Patent Document

BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to the field of latches, and more particularly to a draw latch. 
     2. Brief Description of the Prior Art 
     A variety of draw latches are known for providing a latching action which is achieved by drawing a clamping member against, or over, another member. Generally, a keeper member is mounted to one panel surface and a clamping member of the latch, which is mounted on a second panel surface, engages the keeper and draws the panels together when the clamping member is drawn toward or over the latch body. Draw latches essentially are comprised of a handle assembly and a keeper. The handle assembly generally includes the components of the base, a lever and a catch, with the base and lever being pivotally connected to each other, and with the catch and lever being pivotally connected to each other. In operation, the handle assembly is adapted to be mounted onto a first panel member and the keeper is adapted to be mounted on a second panel member and is designed to receive the catch for latching. Generally, when the catch engages the keeper, a downward force is applied to the lever which causes the catch to pull the panels together and into a fastened position. In essence, the latching action is achieved by rotating the lever about a pivot axis. 
     In the art of over-center draw latches, it is known to provide a draw latch having a base member a lever and a catch. The base and lever are pivotally connected to each other with the catch and lever being pivotally connected to each other. The pivotal connections are generally at the locations of the shafts. Prior art latches of this type, although effective for securing one or more members or panels together, have an undesirable effect of freely movable members. In order to enable the components of this type of latch to be retained in open positions, a technique used includes applying a plastic resistance member between the pivot shaft pivotally connecting the lever and base, and the pivot shaft that connects the lever and the catch. This plastic member provides a sufficient frictional resistance between these pivot shafts, that it will maintain the basic three components in various positions, relative to each other. However, such a plastic member comprises essentially a fourth component which can increase cost and the work associated with assembly of the latch. Generally, the additional plastic member has been replaced, and dimples or detents used to provide a resistance to keep the members of the latch assembly in a variety of given positions. For example, an over-center draw latch having a base and lever pivotally connected to each other, with a catch being pivotally connected to the lever is shown in U.S. Pat. No. 4,890,869 “Over-Center Draw Latch”, the complete disclosure of which is herein incorporated by reference. 
     In the operation of draw latches, the handle assembly is adapted to be mounted onto a first panel member and the keeper is adapted to be mounted on a second panel member. The keeper is further designed to receive the catch for latching. When the catch engages the keeper, a downward force is applied to the lever which causes the catch to pull the panels together into a fastened position. In such a latch, the latching action is achieved by rotating the lever to shift the pivotal connection of the catch and the lever in relation to a line extending between the keeper and the point of pivotal connection of the lever and base. Generally, there are two distinct latching actions for such latches, namely, over-center and under-center. An over-center action provides the pivot connection of the lever and the catch below the centerline between the base and the keeper when in the fastened position. With respect to an under-center action, the pivot of the lever and the catch is positioned above the centerline of the base and the keeper when fastened. For unlatching, an upward force is applied to the lever in order to provide rotation of the lever in the direction opposite that for latching. A disadvantage with conventional draw latches however is that following rotation of the lever for unlatching; the catch must manually be raised in order to be disengaged from the keeper. In one type of draw latch known, a spring which automatically raises or provides “kick-out” of the catch from the keeper when unlatched is utilized. However, in this type of draw latch, the catch movement generally cannot be controlled. For example, when unlatched, the spring operates to force the catch from the keeper in all instances, even in those situations where it is desirable to have the catch remain in other positions. An example of a draw latch which addresses and overcomes such drawbacks is disclosed in U.S. Pat. No. 5,478,125, “Draw Latch With Catch Having Kick-Out Action” wherein controlled kick-out action of the latching member is featured, the complete disclosure of which is herein incorporated by reference. 
     Another example of a draw latch assembly includes a base and a handle and an underlying pawl. The handle is rotated to secure the latch in a latching position by moving the underlying pawl member therewith. In this type of latch assembly, the handle does not itself secure to a keeper. The latching is accomplished by the pawl securing to a keeper member. 
     Other prior known draw latches are provided for use in panels wherein a gasketing member is provided on the panel to supply a biasing force. 
     A need exists for a latch which can provide the benefits of a draw latch with improved locking and securing capabilities. 
     SUMMARY OF THE INVENTION 
     The present invention provides a novel over-center draw latch which can be used to secure a first member to a second member, such as, for example, a panel closure member to an enclosure, or two panels to each other. A locking member enables one or more of the latch elements to be locked to prevent opening of the latch assembly. A primary clamping member and a secondary clamping member are provided. The primary clamping member is pivotally connected to a base member and the secondary clamping member is pivotally connected to the primary clamping member. The primary clamping member or handle is rotatable relative to the base, and partially relative to the secondary clamping member or pawl for a portion of its rotational arc, and rotatable with the secondary clamping member or pawl for another portion of its rotational arc. Engaging means is provided to facilitate the cooperative rotation of the primary and secondary clamping members throughout at least a part of the arc through which the primary clamping member moves. Primary and secondary catches are provided on the keeper member to engage and secure, respectively, the pawl and the handle. 
     It is an object of the present invention to provide a novel latch assembly where a handle actuates a pawl member for engagement with a keeper member and wherein the handle is separately securable to a keeper member. 
     Another object of the present invention is to provide a latch with an alignment feature which aligns two panels which are to be secured with the latch. 
     It is another object of the present invention to provide alignment elements which align the panels relative to each other and/or one or more of the latch components. 
     It is a further object of the present invention to accomplish the above objects by providing a handle member which is pivotally movable with a pawl for a portion of the handle member pivot and relative to the pawl for another portion of the handle member pivot. 
     A further object of the present invention is to provide a novel latch which can be locked with a separately provided locking member. 
     It is another object of the present invention to provide an interference between the handle and pawl members to provide rotation of the handle and pawl together over a portion of the handle&#39;s pivot arc. 
     It is another object of the present invention to provide biasing means which facilitate latching and retention of the panels secured with the latch. 
     Another object of the present invention is to accomplish the above objects where the latch is configured to minimize injury to a user that might otherwise occur from inadvertent contact with one or more of the latch components. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES 
     FIG. 1 is a front perspective view, viewed from the left side, of a latch assembly according to the present invention shown in an installation securing two panel members together. 
     FIG. 2 is a left side perspective view of the front of the keeper member viewed from the bottom left looking toward the top right of the keeper. 
     FIG. 3 is a left side perspective view of the latch assembly of FIG. 1 shown with the primary and secondary catch members disengaged from the keeper through a partial arc of rotation. 
     FIG. 4 is a left side perspective view of the latch assembly of FIG. 1 shown in a fully opened unlatched position. 
     FIG. 5 is a rear elevation view of the handle and pawl shown attached to a base member where the handle and base member are shown in partial sectional view. 
     FIG. 6 is a left side perspective view of the front of an alternate keeper member embodiment viewed from the bottom left looking toward the top right of the keeper. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1, a preferred embodiment of a latch assembly  10  according to the present invention is shown mounted in an installation securing together two members, such as the upper panel  100  and lower panel  101 . The latch assembly includes a keeper member  11  shown mounted to the upper panel  100 , and a base member  12  shown mounted on the lower panel  101 . The base member  12 , as shown in FIG. 4, can be mounted to the lower panel  101  with suitable securing means such as bolts  18 . Actuation means, such as the latch handle  13 , is shown pivotally mounted to the base member  12 . The base member  12  carries the handle  13  which is shown secured to the keeper  11  with a secondary catch member  14 . The handle  13  is provided with securing means, comprising the slot  15  disposed therein. Preferably, the slot  15  comprises a t-shaped configuration to align with and receive the secondary catch  14  therein. While not shown, the secondary catch  14  can be provided as an integral member with the keeper  11  for operation as described herein. The keeper member  11  further includes hasp means shown comprising an outwardly extending flange portion  16  having an aperture therein for receiving locking means. While the locking means is shown in FIG. 1 comprising a padlock  20 , it will be understood that any suitable locking means, such as, for example, a pin, bar, cord, chain, or the like can be used as well, depending on the application and level of security required. 
     Referring to FIG. 2, the keeper member  11  is provided having a mounting portion  21  with a pair of upwardly protruding flange members  22 , 23 . Mounting means is provided for mounting the keeper  11  to a mounting surface, such as the upper panel  100  (FIG.  1 ). The mounting means is shown comprising a plurality of apertures in the mounting portion  21  of the keeper member  11  by which the keeper member  11  is secured with securing means, such as the bolts  18  (FIG.  1 ). The keeper member  11  includes a primary catch  24  for securing a pawl member. The primary catch  24  is shown comprising a pin extending transversely between the upwardly extending flange portions  22 , 23  and secured at either end thereof with securing means, such as, for example, the end fittings  25 , 26 . Alternately, other suitable means for securing the pin  24  to the keeper  11  can be utilized, including compression of the pin ends, washers, nuts, or the like. 
     Closure means is provided on the keeper member  11  for securing the pawl  17  and handle  13  and maintaining the latch assembly  10  in a latched condition. The keeper member  11  is shown comprising a secondary catch  14  which extends outwardly from the top of the keeper member  11 , as shown in FIG.  2 . The secondary catch  14  preferably is provided as a flexible, spring member which has an engaging lip  27  for engaging the handle  13  at the engaging edge  28  of the handle slot  15  and urging the edge  28  of the handle  13  onto the retaining shelf  30  of the secondary catch  14 . Preferably, as shown in FIG. 2, the engaging lip  27  is sloped and, while not shown, is deflected downwardly relative to the top of the keeper  11  when the force of the handle  13  is encountered through engagement with the engaging edge  28 . The engaging lip  27  is further provided with a flange portion for facilitating gripping thereof by a user when the secondary catch  14  is to be depressed for release of the handle  13 . When latched, as shown in FIG. 1, the secondary catch  14  remains slightly stressed by the handle  13  to provide a resistance which facilitates maintenance of the handle  13  in the latched position. The secondary catch  14  is provided having a mounting portion  38  which is mounted to the keeper member mounting portion  21 . As shown in FIGS. 3 and 4, the secondary catch  14  can be mounted to the keeper  11  by a rivet  39 . Other suitable mounting means, such as, for example, bolts, welds, and the like may also be employed. 
     The keeper member  11  is also provided with aligning means for aligning the upper and lower panels  100 ,  101 , respectively, together to ensure proper meeting of the latch components, namely, the alignment of the base member  12  and components carried thereby with the upper panel  100  and keeper member  11  mounted thereon. The central aligning tab  29  extends downwardly from the mounting portion  21  of the keeper member  11  and includes a stepped portion forming an aligning ridge  31 . Preferably, the lower panel  101  can engage the aligning ridge  31  when the latch assembly  10  is brought together for fastening. In addition, aligning tabs  32 , 33  are provided on each end of the keeper member  11 , on opposite lateral sides of the central aligning tab  29 . Preferably, the lateral aligning tabs  32 , 33  each have a stepped portion forming an aligning ridge, respectively,  34 , 35  for facilitating alignment of the assembly  10  by engaging the lower panel  101  as the latch  10  is secured. The aligning tabs  29 , 32 , 33  are shown in a preferred radial configuration in order to avoid the potential danger of rough edges which could otherwise be encountered by a user through inadvertent contact when the latch  10  is installed on a panel. 
     Resistance means is provided on the keeper member  11  to maintain a tight connection of the latch components when the assembly  10  is secured. The resistance means is shown comprising a pair of spring members  36 , 37  extending from the bottom of the keeper member mounting portion  21 . The spring members  36 , 37  distribute a constant force to the assembly as the pawl member  17  is drawn to engage the pawl pin  24  and secure the pawl  17  thereto. 
     FIGS. 4 and 5 show the handle  13  secured to the base member  12  for rotational movement thereabout. A pair of mounting pins  40  secure the handle  13  to the base member  12 . The base member  12  is shown having a pair of outwardly extending flange portions  41 , 42  defining opposite sides of the rotational axis about which the handle  13  and pawl  17  pivot. The pawl  17  is pivotally attached to the handle  13  with suitable mounting means, such as, for example, the pivot member  39 . As alternatives to the pair of mounting pins  40 , bearings, tabs or other like suitable pivot fasteners can be used to secure the handle  13  to the base  12 . Similarly, the pawl mounting means can also comprise a pair of mounting pins, bearings or other suitable fasteners. 
     Referring to FIG. 5, the pawl  17  and handle  13  pivot assembly is shown. The pawl  17  includes a radial lower portion with which the pawl  17  is pivotally mounted with the mounting pin  39  extending through the lower radial portion  49 . The pawl  17  is provided to move with the handle  13  during a portion of the pivot movement of the handle  13 . The handle  13  is also able to pivot over a portion of its pivot arc independent of the pawl  17 . 
     As shown in FIGS. 3 and 4, the latch  10  appears in two conditions. FIG. 3 shows the pawl  17  engages with the pawl pin  24 . The pawl  17  is shown having a radially configured terminal portion  45  which engages the pawl pin  24 . As the handle  13  is moved from its FIG. 3 position to a latching (FIG. 1) position in the direction indicated by arrow “a”, the pawl  17  draws the keeper  11  and panel  100  attached thereto toward the base member  12 . A strengthening rib  43  is provided on the terminal radial portion  45  of the pawl member  17  to fortify the pawl  17 , in particular, during latching and when the latch  10  is secured. 
     The handle  13  preferably is provided with a gripping means, such as the gripping flange  44  for facilitating lifting of the handle  13  into and out of its engaged position. The handle  13  is shown in its disengaged, relaxed position in FIG.  4 . When the handle  13  is raised by lifting from its FIG. 4 position toward the position shown in FIG. 1, the handle  13  pivots toward the keeper  11  over an arc about the pivot axis provided by the pivot member  40 . During a first portion f the pivot, the handle  13  pivots relative to the base  12 . The pawl  17  is lifted and secured on the pawl pin  24 . The lifting of the handle  13  toward engagement with the secondary catch  14  forces the pawl  17  downward to securely engage the pawl pin  24 . The spring members  36 , 37  of the keeper  11  provide a bias which acts upon the pawl  17  as it is pivoted from its FIG. 4 position to its latched position, and continues upon latching of the pawl  17  with the pawl pin or catch  24 . 
     An interference means  60  can preferably be provided between the pawl  17  and the handle  13 . For example, the pawl  17  can be provided with a protruding configuration, such as a raised boss, or can be provided with an enlarged width as shown in FIGS. to create friction between the handle  13  as the handle  13  is pivoted. The interference means permits the latch  10  to be unlatched with the pawl  17  remaining in a partially pivoted position, such as that shown in FIG.  3 . As shown in FIG. 4, the latch  10  is in its fully opened position with the handle  13  close to 180 degrees relative to its latched position of FIG.  1 . The pawl  17  in FIG. 4 is shown open less than 180 degrees. The interference means operates to maintain the pawl  17  at the partially pivoted position relative to the handle  13 . 
     Reference now being made to FIG. 6, wherein an alternate embodiment of a keeper member  111  according to the present invention is shown. The keeper  111  is provided to be used with the handle  13  and base  12  elements described above. Bolt members  18  can, as described above, be used to mount the keeper  111  onto a mounting surface, such as the upper panel  100  described and shown above. The keeper  111  is shown having a hasp means including a flange  116  protruding outwardly therefrom. The flange  116  has a twisted configuration with the lower portion  117  thereof being perpendicular to the upper or outermost portion  118 . An aperture  119  is provided in the outer portion  118  of the flange  116  for receiving a locking member, such as the padlock  20  shown in FIG.  1 . The keeper member  111  has a mounting portion  121  with flanges  122 ,  123  on each side thereof. A catch is provided comprising a pin  124  which is retained on the keeper  111  at the flanges  122 , 123  with attachment means. The attachment means are shown in FIG. 6 comprising retaining members  125 ,  126  which hold the pin  124  in place. As described in connection with the keeper  11  in FIGS. 1-4, the alignment means comprising the alignment tabs,  129 ,  132  and  133  are utilized in the alternate keeper  111  embodiment. Alignment ridges  131 , 134 , and  135  are also provided to facilitate positioning of the panels, such as those  100  and  101 , which are secured by the latch. Spring members  136 ,  137  are also provided. The secondary catch  114  is shown having a mounting portion  150 . The mounting portion  150  has a slot  151  therein. The keeper  111  is provided with catch mounting means comprising a mounting finger  152 . The mounting finger  152  extends from the mounting portion  121  of the keeper  111  and protrudes through the slot  150  of the catch  114 . The mounting portion  150  of the catch  114  extends into a radial arm  159  which includes a shelf portion  156  and a lip  157 . As described above, a tab  158  is shown for facilitating the operation of the secondary catch  114  by a user who depresses the arm  159  of the catch  114  to release a handle, such as the handle  13  of FIGS. 1,  3  and  4 , from engagement therewith. 
     These and other advantages of the present invention can be made consistent with the spirit and scope of the invention as disclosed in the Summary of the Invention, the Brief Description of the Drawing Figures, the Detailed Description of the Preferred Embodiments and the appended claims.

Technology Category: 4