US2854270A - Dead latch - Google Patents

Description

DEAD LATCH Walter .Ward, Anaheim, Calif, assignor, by mesne assignments, to The American Hardware Corporation, New Britain, Conn, a corporation of Connecticut Application April 14, 1955, Serial No. 501,265

9 Claims. (Ci. 292--l69) This invention relates to a dead latch mechanism and, more particularly, to a dead latch mechanism of the character in which the dead locking means incorporated in the dead latch is energizable directly by the retractor mechanism incorporated in the dead latch.

In describing my invention, it will be disclosed as incorporated in a reverse-actuated type dead latch but it is, of course, to be understood that the principles of the invention can be applied with equal cogency to any well known types of retractor mechanisms conventionally uti- Lized in dead latches of the character under consideration ere.

It is most desirable in dead latches to insure that the dead locking means incorporated in the dead latch for preventing unauthorized retraction of the main bolt of the dead latch be immediately drawn out of the path of the main bolt when authorized and voluntary retraction of said main bolt is desired in order that the retractive movement of the main bolt be unimpeded by the dead locking means.

It is, therefore, an object of my invention to provide a dead latch which includes a main latch bolt and a retractor mechanism therefor, said dead latch being maintained in extended position against unauthorized retraction by dead locking means associated therewith, the retractor mechanism and the dead locking means being operatively connected by a clutch which will insure initial simultaneous movement of both the retractor mechanism and the dead locking means but which will permit continued' movement of the retractor mechanism to insure complete retraction of the main bolt while permitting the dead locking means to remain in a first, uppermost position attained by the dead locking means prior to the complete retraction of the main bolt.

Another object of my invention is the provision of a dead latch of the aforementioned character wherein the retractor mechanism includes a retractor which is mounted coaxially with the aforementioned dead locking means and wherein the aforesaid clutch is operatively connected between the retractor and the dead locking means to insure simultaneous initial movement of the dead locking means in conjunction with and by said retractor.

An additional object of my invention is the provision of a dead latch of the aforementioned character wherein the aforementioned clutch is a friction clutch having yoke means engageable with the retractor and a clutch face engageable with the dead locking means whereby initial rotation of the retractor causes concomitant rotation of the clutch to insure simultaneous initial movement of the dead locking means with the retractor.

Therefore, by the dead latch of my invention, it is possible to insure immediate upward movement of the dead locking means from a first, lowermost to a second, uppermost position by the operative connection established between the retractor and the dead locking means States Patent Cir through the medium of the clutch. Thus, when the main Too bolt is retracted by the action of the retractor, the engagement of the clutch with the retractor and the dead locking means will cause simultaneous initial rotation of the retractor and the dead locking means. However, when the upward limit of movement of the dead locking means at its second, uppermost position is reached, the clutch will slip and the retractor be permitted to continue its retractive movement to insure complete retraction of the main bolt into the latch case. Thus, while initial simultaneous movement of the dead locking means and the retractor are insured by the action of the clutch, the clutch also insures that the dead locking means will not be moved beyond its uppermost position by continued movement of the retractor when the dead locking means has reached said uppermost position.

Furthermore, as themain bolt returns to its extended position, the retractor is moved downwardly and engages a portion of the dead locking means to urge said dead locking means downwardly toward the first, lowermost position wherein the clutch once again engages the dead locking means and the entire mechanism is ready for a new sequence of operation.

Other objects and advantages of my invention will be apparent from the following specification and the accompanying drawings which are for the purpose of illustration only and in which:

Fig. 1 is a horizontal, sectional view of a dead latch constructed in accordance with the teachings of my invention;

Fig. 2 is a sectional view taken on the broken line 22 of Fig. 1;

Fig. 3 is a vertical, sectional view taken on the broken line 33 of Fig. l;

Fig. 4 is a horizontal, sectional view showing the dead locking means located in dead locking position to prevent unauthorized retraction of the main bolt;

Fig. 5 is a view similar to Fig. 4 but showing the dead locking means disposed in its second, uppermost position;

Fig. 6 is a perspective view of the retractor incorpo rated in the retracting mechanism of the dead latch;

Fig. 7 is a perspective view of the dead locking lever incorporated in the dead locking means; and

Fig. 8 is a perspective view of the friction clutch which operatively connects. the dead locking means and the retractor of the dead latch to each other.

Referring to the drawings and particularly to Figs. 1-3 thereof, I show a dead latch 10 incorporated in a tubular dead latch case 12 which defines an elongated chamber 14 for the reception of the various working parts of the dead latch.

Disposed within the case 12 is an elongated retractor slide 16, said slide having abutments 18 on its innermost end engageable, as best shown in Figs. 1, 4, and 5 of the drawings, by a half-round spindle 20 to cause outward movement of said retractor slide and the retraction of a main bolt 22 in a manner to be described in greater detail below. The main bolt 22 projects from the end of the dead latch case 12 through a face plate 24 by means of which the dead latch case 12 is secured in operative relationship with the edge of a door, not shown.

Supported within the chamber 14 of the dead latch case 12 upon a shaft 26 is a rotatable retractor 28, said retractor and the retractor slide 16 constituting the retractormeans of the dead latch construction of my invention. The retractor 28 is constituted by an elongated lever 30 which has oppositely oriented bosses 32 and 34 formed integrally therewith on the opposite sides thereof. The boss 32 is provided with oppositely oriented flats 36, as best shown in Fig. 6 of the drawings, while the boss 34 is of substantially cylindrical. configuration.

The retractor slide 16 is, as best shown in Figs. 1-2

and 4-5 of the drawings, provided with an abutment 38 intermediate its ends and has formed integrall-y upon its forward end a projecting spring seat 40 upon which is mounted, as best shown in Figs, 1 and 2 of the drawings, a main bolt actuating compressionspring AZ whose outermostend is'seated in an elongated bore provided in the-main bolt 22. The inner end of thema in ibolt{22 is provided with-a slot 46 and theupper-end of the ret actorlever 30 engages the inner end of said slot so that, as the retractor-slide 16' is urged out-wardly try-the action of the spindle20 in the latch case 12, the'flbutment'38 :will rotate the lower end of the retractor lever 30 causing the rotation of said lever about the shaft 26 and causing the upper end thereof to-rotate counterclockwise against the inner end of the slot '46 of the main bolt-'22 to retract said'main'boltagainst the action of the spring 42. I

On the other hand, when the-spindle 20 is released, the spring 42 ejects the main bolt22 fromthe latch case 12 simultaneously causing the return of the retractor slide 16: to inoperative position, shown in Figs. 1 and 40f the drawings; The outward movement of the main' bolt 22 causes simultaneous clockwise rotation of the retractor lever 30 because of the outward movement of the end oftheslot 46 upon which the upper end of the retractor lever 30 impinges and the lower end of the retractor lever 30 is thus maintained in continual engagement with the abutment 38 provided on the retractor slide '16;

In order toprevent unauthorized retraction of the main bolt 22 by the use of jimmying tools or the like, dead locking means indicated generally at 50 are provided, said dead locking means including, among other operative elements, a dead locking arm 52, best shown in Figs. 1-2, 45, and 7 of the drawings, and an' auxiliary bolt 54. The dead locking arm 52 is provided with an enlarged mounting lobe 56 in which is formed a mountingopening 53 which permits the arm 52 to be mounted adjacent the retractor lever 30 on the boss 34 formed integrally with said retractor lever, as best shown in Figs. 1, 4-5 of the drawings.

An integral lug 60 extends outwardly from the plane of the dead locking arm 52 and is adapted to be engaged by the edge of the retractor lever 30, as best shown in Fig. 1 of the drawings, to urge the dead locking arm 52 downwardly toward its first, lowermost dead lockingposition, as best shown in Fig. 4 of the drawings.

The auxiliary'bolt 54 is, as best shown in Fig; 2 of the drawings, provided with a rearwardly extending spring seat 64, said seat having engaged thereupon a-compression spring 66 which serves to project the auxiliary bolt out-wardly from the latch case, 12. Formed integrally with the body of th auxiliary bolt, as best shown in Figs. 1 and 2 of the drawings, is a laterally extending lug 68 which is engageable with the underside, of the dead locking arm 52 and which, when the auxiliary bolt 54-is in the extended position Shown in Figs. 1 and 2 of the drawings, serves to maintain the outermost end of the dead locking arm 52 out of'dead locking position to permit free retraction of the main bolt 22. v

On the, other "hand, when the auxiliary bolt 54 isretracted into the casing, as best shown in Fig. 4 of the drawings, thelug 68 on the auxiliary bolt 54 is moved rearwardly in the latch case 12 to permit the outermost end of-the dead lockingarm 52 to be deflected downwardly by the action of the retractor lever 30 into a position in which said outermost'end lies behind the'main bolt 22 and prevents unauthorized retraction of said'main bolt.

When" the main bolt 22 is in the retracted position shownin Fig. of the drawin s, the forward. portion of the dead locking arm 52 is received in a slot 70 provided in said main'bolt andsaid slot also receives a leaf spring 71', the free enjd' of which engages the upper surface of the dead locking arm 52 to-urgesaid dead locking-arm into deadlocking positionvwhen the latch case 12 is dis- 4 posed in inverted position in the edge of a door, in a mannerto be described in greater detail below.

From the previous description of the operative relationship between the dead locking arm 52 and the retractor lever 30, it is readily apparent that relative rotation between the dead locking lever 30 and the dead locking arm 52 can occur by virtue of the mounting of the dead locking arm 52 for rotation on the boss 34 of the re tractor lever 30. In order to insure concomitant'initial movement of the retractor lever 'and the dead locking arm 52, clutch means 72 is provided for transmitting rotational movement of the retractor lever 30 to the dead locking arm 52 during the initial movement of the retractor lever 30 as the retractor lever 30 serves to retract the main bolt 22 due to its rotation in a counter- V clockwise direction by the action of the retractor slide 16.

The clutch means 72 is constituted, as best shown in Fig. 8 of the drawings, by a unitary body 74 formed from spring steel or similar material and having provided upon one side thereof a yoke 76 which is secured by means of an intermediate .bar 78 to a clutch face 80. The clutch face 80 is provided with a centrally located opening 82 the dead locking arm 52 by virtue of the fact that theopening '82 in said .face permits the clutch face to be mounted over the laterally extending boss 34 of the -re' tractor lever 30.

The operation of the dead latch'10 of the invention 'is as follows:

When the door, not shown, in which the dead latch .0, is installed is open, both the main bolt 22 and the auxiliary bolt 54 will be projected from the latch case 12' by their respective compression springs42 and 66'.

When. the :bolts are located in this position, as' best shown in Figs. 1 and 2 of the drawings, the lug 68 on-the aux iliary bolt '54 underlies and engages the outermost-end of the dead locking arm 52 preventing the outermost end of said arm from lying behind the main bolt 22 and locking the-same in extended position. 1 r

On the other; hand, when the main bolt 22 is located in the pocket in a strike, not showu,'and the auxiliary bolt 54 is retracted into the case 12 by impingement upon a contiguous portion of said strike, the lug 68 on the auxiliary bolt 54..is .located in its rearmost position which permits the dead locking arm 52 to be urged downwardly into a position in which its'outermost end liesbehind the main bolt 22 to prevent unauthorized retraction of the same. 7

When the dead locking arm 52 is located in the position shown in Fig. 4 of the drawings and the voluntary retraction of the main bolt 22 is initiated, it is essential that the dead locking arm 52 be lifted from behind the main bolt 22 during the initial movement of the main'bolt so that the, dead locking arm 52 will'not impede the inward movement of said main bolt.

To accomplish the upward movement of the dead locking arm 52 from its first, lowermost dead locking position, the clutch means 72 is provided to transmit initial rotary motion of the retractor lever 30 to the deadlocking arm 52. Therefore, when the slide 16 is shifted to the right by the rotation of the half-round spindle .20, as best shown in Fig. 5 of the drawings, the impingement of the abutment 38 on said slide on the lower extremity of the retractor lever- 30 causes counterclockwise rotation of saidlever upon the shaft 26, thus causing simultaneous rotation of the boss 32. r

.The rotation of the boss 32 causes the concomitant rotation of the clutch means 72- by virtue of the engagement of the yoke 76 on the flats 36 provided on the boss 32. When rotation of the yoke 76 occurs, it is transmitted through the bar 78 to the clutch face 80 and to the abutment 84 upon the lower portion thereof. Therefore, since the abutment 84 is engaged upon the lower edge of the dead locking arm 52, when the dead locking arm 52 is located in its first, lowermost dead locking position, initial rotation of the clutch means 72 as caused by the rotation of the retractor lever 30 will cause simultaneous initial movement of the dead locking lever 52.

The clutch face 80 is, of course, utilized to maintain the dead locking lever 52 and the retractor lever 30 in side-by-side relationship with each other and, while the abutment 34 on the clutch face 80 provides a positive means of transmitting the initial rotational movement of the retractor lever 30 to the dead locking arm 52, the clutch face 80 also serves, to a certain extent, as a friction clutch by virtue of the frictional relationship between said face and the exterior side of the dead locking arm 52.

'Ihus, as the retractor lever 30 is rotated in a counterclockwise direction by the action of the retractor slide 16, concomitant rotation of the dead locking arm 52 is caused by the rotation of the clutch means 72 and the dead locking arm 52 is rotated in the counterclockwise direction as the main bolt 22 is drawn inwardly by the action of the upper extremity of the retractor lever 30.

As the dead locking arm 52 is moved upwardly and the upper edge thereof engages the upper Wall of the slot 71), further rotation of the dead locking arm 52 is prevented and the retractor lever 30 continues to rotate to the full retracted position. When this occurs, the abutment 84- on the clutch means 72 rides over the lower edge of the dead locking arm 52 and the clutch face 80 rotates against the outer surface of the now immovable dead locking arm 52. The clutch face 80 is ultimately located in the position shown in Fig. 5 of the drawings when the main bolt 22 is fully retracted.

When the half-round spindle 2G is released to permit the spring 42 to eject the main bolt 22, the action of said spring causes the simultaneous return of the retractor slide 16 to its inoperative position and the outward movement of the main bolt 22, by virtue of the impingement of the upper extremity of the retractor lever 30 on the inner end of the slot 46 in said main bolt, causes the clockwise rotation of said retractor lever. Of course, the outward movement of the main bolt 22 has freed the dead locking arm 52 from the slot 70 therein. Thus, as clockwise rotation of the retractor lever 30 takes place, the edge of the retractor lever 30 engages the inwardly extending lug 69 on the inner face of the dead locking arm 52 and carries the dead locking arm 52 downwardly. Simultaneously, the clutch face 80 of the clutch means 72 is rotated into its original position in which the abutment $4 underlies the lower edge of the dead locking arm 52 to cause upward movement of said dead locking arm when initial rotation of the retractor lever 30 again takes place.

It is thus readily apparent that the clutch means 72, while it insures initial simultaneous rotation of the dead locking lever 52 and the retractor lever 30, also permits relative movement between the same when the dead locking lever 52 has been moved into its second, uppermost position as defined by the top of the slot 70 in the bolt 22.

When the latch case 12 is disposed in the edge of a door, not shown, in inverted position, the spring 71 in the slot 70 serves to urge the dead locking arm 52 upwardly into dead locking position and eliminates the possibility that, due to vibratory or other loads, the dead locking arm 52 might possibly be moved downwardly out of operative relationship with the back of the main bolt 22 and thus permit the main bolt 22 to be retracted by the use of jimmying or other tools.

While I have disclosed the dead latch of my invention as embodied in a reverse-type retractor structure, it is,

of course, obvious that the principles of the invention can be applied with equal cogency to other retractor constructions.

I claim as my invention:

1. In a dead latch, the combination of: a housing; a retractor slide movable in said housing by a spindle engageable therewith; a retractor lever movable by said retractor slide and mounted for rotation on a pivot pin in said housing; a main bolt movable in said housing between extended and retracted positions by said retractor lever; dead locking means rotatable on said pivot pin and engageable with said main bolt to prevent the unauthorized retraction thereof; and clutch means operatively connecting said dead locking means and said retractor lever to cause simultaneous movement of said lever and said dead locking means, said clutch means being positively connected to said retractor lever and having a clutch face in engagement with said dead locking means and movable thereby to release said dead locking means and permit relative movement between said retractor lever and said dead locking means. 7

2. In a dead latch, the combination of: a housing; a main bolt movable in said housing between extended and retracted positions; retractor mechanism in said housing for causing the retraction of said main bolt; a dead lock ing lever mounted in said housing in side-by-side relationship with said retractor mechanism for locking said main bolt in extended position; and a clutch operatively connecting said dead locking lever and said retractor mechanism to cause simultaneous movement of said mechanism and said lever, said clutch having a U-shaped yoke secured to a portion of said retractor mechanism for rotation thereby and a clutch portion resiliently mounted on said yoke for engagement with said dead locking lever to cause said lever to rotate with said portion of said retractor mechanism and to permit relative movement between said retractor portion and said clutch portion.

3. In a dead latch, the combination of: a housing; a main bolt movable in said housing between extended and retracted positions; retractor mechanism in said housing for retracting said main bolt, said mechanism including a retractor lever engageable with said main bolt for retracting the same and mounted on a pivot pin in said housing; dead locking means for said main bolt mounted on said pivot pin in said housing adjacent said retractor lever; and a clutch operatively connecting said dead locking means and said retractor lever for simultaneously moving said dead locking means with said retractor lever, said clutch being of unitary construction and secured to said lever for movement thereby and having a displaceable clutch portion engageable with said dead locking means to permit said lever to move without causing movement of said dead locking means.

4. In a dead latch, the combination of: a housing; a main bolt movable in said housing between extended and retracted positions; retractor mechanism in said housing for retracting said main bolt, said mechanism including a rotatable retractor lever engageable with said main bolt for retracting the same and mounted on a pivot pin in said housing; dead locking means for said main bolt mounted in said housing adjacent said retractor lever, said dead locking means including a dead locking arm mounted concentrically with said lever; and a friction clutch operatively connecting said dead locking arm and said retractor lever for simultaneously rotating said dead locking means with said retractor lever, said retractor lever and said dead locking arm being mounted for rotation about a common axis.

5. In a dead latch, the combination of: a housing; a

main bolt movable in said housing between extended and retracted positions; a retractor lever engageable with said main bolt mounted for rotation on a shaft in said housing intermediate the extremities of said shaft; a dead locking arm mounted for rotation on said shaft relative to 'ment thereof, said clutch having a portionpositively engaged upon one extremity of said shaft and a clutching face frictionally engaging said arm.

' 6. In a dead latch, .the combination of: a housing; a main'bolt movable in said housing between extended and retracted positions; a retractor lever engageable with said mainibolt mounted for rotation on a shaft in said housing intermediate the extremities of said shaft; a dead locking arm mounted for rotation on said shaft relative to said lever; and a clutch for insuring simultaneous rotation of said lever and saidarm during the initial movement thereof, .said clutch having a yoke portion positively engaged upon one extremity of said shaft and a spring-biased clutching face frictionally engaging said arm.

7. A clutch for causing simultaneous movement of driving and driven members including a unitary body having a U-shaped yoke engageable with said driving member'and a clutch facespac ed from and resiliently 'connected to said yoke for engagement with said driven member.

8. A clutch for causingsimultaneous movement of driving and driven members including a unitary body having a U-shaped yoke engageable with said driving memberand a clutch face spaced from and resiliently connected to said yoke for engagement with said driven member, said clutch face/having abutment means thereuponlfor insuring positive engagement between said face and said driven member during the initial movement of said members. I g

9. In a dead latch; the combination of: a housing; a

main .bolt in said housing; a retractor for said main bolt 7 in said housing; dead locking means in said housing for said main bolt; and a clutch voperatively connecting said main bolt .and said retractor, said clutch having a unitary resilient body provided with a yoke engaging said retractor and a clutch face formed integrally with said yoke and engaging said dead locking means to cause simultaneous initial movement of said retractor and said dead locking means.

References Cited in the file of this patent UNITED STATES PATENTS Sparks Aug. 3, 1915

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