Patent Publication Number: US-6702342-B2

Title: Latch assembly

Description:
PRIORITY CLAIM 
     This application is a divisional application of U.S. Application of U.S. application Ser. No. 09/415,296, filed Oct. 8, 1999, now U.S. Pat. No. 6,502, 872, which claimed priority to U.S. Provisional Patent Application Ser. No. 60/103,714, filed Oct. 9, 1998, the entire contents of which are hereby incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to latches and more particularly relates to latch assemblies utilizing handles and secondary handle release mechanisms for use with cabinets and the like. 
     Latch assemblies with handles are known which are lockable by utilization of an internal lock cylinder which prevents the handle from rotating. Typically these latch assemblies can be locked and unlocked and remain in the unlocked position whereby the handle and door attached thereto may be opened with one hand. Standards adopted in the telecommunications industries require that two hands be utilized to operate certain cabinet latching assemblies. There has been minimal development of effective and convenient latching assemblies which have this feature. Additional locking features to accommodate a padlock are also desirable as the primary locking means or a secondary locking means on such latching assemblies. Prior art latch assemblies, particularly locking latch assemblies, normally lack flexibility in being adaptable for varying applications, for example a left or right and door. 
     SUMMARY OF THE INVENTION 
     The present invention provides a latching assembly that requires three distinct operations which must be performed with two hands to allow the handle of the latch assembly to be rotated to unlock a cabinet door or the like. Moreover, the design allows substantial flexibilities in installation. 
     A base portion with a sleeve is secured to a door and receives a handle portion with a shaft attached, the shaft extending through the sleeve. Cooperative rotation restriction portions on the handle and on the base portion restrict the motion of the handle to a limited rotation range. Said limited rotation range may be altered by selectively moving a key guide in one of the cooperative rotation restriction portions. A first release mechanism comprising a trigger portion which extends from the handle and a detent mechanism which engages an opening in the support portion requires depression of the trigger portion before rotation of the handle to an unlatched position. The detent mechanism is within the handle and a cap contains and encloses in the detent mechanism. The cap portion has a bore which receives a second release mechanism which has a shaft portion that may be exteriorly manipulated to move an obstructive member into and out of an obstructing relation with the detent. Thus, the second release mechanism must be manipulated to allow release of the trigger portion which must be depressed to allow rotation of the handle. The cap portion is secured in the handle by screws or other threaded members extending from the handle base portion interface into the cap. 
     In an alternative embodiment, the first release mechanism comprises a trigger portion which pivots with respect to the handle, and the second release mechanism slides linearly with respect to the handle. 
     The trigger portion of the first release mechanism is pivotally connected to the handle of the latch mechanism and includes a first interference portion or detent which extends forwardly into a first slot of the base to prevent rotational movement of the handle relative to the base. 
     The slide portion of the second release mechanism includes a second interference portion or detent, and is operatively connected to the obstructing member of the axially rotatable second release mechanism so that upon rotational movement of the second release mechanism, the second interference portion is brought into and out of engagement with the first slot in the base. Second interference portion also prevents rotational movement of the handle relative to the base. 
     The trigger and slide portions are arranged so that the first and second interference portions are juxtaposed within the first slot in the base so that the second interference portion prevents the first interference portion from being disengaged from the first slot in the base. When the second release mechanism disengages the second interference portion from the first slot in the base, the first interference portion of the first release mechanism may be pivoted out of engagement with the first slot of the base, thus enabling the handle to be rotated to engage or disengage the latch member from the latch receiver. 
     A feature and advantage of the invention is that a finger operated slide member must be depressed into the handle before rotation of the handle. 
     A feature and advantage of the invention is that a release mechanism positioned in the head of the handle must rotate to allow the handle to be rotated. 
     A further feature and advantage of a preferred embodiment is that the release shaft portion must be rotated before the finger operated slide member may be depressed into the handle. 
     A further feature and advantage of the invention is that the handle when rotated to the unlatched seconded position is retained in place by the slide member engaging a second detent recess. 
     A further feature and advantage of the invention is that the handle is easily convertible from a clockwise unlatching rotation to a counterclockwise unlatching rotation by simple internal alteration. The same latching assembly can thus be used for either right or left hand opening doors. 
     A feature and advantage of the invention is that with the same handle, base portion, and shaft, a blank plug may be inserted into the head of the handle eliminating the release shaft portion such that the latching assembly may be operated with one hand. 
     A feature and advantage of the invention is that the release shaft portion may utilize a key operated insert, either radial pin-tumblers or normal flat key cylinders. 
     An additional advantage and feature of the invention is that three separate actions are required to unlatch the latching assembly and only a single action, rotation of the handle is necessary for latching the latching mechanism. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the latch assembly in place on a door with a padlock. 
     FIG. 2 is a exploded perspective view of the latch assembly showing alternative shaft portion ends. 
     FIG. 3A is an exploded perspective view of the invention. 
     FIG. 3B is a portion of FIG. 3A with the trigger portion in a different position. 
     FIG. 3C is a detailed perspective view of the slide member including the trigger portion. 
     FIG. 4 is a cross-sectional view through the device. 
     FIG. 5 is an elevational view of the end of the handle with the cap end and shaft portion removed except for the obstructing portion. 
     FIG. 6 is an elevational view of the inside of the cap with the shaft portion in place illustrating the obstructing portion. 
     FIG. 7 is a front elevational view of the handle and shaft without the base portion and with the slide member in place. 
     FIG. 8 is a front elevational view of the body portion with a key guide in place. 
     FIG. 9 is a schematic view showing different rotational positions of the handle and different range of rotations. 
     FIG. 10 is a partial, sectional plan view of an alternative embodiment of a release mechanism showing the juxtaposition of a first release mechanism and a second release mechanism relative to the base and the handle of the latch mechanism. The plug or cap containing the second release mechanism has been omitted for clarity. 
     FIG. 11A is a side elevational view of the trigger portion of the first release mechanism of FIG.  10 . 
     FIG. 11B is a top plan view of the trigger portion of the first release mechanism of FIG.  10 . 
     FIG. 12A is a front elevational plan view of the slide portion of the second release mechanism of FIG.  10 . 
     FIG. 12B is a rear elevational plan view of the slide portion of the second release mechanism of FIG.  10 . 
     FIG. 12C is a view of the front surface of the slide portion taken from a right perspective. 
     FIG. 12D is a view of the front surface of the slide portion taken from a left perspective. 
     FIG. 13A is a side elevational view of the plug or cap of the alternative embodiment. 
     FIG. 13B is an interior facing end view of the plug or cap of the alternative embodiment of FIG.  13 A. 
     FIG. 14A is a partial plan view of the base engaging side of the handle of the alternative embodiment. 
     FIG. 14B is a partial plan view of the interior chamber of the handle of the alternative embodiment. 
     FIG. 14C is a partial sectional side view of the handle of the alternative embodiment taken along line A—A of FIG.  14 A. 
     FIG. 15A is a plan view of the handle engaging side of the base of the alternative embodiment. 
     FIG. 15B is a side elevational view of the base of FIG.  15 A. 
    
    
     DETAILED SPECIFICATION 
     Referring to FIGS. 1 and 2, the latching mechanism is shown in position on a door and in an exploded view. The latching mechanism is generally designated with the numeral 20 and is tended to be secured to a door  22  in a door frame  24 . The latching mechanism is principally comprised of a base portion  28  with a sleeve  29  defining an aperture  33  sized to rotatingly receive a shaft  34 , a handle  30 , a plug or cap  32 , a first release mechanism  36  and a second release mechanism  38 . The handle has a head portion  31  with an open interior configured as a cap or plug receiving region  42 . 
     The first release mechanism is a detent mechanism in the preferred embodiment and has a protruding portion configured as a trigger portion  44  which comprises a loop  46  sized for receiving a padlock  50 . The second release mechanism  38  has a first end  31  which may be a tool receptacle  54 ,  56  or a key cylinder  58  or a manually manipulatable member  60  and a second end that interferes or obstructs the operation of the detent mechanism. Thus, the rotation of the handle and the actuation of the latch member  48  involves sequential actuation of the second release mechanism by rotation of the first end and depression of the trigger portion  44  at which point the handle  30  may be partially rotated to release an internal latch member  48  from a latch receiver  49  as shown in FIG.  4 . The shaft  34  has a first end  35  and a second end  37  and may have any conventional configuration with the latching member  48  attached to the first end  35  by any suitable means, the shaft received for rotational movement in the aperture  33  of the base portion  28 . 
     Details of the first release mechanism are as follows. Referring to FIGS. 3A,  3 B,  3 C,  4 ,  5 ,  6 , and  7 , the components of the first release mechanism  36  are the finger operated slide member  70  which is shown in isolation in FIG. 3C, the spring  72 , which provides a downward bias to the slide member  70 , the base portion  28 , specifically the first slot  76 , the handle  30 , specifically the second slot  80 . Due to this bias, the slide member  70  is normally in the extended position as shown in FIGS. 3B and 4 in the solid lines and is indicated with the numeral  82 . The depressed position as shown in FIG. 3A in slotted lines and in FIG. 4 in dashed lines has been designated with the numeral  84 . 
     Note that the slide member has regions of a reduced cross sectional portion  85  where the protruding portion extends from the head of the handle whereby when the protruding portion receives a sharp impact such as from someone trying to remove the padlock, the slide member tends to fracture at said reduced cross sectional portion inhibiting further movement of the slide member from the extended position to the depressed position. 
     The slide member  70  has an interface portion or detent  88  which in the extended position is positioned in the slot  76  preventing rotation of the handle  30  and shaft  34  with respect to the base portion  28 . Depression of the trigger portion  44  extends the detent  88  upwardly out of the way of the frustoconically shaped collar portion  94  of the base portion  28 . In such a position the recess  96  on the slide member which conforms to the shape of said frustoconical portion of the base portion freely rotates about the exterior of said frustoconical portion as the handle is rotated. The spring is contained in a spring containment region  98 . 
     The second release mechanism  38  is best shown in FIGS. 2,  3 A,  4 , and  6 . The mechanism  38  has a shaft portion  110  which is comprised of the rotatable portions such as the first end  39  to the opposite end  114  which is configured as a cylindrical member with an obstructing portion  116 . 
     A torsion spring  120  is engaged with the cylindrical member  114  and the cap  32  is constrained by and fits in the bore  122 . A screw  124  secures the cylindrical member  114  to the first end of the shaft portion. The obstructing portion  116  rotates with the shaft portion between an obstructing position as indicated with the numeral  130  and a non-obstructing position as indicated with the numeral  132 . The handle has a recess  134  in which the obstructing member travels and has a first stop portion  136  and a second stop portion  138  both of which in the preferred embodiment are integral with the handle  30 . The obstructing portion  116  in the obstructing position engages with the slot  142  of the slide member  70 . The second release mechanism is secured within the head of the handle portion  30  by securing the cap  32  to the handle head by way of screws  152  in the screw recesses  154  as best shown in FIG.  3 A. 
     Referring to FIG. 9 the use of latching mechanism  20  on a cabinet  166  is illustrated. The cabinet has a door frame  168  and a door  170 . Several different positions of the handle are shown with respective range of rotations. The handle  30  shown in the first position as indicated by the numeral  180  rotates from the first position to the upright position as indicated by the numeral  182  which is designated the second position and is the unlatched position for the latch assembly. The first position and second position define a range of rotation as indicated by the arrows designated with the numeral  184 . Alternative placements of the handle are possible as indicated by the handles drawn in phantom in dashed lines and designated with the numeral  188  which each have their respective range of rotations  190 . The different positioning of the handle are possible with the same latch assembly by way of altering the positioning of internal components and by rotating the base portion on the door. 
     Referring to FIGS. 2,  7 , and  8 , the base portion  28  and the handle each have cooperative rotation restriction portions  192 ,  194  respectively. The cooperative rotation restriction portion  192  on the base portion  28  has alternate seating recesses  202 ,  204  each recess configured to receive and engage a portion of a guide key  206 . The other cooperative rotation restriction portion  194  as best shown on FIG.  7  and as also shown in FIG. 3A, has an open area  214  in which another portion of guide key  206  is allowed to rotate or arcuately translate. The open area and the range of rotation or arcuate translation of the guide key and thus the handle is defined by the opposing stops  232 ,  234  which are both integral with the handle in the preferred embodiment. The guide key  206  is shown as a separate component but it also is understood that said guide key can be integral with the base portion. Additionally the cooperating rotation restriction portions can be reversed as to the base portion and the handle. That is the guide key seating recesses  202 ,  204  could be on the front face  236  of the handle head portion  31  and the stops  232 ,  234  could be on the body portion. Additionally the stop portions could also be separate removable components similar to the guide key  206  to allow alteration or expansion of the range of rotation. 
     Referring to FIGS. 8 and 2 note that the frustoconical portion of the collar portion  28  has an interior surface  256  which is generally cylindrical in shape with the exception of the seating recesses  202 ,  204  and also to secondary detent recesses  262 ,  264  as the handle is rotated through its range of rotation. The slide member  70  is in the depressed or retracted position, although it is continually biased outward. Unless the trigger portion is being manually held in the depressed position, this bias outward causes the surface  196  of the detent  88  to continually engage said inside surface  256 . At the secondary detent recesses  262 ,  264 , the handle will be held in the specific position correlating to these recesses. For example, the handle as shown in FIG. 1 may be raised to an upright portion which would correspond to the detent  88  positioned in one of said recesses. This will operate to secure the handle in the more horizontal position and prevent the handle from falling to the down vertical position and inadvertently locking the cabinet. Note that the two secondary recesses as shown are applicable only in the convertible latching mechanism in which the guide key or similar means provides reconfiguration of the assembly. 
     Referring to FIGS. 10,  11 A,  11 B,  12 A,  12 B,  12 C and  12 D, first release mechanism  280  comprises trigger portion  330 . Trigger portion  330  is similar to first release mechanism  36  as depicted in FIG. 3C in that it includes a loop  332  sized to accept an additional lock mechanism, and a trigger actuation surface  334 . Trigger portion  330  differs from first release mechanism  36  in that it includes an arm  336  which extends rearwardly from trigger portion  330  and terminates in a pivot pins  338 ,  340 . Pivot pins  338 ,  340  are transverse to arm  336  and allows trigger  330  to move relative to the handle. 
     Trigger portion  330  includes a first interference portion or detent  348  which is sized to project into and engage first slot  316  shown in base portion  310  to prevent motion of the handle  410  relative to the base  310 . First interference portion  348  includes a first contacting surface  350  which confrontingly engages a corresponding contacting surface  372  on second interference portion  366  of slide portion  360 . First contacting surface  350  and contacting surface  372  are configured such that if a user attempts to pivotally disengage the first interference portion  348  from first slot  316  without first interface portion  348  slidingly disengaging the second interference portion  366  from the first slot  316 , first contacting surface  350  will impinge upon contacting surface  372  and drive second interference portion  366  into slot  316 . When first and second interference portions  348 ,  366  are disengaged from first slot  316  and the handle is rotated with respect to the base, a second contacting surface  352  comes into sliding contact with a handle contacting surface  320  of base  310 . First interference portion  348  of trigger portion  330  is biased into locking engagement with slot  316  by spring element  346  which extends between a land  342  and a pocket in the plug or cap  390 . One end of spring element  346  is removably attached to land  342  by a spring engaging element or button  344 , while the other end of spring element  346  is received in a pocket  402  in plug or cap  390  (see FIGS.  13 A and  13 B). As spring element  346  biases first interference portion  348  into slot  316 , third contacting surface  354  of first interference portion  348  engages a stop  318  at the bottom of slot  316  of base portion  310 . 
     Slide portion  360  includes a first surface  362  and a second surface  364  which are spaced apart from and parallel to each other. Second interference portion  366  projects a sufficient distance from first surface  362  to enable second interference portion  366  to engage first slot  316 . Slide portion  360  includes an obstruction portion receiver or race  380  on the second surface of slide portion  360 . Race  380 , which is generally transverse to notch  378 , is provided with a web or sidewall extension  382  which forms a foreshortened portion  388  of the longitudinal aspect of notch  378  and creates an aperture  386  at the intersection of notch  378  and race  380 . Web or sidewall extension  382  also defines a land receiving area  384  which spans the distance from web  382  to the lowermost extent of notch  378 . The foreshortened portion  388  is sized to slidingly accept a boss  448 , and the land receiving area  384  is sized to slidingly accept land  454  so that land  454  effectively closes aperture  386  when slide portion  360  is disengages from first slot  316 . 
     Race  380  slidingly receives obstruction portion  116  of second release mechanism  38  (as depicted in FIG.  2 ). Because of the action of torsion spring  120  on obstruction portion  116  of second release mechanism  38 , second interference portion  366  is biased into engaging contact with first slot  316 . Slide portion  360  includes arms  374 ,  376  which define a notch  378  and which serve to guide slide portion  360  as is moves linearly within a slide portion receiving area  462  of handle  420  to engage and disengage second interference portion  366  from first slot  316 . Arms  374 ,  376  slidingly interact with corresponding surfaces in slide portion receiving area  462  of handle  420  (see also, FIGS. 14B,  14 C). 
     Referring to FIGS. 13A and 13B, cap or plug  390  includes an exterior portion  392 , a shoulder  394  and an interior portion  396 . When assembled with handle  420 , interior portion  392  of cap  390  fits into a plug or cap receiving cavity  480  (see FIGS.  10  and  14 C). To facilitate assembly, plug or cap  390  is provided with threaded bores  408 ,  410 ,  412  (shown in dashed lines in FIG. 13A) which receive threaded fasteners (not shown) inserted into countersunk through holes  426 ,  430 ,  434  in handle  420  (see FIGS.  14 A and  14 B). Cap or plug  320  includes a channel  398  with an upper interior surface  400  configured to allow movement of trigger portion  330  between engagement and disengagement positions. Channel  398  includes a pocket  402  configured to receive spring element  346 . Channel  398  includes a flange  404  which serves to lengthen pocket  402 . Flange  404  includes a retaining portion  406  which is configured to maintain pivot pins  338 ,  340  in contact with pivot contacting surfaces  470 ,  472  (see FIG. 14B) and prevent trigger portion  330  from being pivoted past a predetermined position. First release mechanism  38  (shown in dashed lines in FIG. 13A) has been adequately described above and will not be further discussed. Note that obstructing portion  116  extends beyond the plane of the interior portion  396  of plug  390 . Note that when assembled, obstructing portion  116  will be slidingly retained within race  380 . As obstructing portion  116  moves radially about a predetermined range of motion, slide portion  360  will be translated into linear motion. 
     Referring to FIG. 14A, base engaging surface  422  of handle  420  includes through holes  426 ,  430 ,  434  with countersinks  426 ,  428 ,  432  which are sized to passingly accept threaded fasteners (not shown) used to secure plug  390  to handle  420 . A cylindrically shaped land  442  with a longitudinal axis projects away from base engaging surface  422 . A shaft  444 , onto which a latch may be affixed, extends coaxially along the longitudinal axis of cylindrically shaped land  442 . A slot  436  extends from the longitudinal axis of land  224  in a generally radial direction along the longitudinal aspect of base engaging surface  422 . Slot includes notches  438 ,  440  which are sized to accommodate pivot pins  338 ,  340  of trigger portion  330  to facilitate assembly. 
     Referring to FIG. 14B, hole  426  extends through boss  448 , hole  430  extends through boss  450 , and hole  434  extends through boss  452 , which contact interior portion  396  of plug  390  and effectively retain slide portion  360  within slide portion receiving area  460 . Range of linear motion of slide portion within the slide portion receiving area  460  is limited by bosses  448 ,  450 ,  452 . 
     Referring to FIG. 14C, slide portion receiving area  462  includes a rectilinear shaped land  454 , a ramp  458 , and a recess  456  with a contacting surface  460 . Rectilinear shaped land  454  extends inwardly from the plane of the slide receiving area  462  by a distance which allows passage of web  382  of slide portion  360  thereabove. Ramp  458  extends outwardly and downwardly from land  454  and terminates at contacting surface  460  which is parallel to and spaced from the plane of the slide receiving area  462 , the ramp  458  and contacting surface  460  define a recess  456 . Recess  456  is sized to slidingly accept angle portion  368  and forward facing portion  370  of slide portion  360  when slide portion  360  is disengaged from slot  316  of base  310 . Pivot contacting surfaces  470 ,  472  are generally semicircular in shape to facilitate assembly. 
     Referring to FIGS. 15A and 15B, base portion  310  includes a cylindrically shaped land receiving section  312  with a coaxially aligned aperture  314  configured to rotatingly accept cylindrically shaped land  442  and shaft  444  of handle  420 . Contiguous with, and extending radially from the cylindrically shaped land receiving section  312  is slot  316  which terminates in stop  318 . Adjacent to, and coplanar with land receiving section  312  is handle contacting surface  320 . Handle contacting surface  320  also slidingly supports second contacting surface  352  of trigger portion  330  when handle  420  is rotated relative to base  310 . Parallel to handle contacting surface  320  is support or door contacting surface  324 . Handle contacting surface  320  and support contacting surface are spaced apart from each other by a transition  322 . Support contacting surface  324  includes a threaded hollow shaft  326  which extends outwardly therefrom and which is sized to rotatingly accept shaft  444  of latch mechanism. Shaft  326  is attached to a support by a threaded nut (not shown). Support contacting surface  324  also includes an index pin  328  which extends outwardly therefrom collaterally with shaft  326 . 
     The term “slot” when used herein includes any opening accessible by a sliding member such as bores, grooves or the like. The term “substantially” when used herein includes precisely that which is specified as well as not wholly or slightly more than that which is specified. The term “shaft portion” may be an integral piece or may be an assembly. The term “portion” when used herein may be part of an integral component, a separate component, or a combination of components and/or parts of components. The term “mechanism” when used herein may be a single integral piece or more than one linked or engaged pieces. 
     The components parts may be conventionally formed from appropriate metals such as aluminum, steel, stainless steel, and zinc. Additionally, components may be machined or molded form suitable plastics. 
     The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention.