US2871690A - Key-operated latch mechanism - Google Patents

Description

Feb. 3, 1959 R. E. JOHNSON KEY-OPERATED LATCH MECHANISM Filed Maich 21, 1956 2 Sheets-Sheet 1- INVENTOR. 5&5 J ya, 11, 1 41446 M 551/ 1 Feb. 3, 1959 R. E. JOHNSON 3 3 KEY-OPERATED LATCH MECHANISM Filed March 21, 1956 2 Sheets-Sheet 2 United States Patent F KEY-OPERATED LATCH MECHANISM Robert E. Johnson, Marne, Mich, assignor to Jervis Corporation, Grandville, Mich, a corporation of Michigan Application March 21, 1956, Serial No. 572,878

3 Claims. (Cl. 70-146) This invention relates to a latch mechanism which may be operated to open an associated closure only after the latch mechanism has been unlocked by a key, and it is an object of the invention to provide an improved latch mechanism of that character.

In the preferred embodiment of the invention a latch mechanism is releasable by operation of a push button or push rod, and a key-operated locking mechanism is incorporated in and forms a part of the push button or push rod. This permits a simplification of the over-all apparatus. However, the invention also contemplates key-operated latch mechanisms in which a locking device restrains movement of latch parts other than a push button or push rod.

It is another object of the invention to provide an improved key-operated latch mechanism which is much simpler in construction than previously known keyoperated latch mechanisms.

It is another object of the invention to provide an improved key-operated latch mechanism in which a cylinder lock constitutes a major portion of a push button for operating the latch mechanism proper.

It is still another object of the invention to provide an improved key-operated latch mechanism having various of the characteristics recited above, while being rugged, reliable, and inexpensive to manufacture.

This invention, together with further objects and advantages thereof, will best be understood by reference to the following description taken in connection with the accompanying drawings, and its scope will be pointed out in the appended claims.

In the drawings, in which like parts are designated by like reference numerals,

Figure 1 is a sectional plan view of a latch mechanism illustrating one embodiment of the invention;

Fig. 2 is a sectional side elevational view of the same latch mechanism;

Fig. 3 is a partial front elevational view of the same latch mechanism;

Fig. 4 is a cross-sectional view taken along the line 44 of Fig. 2;

Fig. 5 is a sectional side elevational view of an alternative form of lock which may be employed in the latch mechanism of Fig. 1;

Fig. 6 is a sectional plan view of the latch mechanism illustrating another embodiment of the invention; and

Fig. 7 is a front elevational view of the latch mechanism of Fig. 6.

The latch mechanisms proper illustrated in the drawings are of a basic type which does not serve to draw the associated closure tightly shut by virtue of previous energization of a powerful main latch spring. Instead, they employ simple spring-biased latch bolts which spring into latching position only after the door has been manually pushed to its fully closed position. However, it is to be understood that key-operated control apparatus constructed in accordance with the presentinvention may be employed with various types of latch mech- Z,87l,690 Patented Feb. 3, 1959 anisms proper. More particularly, these may include latch mechanisms which draw the associated closure tightly shut by operation of a previously energized main latch spring, whether such main latch spring is energized during the opening of the door or during the closing of the door.

The latch mechanism disclosed in Figs. 14 includes a keeper 11 in the form of a roller or pin which is rotatably mounted on a suitable bracket 12. The bracket may, for example, be rigidly secured to a cabinet 13.

A latch bolt 14 is pivotally mounted through a pin 15 on a door or other closure 16, and a spring 17 which is wound around the pivot pin 15 urges the latch bolt in a clockwise direction, as viewed in Fig. 2.

It will now be seen that latching engagement of the bolt 14 and the keeper 11 may be interrupted, to open the door, by counterclockwise pivotal movement of the latch bolt. After the door has been opened and the latch bolt has been allowed to return to its clockwise or latching position, the latch mechanism will operate automatically upon the door being-closed. More particu larly, as the door approaches its closed position, a sloping approach surface 14a on the latch bolt is engaged by the keeper 11 with the result that the latch bolt is thrust to the left in Fig. 2 against the action of the spring 17. When the door has reached its fully closed position, the latch bolt is free to pivot in a clockwise direction such that the keeper 11 is engaged by a latching surface 14b of the latch bolt.

The latch mechanism is releasable by a push button generally designated 20. It will be seen that as the push button is moved inwardly of the door 16, the inner end of the push button will bear against an arm of the latch bolt and cause counterclockwise pivotal movement thereof. As previously indicated, the push button assembly 20 incorporates a key lock-which prevents inward movement thereof until such time as the lock may be actuated by a key.

In the embodiment of the invention illustrated in Figs. 1 and 2, the push button assembly slides withina generally cylindrical opening in a base 21. This base may have any desired exterior configuration and, in the application shown, is integral with a fixed door-pull 21a.

The principal element of the push button is a cylindrical key lock 22 which extends from the face of the push button assembly and through the base 21. Secured to the inner end thereof is a screw 23 and a washer 24, the head of the screw 23 being the element which actually contacts the arm 14c of the latch bolt. The cylinder 22 is rotatable within an assembly 25 which not only receives and supports the cylinder but forms a pad against which the operator may bear to operate the latch, all as best seen in Fig. 2.

A pin 26 extends through the cylinder 22 and normally engages annular shoulders 27 which are formed in the base 21 and which, in combination, extend over the major portion of the inner circumference of the base" 21. This is best seen in Fig. 4 wherein the pin 26 is shown in engagement with the shoulders 27. A spring 28, seen in Figs. 1 and 2, is compressed between the pin 27 and the bottom of the cylindrical opening in the base 21.

Outward movement of the cylinder 22 is limited by engagement of the washer 24 with the inner end of the base 21, a rubber washer 29 preferably being arranged therebetween. along with the operating pad 25 is normally prevented by engagement of the pin 26 with the shoulders 27. However, when a key is inserted in the cylinder lock 22, the latter may be rotated to bring the ends of the pin 26 into alignment with the spaces between the shoulders 27, whereupon it is possible to depress the pad 25 and force the cylinder 22 inwardly against the Inward movement of the cylinder 22' action of the spring 28. The head of the screw 23 thereupon bears against the arm 140 of the latch bolt and pivots the latter in a counterclockwise direction to release the latch mechanism. As soon as pressure is removed from the push button pad 25, the spring 28 returns the cylinder lock and operating pad to the position illustrated in Fig. 2.

It will be understood that the operating parts within the cylinder 22 do not constitute a feature of the present invention. Furthermore, they may be of any desired well-known form and accordingly are not disclosed in the drawings or described herein. It will furthermore be understood that, depending upon the desired operation, the actual lock construction within the cylinder 22 may be of a type which causes spring return of th cylinder 22 to locking position upon release or reuse of the key, or it may permit removal of the key with the cylinder remaining in its unlocked position. All this depends upon the intended application of the latch mechanism, is well known in the art, and in itself forms no part of the present invention.

It will now be seen that a key-operated latch mechanism has been shown and described which is extremely simple in contruction and which is basically reliable in operation and inexpensive to manufacture. Some of these advantages flow from the fact that the lock itself is incorporated within and forms an operating part of the push button assembly.

The push button assembly illustrated in Fig. 5 diflers only slightly from that illustrated in Figs. 1-4 and may be used in the same over-all latch mechanism. The principal difference lies in the fact that the pin 26 of Figs. 1-4 is removed in favor of a shoulder 26a formed on the body of the cylinder 22a. The lock is illustrated in Fig. 5 in its unlocked position, in which the push button assembly 26a may be pressed inwardly to release the latch mechanism. When the cylinder 22a is in its locked position, the shoulder 26a lies in front of the shoulder 27a formed within the base 21a with the result that inward movement of the push button assembly is prevented.

In the embodiment of the invention illustrated in Figs. 6 and 7, the lock assembly is arranged separate of the actual control member against which the operator bears to release the latch mechanism. However, most of the advantage of simplicity in construction present in the embodiment of Figs. 1-4 is retained and certain other advantages are obtained. In contrast with the embodiment of Figs. 1-4, the latch bolt 31 of Figs. 6 and 7 carries a roller 32 thereon which cooperates with a fixed keeper 33 incorporating a sloping approach surface 33a and a latching surface 33b. The bolt member is pivotally mounted through a pin 34 on a latch housing 35 which is secured to the outer surface of a door 36. 34 and bears against the housing and an ear 31a on the latch bolt to urge clockwise rotation of the bolt.

The latch bolt 31 is in the form of a bell crank and at the right-hand end thereof is pivotally connected through a pin 38 to a push plate 39, the latter being guided within a slot in the latch housing 35. Reference to Fig. 7 reveals that the latch bolt 31 actually comprises spaced-apart arms, the pivot pin 34 passing through both arms and the roller 32 and the push plate 39 extending from one arm to the other.

It will be apparent that as the push plate 39 is pressed inwardly, the latch bolt 31 is pivoted in a counterclockwise direction against the action of the spring 37 such that the latch bolt roller 32 may swing clear of the keeper 33. After the door has been opened and the push plate 39 has been released, the spring 37 returns the latch bolt to the position illustrated in Fig. 6. When the door 36 is subsequently pushed shut, the latch bolt roller 32 rides over the sloping approach surface 33a of the keeper and subsequently snaps into latching posi- A coil spring 37 is wound around the pivot pin 4 tion, in which it engages the latching surface 33b of the keeper.

As indicated above, the locking apparatus in this embodiment of the invention is separated from the control element 39 which is actually contacted by the operator. A cylinder lock 41 is arranged to the left of the push plate 39 and carries at its inner end an arm 42 extending radially outward of the cylinder 41 in opposite directions. When the arm 42 is in. a vertical position, the two ends thereof lie directly in back of a pair of ears 31b formed on the arms of the latch bolt 31. The cylinder 41 is, of course, firmly set in position with respect to the housing 35 whereby the arm 42 prevents inward movement of the right-hand end of the latch bolt. Accordingly, the latch bolt is locked against releasing movement.

However, the cylinder 41 may be turned by a key in counterclockwise direction as viewed in Fig. 7 such that the arm 42 is swung out of the path of the ears 31b. When the cylinder 41 and hence the arm 42 are in this position, the latch bolt is free to pivot in a counterclockwise direction to release the latch mechanism and to openthe door, the operator being required to exert only suificient force to overcome the spring 37.

As in the case of the embodiment illustrated in Figs. l-4, the operating apparatus within the lock cylinder 41 may be of any desired form which does not in itself constitute a feature of the present invention. Accordingly, it is not shown in the drawings or described herein. Again, locks of various conventional forms may be employed depending upon the desired operation.

One advantage of the embodiment illustrated in Figs. 6 and 7 is that when the key is inserted in the lock, the operating handle, namely the push plate 33, is entirely unimpeded by such key. Furthermore, this embodiment retains much of the extreme simplicity of the embodiment illustrated in Figs. l4.

It will now be seen that a key-operated latch mechanism constructed in accordance with the present invention is of an extremely simple form requiring a ininimum ntunber of parts, and accordingly is basically reliable in operation and very economical to manufacture.

It will be apparent that the invention may be varied in its physical embodiment without departing from the spirit of the invention, and it is desired, therefore, that the invention be limited only by scope of the appended claims.

I claim:

1. In a key-operated latch mechanism for releasably maintaining a door in closed position with respect to a cabinet, a bolt member movable between a latching position and a released position, said bolt member including an arm extending laterally of and movable parallel to the direction of opening movement of said door, a push button engageable with said arm for moving said bolt member to said released position, a cylinder lock, and a member on said lock normally maintained in a position to engage said arm and prevent movement ofsaidlatch bolt to said released position, said member being movable away from said position by key operation of said lock.

2. In a key-operated latch mechanism for releasably maintaining a door in closed position with respect to a cabinet, a bolt member movable between a latching position and a released position said bolt member including a pair of parallel spaced-apart arms extending laterally of and movable parallel to the direction of opening movement of said door, a push button operable against said arms for moving said bolt member to said released position, a cylinder lock, and an elongated member mounted on the rotatable portion of said cylinder lock and extending radially outward thereof in diametrically opposed directions, said member normally being maintained in a position wherein it is engageable with said arms to prevent operation of said bolt member by said push button, said elongated member being movable away from said position by key operation of said lock.

3. In a key-operated latch mechanism for releasably maintaining a door in closed position with respect to a cabinet, a bolt member pivotally movable between a latching position and a releasedposition about an axis which is fixed with respect to said door, said bolt member including an arm extending laterally of and movable parallel to the direction of opening movement of said door, a push button engageable with said arm at a point remote from the pivotal axis of said bolt member for moving said bolt member to said released position, a cylinder lock disposed intermediate said push button and the pivotal axis of said bolt member, and a member on said lock normally maintained in a position to engage said arm and prevent movement of said latch bolt to said released position, said member being movable away from said position by key-operation of said lock.

References Cited in the file of this patent UNITED STATES PATENTS 2,208,003 Jacobi July 16, 1940 2,313,711 Jacobi Mar. 9, 1946 2,399,812 Ledin May7, 1946 2,605,630 Kee1er Aug. 5, 1952 i FOREIGN PATENTS 571,326 Great Britain Aug. 20, 1945 829,712 Germany Jan. 28, 1952

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