US3777522A

US3777522A - Closure for cylinder lock mechanism

Info

Publication number: US3777522A
Authority: US
Inventors: H Rubner
Original assignee: Briggs and Stratton Corp
Current assignee: Briggs and Stratton Corp
Priority date: 1972-06-12
Filing date: 1972-06-12
Publication date: 1973-12-11
Anticipated expiration: 1990-12-11
Also published as: CA967388A

Abstract

A lock cylinder rotatable in a lock body has a cavity in its front, closed by a cap having a key aperture aligned with a keyway in the cylinder. A shutter in the cavity slides to and from a closed position blocking the key aperture, guided by a tongue on its rear received in a groove in the bottom of the cavity. A coiled expansion spring reacting between the cavity wall and the tongue is inclined to the cylinder axis to bias the shutter forward into sealing engagement with the rear surface of the cap as well as laterally towards its closed position.

Description

Rubner 51 Dec. 11, 1973 CLOSURE FOR CYLINDER LOCK MECHANISM [75] Inventor: Hugo G. Rubner, Milwaukee, Wis.

[73] Assignee: Briggs & Stratton Corporation,

Wauwatosa, Wis.

22 Filed: June 12,1972

211 Appl. No.: 262,014

[52] U.S. Cl. 70/455 [51] Int. Cl E05b 17/18 [58] Field of Search 70/455, 423, 44 B [56] References Cited UNITED STATES PATENTS 3,077,101 2/1963 Jacobi 70/455 2,932,186 4/1960 Mahrley 70/455 1,965,942 7/1934 Jacobi 70/455 Primary Examiner-Robert L. Wolfe Attorney-4m Milton Jones [57] ABSTRACT A lock cylinder rotatable in a lock body has a cavity in its front, closed by a cap having a key aperture aligned with a keyway in the cylinder. A shutter in the cavity slides to and from a closed position blocking the key aperture, guided by a tongue on its rear received in a groove in the bottom of the cavity. A coiled expansion spring reacting between the cavity wall and the tongue is inclined to the cylinder axis to bias the shutter forward into sealing engagement with the rear surface of the cap as well as laterally towards its closed position.

7 Claims, 6 Drawing Figures 1 CLOSURE FOR CYLINDER LOCK MECHANISM This invention relates to cylinder locks such as are used for automobile doors and rear compartment lids, and the invention is more particularly concerned with improved closure means for preventing the entry of moisture and dirt into the internal mechanism of such a lock through its key aperture.

The general object of the present invention isto provide an improved closure for the key aperture of a cylinder lock; and moreparticularly to provide improvements in a key aperture closure of the generaltype disclosed in US. Pat. No. 1,965,942, issued to E. N. Jacobi on July 10, 1934, wherein the key aperture is normally closed-by a shutter which flatwise underliesa cap on the lock cylinder and the shutter is cammed laterally away from its closed position by the nose of a key being inserted rearwardly into the cylinder.

In the closure disclosed in that patent the shutter is closely butslideably confined between a forwardly facing surface on the lock cylinder and a flat rearwardly facing surface of amp that is secured across the front of the cylinder, and such confinement of the shutter is relied upon to maintain sealing engagement between the front face of the shutter and the rear surface of the cap. However, it will be apparent that such sealing engagement will not be maintained after the mechanism has been actuated often enough to cause slight wear on the slidingly engaged surfaces, and will not be achieved in the first instance unless the mechanism is manufactured to very close tolerances. The shutter of the Jacobi patent also had a tendency to become jammed due to cocking thereof and consequent wedging of guide surfaces on its opposite ends with mating surfaces on the cylinder.

With these considerations in mind, it is an important object of this invention to provide a closure which is of the general character just described but which, however, isnot dependent upon the maintenance of close manufacturing tolerances or the avoidance of wear on sliding surfaces for maintaining the seal intended to be afforded by its shutter.

Hence, it is a purpose of this invention to provide a shutter type closurefor a cylinder lock mechanism wherein guide surfaces on the back of the shutter, spaced from and of greater length than its opposite ends, are engageable with mating surfaces on the cylinder to assure smooth sliding motion of the shutter between open and closed positions.

More specifically, it is an object of this invention to provide a shutter type closure for a cylinder lock mechanism, wherein a spring that urges the shutter laterally towards its closed position also servesto bias the shutter bodily forwardlyso that when the shutter is in its closedposition it is maintained in good flatwise sealing engagement with a cap on the front of the cylinder.

Another specific object of this invention is to reduce the cost of lock closures of the character described by so arranging and organizing the parts thereof as to make it possible for the closure to maintain a good seal without the necessity for holding unduly close tolerances in manufacture of the mechanism.

It is alsoa specific object of this invention to provide a shutter type closure for a cylinder lock mechanism shutter to its closed position to insure that the shutter will move bodily forwardly to the extent necessary to make good sealing engagement with a flat rear surface on a cap that is secured to the front of the cylinder.

With these observations and objectives in mind, the manner in which the invention achieves its purpose will be appreciated from the following description and the accompanying drawing which exemplify the invention.

The accompanying drawing illustrates one complete example of an embodiment of the invention constructed according to the best mode so far devised for the practical application of the principles thereof, and in which:

FIG. 1 is a front perspective view of a cylinder lock mechanism embodying the principles of this invention;

FIG. 2 is a sectional view of the front portion of the lock mechanism, taken on the plane of the line 2-2 in FIG. 1;

FIG. 3 is a view similar to FIG. 2, but with the key shown received in the lock cylinder and the shutter being held in its open position by it;

FIG. 3a is a fragmentary sectional view taken through FIG. 1 on the plane of the line 3a:-3a;

FIG. 4 is a sectional view taken on the plane of the line 44 in FIG. 1; and

.FIG. 5 is a sectional view taken on the plane of the lineS-S in FIG. 4.

Referring now more particularly to the accompanying drawings, the numeral 5 designates generally a lock mechanism embodying the principles of this invention, comprising, in general, a lock body 6 having a bore 7 and a concentric counterbore 8 that opens to its front. Rotatable in the bore is a lock cylinder 9 having at its front an enlarged diameter concentric head IOthat is received in the counterbore 8.

An axially extending keyway 11 in the cylinder opens to the front end. thereof, to receive a key 12 by which the cylinder can be rotated between defined locked and unlocked positions. As isconventional, the keyway is slot-like, narrow and deep, that is, elongated in one dimension transverse to the cylinder axis and rather narrow in its other dimension transverse to said axis. At its front, within its enlarged head 10, the cylinder has a forwardly opening cavity 13. The shape of this cavity is described in detail hereinafter, but at this point it should be noted that the cavity is in part defined by a generally forwardly extending surface 14 along one of the longer dimensions of the keyway, and that the cavity extends laterally from the other side of the keyway nearly to the edge portion of the: head 10. The cavity is closed by a cap 15 that fits over the front of the cylinder and has a flat rear surface 16 facing into the cavity.

The cap has in it a key aperture 17 which is axially in line with the keyway 11 and which is of a shape that corresponds to the shape of the keyway as viewed from the front end of the cylinder. Normally the key aperture 17 is closed and sealed by a shutter or closure element 18 that is disposed in the cavity 13, behind the cap 15. In the closed position of the shutter a flat front surface thereon is snugly engaged against the flat rear surface 16 of the cap, and the shutter extends across the key aperture to block it, with one edge of the shutter engaged against the forwardly extending surface 14 on the cylinder.

As the key is moved rearwardly toward the key aperture 17, its nose tends to engage in a rearwardly inclined depression 19 in the front surface of the cap, directly adjacent to the key aperture and at the same side thereof as the cavity surface 14. The depression 19 in the cap translates rearward thrust on the key into partially lateral motion and guides the key into the key aperture. On the front surface of the shutter, along its edge 20 that engages the cavity surface 14, there is a chamfer or bevel 21 that is rearwardly inclined oppositely to the inclination of the depression 19. The chamfer 21, in cooperation with the depression, causes the shutter to be cammed away from its closed position in consequence of rearward inserting movement of the key.

As viewed from the front of the cylinder the shutter 18 is substantially T-shaped, with a short stem portion 22 that projects laterally from its main body portion at the side of the latter remote from its above mentioned edge 20. The shutter is preferably a die casting, and it has a guide block 23 formed thereon to guide the shutter in its opening and closing motion. The block 23 is in the nature of a rectangular rearwardly and laterally projecting tongue that is received in a rather closely fitting forwardly opening groove 24in the cylinder, at the bottom of the cavity 13.

The block 23 extends lengthwise along the stem portion 22 of the shutter and across the rear of its elongated main body portion, intermediate the ends thereof; and the groove 24 in which the block is received extends laterally away from the keyway at the side thereof opposite the surface 14.

It is important to note that the opposite longitudinal sides 23' of the block provide elongated shutter guide surfaces which are slidingly engaged with the adjacent sides of the groove 24 in the cylinder so that the shutter is guided for translatory movement toward and from its closed position, along a path normal to the long dimension of the shutter. These surfaces on the shutter are located so as to be parallel and closely adjacent to a plane which contains the cylinder axis and which is crosswise of the main body portion of the shutter, and said surfaces are substantially longer than the end surfaces of the shutter.

Not only are the guide surfaces 23 longer than the end surfaces of the shutter, but they are spaced a substantial distance from said end surfaces. This construction assures against jamming or binding of the shutter by minimizing cocking of the guide block in the cylinder groove 24; and is far better than trying to guide shutter movement through the provision of guide surfaces at its opposite ends where slight tilting of the shutter is magnified and can easily result in binding or jamming of the shutter.

Attention is directed to the fact that the guide block 23 is formed with a pocket 25 which opens rearwardly and to the outer end of the stem portion 22. The pocket is closed at its end adjacent to the shutter edge 20, and it more or less houses the inner end portion of a coiled expansion spring 26 by which the shutter is urged toward its closed position. The inner end of the spring bears against a surface 27 at the closed end of the pocket 25, and its outer end bears against an opposing surface 28 on the cylinder at the radially outer end of the cylinder groove 24.

An important feature of the invention resides in the fact that the spring 26 is so oriented that its axis is inclined forwardly and radially inwardly relative to the cylinder axis, so that the spring not only serves to bias the shutter laterally towards its closed position but also urges it forwardly into firm sealing engagement with the flat rear surface of the cap. To insure that the spring will have such oblique orientation, the end surface 27 in the pocket 25, which provides one seat for the spring, and the surface 28 on the cylinder that provides the other spring seat, are correspondingly inclined. Furthermore, the groove 24 in the cylinder is formed with a forwardly opening well 30 in its bottom surface that is tapered to partially receive end coils of the spring and accommodate their oblique orientation.

If desired, pilots which project into the opposite ends of the spring can be provided by

small teats

31 and 32, formed on the shutter and cylinder respectively.

Because the guiding surfaces 23' on the block are elongated and spaced inwardly from the ends of the shutter, and since the axis of the spring is aligned with the center line of the shutter guide means that comprises the tongue or block 23 and the groove 24, and is also aligned with the center of the lateral thrust force that the key exerts against the shutter, there is no occasion for the shutter to be cocked or canted as it slides toward and from its closed position, and it does so with a smooth, easy action.

In cooperation with the oblique orientation of the spring, good sealing closure of the shutter is further insured by reason of the fact that the cylinder head has a surface 14 at the entrance to the key slot which diverges forwardly and radially outwardly, away from the surface 14, at an acute angle to the cylinder axis, as best seen in FIG. 3a; and the edge 20 of the shutter that engages said surface 14 is formed with correspondingly inclined surfaces 20. Hence, in the last stages of motion of the shutter to its fully closed position under the biasing force of the spring, these surfaces 14 and 20' cammingly engage one another to propel the shutter forwardly into snug engagement with the rear surface of the cap.

Those skilled in the art will appreciate that merely sealing the entrance to the key aperture 17 against the ingress of dirt and moisture is not in itself sufficient to insure against the entry of foregin matter into the interior of the lock mechanism. There is necessarily some clearance between the cylinder and the lock body, and it is essential that foreign matter be prevented from entering the lock mechanism through the clearance space. To that end the lock body is provided with an annular bezel 33 which can be clinched over a large diameter head portion 35 on its front. The radially inner portion of this bezel has a flat rearwardly facing circumferential surface that is snugly engaged by a flat, circumferential, radially outermost surface on the cap 15. As illustrated in FIG. 2, the cap has a concentric enlarged diameter portion behind the bezel to provide the forwardly facing surface that engages the bezel, and its smaller diameter front portion projects forwardly through the bezel.

To maintain a good seal between the bezel and the cap, a wave washer 37 is confined between the rearwardly facing shoulder on the enlarged head 10 on the cylinder and the opposing circumferential shoulder surface defined by the junction of the bore 7 and counterbore 8 in the body. The wave washer of course biases the cylinder forwardly in the lock body.

From the foregoing description taken with the accompanying drawings it will be apparent that this invention provides closure means for a cylinder lock mechanism of the type used on automobile doors, rear deck lids and the like, which closure means provides good assurance against entry of dirt and moisture into the lock mechanism without requiring maintenance of unduly close manufacturing tolerances, is substantially unaffected by ordinary wear, and features a smoothworking key actuated shutter for normally sealing the key aperture of the lock.

Those skilled in the art will appreciate that the invention can be embodied in forms other than as herein disclosed for purposes of illustration.

The invention is defined by the following claims:

1. A lock mechanism comprising a rotatable cylinder in which there is a keyway that opens to the front of the cylinder, said cylinder also having a forwardly opening cavity in its front, at one side of the keyway, a cap over the front of the cylinder closing the cavity except for a key receiving aperture in the cap that is aligned with the keyway, and a shutter in the cavity behind the cap, normally in closed position sealing the key aperture but movable laterally, in response to the rearward thrust of a key inserted into the key aperture, to an open position permitting the key to enter the keyway, said lock mechanism being characterized by:

A. the cap having a flat rear surface;

B. the shutter having a flat front surface slidingly and sealingly engageable with said front rear surface on the cap;

C. a tongue-like guide portion on the rear of the shutter, intermediate the ends thereof, and extending a substantial distance laterally to said one side of the keyway;

D. the cylinder having in its cavity a forwardly opening groove that extends to said one side of the keyway and in which the guide portion is guidingly received to constrain the shutter to substantially translatory motion toward and from its closed position;

E. a coiled compression spring in said groove, reacting between said end thereof and said guide portion on the shutter; and

F. cooperating means on the shutter and on the cylinder, in said cavity, engaging end portions of the spring to maintain it with its axis oriented obliquely to the cylinder axis so that the spring urges the shutter forwardly toward flatwise sealing engagement of its front surface with the rear surface of the cap as well as laterally toward its closed position.

2. The lock mechanism of claim 1, further characterized by:

G. said shutter being substantially T-shaped as viewed from the front of the cylinder;

H. said tongue-like guide portion extending along the stem of the T and substantially entirely across the shutter to afford guidance to the shutter in its movement to and from its closed position; and

. said guide portion having a groove therein which opens rearwardly and to said end of the forwardly opening groove in the cylinder, and in which said spring is received, said groove in the guide portion of the shutter beingclosed at one end to provide a seat for the spring.

3. The lock mechanism of claim 2, further characterized by:

J. the closure member having a teat projecting into said groove therein that serves as a pilot for an end portion of the spring.

4. The lock mechanism of claim 1, further characterized by:

another and with the spring to maintain the shutter' in firm flatwise sealing engagement with the cap.

5. The lock mechanism of claim ll wherein the cylinv der is rotatable in a lock body that has a bore and a forwardly opening counterbore, and wherein the cylinder has an enlarged head that is received in said counterbore, further characterized by:

M. an annular bezel on the lock body having a radially inner circumferential surface that flatwise overlies a radially outer forwardly facing circumferential surface on said cap; and

N. a wave washer confined between a forwardly fac ing shoulder in the lock body, defined by the junction of said bore and counterbore, and a rearwardly facing circumferential shoulder on the cylinder, defined by said enlarged head thereon, to bias the cylinder forwardly in the lock body and thus maintain sealing engagement between the cap and the bezel.

6. in a lock mechanism of the type having a rotatable cylinder with a cap on its front, a keyway therein opening forwardly through an aperture in the cap, and a shutter under the cap, at one side of the keyway, movable along a path crosswise of the cylinder axis toward and from an operative position closing the entrance to the keyway, the improvement which comprises:

A. said shutter having a body portion which is elongated in a direction substantially normal to the path of shutter motion and to the cylinder axis, and hav ing a surface at its front shaped to having mating engagement with the rear surface of the cap;

B. means on the rear of the shutter defining a block which is spaced from both ends of the shutter and which extends a substantial distance laterally from the body thereof in a direction away from the key way, said block being hollow so as to define a pocket which opens rearwardly away from the shutter and laterally away from the keyway;

C. the cylinder having a cavity in its front to accommodate the shutter, and a groove in the bottom of the cavity to accommodate said block on the rear of the shutter;

D. means defining said path of shutter motion, comprising elongated surfaces on each side of said block which are contiguous to and cooperate with similar surfaces on the sides of said groove, and other surfaces on the back of the block which are contiguous to the bottom of said groove;

E. a spring disposed partly in said pocket and acting upon the shutter to yieldingly urge it laterally toward the keyway to its operative position;

F. and means connecting the spring with a front portion of the cylinder and with said block on the rear of the shutter to hold the spring in an attitude such that it exerts force on the shutter urging it forwardly into sealing engagement of said front surface thereof with said rear surface of the cap.

7. The lock mechanism of claim 6, further characterized by a cam surface on that portion of the shutter which is adjacent to the keyway, and a mating cam surface on the cylinder adjacent to that side of the keyway which opposes the shutter,

said cam surfaces being cooperable with the spring to force the shutter tightly against the rear surface of the cap in consequence of movement of the shutter to its operative position.

} UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent 3 2 Dated December 11, 1973 Inventor(s) Hugo n r It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Columnlk line HO, "foregin" should read foreign-- Column 5 line 25 (claim 1, para B, line 2 "front" should read T--flat-- Signed and sealed this 9th day of April 19714. 7

(SEAL) Attestz EDWARD I LFLETGHERJR. C. MARSHALL DANN Atte sting Officer Commissioner of Patents FORM PC4050 uscoMM-oc man-P09 U.S, GOVERNMENT PRINTING OFiFlCE l9, O-Jl-334,

Claims

1. A lock mechanism comprising a rotatable cylinder in which there is a keyway that opens to the front of the cylinder, said cylinder also having a forwardly opening cavity in its front, at one side of the keyway, a cap over the front of the cylinder closing the cavity except for a key receiving aperture in the cap that is aligned with the keyway, and a shutter in the cavity behind the cap, normally in closed position sealing the key aperture but movable laterally, in response to the rearward thrust of a key inserted into the key aperture, to an open position peRmitting the key to enter the keyway, said lock mechanism being characterized by: A. the cap having a flat rear surface; B. the shutter having a flat front surface slidingly and sealingly engageable with said front rear surface on the cap; C. a tongue-like guide portion on the rear of the shutter, intermediate the ends thereof, and extending a substantial distance laterally to said one side of the keyway; D. the cylinder having in its cavity a forwardly opening groove that extends to said one side of the keyway and in which the guide portion is guidingly received to constrain the shutter to substantially translatory motion toward and from its closed position; E. a coiled compression spring in said groove, reacting between said end thereof and said guide portion on the shutter; and F. cooperating means on the shutter and on the cylinder, in said cavity, engaging end portions of the spring to maintain it with its axis oriented obliquely to the cylinder axis so that the spring urges the shutter forwardly toward flatwise sealing engagement of its front surface with the rear surface of the cap as well as laterally toward its closed position.

2. The lock mechanism of claim 1, further characterized by: G. said shutter being substantially T-shaped as viewed from the front of the cylinder; H. said tongue-like guide portion extending along the stem of the T and substantially entirely across the shutter to afford guidance to the shutter in its movement to and from its closed position; and I. said guide portion having a groove therein which opens rearwardly and to said end of the forwardly opening groove in the cylinder, and in which said spring is received, said groove in the guide portion of the shutter being closed at one end to provide a seat for the spring.

3. The lock mechanism of claim 2, further characterized by: J. the closure member having a teat projecting into said groove therein that serves as a pilot for an end portion of the spring.

4. The lock mechanism of claim 1, further characterized by: K. the cylinder having, at the opposite side of the keyway and extending along the longer dimension thereof, a surface that diverges forwardly and radially outwardly from the cylinder axis; and L. the shutter having a mating inclined surface engageable with said inclined surface on the cylinder upon movement of the shutter to its closed position, said inclined surfaces cooperating with one another and with the spring to maintain the shutter in firm flatwise sealing engagement with the cap.

5. The lock mechanism of claim 1 wherein the cylinder is rotatable in a lock body that has a bore and a forwardly opening counterbore, and wherein the cylinder has an enlarged head that is received in said counterbore, further characterized by: M. an annular bezel on the lock body having a radially inner circumferential surface that flatwise overlies a radially outer forwardly facing circumferential surface on said cap; and N. a wave washer confined between a forwardly facing shoulder in the lock body, defined by the junction of said bore and counterbore, and a rearwardly facing circumferential shoulder on the cylinder, defined by said enlarged head thereon, to bias the cylinder forwardly in the lock body and thus maintain sealing engagement between the cap and the bezel.

6. In a lock mechanism of the type having a rotatable cylinder with a cap on its front, a keyway therein opening forwardly through an aperture in the cap, and a shutter under the cap, at one side of the keyway, movable along a path crosswise of the cylinder axis toward and from an operative position closing the entrance to the keyway, the improvement which comprises: A. said shutter having a body portion which is elongated in a direction substantially normal to the path of shutter motion and to the cylinder axis, and having a surface at its front shaped to having mating engagement with the rear sUrface of the cap; B. means on the rear of the shutter defining a block which is spaced from both ends of the shutter and which extends a substantial distance laterally from the body thereof in a direction away from the keyway, said block being hollow so as to define a pocket which opens rearwardly away from the shutter and laterally away from the keyway; C. the cylinder having a cavity in its front to accommodate the shutter, and a groove in the bottom of the cavity to accommodate said block on the rear of the shutter; D. means defining said path of shutter motion, comprising elongated surfaces on each side of said block which are contiguous to and cooperate with similar surfaces on the sides of said groove, and other surfaces on the back of the block which are contiguous to the bottom of said groove; E. a spring disposed partly in said pocket and acting upon the shutter to yieldingly urge it laterally toward the keyway to its operative position; F. and means connecting the spring with a front portion of the cylinder and with said block on the rear of the shutter to hold the spring in an attitude such that it exerts force on the shutter urging it forwardly into sealing engagement of said front surface thereof with said rear surface of the cap.

7. The lock mechanism of claim 6, further characterized by a cam surface on that portion of the shutter which is adjacent to the keyway, and a mating cam surface on the cylinder adjacent to that side of the keyway which opposes the shutter, said cam surfaces being cooperable with the spring to force the shutter tightly against the rear surface of the cap in consequence of movement of the shutter to its operative position.