of the clamping device according to one embodiment of the invention. 
           [0018]      FIG. 3  shows another exemplary cam mechanism of the clamping device according to one embodiment of the invention. 
           [0019]      FIG. 4  shows an exemplary clamping base of the clamping device according to one embodiment of the invention. 
           [0020]      FIG. 5  shows a clamping device according to another embodiment of the invention, in which the cam mechanism is omitted for clarity. 
           [0021]      FIGS. 6 to 8  show different operation positions of an exemplary clamping device coupled with glass, in which  FIG. 6  shows completely released position,  FIG. 7  shows completely locked position, and  FIG. 8  shows pre-locked position. 
       
    
    
       [0022]    Elements that are irrelevant to the spirit of the invention are omitted from the drawings for the sake of clarity. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0023]    The present invention will now be described in more detail in reference to the drawings. It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments of the invention. As used herein, the singular forms “a,” “an,” and “the, ” are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the terms “and/or” include any and all combinations of one or more of the associated listed items. It will be further understood that the terms “comprises” “comprising” “includes” and/or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
         [0024]    With reference to  FIG. 1 , a exemplary clamping device according to the present invention is shown. The clamping device comprises a clamping base  10  and a cam mechanism  20 , wherein the clamping base  10  includes two sidewalls  11  and a top wall  12  jointly define an opening  13  in form of a letter “n” for receiving at least a part of the object  40  (see  FIG. 6 ) to be clamped. The clamping base  10  also includes a linkage  19  for connecting the clamping device together with the object  40  to other elements. In the example, the linkage  19  is extended laterally from the clamping base  10 . 
         [0025]    As shown in  FIG. 4 , the clamping base  10  has a first recess  15  on the top wall  12  and a second recess  14  on the sidewall  11 . The first recess  15  and the second recess  14  jointly define a cavity for receiving the cam mechanism  20 . The first recess  15  does not communicate with the opening  13  while the second recess  14  does. 
         [0026]    The cam mechanism  20  is received in the cavity in suitable manner and rotatable with respect to the clamping base  10  at least in a first position and a second position. For example, the cam mechanism  20  and the clamping base  10  are provided with pin holes  16  through which a pin (not shown) passes to dispose the cam mechanism in the cavity. 
         [0027]    The cam mechanism  20  comprises a rod  21 , a cam portion  22  and a linkage portion connecting the rod  21  with the cam portion  22 . Preferably, a handle portion  24  is formed at an end of the rod  21  for facilitating handling of the cam mechanism. In the example, a plurality of notch is formed at the handle portion  24  to increase friction force. The cam mechanism  20  is received within the cavity formed by the recesses  14 ,  15 . 
         [0028]    With reference to  FIG. 2 , an exemplary cam mechanism  20  is shown. The cam mechanism  20  is substantially cylindrical and on a part of the outer surface of the cylinder a protruded surface  221  is formed. As shown in the figure, from the sectional view of the cylinder, R 1  represents the distance between the axis of the cylinder and the outer surface, R 2  represents the distance between the axis of the cylinder and the protruded surface  221 , wherein R2&gt;R1. Therefore, when the clamping base  10  is contact with the outer surface of cylinder with radius R 1 , the clamping device does not interfere with the object to be clamped and the object is able to move freely. When the clamping base  10  is contact with the protruded surface  221 , however, the clamping device applies a force onto the object and enable it to be clamped within the opening and not movable. 
         [0029]      FIG. 3  shows another form of cam mechanism  20 . The cam portion  22  of the cam mechanism  20  is substantially cylindrical and on a part of the outer surface of the cylinder a first protruded surface  223  and a second protruded surface  222  are formed. As shown in the bottom drawing of  FIG. 3 , from the sectional view of the cylinder, R 1  represents the distance between the axis of the cylinder and the outer surface, R 2  represents the distance between the axis of the cylinder and the first protruded surface  223 , and R 3  represents the distance between the axis of the cylinder and the second protruded surface  222 , wherein R3&gt;R2&gt;R1. The differences among R 1 , R 2 , and R 3  enable to achieve different locking/clamping conditions of the clamping device, i.e., completely released position, pre-locked position and completely locked position. 
         [0030]    Specifically, when the clamping base  10  is contact with the outer surface of the cylinder with radius R 1 , clamping device does not interfere with the object to be clamped and the latter can move freely. When the clamping base  10  is contact with the first protruded surface  223 , the clamping device applies a force onto the object to cause the object not to move freely. However, in this position, the object can still be moved when an external force, always generated by a person who carries out the mounting operation, is applied thereon. When the clamping base  10  is contact with the second protruded surface  222 , the clamping device will apply a greater force to the object to enable it to be clamped within the opening and not movable. Therefore, the cam mechanism  20  in this example provides a intermediate position between the completely released position and completely locked position, i.e., the pre-locked position, which facilitates the movement and adjustment of the object to be clamped. 
         [0031]    In the example, the first and second protruded surfaces are non-continuous, which is favorable for full achievement of the pre-locking effect. The space between the protruded surfaces can be determined by a skilled person in the art. In the example, the first protruded surface  223  has a substantially rectangular section while the second protruded surface  222  has a substantially arched section. The person skilled in the art can also contemplate sections with other suitable shapes. 
         [0032]    With reference to  FIG. 5 , another exemplary clamping device is shown. For the sake of clarity, the cam mechanism of the clamping device is omitted, which can be any one of the cam mechanism shown in  FIG. 2  or  FIG. 3 . In the example, the clamping device comprises a flexible cushion in similar shape with the opening so as to be disposed within the opening  13  when in use. The flexible cushion  30  is normally formed by plastic materials such as rubbers, EVA, PE and so on. The flexible cushion  30  is provided with teeth  31  on one or both sidewalls thereof to increase the friction force with the object to be clamped. The object is then disposed within the opening  33  of the flexible cushion  30 . In the example, the flexible cushion  30  may have a concave  32  on the sidewall toward the cam mechanism, for receiving an optional rigid cushion  34 , which will be described in more detail herebelow. 
         [0033]      FIG. 5  shows the rigid cushion  34  which is optionally included in the clamping device of the invention. When the rigid cushion  34  exists, it is received within the concave  32  of the flexible cushion  30 . In the example, the rigid cushion  34  further comprises a lateral wing  35 , for increasing the contact area with the clamping base  10  in a purpose of preventing the rigid cushion  34  from sliding displacement. The rigid cushion  34  is generally in form of metal or non-stainless steel sheet. The provision of rigid cushion  34  is to receive most of the force generated by the protruded surface of the cam mechanism so as to provide buffering for the object to be clamped, such as glass. In the present example, the lateral wing  35  is in contact with the bottom  17  ( FIG. 1 ) of the second recess  14 . 
         [0034]      FIGS. 6 and 7  show different operation position of the clamping device according to one embodiment of the invention in coupled with the object to be clamped (such as glass  40 ).  FIG. 6  shows completely released position in which no force is applied on the object by the clamping device and the glass  40  is free to move in horizontal and vertical directions.  FIG. 7  shows the completely locked position in which the protruded surface ( 221  or  222 ) of the cam mechanism  20  applies a force to the optional rigid cushion  34 , and in turn to the optional flexible cushion  30  and finally to object disposed within the opening  33 , such that the object is clamped. 
         [0035]      FIG. 8  shows the pre-locked position of the clamping device, in which the first protruded surface  223  is contact with the rigid cushion  34  and applies force onto the flexible cushion  30  and in turn the glass  40 . However, because the first protruded surface  223  has less extent of protrusion, the force applied onto the glass  40  is such that it can only hold the object. When an external force is applied, usually by a person carries out the mounting operation, the glass  40  is still movable. Therefore, it is convenient for the person to move and adjust the glass  40 . When the cam mechanism is rotated to enable the second protruded surface  222  to contact with the rigid cushion  34 , the glass  40  will be applied with greater force so as to tightly clamp the glass  40  and make it not movable even under external force. 
         [0036]    It should be understood that various example embodiments have been described with reference to the accompanying drawings in which only some example embodiments are shown. The present invention, however, may be embodied in many alternate forms and should not be construed as limited to only the example embodiments set forth herein.