US3494650A

US3494650A - Reclosable door latch

Info

Publication number: US3494650A
Application number: US685831A
Authority: US
Inventors: Robert E Slopa
Original assignee: Robert E Slopa
Current assignee: Hussmann Corp
Priority date: 1967-11-27
Filing date: 1967-11-27
Publication date: 1970-02-10
Anticipated expiration: 1987-02-10

Description

Fell 10, 1970 l R. E. sLoPA 3,494,650

RECLOSABLE DOOR LATCH Filed Nov. 27, 1967 United States Patent ABSTRACT OF THE DISCLOSURE A latch bolt is slidably carried in a housing and has an L-shaped lever pivotally mounted at its tail end. Aligned.

holes in the housing receive a padlock to prevent opening by an outer handle. An inside release mechanism is provided for pushing the lever to swing the same past the padlock and to retract the latch bolt. 'Ihe base plate has a stop face for holding the latch bolt in partially retracted position.

BACKGROUND This invention pertains generally to devices for doors in which the locking construction is capable of preventing ingress except by proper key but wherein the securing mechanism may be readily released from inside the structure.

The present invention is particularly adapted for use on refrigerator doors such as those used on walk-in refrigerators. The danger of malicious or accidental entrapment of personnel has long been a concern. Several states have enacted safety laws requiring equipment of this nature, and several governmental agencies have similar requirements. Latches of this general type have been provided in the prior art. Some of these provided an inside push rod which operates to disengage a stop face from the padlock shackle and then to actuate the outer handle (see, for example, Patents 2,680,638 and 2,855,771). These have the disadvantage of being inoperable from the inside should the outer handle be broken, or its movement accidentally or maliciously obstructed. Others solved this problem by providing a separate, independent mechanism for retracting the latch bolt (see Patents 2,655,395 and 2,718,421). These require many additional parts and an elaborate or complex mechanism. Additionally, in many prior devices, the latch bolt returns to the extended, locked position after the locked mechanism is opened from the inside. rIhis can prevent reclosure of the door and cause damage to the latch should the door be slammed.

SUMMARY The present invention relates generally to latches for refrigerator doorsor the like and more particularly to a releasable door latch.

It is a general object of the present invention to provide a new and useful releasable door latch which may be locked or rendered inoperative from the outsideV and yet permits the door latch to be retracted from inside the door.

Another object is to provide a door latch of the character described which is simplified and comprises a minimum number of parts, thereby being economical, yet is easy to manipulate and Vpositive in operation.

Still another object is to provide a releasable door latch which permits closing of the door even when the door latch is locked.

Other objects of this invention are to provide a releasable door latch which is strong, durable, and yet practical and eiiicient in use.

3,494,650 Patented Feb. 10, 1970 ICC 'Still other objects and advantages of the present invention will become apparent as the same becomes better understood from the following detailed description when taken in conjunction with the accompanying drawings:

DRAWINGS FIGURE l is a longitudinal sectional view through an embodiment of the present invention;

FIG. 2 is a sectional view taken generally along line 2-2' of FIG. 1;

FIG. 3 is a view similar to FIG. 1 but with the padlock removed and showing the relative position of the parts when the latch bolt is retracted by the outer handle; FIG. 4 is a view similar to FIG. 1 but showing the moved position of the parts 'when actuated by the inside release mechanism; and

FIG. 5 is a partial longitudinal sectional view of a modification which incorporates the reclosability feature.

DESCRIPTION Reference is now made more particularly to the drawings which illustrate the best presently known mode of carrying out the invention and wherein similar reference characters indicate the same parts throughout the several v1ews.

The illustrated embodiment of the present invention includes a latch mechanism, generally designated 10, mounted on a door D and engageable with a keeper K mounted, for example, on a door frame F which may be a part of a wall of a walk-in refrigerator or the like.

The latch mechanism 10 includes a housing made up of a base plate 12, a front |wall 13, spaced side walls 14 and 15, and

end walls

16 and 17. At the base of the side walls 14 and 15 are mounting flanges 18 and 19, respectively, through which lag bolts 21 or other securing means are inserted for securing the housing in place on the outside of the door D, as seen in FIG. 2. Side walls 14 and 15 have inwardly extending ribs 14a and 15a, respectively (see FIG. 2), for a purpose hereinafter explained. On the inside of the housing is an inner wall 24 extending generally crosswise of the housing for a purpose which will hereafter become apparent.

Slidably mounted in the housing is a latch bolt, generally designated 30. The latch bolt includes a substantially large latch end 32 of generally square cross section and a reduced tail end 34, The latch end extends through an opening 16a in Wall 16, and the tail portion extends through an opening 24a in the interior wall 24. The latch portion has a shoulder 32a at its juncture with the tail portion 34. A compression-type spring 36 is circumjacent to the tail portion 34 and interposed between wall 24 and shoulder 32a for resiliently urging the latch bolt to an extended position illustrated in FIGS. 1 and 2. At the outer end of latch portion 32 is an inclined face 32h for engaging a complementary face 39 on the keeper K. The outer end also has a ca-m face 32a` for camming the latch bolt over the keeper when the door is moved to closed position. 1

An outer handle 42 is provided to move the latch bolt 30 to retracted position. The handle 42 extends through an opening 13a in front wall 13, and it may be of any desirable or practical configuration so as to facilitate easy manual engagement therewith. The handle is pivotally mounted as by means of a pin 44, between the ribs 14a and 15a. A lateral projection or nose 4'6 formed integral with the handle 42, adjacent its pivotally mounted end, extends into slot 48 in the latch portion of the latch bolt. Outward pivotal movement of the handle 42 engages the projection 46 with the rear side of slot 48 and normally retracts the latch bolt as illustrated in FIG. 3.

At the tail end of the latch bolt is an L-shaped lever member generally designated 50. .The lever member. in.`

cludes spaced first legs 52 and 54 (see FIG. 2) which are pivotally mounted at the tail end of the latch bolt as by a pin 56. Extending rearwardly from the

first legs

52 and 54 and at an angle toward the base plate 12 is a second leg 58. At the juncture of said first and second legs is mounted a roller 59 for rolling engagement With the back side of wall 24 for a purpose which will hereafter become apparent. At the rear end of second leg 58 is located one leg of a shackle S of a padlock P. The shackle S passes through aligned openings 14b and 15b in side walls 14 and 15, respectively. At the rear end of second leg 58 is a stop face `61 lwhich normally lies in the position shown in FIG. l. The plane of stop face 61 is normally at an angle to a plane perpendicular to the base plate and diverging outwardly from the perpendicular plane in a direction away from the shackle S. In this manner, operation of the outer handle 42, when the shackle is in position, engages stop face 61 against the shackle S and wedges the second leg 58 between the shackie S and the base plate 12. Thus, retraction of the latch bolt 30 by the handle 42 is precluded when the padlock is utilized. In observing FIGS. 1 and 2, it will be noted that roller S9 engages the back side of inner wall 24 when the latch bolt is in extended position to properly position the member 50 so that the wedging action will occur as described above. In this manner, then, the latch mechanism may be locked to prevent access from the outside.

To permit egress from the refrigerator Iwhen the latch mechanism is locked, or even when unlocked, a push rod 64 is provided, The push rod 64 extends through the Vdoor D and through an opening 66 in base plate 12. The

front end of push rod 64 is normally disposed as shown in FIGS. l and 3 with the other end disposed on the inside of the door so as to be easily manipulable from the inside of the enclosure. As illustrated in FIG. 4, when the door is locked as by the insertion of the shackle or pin S so as to prevent its being actuated upon manipulation of the handle 42, the latch mechanism may yet be released instantly upon applying longitudinal pressure to the push rod 64 and lmoving it as illustrated. Extension of push rod 64 from its normal position engages its front end against second leg 58 and causes the member 50 to swing past the shackle S and move the latch bolt 30 to retracted position independent of the outer handle. During this movement of the member 50, roller 59 engages the wall or abutment 24 and provides a fulcrum about which the lever operates. Thus, as the push rod 64 is extended, the

first legs

52 and 54 swing rearwardly, pivoting about pin 56 and retracting the latch bolt 30 to the retracted position illustrated in FIG. 4.

In the modification illustrated in FIG. 5, means is provided for holding the latch bolt 30 in a partially retracted position. As illustrated, a wedge-shaped portion 68 is formed integral with the base plate 12. The wedgeshaped portion -68 extends generally crosswise of the latch bolt 30 and defines a stop face at the side facing the tail end of the latch bolt and an inclined face at the side opposite the stop face. A complementary shaped -groove 72 is provided in the side of the latch bolt 30 adjacent the 1base plate for receiving the wedge-shaped member 68 when the latch bolt is in the extended position illustrated in FIG. 5. Forwardly of groove 72, the latch bolt has a recess which defines a stop 74 engageable with the stop face on wedgemember 68. The positioning of stop 74 is such that the latch bolt will be in partially retracted or partially extended position so that thecam face 32e will engage the keeper upon swinging the door closed. Upon engaging the keeper, the cam face 32C will swing the latch bolt .30 outwardly slightly, away from the base plate and, after the latch bolt has passed the keeper, the spring 36 will quickly extend the latch bolt past the wedge-shaped portion 68 to the final position illustrated in FIG. 5. For retraction of the latch bolt 30, it must ride over the wedge-shaped portion 68. For this purpose,

. the inclined surface of the wedge-shaped portion 68 is inclined at an angle approximating that of face 32b and its complementary keeper face 39 so that no binding occurs during retraction of'the latch bolt. Additionally in this modification, opening 16a has its outer edge 16b spaced from the outer face-oflatch bolt 30 a distance at least equal to the thickness'of Wedge member `68. This allows the latch bolt'30 to cam outwardly as it passes the wedge member 68. t 'A It is now deemed obvious that the present invention provides a retractable latch bolt which can be operated from the inside of the door independent of the outer handle and which assures relatching of the latch bolt even with a lock in place.

While a preferred embodiment of the present invention has herein been illustrated and described, this has been done by way of illustration and not limitation, and it is to be understood that various modifications in structure will occur to a person skilled in the art.

What is claimed is:

1. In a releasable door latch including a housing adapted to be mounted on the outside of a door; a longitudinally extending latch bolt having a latch end and a tail end and slidably mounted in the housing for movement between extended and retracted positions; spring means for resiliently urging the latch bolt toward said extended position; an outer handle operatively connected to the latch bolt to selectively move the same to the retracted position; and stop means longitudinally spaced from said tail end and selectively positioned and fixed with respect to the housing for rendering the latch bolt inoperative by the outer handle and thereby locking the door latch; the improvement comprising:

a wall on the inside of the housing adjacent the tail end of the latch bolt;

a member having: first and second ends, means for pivotally mounting the first end at the tail end of the latch bolt, a stop face at the second end for engaging the stop means when in position to render the latch bolt inoperative, means defining a surface spaced from both the first and second ends and engageable with the Wall to provide a fulcrum when the member is pivoted, the stop face being swingable past the stop means when the member is pivoted about the fulcrum;

and release means operable from inside the door for selectively pivoting the member. about the fulcrum, swinging the stop face past the stop means, and moving the latch bolt to retracted position independent of the outer handle.

2. The combination of claim-1 wherein the wall extends laterally of the housing and hasan opening for passage 0f the latch bolt, the latch bolt has a shoulder longitudinally spaced toward the latch end from the wall and facing the wall, and the spring means comprises a compression-type spring interposed between the wall and the shoulder.

3. The combination of claim 1 wherein the housing has first and second aligned openings longitudinally spaced from the tail end of the latchbolt, and whereinfthe stop means comprises a padlock shackle extending through said aligned openings.

4. The combination of claim 3 wherein the housing includes a base plate, the shackle is spaced slightly from the base plate, and the stop face on the member normally lies in a plane at an angle to Va plane perpendicular to the base plate and divergingloutwardly therefrom and away from the shackle, whereby operation of the outer handle when the shackle is in position wedges'the member between the shackle and thebase plate. Y I

5. The combination of claim 1 wherein the member has a generally L-shaped body including first and-second legs; the first leg being pivotally-mounted about a generally upright axis at the tailend of--the latch bolt and with the legs in a generally horizontal plane; the stop face being at the end of the second leg; the release means including a generally horizontal rod extending into the housing and slidable into engagement with the second leg to swing the stop face past the sto'p means; and the means defininga surface engageable with the wall being at the juncture of the legs.

6. The combination of claim S-wherein the means defining a surface engageable with the wall engages the wall when the latch bolt is in extended position to position the member for engaging the stop means. y

7. The combination of claim 1 wherein the housing includes Va base plate having an outwardly extending portion extending crosswise of the latch bolt, said portion having a` stop face at the side facing the tail end of the latch bolt and an inclined face at the opposite side thereof, and the latch bolt having means d ening a stop for engaging said stop face to hold the latch bolt in partially retracted' position.

8. The combination of claim 7 including a keeper for engaging the latch bolt in extended position; and wherein the latch bolt has a cam face at the latch end thereof for camming the latch bolt over the keeper, said camming action operable to disengage the latch bolt stop from said stop face for extension of the latch bolt byfthe spring means.

9. In a safety release door latch especially adapted for latching refrigerator doors and the like, a "housing, a latch bolt slidably carried in the housing for movement in a longitudinal path between extended and retracted positions, an` outer handle normally `operable to move the latch bolt to retracted position, a lever arm pivotally mounted on the latch bolt and movable bodily therewith, stop means insertable in the path of the lever arm to prevent movement of the lever arm and the latch bolt to retracted position by the outer handle, an abutment on the housing laterally offset from the latch bolt, manually actuable release means operable from inside the door for laterally pivoting the lever arm to move it to ay position of non-engagement with the stop means, and a roller on the lever arm for engaging the abutment when the lever arm is swung and providing a fulcrum around which the lever arm swings when actuated by the release means to move the latch bolt to retracted position independent of the outer handle. ,I

10. In a releasable refrigerator door latch including a housing; a longitudinal latch bolt slidably mounted in the housing for movement between extended and retracted positions; means for ordinarily urging the latch bolt to the extended position; an outer handle operable from outside the door for moving the latch bolt to the retracted position; and a lock longitudinally spaced from the latch bolt and selectively positioned and fixed with respect 1o the housing for rendering the latch bolt inoperative by the outer handle; the limprovement comprising:

a member havingz-a first end swingably connected to the latch bolt, a second end for engaging the lock when in position to render the latch bolt inoperative by the outer handle, and a surface laterally offset from the latch bolt;

an abutment on the inside of the housing and laterally offset from the latch bolt;

and a release operable from inside the door and movable against the member to move said surface against the abutment, swing the second end past the lock, and move the Vlatch bolt to retracted position `independent of the outer handle.

References Cited UNITED STATES PATENTS 160,525 3/1873 Husted 292-332 2,680,638 6/1954 Groeger 292-92 2,969,999 1/ 1961 Herman 292-92 MARVIN A. CHAMPION, Primary Examiner R. L. WOLFF, Assistant Examiner U.S. Cl. X.R.