Abstract:
A closure retainment latch for cabinet doors and the like that provides a child resistant access protocol restricting opening to required user specific actions. A cabinet door handle selectively engages an interior magnet retainer latch allowing the door to open. Multiple handle engagement indicated operations are required to initiate handle drive activation and latch release in a rotational longitudinally engagement configurations of contoured interdependent engagement activation elements within the handle and latch specific cam engagement surfaces.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     This invention relates to safety devices for door latches to restrict access by children, specifically cabinets and cupboards. 
     2. Description of Prior Art 
     Prior art devices of this type have been directed towards a variety of profile locks and handles wherein children are unable to open the door by the usual handle rotation and latch movement associated therewith. 
     Such prior art devices can be seen, for example, in U.S. Pat. Nos. 5,360,243, 5,785,363 and U.S. Publications 2009/0030427 and 2009/0266121. 
     In U.S. Pat. No. 5,785,363 a child safety latch can be seen having a dual activation push button configuration wherein both the buttons must be pushed and held simultaneously to activate release of the engagement of an interior latch. 
     U.S. Pat. No. 5,360,243 claims a latching structure for use with cabinets having electromagnetic member to engage a latch member. A switch provides activation and release of the mechanical latch allowing the cabinet to be open. 
     U.S. Patent Publication 2009/0030427 A1 illustrates a control handle for a lock wherein a release button is slidably advanced and held to directly engage a shaft or door latch retraction allowing the door to open. 
     U.S. Patent Publication 2009/0266121 A1 shows a child proofing of a door latch that is adapted to a standard lock set that prevents the door knob from turning when engaged. A sliding plate holds a locking post in place with a notch preventing the door knob rotation unless disengaged by a control lever interengaged therewith. 
     SUMMARY OF THE INVENTION 
     A cupboard safety latch device that provides a handle and interior release mechanism which requires multiple user actions to activate and release for access. The handle having a secondary movable element that interconnects rotatable handle input with an interior magnetic release by interlocking drive elements. Two movements are user required both handle rotation and simultaneous button depression to achieve inner latch and interior release engagement. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a sectional view of the invention assembly with portions broken away. 
         FIG. 2  is an exploded side elevational accessible view thereof. 
         FIG. 3  is a front elevational view of a drive lock element in the handle thereof. 
         FIG. 4  is a side elevational view thereof. 
         FIG. 5  is on lines  5 - 5  of  FIG. 4 . 
         FIG. 6  is front elevational view of an activation button in the handle thereof. 
         FIG. 7  is a side elevational view thereof. 
         FIG. 8  is on lines  8 - 8  of  FIG. 7 . 
         FIG. 9  is a front elevational view of a locking nut. 
         FIG. 10  is a side elevational view thereof. 
         FIG. 11  is a front elevational view of the drive shaft and sleeve of the invention. 
         FIG. 12  is a rear elevational view thereof. 
         FIG. 13  is a side elevational view of a cam release activation rod assembly of the invention. 
         FIG. 14  is a front elevational view thereof. 
         FIG. 15  is a partial rear elevational view of a horizontal mount of the cam release activation rod assembly. 
         FIG. 16  is a front elevational view of a cam assembly retaining disk. 
         FIG. 17  is a side elevational view thereof. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1 and 2  of the drawings, a safety door latch  10  of the invention can be seen having a handle assembly  11 , a cam rod release assembly  12  and a rod latch assembly  13 . The handle assembly  11  has two-part handle housing  14  and  15  respectively with a spring driven activator control button  16  which must be pushed in while the handle is being turned as will be described in greater detail hereinafter for operational engagement. 
     The control button  16 , best seen in  FIGS. 1 ,  6 ,  7  and  8  of the drawings has a main stepped annular body member  17  with a user end engagement portion  17 A and drive engagement portion  17 B. The drive portion  17 B has an annular gear surface  18  with a plurality of radially spaced teeth  18 A thereon. A rotational limitation engagement channel  19  extends partially within the control button  16 &#39;s main body member and an annular spring seat  20  in spaced relation thereto as best seen in  FIG. 6  of the drawings. A centered drive shaft receiving cavity  21  extends partially therewithin providing an engagement surface as will be described. 
     A drive lock fitting  22 , best seen in  FIGS. 1 ,  3 ,  4  and  5  of the drawings has a stepped annular body member  23  having a gear portion  23 A, a housing engagement portion  24  and a nut engagement portion  25  with a central bore at  26  extending therethrough. The gear portions  23 A has a plurality radially spaced teeth  27  for select engagement with the teeth  18 A on the button  16 . The housing engagement portion  24  has annular threads  28  extending therefrom for registration with corresponding threads  28 A on the inner surface IS of the housing part  15  as best seen in  FIG. 1  of the drawings. 
     As assembled, the drive lock fitting  22  is rotatably positioned on a drive shaft housing  29  having a central drive shaft  30  therewithin and extending therefrom as will be described in greater detail hereinafter. 
     The drive shaft housing  29  is cylindrical having a threaded exterior surface S with a compound smooth annular flange end  31  from which extends a rotational restriction about stopper bar  32  as best seen in  FIGS. 1 and 11  of the drawings. The drive lock fitting  22 , as noted, slips over the drive shaft housing  29  and abuts against the end flange  31  and is retained thereagainst by a drive lock nut  33 , best seen in  FIGS. 1 ,  9  and  10  of the drawings. The drive shaft  30  has a corresponding retainment flange  30 A in retaining registration with the hereinbefore described flange end  31  of the drive shaft housing  29 . The drive shaft  30  has an area of reduced transverse dimension  34  extending from the flange end  31  of the drive shaft housing  29  registering within the shaft receiving cavity  21  of the button  16 . A spring  35  in the spring seat  20  extends about a portion of the drive shaft extension  34  and against the drive shaft  30  imparting a resilient action to the button  16  during use. 
     Referring now to  FIG. 1  of the drawings, the handle housing  15  can be seen having an interior annular stepped configuration corresponding to an exterior stepped surface of the button  16  and with the drive lock fitting  22  aligning same to afford selective button gear teeth  18 A and drive lock fitting  22  gear teeth  27  for selective engagement indicated by directional arrows A upon button  16  displacement within the handle housing portion  15  when in assembly as shown in  FIG. 1  of the drawings. The handle housing  14  rotatably supports the drive shaft housing  29 , drive shaft  30  therein and threaded engagement lock nut  33 , as assembled. 
     A handle spacer  36  and spacer lock retaining nut  36 A are threadably secured on the drive shaft housing  29  retaining the handle housing  14  for adjustable resistant rotation thereon. 
     The handle assembly  11  as hereinbefore described will provide for select operational rotation of the drive shaft  30  in the following user sequence. 
     The handle housings  14  and  15  can be freely rotated independently on the drive shaft assembly in non-engagement position illustrated in  FIG. 1  of the drawings, however, once the button  16  is depressed indicated by activation arrows A inwardly against the spring  35 , the respective gear teeth  18 A and  27 A engage effectively locking the button  16  to the rotatable drive lock fitting  22  thereby rotating the drive shaft  30  keyed therewithin. The rotational restriction stopper bar  32  extending from the drive shaft flange housing end  32  as described is correspondingly registered within the rotational limitation engagement channel  19  limiting the effective drive shaft  30  and therefore handle rotation when so engaged and turned. 
     Referring now to the cam rod release assembly  12 , best seen in  FIGS. 1 ,  2 ,  13  and  14  of the drawings, the cam rod release assembly  12  has a rectangular activation frame  37 , best seen in  FIG. 1  of the drawings with oppositely disposed top and bottom surfaces  37 A and  37 B respectively and spaced parallel front and back surfaces  37 C and  37 D as positioned in this illustration. The frame  37  has a central contoured opening therethrough at  38  and elongated lug  39  extending from the so defined front surface  37 C in co-planar relation to its bottom surface  37 B. 
     Pairs of surface engagement arcuate guide feet  40 A and  40 B extend in spaced parallel opposing relation to one another from the so-defined back surface  37 D of the rectangular activation frame  37 . 
     A cam fitting  41  can be seen in broken lines in  FIG. 14  of the drawings and best seen in solid lines in  FIGS. 1 and 2  of the drawings, has a cam engagement surface  42  with an extending annular drive shaft engagement sleeve  43  having an interior annular sidewall  44  with oppositely disposed parallel interior key engagement surfaces  44 A and  44 B therewithin. An outer annular spaced sidewall  45  defines therefore a spring channel  46  therebetween with a central opening at  47  extending through the cam fitting providing access for a fastener screw  48  to engage within an apertured end  49  of the drive shaft  30 . 
     The cam fitting  41  is registerable on the front surface  37 C of the frame  37  so as to rest in non-activated position on top of the elongated lug  39  with the drive shaft support sleeve  43  therefore extending into the contoured opening  38  as shown in  FIG. 1  of the drawings. The heretofore free end of the drive shaft  49  has a keyed surface extension of reduced transverse diameter  49 A which is engaged in the inner annular sidewall  44  keyed engagement surfaces  44 A and  44 B when assembled. 
     An apertured retaining disk  50 , see in  FIGS. 1 ,  2 ,  16  and  17  of the drawings is provided with a disk lock nut  51  is secured to the drive shaft housing  29 . The apertured retaining disk  50  has aligned spring engagement tabs  52  registerable against the outer sleeve  45 . A return spring  53  is secured at  53 A into the cam fitting  41  and extends between the respective inner and outer sleeves  44  and  45  being secured between the engagement tabs  52  of the retaining disk  50  so as to provide rotational spring return resistance to the cam fitting  41  when rotated by the drive shaft  30  during activation as hereinbefore described. 
     Referring back to  FIG. 2  of the drawings the rod latch assembly  13  can be seen having a latch activation rod  54  secured in and extending from the top surface  37 A of the hereinbefore described frame  37 . A rod guide bracket  56  is provided and mounted on the door D assuring latch activation rod  54  retention and alignment. The bracket  56  has a grub adjustment screw  55  therein that when engaged stops the rod  54  from moving so the magnet fitting  58  cannot draw the rod  54  into the locked position. A ferrous metal plate  57  secured to the free end of the activation rod  54  and is magnetically engaged by a magnet retaining fitting  58  mounted on the interior surface of a cabinet C on which the door D, in this example, is positioned. 
     It will be evident that the engagement rod  54  orientation when retained by the magnet fitting  58  will prevent the door D from freely opening until the handle assembly  10  of the invention is properly activated. 
     In operation, once the button  16  is pressed and the handle  15  is rotated simultaneously, the drive shaft  30  so engaged will correspondingly rotate the cam fitting  41  engaging and “sliding the frame  37 ” on the inside of the door D thus pulling down in this illustrated orientation the activation rod  54  within the guide bracket  56  releasing same from the magnetic fitting  58 . At this point, the door D can be opened by pulling the handle assembly  10  as will be well understood by those skilled in the art. 
     As noted, the cam retaining spring  53  will return the cam fitting  41  once the handle  15  is released by the user, not shown. The rod  54  and frame  37  will remain in position and not return with the cam fitting  41  staying in the unlocked position until the magnetic fitting  58  can so engage and draw same to the lock as noted. It will be seen that the cam rod assembly  12  can be mounted in a horizontal orientation as shown in  FIG. 15  of the drawings so as wherein the cam fitting  41  is rotated with the engagement sleeve  43  shown in solid lines. The frame  37  will be slid horizontally as indicated by broken lines and the sleeve  43  will slidably engage into the enlarged area of the contoured opening  38  and retain the frame  37  in the “open” position by frictional gravity at  59  as the frame  37  drops slightly down vertical indicated by broken arrow V as well as horizontally as noted, by broken arrow H. 
     It will be evident from the above description that unless the button  16  is depressed, engaging the drive lock fitting  22 , that the handle  15  will just rotate without effective articulated latch release engagement. 
     It will thus be seen that a new and novel child safety door latch has been illustrated and described and it will be apparent to those skilled in the art that various changes and modifications may be made thereto without departing from the spirit of the invention.