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Publication numberUS3400564 A
Publication typeGrant
Publication dateSep 10, 1968
Filing dateOct 18, 1965
Priority dateOct 18, 1965
Publication numberUS 3400564 A, US 3400564A, US-A-3400564, US3400564 A, US3400564A
InventorsGlass Dwight W, Sewell Robert A
Original AssigneeNat Lock Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Dust cap assembly for tumbler locks
US 3400564 A
Abstract  available in
Images(1)
Previous page
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Claims  available in
Description  (OCR text may contain errors)

Sept. 10, 1968 0. w. GLASS ETAL 3,400,564

DUST CAP ASSEMBLY FOR TUMBLER LOCKS Filed Oct. 18, 1965 United States Patent 3,400,564 DUST CAP ASSEMBLY FOR TUMBLER LOCKS Dwight W. Glass and Robert A. Sewell, Rockford, Ill.,

assignors to National Lock Co., Rockford, III., a corporation of Delaware Filed Oct. 18, 1965, Ser. No. 497,368 3 Claims. (Cl. 70-455) ABSTRACT OF THE DISCLOSURE A dust cap assembly for tumbler locks having a locking plug rotatable in a cylindrical housing utilizing a movable cam or pair of cams positioned between the face of the lock plug and a dust cap or cover fitting over the face of the plug; the dust cap or .the face of the plug having a recess receiving the cam or cam-s. The dust cap has an opening therein generally aligned with a keyway in the lock plug, and the plug includes circumferentially spaced pockets on the rear surface of the front flange receiving lips formed on an annular flange extending rearwardly of the dust cap. A single cam has an opening to be aligned with the keyway, an outwardly projecting arm received in the opening in the cap to limit movement of the cam, and an integral curved spring arm cooperating with a projection in the recess for the cam. If a pair of cams are utilized, the cams meet at a central parting line, each having a sloping lead-in surface and a pair of outwardly curved integral spring arms opposite the lead-in surface and cooperating with projections in the cam recess.

The present invention relates to a dust cap for a pin or plate tumbler lock and more particularly to a two-part dust cap assembly which is snapped onto the plug of a tumbler lock and has a yieldably biased cam normally covering the keyway in the plug to prevent the entry of dust or other foreign matter.

Among the objects of the present invention is the provision of a dust cap assembly for a tumbler lock having a movable cam and a cap or cover. The cam includes an opening to be aligned in one position with the keyway in the plug and an actuating spring means to yieldably urge the cam to a second position covering the keyway. The cap or cover is snapped over or staked onto the outer face of the plug in the tumber lock and is prevented from rotating relative to the plug.

Another object of the present invention is the provision of a dust cap assembly having a cap with a cylindrical depending flange which encompasses the face of the tumbler plug, and the cap has an interior recess receiving a cam. The cap also has an angular lead-in or camming portion serving to direct the key into the keyway and urge the movable cam :to open position. If a single cam is utilized, it includes a projection adapted to be engaged by the key at the lead-in surface on the cap and an opening adjacent the projection to be moved into alignment with the keyway.

A further object of the present invention is the provision of a dust cap assembly having a two-part cam received within the cap. The cam is divided symmetrically into two parts which are mirror images, each part having an integral yieldable biasing means. The two parts are divided at the center over the keyway and separate upon insertion of a key. The two parts form a central V-shaped incline or groove to guide the key and force the cams outwardly in opposite directions to allow the key to enter the keyway.

The present invention also comprehends the provision of a dust cap assembly where the face of the plug is recessed to receive the cam or cams and the dust cap is being used as an escutcheon or snap-on scalp. Also the ice dust cap, whether recessed or used as an escutcheon, provides a peripheral ridge overlapping the oute face of the cylindrical housing for the plug to prevent entry of dust between the plug and housing.

The present invention further comprehends the provision of a dust cap assembly where both the cam or cams and the cap are formed from a resilient plastic material. The dust cap formed from a plastic or other flexible material can be snapped onto the plug and the cam or cam-s have the yieldable biasing means formed of the same material and integral with the cam body.

Further objects are to provide a construction of maximum simplicity, efiiciency, economy and ease of assembly and operation, and such further objects, advantages and capabilities as will later more fully appear and are inherently possessed thereby.

In the drawing:

FIGURE 1 is a front elevational view of a cylinder lock having the dust cap assembly of the present invention secured thereto. I

FIG. 2 is a vertical cross sectional'view through the tumbler lock and dust cap assembly taken on the line 2-2 of FIG. 1.

FIG. 3 is a partial horizontal cross sectional view taken on the line 33 of FIG. 1.

FIG. 4 is a front elevational view of a tumbler lock having an alternate embodiment of dust cap assembly secured thereto.

FIG. 5 is a partial vertical cross sectional view taken on the line 5-5 of FIG. 4.

FIG. 6 is a partial horizontal cross sectional view taken on the line 66 of FIG. 4.

FIG. 8 is a partial vertical cross sectional view taken on the line 88 of FIG. 7.

FIG. 9 is a partial horizontal cross sectional view taken on the line 9-9 of FIG. 7.

Referring more particularly to the disclosure in the drawing wherein is shown illustrative embodiments of the present invention, FIGS. 1 to 3 disclose a cylinder tumbler lock 10 having a cylinder or housing ll'with a peripheral flange 12 on the face thereof and having a longitudinal passage 13 therethrough which is counterbored at 14 in the flange 12. The counterbored passage receives a cylindrical plug 15 having an enlarged face or flange 16 received in the counterbore 14; the plug housing either conventional pin or plate tumblers.

The diameter of the face 16 of the plug is slightly smaller than the diameter of the counterbore 14 and the face is provided with three equally spaced recesses or pockets 17 formed on the rear edge of the face 16 of the plug. The plug also includes a conventional keyway 18 for a key (not shown) to be inserted and actuate the tumblers so that the plug 15 can be rotated within the .housing 11 to unlock a door or other member to which the lock 10 is applied.

A dust cap assembly 19 is provided to cover the face 16 of the plug 15 and partially overlap the flange 12 of the housing 11. The assembly is preferably formed of a plastic or other flexible material and includes a cap or cover 21 having a rearwardly extending annular flange 22 provided with three equally spaced lips 23 which are of slightly greater thickness than the flange. The flexibility of the cap material allows the cap to be snapped over the face 16 of the plug 15 with the annular flange 22 entering the annular space around the plug face 16 in the counterbore 14 and the lips 23 snapping into the corresponding recesses or pockets 17 so that the cap 21 is retained on the plug 15 and does not rotate relative thereto;

The cap 21 is provided with a peripheral ridge 24 which overlaps the inner periphery of the housing 11 at the counterbore 14 to prevent dust from entering therein between the cylinder and the plug 15. The cap also has a centrally disposed generally rectangular opening 25 which is generally aligned with the keyway 18 as will be later seen, and a semi-circular lead-in camming surface 26 at one side of the keyway 18. The cap 21 is further provided with an interior recess 27 having parallel side walls 28 to allow for movement of a cam 29.

The cam 29 is also preferably molded from a resilient or flexible material having a generally rectangular body and an integral curved spring arm 31 projecting from one side of the body. The body is formed with parallel sides complementary to the sides 28 of the recess 27 in the cap. The cam also has a rectangular opening 32 therethrough and an outwardly projecting arm 33 which is received in the opening 25 in the cap. The recess 27 also is provided with one or more interior projections 34, one of which cooperates with the outer end of the actuating spring 31 to urge the cam 29 to the left as seen in FIG. 1.

The dust cap assembly 19 is shown in its closed position in FIG. 1 with the cam 29 urged to the left by the spring 31 so that the arm 33 abuts the edge of the opening 25 at the lead-in surface 26 whereby the opening 32 in the cam is covered by the cap, and the cam closes the opening 25 in the cap to prevent entry of dust or other foreign matter into the keyway 18. When a key (not shown) is utilized to actuate the tumbler lock, the end of the key engages the lead-in camming surface 26 and is cammed against the arm 33 of the cam 29 and urges the arm 33 and cam 29 away from the lead-in surface 26 so that the opening 32 in the cam is aligned with the keyway 18 and the opening 25 in the cover to allow the key to enter the keyway 18 to actuate the lock.

When the key is removed, the spring arm 31 cooperating with the projection 34 urges the cam 29 to the left in FIG. 1 to close the opening 25 in the cover; the arm 33 in the opening 25 limiting movement of cam 29. The opening 25 in the cover 21 is slightly offset to the right of the axis for the plug as seen in FIG. 1 to receive the arm 33 on the cam 28 and allow the keyway to be completely uncovered for entrance of a key.

FIGS. 4 to 6 disclosed an alternate embodiment of the dust cap assembly 35 utilized with a tumbler lock identical to that shown in FIGS. 1 to 3 with like parts identified with corresponding numerals having a superscript a. The housing 11 contains a plug with an enlarged face 16 having pockets 17 and a keyway 18a.

The dust cap assembly includes a cover or cap 36 having an annular rearwardly extending flange 37 with lips 38 received in the pockets 17 to snap the assembly 35 onto the plug 15*. The cover has a peripheral ridge 39 overlapping the inner periphery of the flange 12 of the housing 11 and a substantially centrally positioned generally rectangular opening 41 therethrough aligned with the keyway 18 Also, the cover has an interior recess 42 having a pair of parallel sides 43 and generally equally spaced projections 44 therein.

The cam in the recess 42 is divided into a pair of generally symmetrical parts 45, 45', each part having a pair of diverging outwardly curved spring arms 46, 46, 46', 46' with the outer end of each arm cooperating with one of the projections 44 in the recess. Each part also has a generally rectangular camming or lead-in surface 47, 47' with the two surfaces converging to a point where they abut to cover the keyway 18 and form a generally V- shaped groove.

In utilizing this embodiment, the key is inserted in the opening 41 in the cover and engages the lead-in surfaces 47, 47' on the cam parts 45, 45', urging the cam parts outwardly against the action of the spring arms 46, 46, 46', 46' to expose the keyway 18 and allow the entrance of the key therein. When the key is removed, the spring 4 arms 46, 46, 46', 46' urge the cam parts 45, together to cover the keyway.

FIGS. 7 to 9 disclose a third embodiment of dust cap assembly 48 applied to a tumbler lock 10 which is generally similar to the embodiment of FIGS. 1 to 3 except that the dust cap 49 is not provided with an interior recess for the cam. The cover or cap 49 includes the annular flange 51 with the lips 52 cooperating with the pockets 17 on the plug 15 and the opening 53 therein adjacent a lead-in surface 54. The plug 15 is rotatable in the housing 11 has a keyway 18 extending therethrough and is provided on the face 16 with a recess 55 having a pair of generally parallel sides 56 and a pair of interior projections 57.

The cam 58 is identical with the cam 29 of FIGS. 1 to 3 and includes the spring arm 59 at one side cooperatcams 45, 45' with each cam having a pair of resilient legs 46, 46 or 46', 46', as shown in FIGS. 4 to 6, could be utilized instead of the single cam 58 shown. To utilize the double cam arrangement, four projections 57 would be rearm or projection 62 at one side of the opening; the arm 62 projecting through the opening 53 in the cap 49 for 55 1s provided in the enlarged face 16 of the plug 15 it is obvious that the cam assembly having the pair of entially equally spaced lips, the enlarged head of said plug being spaced from the housing to receive said annular quired in the recess instead of two and the cap 49 would have the rectangular opening 53 centrally positioned in alignment with the keyway 18 After assembly of either of the three embodiments, the dust cap is held captive against a forced pop-off since the three lips overlap with the back of the plug flange is greater than the clearance between the cylinder or shell limited movement. Operation of the dust cap assembly 48 is identical with that of the assembly 19 of FIGS. 1 to 3.

In the embodiment of 'FIGS. 7 to 9 where the recess counterbore and the dust cap diameter. Although the dust cap assembly has been shown as preferably formed of a plastic or similar resilient material, either the dust cap or the cam or both members could be formed of metal by die casting, compression of powdered metal, stamping, etc. If the cam member is formed of metal, a spring would have to be staked in place, and if the cap were made of metal, a staking operation would be necessary in the area of the pockets in the back of the plug head or flange to retain the cap in place.

Having thus disclosed the invention, we claim:

1. A dust cap assembly for a tubular lock having a rotatable plug with an enlarged head and a keyway therethrough within a lock housing, comprising a dust cap extending across the enlarged head of the plug and partially overlapping the end of the housing, said dust cap having a generally, central opening and an annular rearwardly extending flange terminating in a plurality of circumfering with one of the projections 57 on the plug 15 a generally central opening 61 with an outwardly extending flange and having a plurality of circumferentially equally spaced pockets in the rear surface thereof to receive said lips, and a generally flat cam positioned between said dust cap and the enlarged head of said plug for reciprocation between an open position uncovering the keyway and a closed position covering the keyway, said cam having an opening therethrough adapted to be aligned with said key- Way in open position, an arm formed on said cam adjacent said opening to project outwardly through the opening in said dust cap and limit reciprocation of said cam, and an integral resilient arm extending outwardly from said cam and curving to generally parallel with said first mentioned arm and cooperating with the dust cap to bias said cam to closed position.

2. A dust cap assembly as set forth in claim 1, in which said dust cap has a recess receiving said cam therein, said cam and recess having cooperating parallel surfaces to guide the reciprocable movement of said cam, and at least one interior projection in said recess cooperating with the end of said resilient arm.

3. A dust cap assembly for a tumbler lock having a rotatable plug with an enlarged head and a keyway therethrough within a lock housing, comprising a dust cap extending across the enlarged head of the rotatable plug and partially overlapping the end of the lock housing, said dust cap having a centrally positioned opening therein aligned with the keyway and an annular rearwardly extending flange terminating in a plurality of circumferentially equally spaced lips, the lock housing being spaced from the enlarged head of the plug to provide an annular space accommodating said annular flange, said enlarged head having a plurality of circumferentially equally spaced pockets in the rear surface thereof to receive said lips, said dust cap having a recess therein facing said plug, and a pair of oppositely moving generally fiat cams received in said recess, each cam having a pair of oppositely outwardly curved resilient arms integral with said cam and urging the cams together to cover the keyway, a downwardly and inwardly slanting camming surface on the inner edge of each cam, said slanting surfaces cooperating to form a generally V-shaped recess cooperating with a key to separate the cams and uncover the keyway, said recess and said cams having complementary parallel guiding surfaces to guide reciprocation of said cams, and an interior projection in said recess cooperating with each resilient arm to bias the cams to closed position.

References Cited UNITED STATES PATENTS 952,643 3/1910 Roche 70-455 1,560,868 11/1925 Shinn 70-455 1,652,897 12/ 1927 Hill 70-455 X 1,757,387 5/1930 Rabkin. 1,811,141 6/1931 Leventhal 70-455 1,965,942 7/1934 Jacobi 7( )455 2,874,563 2/1959 Schlage 70455 2,956,430 10/1960 Simmons 70-455 3,267,707 8/1966 Adams 70-455 X FOREIGN PATENTS 1,368,253 6/1964 France.

606,252 7/ 1960 Italy.

606,253 7/ 1960 Italy.

OTHER REFERENCES German printed application, Wolf et 211., 1,118,649, November 1961.

MARVIN A. CHAMPION, Primary Examiner.

P. TEITELBAUM, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,400,564 September 10, 1968 Dwight W. Glass et al.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, after line 17, insert ing with one of the projections 57 on the plug 15 a generally central opening 61 with an outwardly extending arm or projection 62 at one side of the opening; the arm 62 projecting through the opening 53 in the cap 49 for limited movement. Operation of the dust cap assembly 48 is identical with that of the assembly 19 of FIGS. 1 to 3 In the embodiment of FIGS. 7 to 9 where the recess 55 is provided in the enlarged face 16 of the plug 15 it is obviou that the cam assembly having the pair of lines 21 to 26, cancel "arm or projection 62 at one side of the opening; the arm 62 projecting through the opening 53 in the cap 49 for 55 is provided in the enlarged face 16 of the plug 15 it is obvious that the cam assembly having the pair of entially equally spaced lips, the enlarged head of said plug being spaced from the housing to receive said annular"; lines 34 to 36, cancel "limited movement. Operation of the dust cap assembly 48 is identical with that of the assembly 19 of FIGS. 1 to 3. In the embodiment of FIGS. 7 to 9 where the recess"; line 47, "tubular" should read tumbler lines 54 and 55, cancel "ing with one of the projections 57 on the plug 15 a generally central opening 61 with an outwardly extending" and insert entially equally spaced lips, the enlarged head of said plug being spaced from the housing to receive said annular Signed and sealed this 10th day of February 1970.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents

Patent Citations
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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4638652 *Aug 22, 1983Jan 27, 1987Nena MorseSealing cap
US5056344 *Sep 20, 1990Oct 15, 1991Ktm Locks, Division Of Atoma International Inc.Bezel
Classifications
U.S. Classification70/455, 70/452
International ClassificationE05B17/18, E05B17/00
Cooperative ClassificationE05B17/186
European ClassificationE05B17/18E