US3423118A

US3423118A - Door latch mechanism

Info

Publication number: US3423118A
Authority: US
Inventors: Russell W Waldo
Original assignee: Ideal Brass Works Inc
Current assignee: Ideal Brass Works Inc
Priority date: 1967-08-16
Filing date: 1967-08-16
Publication date: 1969-01-21
Anticipated expiration: 1986-01-21

Description

Jan 21, 1969 R.W.WALDO 3,423,118

DOOR LATCH MECHANISM Filed Aug. 16, 1967 Sheet 7 of 3 4a 49 212 30 34 7 54 i I 75 74 23/ 23 I g 23 v INVENTOR. RUSSELL W 14641.00

AT TORNEYJ Jan. 21, 1969 R. w. WALDO noon LATCH MECHANISM Filed Aug. 16, 1967 Sheet 36 FIG 4 37 7/ 7! 39 g I NVENTOR.

RUSSELL W M1420 AT TORNEKS Jan. 21, 1969 R. w. WALDO DOOR LATCH MECHANISM Sheet 3 of5 Filed Aug. 16, 1967 INVENTOR. RUSSELL WT TviqLoo AT T'ORNE'YS United States Patent Claims ABSTRACT OF THE DISCLOSURE Door latch mechanism including a stationary strike, a cooperating latch bolt pivotally secured in a door mounted casing and defining a ratchet portion, a pawl engaging the ratchet and an actuator for the pawl. A spring biased latch bolt driver in the casing urges the latch bolt in an unlatching direction and engages the strike to urge the door in a door opening direction when the pawl is disengaged from the ratchet portion. The actuator is moved in a door opening direction to disengage the pawl from the ratchet portion, and an anti lock-out looking device is operable to prevent disengagement from the pawl from the ratchet portion.

BACKGROUND OF THE INVENTION In many door latch mechanisms heretofore produced, latch actuators such as door handles, are directly connected to or integrally formed with, latch bolts, requiring relatively heavy pressure against spring means or movement of the actuator in a direction opposite that of door opening movement or both, to unlatch the door. In such mechanisms, involving the use of a panic bar, relatively heavy pressure against the bar is required to unlatch the door.

SUMMARY OF THE INVENTION An important object of this invention is the provision of latch mechanism including a latch actuator which is movable in the direction of opening movement of the door to release the latch; in which but a minimum of pressure against the actuator and a minimum movement thereof is required to unlatch the door; and including novel mechanism tending to open the door when the latch isreleased, and positive anti-lockout means for said latch. To this end, a latch is provided including a casing for mounting on one side of a hinged door adjacent a swinging edge thereof, a latch bolt pivotally mounted in the casing, a cooperating fixed strike for mounting on a door frame for engagement with the latch bolt, and a latch bolt driver movably mounted in the casing and having a latch bolt engaging portion and another portion for engagement with the strike urpon closing movements of the door and in opposition to the latch bolt. Said driver is yieldingly urged in a direction toward the strike and to move the latch bolt in a strike releasing direction. A pawl is pivotally mounted in the casing for engagement with a ratchet portion of the latch bolt to releasably hold the latch bolt in latched engagement with the strike, and an actuator is disposed to be moved in a door opening direction to engage and move the pawl out of engagement with the ratchet portion, whereby the latch bolt driver moves the latch bolt out of engagement with the strike and urges the door toward an open position. A locking device is operative to engage the pawl to positively lock the same in engagement with the ratchet portion of the latch bolt.

DESCRIPTION OF THE DRAWINGS Referring to the drawings, which illustrate the inven- 3,423,118 Patented Jan. 21, 1969 tion, and in which like reference characters indicate like parts throughout the several views:

FIG. 1 is a fragmentary horizontal section through a door and door frame, showing the door latch mechanism of this invention in top plan, some parts being broken away;

FIG. 2 is a fragmentary view partly in section and partly in side elevation, as seen from the line 2-2 of FIG. 1;

FIG. 3 is an enlarged fragmentary detail, partly in end elevation and partly in section, taken substantially on the line 33 of FIG. 2, some parts being broken away;

FIG. 4 is an enlarged fragmentary horizontal section taken substantially on the line 44 of FIG. 2;

FIG. 5 is a view corresponding to FIG. 4 but showing a different position of some of the parts;

FIG. 6 is an enlarged fragmentary view partly in side elevation and partly in section, taken on the line 66 of FIG. 1;

FIG. 7 is an enlarged fragmentary section taken on the line 77 of FIG. 1;

FIG. 8 is an enlarged fragmentary section taken on the line 88 of FIG. 1;

FIG. 9 is a view in perspective of a latch bolt driver;

FIG. 10 is a view in perspective of a locking device;

FIG. 11 is a view in perspective of a pawl;

FIG. 12 is a view in perspective of a latch bolt; and

FIG. 13 is a view corresponding to a portion of FIG. 1 but showing a modified form of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring with greater detail to the drawings, a conventional door frame is fragmentarily shown as including a pair of laterally spaced

door frame members

1 and 2 between which is mounted a door 3 supported by hinges 4, one of which is shown in FIG. 2, in the usual manner. For the purpose of the present example, the door 3 is of the combination storm and screen variety. The door latch mechanism of the present invention is indicated generally at 5, and involves inner and

outer casings

6 and 7 respectively secured to the inner and outer sides 8 and 9 respectively of the door 3, adjacent the door frame member 2. A stationary strike 10 is formed to provide a mounting flange 11 that is rigidly secured to the door frame 2 by mounting screws 12, the strike 10 defining flat inner and

outer faces

13 and 14 respectively, the latter facing the inner surface 8 of the door 3.

The inner casing 6 is formed to provide a generally vertical base portion 15 and a pair of vertically spaced parallel side walls 16 that project horizontally from the base portion 15. As shown particularly in FIG. 8, the outer latch casing 7 is formed to provide a pair of vertically spaced bosses 17 that are received in spaced openings 18 drilled through the door 3. A pair of anchoring screws 19 extend through suitable openings in the base portion 15, and are screw threaded into the bosses 17 to securely mount the

latch casings

6 and 7 to opposite sides of the door 3. The outer casing 7 is formed to provide a handle portion 20, the lower end of 21 of which is anchored to the door 3 by a mounting screw or the like 22.

A latch bolt 23, disposed between the casing sidewalls 16 is journalled on a vertical pin or shaft 24 having its opposite ends mounted in the sidewalls 16, for limited pivotal movements between a latching position, shown in FIG. 4, and a release position, shown in FIG. 5. The latch bolt 23 is formed to provide a latch hook 25 that is adapted to engage the inner face 13 of the strike 10 to hold the door 3 against opening movements see FIG. 4. The latch bolt 23 is further formed to provide a radially outwardly projecting tongue 26, a ratchet portion 27, and

a stop face 28, the purpose of which will hereinafter become apparent.

Adjacent the base portion 15 of the inner latch casing 6, the sidewalls 16 thereof are connected by

transverse wall portions

29 and 30, the latter of which cooperates with adjacent portions of the sidewalls 16 to slidably receive a reciprocatory latch bolt driver 31 having a head end portion 32 that is adapted to engage the outer face 14 of the strike 10. The driver 31 is formed to provide a cavity 33 for reception of the latch bolt tongue 26 whereby reciprocatory movement of the driver 31 toward and away from the base portion 15 of the inner latch casing imparts pivotal or swinging movement of the latch bolt 23 between its latching and release positions of FIGS. 4 and 5. The latch bolt driver 31 is further formed to provide a recess 34 for reception of a coil compression spring 35 which yieldingly urges the driver 31 in a direction to move the latch bolt 23 toward its release position of FIG. 5. As shown, one end of the spring 35 engages an adjacent end of the recess 34, the opposite end thereof being seated on a supporting portion 36 of a rotary locking member 37 having a hub portion 38 journalled in an opening 39 extending through the inner latch casing base portion 15. The spring 35 yieldingly urges the locking member 37 against the base portion 15 to hold the hub portion 38 within the opening 39.

A pawl 40 is journalled on a pin or shaft 41 between the sidewall 16, the shaft 41 being parallel to the shaft 24 and mounted at its opposite ends in the sidewalls 16. The pawl 40 is formed to provide a generally radially outwardly projecting ratchet engaging portion 42, a generally radially outwardly projecting lug 43 angularly displaced from the portion 42 and axially spaced from a cross-sectionally rectangular axial opening 37a in a locking member 37 and a radially outwardly projecting wing portion 44 substantially diametrically opposite the lug 43. Centrally of its ends, the wing portion 44 is formed to provide a boss 45 that extends generally toward and faces the base portion 15 of the inner casing 6. A coil compression spring 46 has one end portion mounted in a recess 47 in the base 15, the other end of the spring 46 engaging the wing 44 at one side of the boss 45 to yieldingly urge the pawl 40 in a direction of rotation to bring the pawl portion 42 into operative latching engagement with the latch bolt 23 or into its position shown in FIG. 4.

Means for moving the pawl 40 in a direction to release the latch bolt 23 from its latching position shown in FIG. 4, includes an actuator 48 which defines a pair of laterally spaced parallel sidewalls 49 and angularly displaced connecting

walls

50 and 51. The sidewalls 50 are each interposed between a different axial side of the latch bolt 23 and the adjacent sidewall 16 of the inner casing 6, and journalled on the pin or shaft 24, for limited swinging movement of the actuator 48 independently of the latch bolt 23. The sidewalls 49, opposite the connecting wall 51, have edge portions 52 which engage opposite end portions of the wing 44, responsive to pivotal movement of the actuator 48 in one direction, to pivotally move the pawl 40 a direction to swing the ratchet engaging portion 42 generally radially with respect to the ratchet portion 27 f the latch bolt 23, as shown in FIGS. 4 and 5. This action is very similar to that which occurs in a firearm, the actuator 48 operating as a trigger to pivotally move the pawl 40 in a direction to swing the ratchet engaging portion as a sear with respect to the ratchet portion 27, the action being smooth and light, requiring substantially only sulficient turning effort on the actuator 48 to overcome the bias exerted by the spring 46. As shown in FIGS. 4 and 5, the pawl 40 limits rotary movement of the actuator 48 in one direction, rotary movement of the actuator 48 in the opposite direction being limited by engagement of a pair of abutment portions 52a on the sidewalls 49 with shoulders 53 on the casing sidewalls 16, see particularly FIGS. 4, and 7. The connecting wall 50 is formed to provide a shoulder or lug 54 that engages the stop face 4 28 of the latch bolt 23 to limit swinging movement of the latch bolt 23 toward its released position of FIG. 5.

An elongated hollow handle or panic bar 55 extends across the door opening defined by the

door frame members

1 and 2 in inwardly spaced generally parallel relationship to the door 3, and is provided at one end with a hollow head 56 that contains the actuator 48 and which is connected to the actuator 48 by a pivot pin or shaft 57, the actuator 48 having a hub portion 58 journalled on the shaft 57 on an axis parallel to the shafts 24 and 41. A door closer 59 is mounted within the opposite end portion of the panic bar 55 and comprises a cylinder 60 and a cooperating piston-equipped plunger rod 61 that is pivotally connected, as indicated at 62, to a mounting bracket 63 rigidly secured to the door frame member 1, see FIGS. 1 and 2. The axis of the pivotal connection 62 is parallel to the axes of the

shafts

24, 41 and 57. The door closer 59 may be pneumatic or hydraulic, and is preferably of the type disclosed in US. Letters Patent to Bert A. Quinn, No. 3,249,961. The door closer 59 differs from that of Patent 3,249,961 and similar closers only in its connection to the door, the closer 59 being connected to the door 3 through the panic bar 55 and its connection to the latch mechanism above described, the cylinder 60 being rigidly secured within the panic bar 55.

The locking member 7 is formed to provide a generally radially outwardly projecting locking lug 64 that is movable, responsive to rotation of the locking member 37, between a locking position wherein the locking lug 64 is disposed between the base 15 and the boss 45 on the pawl 40, and an unlocked position wherein the locking lug 64 is disposed to one side of the boss 45, as shown in FIG. 7. In its locking position, the locking lug 64 affords substantially only working clearance therebetween and the boss 45, to prevent the pawl 40 from being rotated sufficiently to disengage the portion 42 thereof from the ratchet portion 27 of the latch bolt 23. The locking member 37 is provided with an operating handle 65 that projects radially outwardly therefrom through an opening 66 in one of the casing sidewalls 16, the handle portion 65 alternately engaging opposite sides of the opening 66 to limit rotary movement of the locking member 37.

The outer casing 7 is provided with a trigger-like unlatching member 67 that is disposed adjacent the upper end portion of the handle 20, and which is pivotally mounted in the casing 7, as indicated at 68. The member 67 has a bifurcated upper portion to provide a pair of upwardly extending arms 69, one of which is shown in FIG. 8, that engage a flange 70 at one end portion of a cross-sectionally rectangular spindle 71. The spindle 71 extends freely through a transverse opening 72 in the door 3 and axially slidably fits the rectangular opening 37a in the locking member 37, the inner end of the spindle 71 being in substantial abutment with or in closely spaced relation to the lug 43 on the pawl 40 when the pawl 40 is in its door-latched position of FIG. 4. Pivotal movement of the trigger-like member 67 generally in a door opening direction will impart rotary movement to the pawl 40 to release the latch bolt 23 independently of the actuator 48. The outer end of the spindle 71 is operatively connected to a conventional key operated lock 73 by means of which the locking member 37 may be rotated between its locked and unlocked positions from the exterior of the door.

To open the door 3 from the inside, when the lock 37 is in its unlocked position shown in FIGS. 6 and 7, it is only necessary to exert light pressure upon the panic bar 55 in the direction of the door 3, which is the direction of opening movement of the door. Such pressure will cause the bar 55 to swing about the axis of the pivotal connection 62, imparting rotary movement to the actuator 48 about the axis of the shaft 24 in a counterclockwise direction with respect to FIG. 4. Engagement of the edge portions 52 of the actuator 48 with the wing 44 of the pawl 40 will impart rotation to the pawl 40 to disengage the portion 42 thereof from the ratchet portion 27 of the latch bar 23, whereupon yielding bias of the spring 35 will impart opening movement to the door 3 and simultaneous swinging movement to the latch bolt 23 toward its release position of FIG. 5. Thus, the spring 35 and driver 31 assist the operator in opening the door 3. When the opened door is released to close, the door closer 59 will impart closing movement to the door while swinging the actuator 48 in a clockwise direction with respect to FIGS. 4 and 5, this swinging movement of the actuator 48 being limited by engagement of the abutment portions 52a with the shoulders 53. During final closing movements of the door, the head end portion 32 of the driver 31 moves into abutting engagement with the outer face 14 of the strike 10, after which the driver 31 will move relatively toward the door 3, thereby swinging the latch bolt 23 into engagement of the hook portion 25 with the inner surface 13 of the strike 10. With the door in a fully closed position, the spring 46 will pivotally move the pawl 40 into engagement of the portion 42 thereof with the latch bolt ratchet portion 27. It will be appreciated that the door closer 59 exerts closing effort on the door 3 suflicient to compress the drive spring 35 during final closing movements of the door.

The above-described latch mechanism provides a positive anti lock-out arrangement. As shown in FIG. 5, the locking member 37 cannot be rotated to lock the latch mechanism when the door is open, due to the fact that the boss 45 on the pawl 40 lies in the path of the locking lug 64, when the latch bolt 23 is in its released position. Should the latch bolt driver 31 be accidentally moved toward the door 3 against bias of the spring 35 to move the latch bolt 23 to its latching position, when the door is open, the outer surface of the latch hook portion 25 will engage the outer face 14 of the rigid strike and prevent the door from being closed until the latch bolt 23 is released either by pushing on the bar 55 or pulling on the trigger-like member 67. Thus, the door 3 may be locked closed only by intent, either by swinging the locking member handle 65 from the inside of the door or with the use of a key in the lock 73 from the outside of the door.

The modified form of latch mechanism shown in FIG. 13 differs from that of FIGS. 1-12 only in the actuator 74, which in lieu of being connected to a panic bar, such as the bar 55, is provided with a handle 75 and means, such as a lightweight spring or the like 76, for yieldingly urging the actuator 74 in a direction of swinging movement of the handle 75 thereof away from the door 3. The acutator 74 is used where a panic bar type handle is not required, and wherein a pneumatic or hydraulic door closer of the type disclosed in the-above-identified Quinn patent, is utilized. Except for the actuator 74, all of the parts shown in FIG. 13 are identical to those shown in FIGS. 112 and are identified with corresponding reference numerals.

While I have shown and described a commercial embodiment of my improved door latch mechanism and one modified form thereof, it will be appreciated that the same is capable of further modification without departure from the spirit and scope of the invention, as defined in the claims.

What is claimed is:

1. A door latch mechanism comprising:

(a) a casing adapted to be mounted fast on one side of a hinged door for common swinging movements therewith;

(b) a latch bolt pivotally mounted in said casing for movements between angularly spaced latching and release positions and defining a ratchet portion;

(c) a stationary strike element adapted to be mounted on a door frame, said strike element having opposed surface portions one of which engages said latch bolt to latch the door in closed positions;

(d) a latch bolt driver movably mounted in the casing and having a portion engaging said latch bolt for common movement therewith in opposite directions and another portion engageable with the other surface portion of said strike upon closing movements of the door;

(e) yielding means urging said driver in a direction to move the latch bolt toward its release position and to engage the other surface portion of the strike element to urge the door in an opening direction;

(f) a pawl mounted in said casing for movement toward and away from said ratchet portion and in a direction generally normal to movement of the ratchet portion to releasably hold the latch bolt in its latching position;

(g) yielding means urging the pawl toward engagement with said ratchet portion; and

(h) manually operated means for moving said pawl out of engagement with the ratchet portion against bias of said last-mentioned yielding means, including an actuator pivotally mounted in said casing for pivotal movements toward and away from engagement with said pawl independently of said latch bolt.

2. The door latch mechanism defined in claim 1, in which said latch bolt driver is slidably mounted in said casing for reciprocatory movements in the direction of opening and closing movement-s of the door, said driver defining a recess, said first-mentioned yielding means comprising a compression spring in said recess.

3. The door latch mechanism defined in claim 1 in which said latch bolt driver is slidably mounted in said casing for reci-procatory movement in the direction of opening and closing movements of the door, one of said driver and latch bolt defining a cavity and the other thereof having a tongue received in said cavity.

4. The door latch mechanism defined in claim 1, characterized by a locking member ,journalled in said casing for rotary movement on an axis extending transversely of the latch bolt axis and of the door when said casing is mounted on the door, said locking member having a portion engaging said..pawl, responsive to rotary movement of the locking member in one direction, to positively hold the pawl against pivotal movements away from engagement thereof with said ratchet portion.

5. The door latch mechanism defined in claim 4, characterized by a handle on said locking member, said casing defining an opening through which said handle extends radially of said locking member, said opening having opposite sides engaged by said handle to limit said rotary movement of the locking member in opposite directions.

6. The door latch mechanism defined in claim 2, in which said locking member defines a supporting portion underlying said latch bolt driver recess, said spring being seated at one end on said supporting portion and yieldingly holding said locking member against axial movement in one direction in said casing, said casing having a wall surface engaging and holding said locking member against axial movement in the opposite direction.

7. The door latch mechanism defined in claim 1 in which said actuator defines a stop portion engaging said latch bolt to limit movement of said latch bolt toward its release position.

8. The door latch mechanism defined in claim 1 in which said pawl includes a radially projecting lug, characterized by a door handle adapted for mounting on the side of the door opposite said casing, a spindle extending transversely through the door and having an outer end mounted in said door handle for longitudinal movements transversely of the door, and a spindle actuator movably mounted in said door handle, said spindle having an inner end engaging said lug to move the pawl out of engagement with said ratchet portion responsive to spindle actuator imparted movement of said spindle in one direction and independently of said first-mentioned actuator.

9. The door latch mechanism defined in claim 1, in which said manually operated means further includes an elongated bar structure having one end secured to said actuator and means on its other end for pivotally mounting the bar structure to the door frame on an axis generally parallel to the axes of pivotal movement of the actuator and to the hinge axis of the door, said bar structure comprising a door closer.

10. The door latch mechanism defined in claim 1, in which said manually operated means further includes a handle member extending from said actuator in a direction generally parallel to the adjacent side of the door.

References Cited UNITED STATES PATENTS 1/1950 Ledin 292227 6/ 1954 Vigmostad 292-229 X 7/1961 Schwanz et a1 292-92 X 8/1967 Sandor 292216 FOREIGN PATENTS 6/1936 Italy.

US. Cl. X.R.