Abstract:
A toggle clamp locking mechanism for selectively coupling a work piece. The mechanism includes a base structure; a primary locking system movement between a retaining position and a release position, the primary locking system having a handle member pivotally coupled to the base structure, an action for engaging the workpiece in the retaining position and releasing the workpiece in the release position, and a linkage system mechanically interconnecting the handle member with the action. A second locking system having an engagement member is provided having a cam follower cammingly engaging a first detent when the primary locking system is in the retaining position preventing the primary locking system from moving from the retaining position. The second locking system is actuatable to disengage the cam follower from the first detent to enable movement of the primary locking system to move from the retaining position.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 62/153,560, filed on Apr. 28, 2015. The entire disclosure of the above application is incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The present disclosure relates to toggle clamps and, more particularly, relates to toggle clamps having a locking mechanism. 
       BACKGROUND 
       [0003]    This section provides background information related to the present disclosure which is not necessarily prior art. 
         [0004]    Toggle clamps are used for a variety of purposes, such as retaining and/or fixturing a work piece. A conventional toggle clamp comprises a clamp body that can be fastened to a work station or other supporting structure. A retaining arm is pivotally coupled to the clamp body to permit articulation of the retaining arm relative to the generally-stationary clamp body. A hold down member can extend from a distal end of the retaining arm and operably engage the work piece. A handle member is further pivotally coupled to the clamp body and operably engages the retaining arm to articulate the retaining arm between a raised and disengaged position (e.g. release position) and a lowered and engaged position (e.g. retaining position). The lowered and engaged position engaging the work piece to retain and/or fixture the work piece in position. 
         [0005]    Conventional toggle clamps can include a variety of handles structures, including elongated members and the like, and a variety of configurations, including vertical or horizontal-handle Hold-Down style clamps. Conventional toggle clamps can further include push-pull, push-pull drawbar, hook, and latch type linear actuating clamps. Many of these configurations are offered in heavy duty configurations for some applications. 
         [0006]    Generally, toggle clamps are a quick-acting mechanical linkage with three basic elements—an action, a linkage, and a handle or actuator. During operation, the clamp is first moved into position to contact the work piece and then actuated to apply a clamping force. This clamping force is generated by compressing or stretching the linkage elements. 
         [0007]    In some cases, conventional toggle clamps can include a locking mechanism. In conventional toggle clamps, the locking mechanism can be engaged by moving a center pivot of the toggle action past the centerline of two other pivots, against a stop. The lock achieved by the movement of the center pivot past centerline is referred to as the “toggle lock.” However, conventional toggle locks have at least two primary disadvantages. The first disadvantage is that heavy vibration or impact can cause the center pivot to move from its past center position and, thus, “unlock” the mechanism. The second disadvantage, and potentially more prevalent, is that the clamp can be inadvertently actuated by inadvertent contact with the actuator. 
         [0008]    For these and other reasons, some toggle clamps include a secondary locking mechanism that must be activated before the clamp mechanism itself can be actuated. The vast majority of these secondary locking mechanisms fall into two categories. The first involves the base clamp components remaining essentially unchanged from its typical configuration and the secondary locking mechanism being simply added on in some way that restricts normal operation of the clamp until it has been activated. In the second, some of the clamps primary components have been altered from the base model, but the lock functions via a wedging or jamming action as opposed to a true locking action. In some applications, these locking mechanisms, or secondary locks, must be actuated in a clumsy or awkward action by the operator. 
         [0009]    Although this arrangement may be useful for some applications, it has been found that they often fail to provide a simple and consistent locking method. In fact, in many cases, these conventional secondary locking mechanisms are less reliable and can be overcome with moderate force. Frequently they require the operator to activate them though a clumsy or awkward action that cannot be integrated into the normal and deliberate clamp activation. For example, if the clamp is normally activated by a left to right motion of the operators hand along the linear axis of the clamp, the secondary locking mechanism may require a pushing or pulling motion perpendicular to the long axis before the primary activation motion can be initiated. In many cases, they only allow the clamp to be locked in a single position, usually closed. 
         [0010]    Accordingly, there exists a need in the relevant art to provide a toggle clamp that overcomes the deficiencies of conventional toggle clamp designs. Moreover, there exists a need in the relevant art to provide a toggle clamp that provides a suitable, robust locking mechanism that can retain the handle member and/or retaining arm in both a release and retaining position. 
       SUMMARY 
       [0011]    This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
         [0012]    According to the principles of the present teachings, a toggle clamp is provided for retaining a work piece. The toggle clamp includes a base structure, a primary clamp handle pivotally coupled to the base structure, an action for engaging a work piece, a linkage system mechanically interconnecting the primary clamp handle with the action, and a locking system having a locking lever and a clamp link. The locking lever is pivotally coupled to the primary clamp handle at a first end and includes a pin extending from an opposing second end. The clamp link is pivotally coupled to the action at a first end and includes a pair of notches and a cam surface at an opposing second end. The cam surface is disposed between the pair of notches. The pin of the locking lever is configured to be lockingly received with at least one of the pair of notches to define a locked configuration of the primary clamp handle. The pin is operable to cammingly engage the cam surface during movement between the pair of notches. 
         [0013]    Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       DRAWINGS 
         [0014]    The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
           [0015]      FIG. 1  is a side view of a toggle clamp locking mechanism having a pivoting engagement member, in a retaining position, according some embodiments of the present invention; 
           [0016]      FIG. 2  is a side view of the toggle clamp locking mechanism of  FIG. 1  in an intermediate position; 
           [0017]      FIG. 3  is a side view of the toggle clamp locking mechanism of  FIG. 1  in a release position; 
           [0018]      FIG. 4  is a side view of a toggle clamp locking mechanism having a pivoting engagement member according some embodiments of the present invention in a release position; 
           [0019]      FIG. 5  is a side view of the toggle clamp locking mechanism of  FIG. 4  in a retaining position; 
           [0020]      FIG. 6  is a top view of a toggle clamp locking mechanism having a pivoting engagement member according some embodiments of the present invention; 
           [0021]      FIG. 7  is a front view of the toggle clamp locking mechanism of  FIG. 6  in a release position; 
           [0022]      FIG. 8  is an end view of the toggle clamp locking mechanism of  FIG. 6 ; 
           [0023]      FIG. 9  is a side view of a toggle clamp locking mechanism having a linear engagement member according some embodiments of the present invention in a release position; 
           [0024]      FIG. 10  is a side view of the toggle clamp locking mechanism of  FIG. 9  in a retaining position; 
           [0025]      FIG. 11  is a perspective view of a toggle clamp locking mechanism having a linear engagement member according some embodiments of the present invention in a release position; 
           [0026]      FIG. 12  is a perspective view of the toggle clamp locking mechanism of  FIG. 11  in a retaining position; 
           [0027]      FIG. 13  is a perspective view of a toggle clamp locking mechanism having a linear engagement member according some embodiments of the present invention in a release position; and 
           [0028]      FIG. 14  is a perspective view of the toggle clamp locking mechanism of  FIG. 13  in a retaining position. 
       
    
    
       [0029]    Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION 
       [0030]    Example embodiments will now be described more fully with reference to the accompanying drawings. 
         [0031]    Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail. 
         [0032]    The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore 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. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
         [0033]    When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
         [0034]    Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments. 
         [0035]    According to the principles of the present invention, a toggle clamp locking mechanism  10  is provided having a primary locking system  12  for retaining or fixturing a workpiece and a secondary locking system  14  for retaining primary locking system  12  in at least a retaining position. In some embodiments, secondary locking system  14  can further retain primary locking system  12  in a release position. 
         [0036]    In some embodiments, as illustrated in  FIGS. 1-3 , toggle clamp locking mechanism  10  can comprise a base structure  16  connectable to a work station or other supporting structure. A handle member  18  is pivotally coupled to base structure  16  at a pivot  20 . Handle member  18  is pivotable about pivot  20  between a retaining position retaining a workpiece (not shown) (see  FIGS. 1, 5, 7, 10, 12, and 14 ) and a release position releasing a workpiece (see  FIGS. 3, 4, 9, 11, and 13 ). Toggle clamp locking mechanism  10  can further comprise a clamp link  22  operably coupled between handle member  18  and a clamp  24 . Clamp  24  can be configured to retain a workpiece retaining implement (not shown) using conventional fastening means, such as threaded fasteners and the like. Moreover, clamp  24  can comprise a toggle bar, spindle, hook, u-bar or other element. Clamp  24  can be part of any one of a number of conventional actions for engaging workpieces. In some embodiments, clamp link  22  can operably engage clamp  24  to permit linear translation of clamp  24  (see  FIGS. 1-3 and 6-8 ) or pivotal translation of clamp  24  (see  FIGS. 4-5 and 9-14 ). In some embodiments employing linear translation of clamp  24 , base structure  16  can comprise a feature or sleeve  26  for supporting clamp  24  to permit translation of clamp  24  along a single axis. In this way, pivotal movement of handle member  18  between the retaining position and the release position is translated along clamp link  22  into linear translation of clamp  24 . Similarly, in some embodiments employing pivotal translation of clamp  24 , clamp  24  can be pivotally coupled to base structure  16  at pivot  28 . In this way, pivotal movement of handle member  18  between the retaining position and the release position is translated along clamp link  22  into pivotal movement of clamp  24 . 
         [0037]    It should be understood that handle member  18  can define any one of a number of shapes and contours that are specific to a particular use, application, or desired ergonomics. Generally, however, handle member  18  can comprise a handle section  30  to be gripped and/or actuated by an operator. As will be appreciated from the discussion herein, secondary locking system  14  is configured to be actuated by an operator in a natural and convenient relation to actuation of handle member  18  of primary locking system  12 . In some embodiments, handle member  18  can define an orthogonal section disposed at an angle relative to a main section (see  FIGS. 1-3 ) or can define a generally elongated member (see  FIGS. 4-14 ). In either configuration, handle member  18  is configured to provide sufficient mechanical advantage to permit an operator to conveniently actuate primary locking system  12  to retain and release the workpiece in a safe and reliable manner. 
         [0038]    According to the principles of the present teachings, secondary locking system  14  is employed to permit safe retention of the primary locking system  12  in at least the retaining position, and, in some embodiments, permit safe retention of the primary locking system  12  in the release position. This permits that toggle clamp locking mechanism  10  to be safely locked in the retaining position and/or release position and provide a suitable, robust locking mechanism that can retain the handle member and/or retaining arm in both a release and retaining position. 
         [0039]    In some embodiments, secondary locking system  14  comprises an engagement member  40  that cammingly engages a corresponding detent and cam system  38  disposed on clamp link  22 . It should be understood that engagement member  40  can comprise any one of a number of shapes and deployment systems; however, each engagement member  40  is configured to engage a detent formed on clamp link  22  to retain primary locking system  12  in the retaining position and/or retention position. 
         [0040]    In some embodiments, as illustrated in  FIGS. 1-3 , engagement member  40  can comprise a generally T-shaped member having a first end  42  pivotally coupled to handle member  18  at pivot  44 . Engagement member  40  can further comprise a cam follower  46  extending from an opposing end  48 . Cam follower  46  is sized and shaped to be captured within a first detent  50  formed in clamp link  22  when handle member  18  is in the retaining position (see  FIG. 1 ) and a second detent  52  formed in clamp link  22  when handle member  18  is in the release position (see  FIG. 3 ). During actuation of toggle clamp locking mechanism  10  between the retaining position and the release position, cam follower  46  is configured to ride along a cam surface  54  extending between first detect  50  and second detent  52 . Therefore, when cam follower  46  is disposed within first detent  50 , handle member  18  is locked in the retaining position preventing inadvertent release of toggle clamp locking mechanism  10  causing release of the workpiece. Likewise, when cam follower  46  is disposed within second detent  52 , handle member  18  is locked in the release position preventing inadvertent closure of toggle clamp locking mechanism  10  upon the workpiece or operator. Cam surface  54  provides, at least in part, a smooth transition for cam follower  46  from first detent  50  to second detent  52 . Engagement of cam follower  46  within first detent  50  and/or second detent  52  results in primary locking system  12  resisting actuation between the retaining position and the release position (and vice versa). 
         [0041]    With continued reference to  FIGS. 1-3 , in some embodiments engagement member  40  can comprise a gripping portion  56  configured to be actuated by the operator. In some embodiments, gripping portion  56  can comprise an elongated handle extending orthogonally from engagement member  40  between ends  42  and  48 . Gripping portion  56  can be shaped to be positioned adjacent a gripping portion  58  of handle member  18  in both the retaining position ( FIG. 1 ) and the release position ( FIG. 3 ). 
         [0042]    In some embodiments, as illustrated in  FIGS. 1-3, 7, and 9-14 , engagement member  40  can be biased via a biasing member  60  (e.g. spring) to engage cam follower  46  within first detent  50  and second detent  52 . It should be understood that any biasing member can be used in any of the illustrated embodiments. Moreover, it should be understood that alternative systems are envisioned. 
         [0043]    With particular reference to  FIGS. 4-8 , it should be understood that in some embodiments engagement member  40  can be alternatively shaped to define a cantilevered shape pivotally coupled to handle member  18  at a midpoint location (rather than an end location of  FIGS. 1-3 ). In this way, an operator can benefit from mechanical advantage/leverage to actuate cam follower  46  between first detent  50  and second detent  52 . This configuration does not depart from the common configuration of engagement member  40  engaging a first detent  50  and second detent  52  formed on clamp link  22 . 
         [0044]    In some embodiments, as illustrated in  FIGS. 9-14 , engagement member  40  can be elongated and actuated along a linear direction (rather than a pivotal direction of  FIGS. 1-8 ), hereinafter referenced as engagement member  40 ′. In some embodiments, engagement member  40 ′ is disposed within an interior portion of handle member  18 , however this should not be regarded as a requirement unless other claimed. Engagement member  40 ′ can be actuated via one or more gripping portions or members  56 ′ extending therefrom. In some embodiments, gripping portions  56 ′ can extend through engagement member  40 ′ and be fixedly coupled therewith. Gripping portions  56 ′ can be captured within slots  62  formed in handle member  18 . Similarly, guide posts  64  can extend from engagement member  40 ′ and be captured within slots  62  thereby forming pins permitting linear translation of engagement member  40 ′. Cam follower  46  of engagement member  40 ′ can engage first detent  50 , second detent  52 , and cam surface  54  as described herein. Engagement member  40 ′ can be similarly biased into engagement with first detent  50 , second detent  52 , and cam surface  54  by biasing member  60 . 
         [0045]    During operation, an operator can actuate toggle clamp locking mechanism  10  from a retaining position to a release position by simultaneously grasping engagement member  40 ,  40 ′ and handle member  18 , thereby releasing cam follower  46  from first detent  50  of secondary locking system  14 . Handle member  18  is then pivoted about pivot  20  thereby causing clamp link  22  to actuate clamp  24  from the retaining position to the release position. During this movement, engagement member  40 ,  40 ′ can be released thereby permitting cam follower  46  to cammingly engage cam surface  54 . Upon reaching the release position, cam follower  46  can biasingly engage second detent  52  thereby locking toggle clamp locking mechanism  10  in the release position. 
         [0046]    Likewise, an operator can actuate toggle clamp locking mechanism  10  from the release position to the retaining position by simultaneously grasping engagement member  40 ,  40 ′ and handle member  18 , thereby releasing cam follower  46  from second detent  52  of secondary locking system  14 . Handle member  18  is then pivoted about pivot  20  thereby causing clamp link  22  to actuate clamp  24  from the release position to the retaining position. During this movement, engagement member  40 ,  40 ′ can be released thereby permitting cam follower  46  to cammingly engage cam surface  54 . Upon reaching the retaining position, cam follower  46  can biasingly engage first detent  50  thereby locking toggle clamp locking mechanism  10  in the retaining position. 
         [0047]    The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.