US2662790A - Door latching mechanism - Google Patents

Description

2 Sheets-Sheet 1 F. M. HOGG DOOR LATCHING MECHANISM Dec. 15, 1 953 Filed Jan. 1, 1945 Inverfitor: Francis M. Hogg, by W CVMZM His Attorney Dec. 15, 1953 F. M. HOGG DOOR LATCHING MECHANISM- 2 Sheets-Sheet 2' Filed Jan. 1, 1945 Inverwtor. Francis M. H gg,

H is Attorney Patented Dec. 15, 1953 DOOR LATCHING MECHANISM Francis M. Hogg, Findley Lake, -N;Y., assignor to General Electric Company, "a corporation of "New'York Application. Januaryl, 1945, Serial No.:570,870

' '8 Claims. il

Myinvention relates to door latching mechanisms and particularly such mechanisms for latching relatively heavy .Idoorson portable cabinetslsuch as household refrigerator cabinets.

It. frequently happens that in portable storage apparatus such. as. household refrigerators it is necessary to provide .a .door which .is held tightly closed under pressureinorderuto maintain an adequate seal about theidoor opening. .A- gasket of rubber or similar material iscommonlyprovided about .the door opening. and this gasket is held under'pressure when thedooris latched in itsclosed position. In order to secure adequate compression of the gasket it is necessarytoprovide some arrangement 'for obtaining pressure during latching and for retaining .the pressure after latching. Latching mechanisms vhavingsti-fi actions which may require slamming-of the door are objectionable because of the possibility-f jarring" and damage to'thecontents of the cabinet. "Other latching deviceshaving trip mechanisms' have been providedwhichmay be closed without slamming; "however, thesemechanisms have not beenentirely satisfactory for thepurpose of compressingthesealinggasket. .Accordingly it is an object of' my invention to provide an improved latching mechanism of thetrip or triggered type.

It is another object ofimy invention to provide a door latching mechanismincluding an improved: arrangement for effecting tripping and latching of the' mechanism forcibly to "close the door without the necessity of exerting external pressure.

Further objects;arid2advantages of'my invention will become. apparent as'the following description proceeds --and theifeatures of *novelty whichcharacterize any invention'iwillsbe'pointed out withparticularity-in the claims annexed to and forming part of this specification.

For a better understanding oi my invention reference maybe had tothe accompany-ingzdrawings in which Fig. 1 represents in section a door latching mechanism embodying my..invention-ap-. plied to a refrigerator cabinet and shown-in its latched position,'-andrFig. 2 shows. the mechanism of- Fig. l with the door open and thelatch mechanism in its-locked out "position, the principal moving parts being shown in full rather thanin section.

the drawings comprises a "rotatable latch membermounted "on the "door'and arranged to engage the keeper portion of" astrike mounted .on the stationary cabinet structure. The rotatable Briefly, the latching mechanism illustrated in 2 latch is arrangedlto" be held in an open or locked out position by. a. toggle which is held in' its broken position by. a suitable overcenterspring. A trigger or trip member is provided which. is .actuated on closing of the door by. engagement with the" strike. 'Movementof the-trip requires very little force and effects'reversed overcenter movement of the toggle spring .to'throw'the toggle into its lockedhpositiomnand rotate the bolt to engage the keeper .portionof the strike-.and-lat'ch the door. The. arrangement. of the. spring and toggle is. such that the iorceof-the spring isimultiplied on rotating thellatchi into its lockingapo sition and. is sufiicient .to compress the .gasket during the lockingoperation. When the .door is closed it is securely lockedin position bya locked toggle and normallycan be opened only by movement of the .latchlhandle whicheffects reverse movement. of thetoggle. .A second spring-is provided whicha'fiords movement of the. latch bolt under excessive.pressuressuch as might occur on closing.thefdoorwhenthe-bolt is in its latched position.

Referring now .to .the drawing, the latch mechanism inFig..1.is mountedwithin a refrigerator cabinet door l...at.one edge thereof. Thexloor comprises .an-outer sheet metal wall orshell 2 and an inner wall or liner 3 whichmay be constructedof .heat. insulating material. .Theispace .betweenithe walls .2 and-:3 isfilledwith suitable heat insulating material (not shown). The-walls 2 andLBTare secured together at their adjoining edges byscrews 4 -which :also hold a-resilient ga'sketJiimposition about-.thedoor opening, a

. flanged -por.tion.6. of. the gasket being. compressed between the wallsl and The refrigerator cabinetcomprisesanoutersheetsmetal wall-l and an innerliner-t secured together by suitable spacers (notshown) and -.having :a' breaker-strip. Bfiof thermal insulation closingthe space between the walls about-the .door opening. The .gasket 5 'is compressed between the" outer liner '1 and the door I when'the latching nmechanisml is' in its locked position-asshownin-Fig. 1. The door is held in.its closed-position bya rotatablelatch bolt [0 which isarranged to engagea keeper portion. I I of a: strike I2. The strike I2 is secured by a-screw l3to a bridge or brace rigidly mounted between the .walls 1-" and=- 8 .of the .cabinet. Thelatch bolt. H1 is held in latching position bya. latching mechanism 15" mounted in the door and .arranged-.-to= be vunlatched by 1 operation of a handle. 16. The handle lt istpivotedi at its :lower .endat H. .The pivot 11- ismountedton anouter supporting plate 18 which, together with an inher supporting plate I9, is secured to the outer wall 2 of the door by screws 20. Clockwise rotation of the handle |6 about the pivot draws a lost motion link 2| outwardly from the door and unlatches the bolt l0, in a manner to be described. later, so that the parts of the mechanism assume their positions as shown in Fig. 2, the door being opened and the handle i6 returned to its original position as permitted by the lost motion connection 2|.

The latching mechanism I is mounted upon a supporting structure including a plate 22 of generally U-shaped cross section only one side of which is shown in the drawing, it being understood that the several pivots indicated have their axes normal to the two sides of the U. The wall 2 is provided with a reinforcing strip 23 relative thereto, and the plate 22 is secured to the strip 23 by screws 24. The supporting plate 22 is also secured in any suitable manner to the supporting member 9. The supporting structure also includes a member 25 pivoted to the member 22 at 26 and held against a stop 21 by a compression spring 28. The latch bolt I0 is rotatably mounted on the member 25 about a pivot 29 and is arranged to be actuated by a spring 30 through a toggle joint comprising links 3| and 32. The link 3! is rotatably mounted on the supporting structure about the pivot 26, and the two links are pivotally connected at 33, the link 32 being pivotally connected to the latch bolt H] at 34 eccentrically of pivot 29.

In the position shown in Fig. 'l the toggle comprising links 3| and 32 is held by the pressure of the spring 30 in a position such that the common pivot 33 is in substantial alignment with the pivots 26 and 34. It will readily be understood that since the force of the spring 30 is exerted in a direction transversely of the line of the pivots, the toggle mechanism constitutes a force-multiplying connection such that the force for rotating the latch bolt in into its latching position is much greater than the force of the spring 3| against the pivot 33. The toggle is therefore effectively locked in this latching position and if desired the pivot 33 may be arranged to move slightly past the center line through the pivots 26 and 34 so that the toggle is positively locked against reverse movement.

When the handle I6 is rotated in a clockwise direction about the pivot [1, the link 2| is pulled outwardly and carries with it a pin 35 on the link 3| and which fits in a cross slot 36 in the link 2|. This outward movement causes the link 3| to rotate in a clockwise direction about the pivot 26. Clockwise rotation of the link 3| compresses the spring 30 between the pivot 33 and a pin 3'! about which the spring is pivoted on the support 22. The spring is provided with a longitudinal guide 38 having one end pivoted at 33 and its other end engaging a pin 3'! connected between the two sides of the support 22, the guide 38 being provided with a slot 39 permitting longitudinal movement of the guide with respect to the pin 31. It is the link 38 which limits the expansion of the spring 30 and determines the locking position of the toggle. When the pivot 33 passes the common center line between the centers of pivot 26 and pin 31, the link 3| is snapped into and held in the extreme clockwise position illustrated in Fig. 2, the spring 36 acting as an overcenter spring, thereby locking the link in that position. Rotation of the link 3| carries with it the link 32 and thereby rotates the latch bolt I!) about its pivot 29 in a clock- 4 wise direction; and in the final position of the link 3| the latch bolt I0 is in its extreme clockwise position where it is retained by the looking out of the link 3|, the toggle joint being locked in its broken position.

The latch bolt ID has formed on it a trip or trigger member 40 which lies in the path of the strike |2 when the mechanism is in its unlatched position shown in Fig. 2. It will be noted that the position of the pivot 33 in Fig. 2 is only slightly past the center line of the pivots 26 and 31 so that only slight movement of the pivot 33 is necessary to push the spring 30 overcenter in the reverse direction. When the door is moved toward its closed position the strike |2 engages the trigger 40 and on slight movement thereof, which requires very little pressure, the latch member I0 is rotated suificiently to pull the pivot 33 past the center of the pivots 26 and 31 whereupon the spring 30 moves the toggle to its locked position with snap action. During this movement the latch member I3 engages the keeper portion H of the strike and continues to rotate and draw the door forcibly into its closed position. A roller 4| is provided on the bolt H! to minimize friction. It will be noted that since the spring 30 exerts force laterally of the toggle and against the pivot 33 the force of the spring is multiplied during the latching operation. The force exerted by the latch bolt l0 when rotated to its locked position by the toggle is suflicient to compress the gasket 5 about the door opening and secure effective sealing. This force of compression is far in excess of the force necessary to release the trip and elfect operation of the latching mechanism.

If it should happen that the trigger 40 is operated when the door is open so that the bolt I0 is in the path of the strike when the door is closed, then the jar or shock which might be produced upon slamming of the door will be taken up by the spring 28. The impact of the roller 4| against the sloping surface of the strike I2 produces rotation of the supporting member 25 about the pivot 26 against the force of the spring 28 as well as against the force of the spring 30. During this rotation the toggle remains in its locked position, and should the door be forced closed the roller 4| will ride down the sloping surface of the strike I2 and engage the keeper portion II in a manner similar to that in conventional latches. If when the door is closed an attempt should be made to force or pry it open, the spring 26 again will permit rotation of the support member 25 and prevent damage to the latching mechanism. The spring 28, however, is sufiiciently strong so that during all normal operation of the latching mechanism there is no movement between the supporting members 22 and 25.

During the operation of the latching mechanism illustrated, Whenever the handle I6 is rotated to unlatch the bolt l0 it engages a pin 42 on the link 2! and draws the link outwardly from the door. When the handle is released it is returned to its normal position by a spring 43, the pin 42 riding in a slot 44 in the handle structure.

It will readily be apparent from the foregoing that I have provided a simple and eifective latching mechanism which makes it possible to move a door toward its closed position with relatively little force and yet upon operation of the mechanism the door is drawn into its completely closed positiongwith sufiicient: force-to,- compress .3fiiea1" inggasket.

.While IZhaIVGEdQSQIj-bEd a speclficembodiment of my invention-in connection with arefrigerator cabinet, other :arrangementsxand embodiments will .occur to those-,skilledrin the art. IzidQiIlOl; therefore desirermy invention to :be: limitedto'the particular. construction illustrated Y and described, and. I ,intendby the appended claims to. .coverall modifications within; thegspiritn and scope .of: ;my

invention. I

' What: I claim as new and :desire to :securecby Letters Patent of the United States, is:

1.; A door latch; comprising a rsupportingstructure, a latch bolt ,pivotallyimountedx on: said: structure, a spring guide pivotally mounted ,onL-said;

structure, a spring acting through said guide, a first link pivoted on said structure and cooperatingwith said guide topprovideta snap acting mechanism movable into either of two positions, and a second link for connecting.saidiguide and said bolt for rotating said bolt on movement of said :guide between said two positions whereby saidbolt is iunlatched in one-of-said positions and latched in the otherof said positions, said second link being constructedand arranged to multiply thev force ofsaid spring on-movement toward-said other position for urging said bolt toward its latching position.

2. A door latch comprising a supporting structure, a latch bolt pivotally mounted on said structure, a toggle comprising a first link pivoted on said structure and a second link pivoted on said first link and on said bolt eccentrically of the pivotal axis of said bolt, a spring guide mounted on said structure, a spring acting through said guide, said guide being connected to said toggle for moving said first link to lock said toggle in one position thereof and to break said toggle in its other position, said toggle in its locked position retaining said bolt in its latching position and the force of said spring being multiplied upon movement of said toggle toward its locked position forcibly to effect rotation of said bolt toward its latching position, and means for selectively moving said guide overcenter from either of its positions into the other to latch and unlatch said bolt.

3. A door latch comprising a supporting structure, a latch bolt pivotally mounted on said structure, a toggle comprising a first link pivoted on said structure and a second link pivoted on said first link and on said bolt eccentrically of the pivotal axis of said bolt, a spring mounted on said structure laterally of said toggle and arranged to exert pressure on the pivotal connection between said first and second links, said spring being arranged for movement overcenter with respect to the pivot of said first link on said structure to force said toggle into its locked and broken positions, said toggle in its broken osition holding said bolt in its retracted position and said toggle in its locked position locking said bolt in its latching position, the force of said spring being multiplied during movement of said toggle toward its locked position, manually operable means for moving said spring overcenter to unlock said toggle, and tripping means for moving said spring overcenter to lock said toggle.

4. A door latch comprising a supporting structure, a latch bolt member pivotally mounted on said structure, a link member spaced from said bolt member and pivotally mounted on said structure, a link pivotally connected to both said members, eccentrically of their respective pivots on berin latching position whensaid toggleiszlocked and for holding saidboltzmemberin :itsretractd positionfiwhen said toggle is'broken, a spring arranged toxmovebovercenter with IGSDGCt'JOYt-hfl pivot of said linkv memberonsaid- StIllCtUIBJ-J'OI' retaining said itoggle inaeither. .of. its:.positions, manually operable means for imoving-saidtog'g-le out of its locked positionandfor :movingssaid spring overcenter to effect breaking-of said toggle, one of saidxmembers. havinga'trigger'thereon adapted to engage a strike for'movingsaidispring overcenter to move said toggle from its broken position and to effect ;latchingof said bolt memher, said spring. being arranged to=exert a force laterally of said toggle when in itslockedr position wherebyv the forceof said spring is multiplie'd' when-rotating said bolt member'toward its latching position. I 5. A'doorlatch comprising a supporting structure including a stationary supporting member and a pivoted supporting member mounted thereon, a latch bolt pivotally-mounted on said pivoted member eccentrically of the pivot between said members, a toggle comprising a first. link pivoted on said 'structure. and a second link pivoted onsaid first link and on said bolt eccentrically of the respective pivotal axes of said bolt and said first link, a spring mounted on said stationary member and connected to said toggle for moving said first link to lock said toggle in one position thereof and to break said toggle in its other position, said toggle in its locked position retaining said bolt in its latching position and the force of said spring being multiplied upon movement of said toggle toward its locked position forcibly to efiect rotation of said bolt toward its latching position, manually operable meansfor moving said spring overcenter in one direction to unlock said toggle, tripping means for moving said spring overcenter in the other direction to move said bolt to its latching position and to lock said toggle, means including a second spring for preventing pivotal movement of said pivoted supporting member during normal operation of said latch, said second spring affording relative movement between said supporting members when a predetermined force is applied to said bolt in its latched position. i

6. A door latch comprising a supporting structure, a latch bolt pivotally mounted on said structure, a toggle comprising a first link pivoted on said structureand a second link pivoted on said first link and on said bolt eccentrically of the pivotal axis of said bolt, a spring mounted on said structure laterally of said toggle and arranged to exert pressure on the pivotal connection between said first and second links, said spring being arranged for movement overcenter with respect to the pivot of said first link on said structure to force said toggle into its locked and broken positions, said toggle in its broken position holding said bolt in its retracted position and said toggle in its locked position locking said bolt in its latching position, the force of said spring being multiplied during movement of said toggle toward its locked position, manually operablemeans including a handle and a lost motion connection between said handle and said first link for moving said toggle out of its locked position and for moving said spring overcenter whereby said toggle is driven to its broken position, and tripping means for moving said toggle out of its unlocked position and overcenter to rotate said bolt and move it into latching position.

7. In a door latch, a latch bolt movable in a plane substantially normal to the door axis and adapted to engage a keeper having a bolt-retaining surface substantially parallel to said axis, a toggle associated with said bolt and arranged to operate by expansion to advance the bolt into interlocking engagement with said keeper with increasingly amplified force as the toggle approaches the fully expanded position, resilient means operatively connected with said toggle for urging the toggle into the expanded position, and means for retracting the toggle against the action of said resilient means to disengage the bolt from the keeper, said bolt, toggle and keeper being constructed and relatively arranged so that the bolt when advanced into said engagement will meet the said retaining surface of the keeper substantially before the bolt has moved into the fully advanced position whereby the said resilient means may be effective through the expanding toggle to draw the door securely to a tightly closed position.

8. A latching mechanism comprising a movable latching member adapted to engage a keeper, a 2

support, a toggle joint having a first link pivotally mounted on said support and provided with an car portion and a, second link operatively associated with said member, said tog le being movable to extended and retracted positions to move said member into and out of latching position with said keeper respectively, spring means operable to effect actuation of said toggle to its extended position, and manual means for effecting actuation of said toggle to its retracted position, said manual means including a pivotally mounted handle and a connecting rod having one end thereof pivotally connected to said ear portion of said first link and its other end pivotally attached to said handle so that rotation of said handle operates to rotate said first link about its axis and move said toggle to said retracted position.

FRANCIS M. HOGG.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,192,448 Ottinger July 25, 1916 1,222,396 Hagstrom Apr. 10, 1917 1,703,249 Schrader Feb. 26, 1929 1,873,560 Ekman Aug. 23, 1932

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