Abstract:
Lockable tongs including a pair of elongate tong members joined at a hinge point for pivotal movement between an open position and a closed position for grasping an item; and, a locking mechanism disposed for rotation about a longitudinal axis extending between the elongate members and configured to rotate between an unlocking position and a locking position which releasably locks the elongate members in the closed position.

Description:
TECHNICAL FIELD  
       [0001]     The invention is directed to tongs for gripping items and more particularly to tongs that may be locked in a closed position.  
       BACKGROUND OF THE INVENTION  
       [0002]     Tongs are a common hand tool used for grasping items, for example, where items are hot or inaccessible or where touching an item by hand may be unsanitary. Various biasing configurations are disclosed in the prior art to bias hinged tong members to an open position. Tongs that are biased to a normally open position often present a storage problem due to their spread shape. Various means have therefore been proposed to releasably lock tongs in a closed position.  
         [0003]     One device which is used to hold tongs closed during storage involves placing a rubber band over the tong members. However, rubber bands are not dishwasher-safe or sanitary and can leave a residue on tongs used for food preparation or service.  
         [0004]     One mechanism that has been used as a locking means to keep spring-loaded tongs closed involves a sliding bar or ring mounted near the hinged end of the tongs. When the tongs are in a closed position, the ring or bar may be moved toward the gripping end of the tongs to a position where the ring or bar locks the tongs closed, similar to a rubber band. However, such bars or rings have an annoying tendency to slip into the locked position, when the tongs are in use, locking the tongs closed when the user squeezes the tong members together in order to grasp an item.  
         [0005]     Complicated mechanisms for locking tongs closed are undesirable for food handling tongs as they provide crevices, ridges or other areas within which food particles and bacteria may accumulate. Complicated mechanisms also increase the number of parts to be assembled and the amount of labor required to produce the finished product.  
         [0006]     Therefore, it is desirable to provide tongs which are simple and inexpensive to manufacture.  
         [0007]     It is also desirable to provide food service tongs which are easily cleaned using existing kitchen cleaning equipment.  
         [0008]     It is further desirable to provide tongs with a locking mechanism that does not engage unexpectedly.  
       SUMMARY OF THE INVENTION  
       [0009]     The invention provides tongs for grasping items that may be releasably locked in a closed position by a rotating locking mechanism. In accordance with the invention, the tongs comprise a pair of elongate members joined at a hinge point for pivotal movement between an open position and a closed position for gripping items. A locking mechanism is disposed for rotation about a longitudinal axis extending between the elongate members and configured to rotate between an unlocking position and a locking position, releasably locking the elongate member in the closed position.  
         [0010]     Preferably the locking mechanism comprises a stop portion defining, in cross-section, a first wider dimension and a second narrower dimension whereby when the locking mechanism is rotated to the locking position, the wider dimension stops pivotal movement of the elongate members.  
         [0011]     In accordance with an embodiment of the invention, each tong member has a forward portion and a rearward portion projecting in opposite directions from the hinge point. The locking mechanism may be positioned rearward of the hinge point between the tong members. The locking mechanism comprises a stop portion and a rearward projecting grip portion. The locking mechanism may be rotated about the axis by application of a twisting force to the grip portion. Alternate quarter turns of about 90° of the locking mechanism rotates the stop portion such that the elongate members are forced apart rearward of the hinge point, locking the forward members of the elongate members closed, or released for relative movement. In this manner, the tongs may be unlocked and locked by a simple twist of the locking mechanism.  
         [0012]     The grip portion optionally defines a means for hanging the tongs for storage. The tongs are preferably biased toward the open position by a suitable biasing mechanism such as a spring. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]     Further features and advantages of the present invention will become apparent from the following detailed description, taken in combination with the appended drawings, in which:  
         [0014]      FIGS. 1A and 1B  are an elevational view of the tongs in the closed position in accordance with the invention from a front and side respectively;  
         [0015]      FIGS. 2A and 2B  are an elevational view of the tongs of  FIG. 1  in the open position from a front and side respectively;  
         [0016]      FIG. 3  is a partial view of the tongs in disassembly in accordance with the invention; and  
         [0017]      FIGS. 4A and 4B  are a view of the locking mechanism and hinge pin showing a locked/closed position and an unlocked/open position respectively.  
         [0018]     It will be noted that throughout the appended drawings, like features are identified by like reference numerals. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0019]      FIGS. 1A and 1B  illustrate views of a pair tongs  10  in a closed position and  FIGS. 2A and 2B  illustrate views of tongs  10  in an open position in accordance with the invention. The tongs  10 , as is conventional, are for manually grasping items between forward grasping ends  12  and  13  of a pair elongate tong members  14  and  16 . With additional reference to  FIG. 3 , elongate members  14  and  16  are pivotally joined at a hinge point  17  by a hinge pin  18 . In the embodiment shown, the elongate members are formed of sheet metal, preferably stainless steel bent into a U-shaped channel  24  with grasping ends  12  and  13  formed in an open spoon shape. In the area of the hinge pin  18 , flanges  20  are increased in height to overlap and provide a hinge structure for hinge pin  18 . In accordance with an aspect of the invention, the U-shaped tong members  14  and  16  together form a generally rectangular channel within which a rotatable locking mechanism  22  may be disposed for rotation as discussed further below.  
         [0020]     Each elongate member  14  and  16  has a forward portion  25  defined forwardly of hinge point  17  and a rearward portion  26  projecting rearwardly of hinge point  17 . Channel  24  extends both forwardly and rearwardly from hinge point  17  providing a means to laterally contain the movement of locking mechanism  22 .  
         [0021]     It will be apparent that although the embodiment illustrated shows a generally rectangular channel defined by bent sheet metal elongate members  14  and  16 , the invention is applicable to other types of elongate member  14  and  16  in which a channel  24  for containing the locking mechanism  22  may be formed. For example, elongate members  14  and  16  may be formed of cast metal or molded plastic. Forward grasping ends  12  and  13  may be covered with a heat resilient material for protecting food preparation surfaces such as a silicone or other plastic material (not shown). Covered tongs are preferable for use with non-stick or other delicate cookware.  
         [0022]     Tongs  10  include a biasing mechanism to urge the tongs to an open position. In the preferred embodiment shown in  FIG. 3 , channel  24  defines a means to contain the movement of a double torsion spring  28 . Spring  28  has end portions  30  and  31  and an intermediate portion  32  that are preformed for biasing against sides of channel  24  and a pair of wound portions  34  and  35  defining a coupling for hinge pin  18 . End portions  30  and  31  and intermediate portion  32  extend forward of hinge point  17  to bias tongs  10  toward a normally open position.  
         [0023]      FIGS. 4A and 4B  illustrate the rotatable locking mechanism  22  as it appears when tongs  10  are in the locked and closed position and the unlocked and open position respectively. Locking mechanism  22  is disposed for rotation about a longitudinal axis extending between elongate members  12  and  13 . Locking mechanism  22  comprises a grip portion  40  coupled to a stop portion  42 . Stop portion  42  is dimensioned to define a wider dimension  44  and a narrower dimension  46 . Alternate quarter turns of the grip portion  40  causes the stop portion  42  to be oriented with the wider dimension  44  perpendicular ( FIG. 4B ) or parallel ( FIG. 4A ) to the hinge pin  18 .  
         [0024]     Locking mechanism  22  is preferably coupled to hinge pin  18  such as through hinge channel  48  formed in locking mechanism  22 . Grip portion  40  preferably includes a means for hanging the tongs, for example, on a hook (not shown), such as a channel  50  formed through the grip portion near its end.  
         [0025]     Though channel  50  is illustrated, other means for hanging are contemplated and are apparent to those skilled in the art, such means for hanging may comprise a hook for example.  
         [0026]     When the wider dimension  44  of stop portion  42  is oriented to the locking position, perpendicular to the hinge pin  18 , ( FIGS. 4A, 2A  and  2 B) stop portion  42  forces apart the rearward portion  26  of each elongate member  14  and  16 , stopping relative movement of the elongate members and closing grasping ends  12  and  13 . Rotating locking mechanism  22  to the unlocking position where the wider dimension  44  is parallel to hinge pin  18 , frees each rearward portion  26  for relative movement.  
         [0027]     Preferably, stop portion  42  defines a smooth, gradual transition between wider dimension  42  and narrower dimension  44  to provide a cam-like surface for contact with elongate members  14  and  16 . Though locking mechanism  22  is shown as a unitary member, persons skilled in the art will understand that it may be constructed of more than one part.  
         [0028]     The embodiment(s) of the invention described above is(are) intended to be exemplary only. The scope of the invention is therefore intended to be limited solely by the scope of the appended claims.