US2796281A - Latch guard - Google Patents

Description

June 18, 1957 R. D. PHILPOTT LATCH GUARD Filed Oct. 9, 1953 D. PH/LPOTT /N VEN TOR aEEHLf/e,

HUBNER,

' WORREL s HERZ/G r Afro/wem fwm' United States Patent The present invention relates to latches for doors, Windows, hatches and other closure members and more particularly to a latch guard for preventing unauthorized Y releasing of such latches.

As is well known, the conventional closure' members of the character referred to close against jambs and are releasably held in closed position by latch bolts. Because of normal clearance or space between closure members and their frames the latch bolts are accessible for retraction by a knife blade or other ilat instrument inserted between the closure members and their frames and worked against the bolts. Many devices have been constructed to guard against this danger but few, if any, of the known structures are designed for attachment as auxiliary members to previously installed closure members and their latches. Stated otherwise, most conventional latch guards are integral portions of their respective latches. With these devices much modification of the door and jamb is necessary to eifect proper installation. Furthermore, many of the known guarding devices .are bulky and mar the appearance of the door.

Of even greater functional signicance, conventional latch guards which are integral with their respective latches are rigidly mounted with their latches on either closure members or frames for the closure members. The greatest hazards of having latches picked or jimmied are encountered as the closure members shrink from their respective frames because of wood seasoning, climatic changes, or the like so as to make the bolts of the latches accessible between the closure members and frames. The latch guards which are integral with their latches do not successfully adjust to closure shrinkage or expansion inasmuch as such guards are either mounted on the closure and thus move away from their adjacent frame as the closure shrinks or are mounted on the frame and are rendered ineffective by closure shrinkage therefrom.

It is therefore an object of the present invention to provide a latch guard which automatically compensates for shrinkage and/ or swelling of closure members in their frames so as to provide dependable guarding even through excessive variations in relative sizes of closure members and their frames are encountered.

Another object is to provide an improved latch guard including cooperative elements, one thereof being mountable on a closure member and another on a frame for the closure member so as to overlap in shielding relation to the latch of the closure member during all normal ranges of shrinkage and/ or swelling of the closure member.

Another object of the invention is to provide a latch guard that can conveniently be installed on any conventional closure member without altering the design thereof.

Another object of this invention is to provide a latch guard for closure members of the nature described which is invisible from the exterior of the closure member when it is closed.

Another object is to provide a latch guard for door latches which is self-adjusting under varying climatic conditions, and will operate regardless of expansion and Patented June 18, 1957 ice contraction of the door or jamb within reasonable limits.

Another object is to provide a latch guard of the nature described which aids in centering closure members in their frames in the event of departure from desired position by closure member settling or frame distortion.

Another object is to provide a latch guard which aids in increasing the bite of the latch bolt when shrinkage has occurred.

These and other objects of this invention will become more apparent with reference to the following description and accompanying drawings, in which:

Fig. l is a fragmentary elevation of a door, representative of closure members generally, in closed position in a frame therefor and showing a conventional latch adapted releasably to retain the door in closed position, all of which constitute exemplary operational environment for the latch guard of the present invention a portion of which is shown in dash line. v

Fig. 2 is a section taken on line 2 2 of Fig. l.

Fig. 3 is a fragmentary edge elevation of the door showing the latch thereof and a portion of the latch guard of the present invention.

Fig. 4 is a fragmentary edge elevation of the door frame showing a latch keeper mounted therein and a portion of the latch guard of the present invention having a cooperative relation with the portion shown in Fig. 3.

Fig. 5 is a section taken on line 5-5 of Fig. 1. e

Fig. 6 is a section taken on line 6 6 of Fig. l.

Fig. 7 is an exploded view of cooperative elements o the latch guard of the present invention.

Referring in greater detail to the drawing: v

The latch guard of the present invention consists of a plurality of cooperative flat plates 10 and 12 of two different sizes. sired plurality may be utilized as suggested by the functional requirements but the full -advantages desired are not attained unless at least two cooperative plates are utilized.

The plate 12 is adapted to nest within the plate 10 in substantially co-planar relation therewith. The outer plate 10 is conveniently formed from a substantially rectangular blank of sheet metal or the like having opposite end edges 13 and side edges 14. An edgewardly disposed notch 15 is formed in one of the side edges 14 leaving ears 16 at opposite' ends of the plate integrally interconnected by a leg 17 longitudinally of the plate.l The ears provide facing, upwardly and downwardly disposed, edges 18 and 19, respectively. The deined form of the platey 10 is readily observable in Figs. 3, 5 and 7.

The inner plate 12 is conveniently formed of a trapezoidal blank of suitable sheet material having opposite end edges 20 and substantially parallel side edges 21. A notch 22 is formed in one of the side edges 21 to receive the bolt of a latch, as will be subsequently described. The end edges 20 converge toward the side edge opposite that in which the notch 22 is provided at substantially the same angle of convergence as the angle of divergence of the edges 18 and 19 of the outer plate 10. It will be noted in Figs. 5 and 7 that the inner plate 12 is loosely complementarily fitted to the outer plate 10. So formed, the inner plate has ears 23 at opposite ends thereof integrally interconnected by a leg 24 longitudinal of the plate. For mounting convenience, counter-sunk bores 2S are formed through the ears 23 of the plate 12 and through the ears 16 of the plate 10. v

Inasmuoh as various thicknesses of the plates 10 and 112 are desiralble in dilering environments, shim plates 10 similar to the outer plate 10 and shim plates V12 similar to the inner plate 12 are provided. When a plate thicker than plate 10 is desired, any desired number of shim plates 10' are utilized in stacked relation therewith. Sim- As will soon become apparent, any de-` ilarly, greater thickness is attained by employing any desired number of shim plates12 with the plates 12.

Referring now to Figs. 1 to 6, there is seen the application of plates 1f) and 12 to a closure member, such as a door 2,6, and its associated frame 28. Fig. 3 shows the larger plate 10 vertically mounted and attached by means of screws y29 positioned in the bores 2S and fastened into the edge of the door. The plate is mounted directly on the door or i-n the event that the door lock is provided with a latch plate, as 3f), it is mounted over the latter. In any case, the plate 1f) is not flush with the doors edge but-rather extends radially outwardly ltherefrom itl-s thickness in the direction -of the frame `.28as best seen in Figs. l, 2 and 6. The outside edge of intermediate portion 17 is, however, preferably flush with the outside face 31 of the door. Furthermore, plate 10 is mounted so that the notch 1S thereof partially surrounds, or spans, the bolt 32 ofthe door lock, as seen in Pig. 3.

With reference to Fig. 4, the smaller plate 12 is mounted in a manner similar to plate 1f) but on the frame 23. Thesquared inner notch 22 of this plate surrounds the keeper or latch bolt opening 36 in the frame and the outer edge 21 of the-intermediate portion 24 of the plate is arranged to face in the direction of the strike plate 37. As above, the smaller plate 12 extends outwardly from the frame 28 in the direction of the edge of the door 26. The plates are vertically aligned on their respective door and frame so that when the door closes in the frame, as represented in Fig. 5, the plates overlap in the nesting relation described above. l

The above will be more clearly apparent upon the explanation of the use of the lock safety device described above. It is assumed that the door 26 .and frame 23 desired to be protected are provided with plates in the `manner shown in Figs. 1 to 6, both inclusive. Whenever fthe door is closed the notch or cut-out portion of tl e plate 10 mates with the outer peripheral edge of plate 12 in the co-planar relation shown in Fig. 5. With the door thus closed and the plates so mated, access to the bolt 32 from between the door and frame in the direction of the arrow in Fig. 6 is prevented. This is true because the plates are designed overlappingly to fill the space between the door and frame arou-nd the lock bolt 32.

Due .to this overlapping relation of the plates, a certain amount of shrinkage or expansion may be allowed for and accommodated by the plates. As is most evident from Fig. 6, lateral or transverse movement of the door does not affect the mating of the plates and the bolt is not exposed unless the door or frame shrinks an amount greater than the width of one of the plates, assuming that plates 10 and 12 are not in use. in the event that it is indeterminate from the outset whether shrinkage or expansion will occur, the plates are mounted in offset relation a-nd instead of a full overlap as shown, are only partially overlapped. When so mounted, both shrinkage and expansion may occur to an extent approximately equal to one-half the wid-th of the plates without destroying the protective effect of the plates.

.Furthermore, if the space between door and frame when the door is closed, is greater than the combined thickness of the plates, a duplicate of either plate such as 1d and/ or 12 is mounted beneath its companion plate effectively increasing its width and filling the space.

An add-ed advantage of the safety device when shrinkage occurs is that of increasing the bite ofthe bolt thereby aiding in latohing thereof by engagement with the portion 24 of the plate 12.

With the device of this invention, operation of the door or other closure member is not changed in any marmer nor is the structure of the door modified to such an extent that the appearance of the door is marred. Because of the location of plates, the latch guard is normally substantially invisible from the exterior of the door when the door is closed.

An additional advantage resulting from the particular construction of plates 10 and 12 is the camming effect which edges 18 and/ or 19 exert on edges 20. Since closure members and associated frames often become misaligned due to improper hanging @if the door or sagging thereof, proper operation is sometimes difficult. If closed, a misaligned door causes the bolt to be out of line with the keeper opening and thus the door will not properly latch and remain closed. This invention prevents or minimizes this undesirable condition.

When the door and frame are in preferred elevational relation, for convenience designated as a neutral position, plates lil and 12 mate as described, generally with a small clearance therebetween, as at 40. However if door 25 moves up or down relative to this neutral position, the plate 1f) will be offset slightly in a vertical direction from plate 12. When the door is closed in the frame the edges 18 and/or 19 cam against the edges 20 to urge the door up or down into its proper vertical or neutral position, thereby permitting the bolt to fit in the keeper opening.

'Since the lat-ch guard of this invention is intended to protect the latch bolt from unauthorized tampering, it is apparent that the intermediate portion 17 of plate 10 must be disposedV between the bolt and the outside surface of the door, thus surrounding or shielding the lock bolt from the outside. Furthermore, since plate 12 properly fits withinplate 1f) in only one manner, namely with the outer peripheral edge nested wit-hin the cutout portion of plate 1t), it is apparent that plate 1,2 must also have its portion 24 disposed between the bolt opening and the outside of the door.

Therefore, when door 26 opens outwardly toward A in the manner shown in Fig. 2 and the outside of the door is at A, the larger plate 10 will be attached to the door, and the smaller plate 12 to the frame, in the manner illustrated. However, when the outside of the door is at B, the outside edge of intermediate portion 17 must face in the direction B, thereby to shield bolt 32 from access in that direction, as between the jamb 42 and the frame. With the door opening in the same direction (that is toward A), it is necessary to reverse the location of the plates 10 and 12 so that proper mating in the overlapping position will be effected. Thus plate 1@ is mounted on the frame and plate 12 is mounted on the door, the latter, of course, having the outside edge of intermediate portion 24 facing in direction B.

Although the invention has been herein shown and described in what is conceived to be the most prac-tical and preferred embodiments, it is recognized that departures may be made therefrom within the scope of the invention, which is not to be limited tothe details disclosed herein but is tobe accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus,

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a door having a latch bolt extending outwardly therefrom, and a frame adapted to receive the door and having an openingrfor receiving the bolt; a safety device for preventing jimmying of the bolt comprising a first flat plate mounted on the frame around the opening having opposite plane surfaces and a peripheral edge, the peripheral'edge defining opposite end and side edges, and a second flat plate mounted on the door around the bolt having opposite plane surfaces and a peripheral edge, the peripheral edge defining opposite end and side edges, a side edge of one of said plates having a substantially U-shaped cut-out portion therein defined by an inner longitudinal edge and facing transverse edges, the transverse edges being relatively divergent outwardly of the inner` edge, the end edges of the other of said plates being divergent from one side edge thereof, the end edges and said one side edge of said other plate being complementarily fitted against the transverse edges and inner edge, respectively, ofthe cut-.out portion of said one plate when the door is received in the frame, the transverse edges of the cut-out portion and the end edges of said other plate acting as a camming means for guiding the plates to nested relation when the door is closed and also guiding the door into predetermined elevational position in the frame when the door is in a closed position.

2. In a door having a latch bolt extending outwardly therefrom, and a frame adapted to receive the door having an opening for receiving the bolt when ,the door is closed, the door and frame providing flat edges around the bolt and the opening and adapted to lie in spaced facing relation when the door is closed, a latch guard for the bolt comprising an outer ilat plate having opposed plane surfaces and of substantially uniform thickness throughout, the plate providing one side edge having a substantially U-shaped notched portion therein and being fitted with one of its plane surfaces in flush relation against the flat edge of the door with the notched portion thereof disposed around the latch bolt and facing toward the frame when the door moves toward closed position, an inner plate having opposed plane surfaces and of substantially the same thickness throughout as the outer plate, the inner plate providing opposite end and side edges, the end edges and one of the side edges of the inner plate defining a substantially U-shaped contour adapted to mate with the U-shaped notch in the side edge of the outer plate, the other side edge of the inner plate being notched, the inner plate being fitted with one of its plane surfaces in iiush relation against the at edge of the frame with the notched side edge thereof disposed around the bolt receiving opening of the frame and facing in the same direction as the notched portion of the outer plate, said plates being elevationally aligned when the door is closed in the frame with the U-shaped side and end edges of the inner plate fitting within the U- shaped notched edge of the outer plate and both plates lying in substantially, Vthe same plane around the latch bolt.

3. In a door having a latch bolt extending outwardly therefrom, and a frame adapted to receive the door having an opening for receiving the bolt when the door is closed, the door and frame providing iiat edges around the bolt and the opening and :adapted to lie in spaced facing relation when the door is closed, a latch guard for the bolt comprising an outer flat plate having opposed plane surfaces and of substantially uniform thickness throughout, the plate providing one side edge having a substantially U-shaped notched portion therein defining an inner edge and outwardly divergent camming edges, the outer plate being fitted with one of its plane surfaces in ush relation against the flat edge of the door with the notched portion thereof disposed around the latch bolt Iand facing toward the frame when the door moves toward closed position, an inner plate having opposed plane surfaces and of substantially the same thickness throughout `as the outer plate, the inner plate providing opposite end and side edges, the end edges and one of the side edges of the inner plate defining a substantially U-shaped contour with the end edges forming outwardly divergent camming edges relative to said one side edge adapted to mate with the Urshaped notch in the side edge of the outer plate, the other side edge of the inner plate being notched, the inner plate being fitted with one of its plane surfaces in flush relation against the flat edge of the frame with the notched side edge thereof disposed around the bolt receiving opening of the frame and facing in the same direction as the notched portion of the outer plate, said plates being elevationally aligned when the door is closed in the frame by camming action between said camming edges so that the U-shaped side and end edges of the inner plate fit within the U-shaped notched edge of the outer plate and both plates lying in substantially the same plane around the latch bolt.

4. ln a door having a latch bolt extending outwardly therefrom, and a frame adapted to receive the door having an opening for receiving the bolt when the door is closed;'a safety dev-ice for preventing jimmying of said bolt comprising a rst at plate mounted on the frame around the opening having opposite plane surfaces and opposite end and side edges, and a second flat plate mounted on the door around the bolt having opposite plane surfaces and opposite end and side edges, a side edge of one of said plates having a substantially U-shaped cut-out portion therein, and the end edges and a side edge of the other plate having a substantially U-shaped contour complementary to said cut-out portion and received in said cut-out portion when the door is in closed position thereby aligning corresponding opposite surfaces of said plates in substantially co-planar relation around the bolt.

5. A latch guard for shielding the bolt of a door cornprising a lirst iiat plate having opposite plane surfaces and opposite end and side edges adapted to be secured 4to the frame for the door, and a second iiat plate also having opposite plane surfaces and opposite end and side edges adapted to be lsecured to the door around the bolt, the side edge of one of said plates defining therein a substantially trapezoidal edgewardly disposed notch having an inner longitudinal edge portion and lateral edge portions, the end edges and one of the side edges of the other of said plates having a substantially trapezoidal configuration complementary to said notch, the lateral edge portions of said notch and the end edges of said other plate acting as a camming means whereby upon closing the door into the frame the plates rest in substantial co-planar relationship and guide the door into .predetermined position in the frame.

References Cited in the le of this patent UNITED STATES PATENTS 915,873 Mosher Mar. 23, 1909 1,092,946 Page Apr. 14, 1914 1,853,456 Ross Apr. 12, 1932 2,631,881 Trachsler Mar. 17, 1953

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