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Publication numberUS3273925 A
Publication typeGrant
Publication dateSep 20, 1966
Filing dateApr 20, 1964
Priority dateApr 20, 1964
Publication numberUS 3273925 A, US 3273925A, US-A-3273925, US3273925 A, US3273925A
InventorsGraham Percy R
Original AssigneeGraham Percy R
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Latches and locks
US 3273925 A
Abstract  available in
Images(1)
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Claims  available in
Description  (OCR text may contain errors)

Sept. 20, 1966 P. R. GRAHAM LATCHES AND LOCKS Filed April 20, 1964 INVENTOR Per cy Gra/mm United States Patent O 3,273,925 LATCHES AND LGCKS Percy R. Graham, 7342 24th Ave. NW., Seattle, Wash. Fired Apr. 2a, 196s, ser. N0. 360,974 7 Creams, (ci. 292-401) This invention relates to improvements in latches and locks and is in the nature of an improvement on thc latch and lock disclosed in my copending `application Serial No. 105,251, now Patent No. 3,129,968.

An object of my invention is to improve, simplify, render more efficient and reliable and reduce the cost of production of latches and locks of the type herein disclosed.

A further object of this invention is to provide simplied and improved means for positively locking a swingingly mounted magnetically operated bolt in a position of engagement with a strike member.

Another object is to provide, in a tubular latch and lock in which the cylindrical housing is of relatively small diameter, a swingingly and pivotally mounted bolt having a throw or distance of maximum protrusion from the edge of the door suiiicient to meet any and `all ordinary rules, requirements and -ordinances relating to maximum throw of latch and lock bolts.

Other objects are to provide a magnetic latch and lock in which the use of springs is eliminated and the construction is otherwise simplied and rendered more reliable `without sacrificing any of the objects and `advantages of the latch and lock mechanism disclosed in my prior patent application hereinbefore referred to.

Other and more specific objects of this invention will be apparent from the following description and accompany ing drawings.

In the drawings FIGURE l is a fragmentary longitudinal sectional view on an enlarged scale, taken on a horizontal plane and with parts in plan, showing my improved magnetic latch and lock as it may appear when it is installed in a door and set up for operat-ion as a lock and when the lbolt is in a locked position.

FIG. 2 is a view similar to FIG. 1 showing the bolt and bolt operating slide fully retracted and showing a bolt locking pawl held clear of the bolt. l

FIG. 3 is a view in cross section, with parts in elevation, taken substantially on broken line 3--3 of FIG. l.

FIG. 4 is a detached elevational view of the bolt showing the front or outer 4face of the same, a fragment being broken away.

FIG. 5 is a detached view in elevation, on a smaller scale than the other views, showing the face of the strike member.

FIG. 6 is a detached elevational view showing a reversible locking pawl together with means used to support said pawl in two diiferent longitudinal positions and wih different sides of the pawl facing the bolt.

FIG. 7 is a fragmentary sectional view showing guide and supporting means for said locking pawl.

FIG. 8 is a detached perspective view showing a pawl lifting device.

Like reference numerals refer to like parts throughout the several views.

In the drawings 10 indicates a door and 11 a door jamb, both of conventional construction. A stop memlber 12 is rigid with the jamb 11. The door 10 has a 'bored recess 13 for the reception of a tubular lock housing which preferably is formed of two parts 14 and 1S divided along longitudinal lines in accordance with conventional construction of tubular lock housings of this type. When they are in use the two housing parts 14 and 15 are rigidly secured together. A flange 16 is rigid `with the front end of one part, such as the part 14, of the lock housing and a face plate 17 overlies the flange 115 and is rigidly secured thereto. The face plate 17 has a suitably ICC shaped `bolt accommodation opening 18. The edge of the door is suitably mortised to receive the.` flange 16 and face plate 17 and to leave the -outer `side of the face plate flush with the edge of the door 10. The face plate 17 is secured to the door in the usual manner.

The door jamb 11 is provided with a cylindrical recess 19 to receive a similarly shaped strike member 20` which preferably is a permanent magnet but can be of magnetic material not permanently magnetized. Preferably the circumferential portion of the strike member 20 is provided with splines 21, FIG. 5. The recess 19 and strike member 2t) are suitably sized so that the strike member 20 will t snugly within the recess 19 `and the splines 20` will indent or embed themselves into the wooden jamb 11 as the strike member is inserted into the opening 19 by applying torce to said strike member. The splines 21 make it possibie to securely anchor the strike member 20 in the jamb 11 without the use of screws or other securing means. All of the recesses in the door 10 `and jamb 11, except the recess for the face plate 17, can be made by boring thus saving much time and labor in installation.

The 4outer side of the strike member 20 has `a concave recess Z2 provided therein. The `bottom of this recess 22 is of cam shape. Its curvature .adjacent its forward or outer edge, shown uppermost in FIGS. 1 and 2 and at the right in FIG. 5, is fairly sharp to provide a somewhat abrupt shoulder portion 23 for bolt engaging purposes and the curvature of the cam surface then flattens out toward the rear edge of the recess 22. The cam surface formed *by the bottom of said recess 22 is preferably roughened or scored, as shown in FIGS. l and 2 and indicated by stippling in FIG. 5. Said cam surface is wide in vertical directions to afford tolerance as respects positioning of the locks and to compensate for sagging of doors.

A bolt, referred to generally by numeral 24, and which is permanently magnetized and of opposite polarity from the strike member 20 if said strike member is magnetzed, is pivotally mounted in the lock housing for engagement with said strike member 20. The bolt 24 is of generally triangular shape when viewed from the side, `as shown in FIGS. l and 2. It has a flat forward end or face 25, a flat rear end 26, a rounded or semi-cylindrical outer wall 27 and a narrow inner edge portion 28 provided with a bearing groove or recess 30. A stop member 39 protrudes from the rear end portion of the bolt 24 in a suitabie position to engage with the housing member 14 and limit retractile movement of said bolt. The outermost end 39 of said stop member 39 is beveled for reasons hereinafter explained.

The bearing groove 31) extends entirely across the bolt 24 and fits over a bearing member 31 of partially cylindrical cross sectional shape which is integral with the face plate 17 and extends :across the bolt accommodation opening 18 and said face plate 17. The shape of the bolt accommodation opening 18, in outline, is similar to that of the face 25 of the bolt, see FIG. 4. Preferably the part of the wall of housing member 14 which is in alignment with bearing member 31 is thicker than the other par-ts of said housing wall, as best shown in FIG. 3. The bearing for bolt 24, formed by parts 28, 3i) land 31, extends entirely across the bolt 24, is close to the outer plane of the face plate 17, and is at a maximum distance from the axis of the lock housing for the purpose of obtaining a long throw of the bolt 24. This long throw is not essential in my lock and only part of this throw is ordinarily used but, in many instances building codes, rules and ordinances require the bolts of latches and locks to be capable of extending a predetermined distance, such as iive-eighths of -an inch from edge of the door. With so called tubular locks, which have cylindrical housings capable of being installed in cylindrical bores in the edge portions of doors of limited thickness, it is difficult to provide swinging or pivotally mounted bolts having enough throw t-o satisfy all statutory building requirements. By pivoting my bolt 24 close to the plane -of the edge of the door and by positioning the pivot of this bolt at ysubstan-tially the maximum possible distance outwardly from the axis of the housin-g I am able to provide ample bolt throw to meet all statutory requirements.

The part of the bolt 24 which makes contact with the strike member 20 at the location of the sharply curved shoulder portion 23 is narrow yand the recess 22 `of the strike member is of maximum vertical width at this location where it is engaged by the bolt. This provides for a relatively great amount of tolerance in the relative vertical positioning of the strike member 20 and the bolt 24, in installation, and it compensates for a substantial amount of sagging of a door, which may occur after installation.

A bolt retracting link 32 is connected by a pivot member 33 with the bolt 24. A notch 29 in the bolt 24 provides clearance in which the link 32 operates. The link 32 has a longitudinal slot 34 which lits over a pin 3S. Said pin 35 is rigidly attached to =a bolt retracting slide member 36. Suitable track members 37 and 3S in the respective housing parts 14 and 15 cooperate with said housing parts in receiving and supporting and guiding the slide member 36 for longitudinal movement in the housing. Suitable means, such as a link 40, can be used to connect the slide member 36 with conventional door knob mech- .anism, not shown, by which said slide member 36 can be retracted. It will be understood that a yielding pressure is exerted at all times on the link 40 by the conventional knob mechanism tending to move the slide member 36 toward the bolt 24 into an initial or starting position in which said slide member is shown in FIG. l.

Ratchet teeth 42, of preferably line or small size, are provided in a row on the rounded outer peripheral wall 27 of the bolt 24 midway between the two sides of said bolt. These ratchet teeth do not need to extend entirely to the forward end or face Iof said bolt. A locking pawl 43 of magnetic material, but which could be magnetized and of opposite polarity from the bolt 24, is reversibly supported by the housing member 15. One end portion of the pawl 43 has a curved tip 44 which is positioned to engage with the ratchet teeth 40 when the pawl is positioned so the tip 44 curves toward the bolt 24. The side of the pawl 43 close to and opposite the tip 44 is convexly curved, as indicated by 45, or is otherwise shaped so that it can rest slidably on the ratchet teeth 42 without lockingly engaging said teeth. The end of the pawl 43 remote from the bolt 24 has a transversely extending lug 46, PIG. 6, adapted to be fitted into either of two notches 47 or 48 in a mounting block 50, depending on the positioning of the pawl in the mounting block. The mounting block 50 is rigidly att-ached to the housing member l5. If this mechanism is to be set up for use as a lock the pawl 43 is positioned as shown in FIGS. l, 2 and 6, with its tip 44 directed toward the bolt 24. If the mechanism is to be set up for use merely as a latch'then the pawl 43 is turned Iover so that its rounded forward end portion 45 can rest on the teeth 42 of bolt 24. The notches 47 and 48 are relatively offset longitudinally and this desirably Varies the longitudinal positioning of the pawl 43 ydepending on whether the mechanism is set up for operation as a lock `or as a latch. In so doing it insures that the forward end of the pawl 43 will always rest on and be magnetically held in contact with the bolt 24, except when the pawl is lifted clear `of said bolt by devices hereinafter described.

Two spaced apart guide members 52 are rigid with the housing part and are positioned on opposite sides of the pawl 43 to support and guide said pawl. A spring clip 53, FIG. 7, of U-shape, is provided for application to the two guide members 52 to limit movement of the pawl 43 toward the bolt 24 in the event the bolt 24 should be moved outwardly far enough so that the end of the i pawl 43 could drop back of the stop member 39. The bevel 39' on the extremity of the stop member 39 is a further safeguard in that it will replace the pawl 43 on the bolt 24 if said bolt is moved outwardly beyond the tip 44 of said pawl.

A pawl lifting device, shaped somewhat like a crank shaft so that it provides two aligned bearing members 54 and 55 and a cam or lever part 56, is used lto lift the pawl 43 out of engagment with the ratchet teeth 42 when this apparatus is set up for use as a lock. When the apparatus is set up for use as a latch this pawl lifting device is omitted and the pawl is turned over so that the rounded forward end part 45 thereof is next to the bolt 24. The bearing parts S4 and 55 of the pawl lifting device are supported for oscillation by two transversely spaced apart bearing plates 57 and 58 which are rigid with the housing member l5 and extend inwardly toward the bolt 24. Preferably the wall part of the housing member 15 to which the bearing plates 57 and 58 are attached is thicker than the other parts of said housing member 15. A spring clip 60, of U-shape, fits over and snaps onto each of the bearing plates 57 and 58 and cooperates with said bearing plates in supporting the bearing parts 54 or 55 of the pawl lifting device.

The bearing part 54 nearest to the bolt operating slide 36 terminates in two rigidly attached arms 6l and 62 which diverge from each other at an angle in the order of ninety degrees and are positioned so that one of said arms is always inthe path of movement of a pin 63 which is rigid with the slide member 36. Two stop members 64 and 65 are provided on the bearing plate 57 nearest said slide 36 for engagement by the respective arms 61 and 62.

The bolt 24 and strike 20 are constructed of materials which will cause them to be magnetically -attracted to each other and to be magnetically held in locking engagement with each other, if the set up is for a lock, until the bolt is retracted by application of external force to it through link 40. I prefer that the bolt 24 be -a magnet of one polarity 'and the strike member be a magnet of opposite polarity. However I can make the bolt 24 a permanent magnet and the strike member 20 of magnetic material, such as iron or at -least partly iron. The pawl 43 i-s preferably made of magnetic material which will be attracted to the bolt 24. Thus the movable end portion of the pawl 43 will yalways rest on the ratchet teeth 24 unless it is being held clear of said ratchet teeth by the cam 56. `Either the bolt 24 or strike member 20, or both of said parts, can be made of sound deadening materials which 'are magnetic or are capable of being permanently magnetized and which may be formed partly of hard rubber, nylon, or the like.

In the operation of this apparatus, either as a lock or as a latch, the bolt 24 will always be magnetically held in engagement with the strike member 20 when the door is closed and said bolt is aligned with said strike member, except at the time the bolt is being positively held, by the link 40, in a retracted position, as illust-rated in FIG. 2. When the door is open and said bolt 24 is not aligned with the strike member 20 said bolt will always stand in a retracted position, due to the magnetic attraction between the lbolt 2-4 and pawl 43 and also due to magnetic attraction between the bolt 24 .and any other parts of the lock housing or parts within the lock housing which are stormed partly or wholly of magnetic material.

In the operation of this apparatus as a lock, when the door is closed the parts will stand in the positions shown in FIG. 1 with the slide 36 held in its forward position by the link 40 and the bolt 24 locked in engagement with the strike member 20 bythe pawl 43. To retract the bolt it is necessary, through any conventional and suitable knob mechanism to move link 40 and slide member 36 to the right. Due to the lost motion of pin 35 in slot 34 the initial retractile movement of slide 36 will cause pin 63 to engage with arm 61 and lift the pawl 43 clear of the bolt 24. Upon further retractile movement of slide 36 the pin 35 will engage with link 32 at the end of slot 34 'and retract the bolt 24 into the position in which it is shown in FIG. 2. The door can then be opened and as soon as the pull on link 40 i-s released said link 40 and the slide 36 will move back to their initial position in which they are shown in FIG. l but the bolt 24 will remain retracted until the door is again closed. As the slide `36 moves `back toward its initial position the pin 63 will engage with the arm 62 and release the pawl 43 from the bol-t 24 by moving the pawl lifting device back into the position in which it is shown in FIG. 1.

Because the pawl 43 is always drawn by magnetic force toward the bolt 24 it will always hold the cam lifting device in either the position shown in FIG. l, or the position shown in FIG. 2, it being noted that the cam 56 is past center in both of these positions. Thus the cam lifting device can not move angularly except when it is moved by the pin 63.

If the pawl lifting device is left out and not used in .the assembly and the pawl 43 is turned over or reversed as respects the position in which it is shown in FIGS. l and 2 then the apparatus will operate las a latch with the rounded end part 45 of the pawl always resting on the ratchet -teeth `42.

`It is to be noted that, in both the lock and the latch set up the bolt 24 is always fully retracted when the door is open. Thus it is not out inthe open for clothing and Vlike articles to catch on and it does not have to be pushed back by any strike plate in the act of closing the door.

The foregoing description and accompanying drawings clearly disclose a preferred em'bodiment lof this invention but it will be understood that this disclosure is merely illustrative and that changes may be made Within the scope of the following claims.

I claim:

1. In latch and lock means for use in a door, a bolt housing capable of being embedded in la door; a bolt of permanently magnetized material having its inner end portion pivotally supported by said housing for swinging movement of its outer end portion between a retracted position and a position in which it protrudes from said housing; ratchet teeth on the outer end portion of said bolt; and a pawl in the housing said pawl being constructed of material capable of being magnetically attracted to lsaid lbolt and having a movable end portion positioned to rest on said ratchet teeth.

2. The 'apparatus as claimed in claim 1 in which a strike member of material capable of magnetic attraction as respects the bolt is provided for engagement by said bolt.

3. The apparatus as claimed in claim 1 in which a permanently magnetized strike member Iof opposite polarity from the bolt is positioned for engagement by the bolt.

4. `In latch and lock means for use in a door, a housing capable of being embedded in a door and having a bolt accommodation opening flush with the edge of the door; a bolt having an inner end portion pivotally supported by said housing closely adjacent the plane 'of the edge of the door for swinging movement of at least part of the outer end portion of said bolt into and out of said housing through said bolt accommodation opening; ratchet teeth on the outer end portion of said bolt; a bolt locking pawl disposed within said housing and positioned to lookingly engage said ratchet teeth, said pawl being reversibly supported in the housing for selective positioning of either side thereof toward said bolt andthe movable end portion of said pawl having on one side a tip capable of locking engagement with said ratchet teeth and on the other side 'a smooth surface adapted to rest against said ratchet teeth and over which said ratchet teeth are slidably movable; and bolt retracting means capable of moving said pawl clear of said ratchet teeth and retracting said bolt.

S. Lock means for use on a door which is swingingly movable relative to a xed door jamb, comprising a tubular housing capable of being embedded in the door and having a bolt accommodation opening flush with an edge of the door; a strike member embedded in the door jamb and having a bolt receiving recess aligned with said bolt accommodation opening when the door is in a closed position; a bolt having lan inner end portion pivot-ally supported by said housing closely adjacent the plane of the edge of the door for swinging movement of at least part of the outer end portion of said bolt outwardly `through said bolt accommodation opening, `said bolt and strike member forming two cooperating parts capable of locking engagement when the door is fully closed, atleast one of said cooperating parts being permanently magnetized whereby the bolt will be magnetically attracted to and yieldingly held in locking `engagement with the strike member when the door is fully closed; ratchet tee-th on the outer end portion of said bolt; a pawl in said housing positioned to engage with said ratchet teeth and lock said bolt in engagement with said strike member; bolt retracting means connected with said bolt, said bolt retracting means including a lost motion device; and pawl disengaging means operated by initial movement of `said bolt retracting means for disengaging said pawl from said ratchet teeth preparato-ry to retracting said bolt.

6. The apparatus as claimed in claim 5 in which the bolt retracting means includes a .slide member connected by pin ,and slotted link means with the bolt, yand in which the pawl disengaging means includes a cam movable by s-aid slide and controlling the engagement and disengagement of said pawl relative to said ratchet teeth.

In a lock, a housing embedded in a door and having a bolt accommodation opening flush with the edge of the door; a bolt having an inner end portion pivotally supported by said housing closely adjacent the plane of the edge of the door for swinging movement of at least part of the outer end portion of said bolt into and out of said housing through said bolt accommodation opening; ratchet teeth on the outer end portion of said bolt; a bolt locking pawl disposed within said housing and positioned to lockingly engage said ratchet teeth; a bolt retracting slide longitudinally movable in said housing and yieldingly urged toward said bolt; a cam member supported for oscillation and positioned to contact the side of said pawl adjacent said bolt; two divergent cam operating arms rigid with said cam member; a lost motion device connecting said bolt with said slide member providing lost motion between said slide member and said bolt when said slide member is near the limit of its movement in which it is closest to said bolt; and a cam operating pin on said slide member positioned to engage with one of said cam operating arms and move said cam in releasing said pawl from said ratchet teeth as said slide is moved away from a position in which it is closest to said bolt and to engage with the other cam operating arm and release said pawl for engagement with said ratchet teeth as said slide approaches the limit of its movement toward said bolt.

References Cited by the Examiner UNITED STATES PATENTS 418,075 12/1889 Seely et al 292-210 2,219,186 10/1940 Hornfeck 292-144 2,246,787 8/1941 Dall 292-99 2,469,283 5/ 1949 Steele 292--201 2,475,226 7/ 1949 Ellis 292-201 X FOREIGN PATENTS 603,561 4/1960 Italy.

EDWARD C. ALLEN, Primary Examiner. R. E. MOORE, Examiner.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US418075 *Sep 16, 1889Dec 24, 1889 Sash-holder
US2219186 *Nov 2, 1938Oct 22, 1940Gen ElectricMagnetic latch
US2246787 *May 23, 1940Jun 24, 1941Houdaille Hershey CorpLatch structure
US2469283 *Jan 30, 1947May 3, 1949Homer M SteeleFender door lock
US2475226 *Feb 1, 1945Jul 5, 1949Robert P EllisMagnetic fastener
IT603561B * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3413026 *Mar 11, 1966Nov 26, 1968Schlage Lock CoMagnetic latch
US3794366 *Dec 11, 1972Feb 26, 1974Graham PMagnetic latch and lock
US5394716 *Feb 27, 1992Mar 7, 1995Maurice RiesLock system
US7044511Oct 25, 2004May 16, 2006Nationwide IndustriesMagnetic latch system
US7390035 *Jan 13, 2005Jun 24, 2008D&D Group Pty LimitedSelf-latching magnetic latching device
US20050184532 *Jan 13, 2005Aug 25, 2005D & D TechnologiesSelf-latching magnetic latching device
US20050225098 *Oct 25, 2004Oct 13, 2005Christopher KliefothMagnetic latch system
US20060220391 *Feb 21, 2006Oct 5, 2006Baragano Gonzalez Jose RModular folding/sliding latch system with self-locking and multi-functional operation
US20080054648 *Aug 27, 2007Mar 6, 2008Baragano Gonzalez Jose RModular folding/sliding latch system with self-locking and multi-functional operation
US20080296915 *Jun 23, 2008Dec 4, 2008D & D Group Pty LimitedMagnetic latch
USD647779Feb 4, 2011Nov 1, 2011D & D Group Pty LtdHinge
USD647781Feb 4, 2011Nov 1, 2011D&D Group Pty LtdHandle
USD647782Feb 4, 2011Nov 1, 2011D&D Group Pty LtdLatch
USD649007Feb 4, 2011Nov 22, 2011D & D Group Pty LtdHinge
USD649008Feb 4, 2011Nov 22, 2011D & D Group Pty Ltd.Hinge
USD649009Feb 7, 2011Nov 22, 2011D & D Group Pty LtdHinge
USD661173Feb 4, 2011Jun 5, 2012D&D Group Pty Ltd.Hinge
USD672631Feb 4, 2011Dec 18, 2012D & D Group Pty Ltd.Striker for latch
USD673024Feb 4, 2011Dec 25, 2012D & D Group Pty Ltd.Hinge
USD675080Feb 4, 2011Jan 29, 2013D & D Group Pty LtdHandle
Classifications
U.S. Classification292/201, 292/251.5
International ClassificationE05C3/00, E05C3/12
Cooperative ClassificationE05C3/124
European ClassificationE05C3/12D