US3548621A - Cylinder lock - Google Patents

Description

Dec.22,;1970 C. RQSSETT. 3,548,62fl

CYLINDER LOCK Filed July 3, 1968 fiql L1 T PRIOR ART 3 1 United States Patent CYLINDER LOCK Charles Rossetti, Avenue du Servan 24, Lausanne, Switzerland Filed July 3, 1968, Ser. No. 742,414 Claims priority, application Switzerland, July 7, 1967,

Int. Cl. Eb 9/08 US. Cl. 70-370 2 Claims ABSTRACT OF THE DISCLOSURE A cylinder lock comprising a casing having a bore to receive a rotatable cylinder. An entry part of the bore and an end part of the cylinder have complementary conical bearing surfaces and the cylinder is located axially in the casing by a resilient ring engaged in facing grooves formed in bearing surfaces. The lock is assembled by threading the ring onto the cylinder then pushing the cylinder, into the bore to expand or contract the ring so that it can enter the grooves, the resiliency of the ring thereafter holding the lock together.

The present invention relates to cylinder locks.

Known locks comprise a cylinder or barrel rotating in a bore in a lock casing and carrying a plurality of locking elements in the form of pins or the like adapted to engage in corresponding recesses in the bore in the casing. If the locking members carried by the cylinder are to be in alignment with the corresponding recesses in the casing, the cylinder must be accurately located axially in the bore.

In known locks of this kind the cylinder has at one end a bearing surface of enlarged diameter, which abuts the lock casing and is formed at its other end with a groove receiving a resilient ring or clip which abuts the opposite end of the lock casing.

This arrangement has a number of disadvantages. The lock casing must be manufactured accurately to length, as must the corresponding cylinder part between the enlarged-diameter bearing surface and the clip-receiving groove. The recesses in the cylinder and in the casing for the locking elements must also be accurately positioned relatively to the end faces of the pins, and such end faces are readily distorted. The resulting close rnachining tolerances make manufacture complex and costly. Also, the resilient ring is disposed outside the casing and is readily accessible, and so the cylinder can be removed by unauthorized people who may not always be able to provide a satisfactory reassembling.

It is an object of the invention to provide a lock which is of greatly simplified manufacture and which has the further advantage of preventing any disassembling of the cylinder.

It is yet another object of the present invention to provide a cylinder lock comprising a cylinder rotatably mounted in a bore in a lock casing, the cylinder being located axially in the casing by a resilient ring which is received in co-operating facing grooves in the casing and the cylinder.

With these and other objects in view which will become apparent in the following detailed description, the present invention will be clearly understood in connection with the accompanying drawing, in which:

FIG. 1 is a fragmentary elevational view of a known lock;

FIG. 2 is a view similar to that of FIG. 1 of a lock according to the present invention;

FIG. 3 is an enlarged fragmentary view showing some details of the lock shown in FIG. 2;

FIGS. 4 and 5 are views similar to that of FIG. 3

ice

showing the phases of assembling the cylinder in the lock casing;

FIGS. 6, 6a, 7 and 7a are diagrammatic views showing phases in the manufacture of the lock cylinder and casing, and

FIG. 8 is a fragmentary view of another embodiment of the present invention.

In the known lock shown in FIG. 1, a cylinder 1 rotates in a bore 2 of a lock casing 3. For axial location of the cylinder 1 in the bore 2. The cylinder 1 has at its left-hand end a head 4 which is of larger diameter than the rest of the cylinder 1 and which abuts the casing 3, while at its right-hand end the cylinder 1 is formed with a groove 5 receiving a resilient ring 6 abutting the opposite end of the casing 3.

The axial play of the cylinder in the casing (which play is necessary if the cylinder 1 is to rotate satisfactorily) is shown to an exaggerated scale by the reference T and depends upon the accuracy of three dimensions, namely the length L1 of the cylinder 1, the length L2 of the casing 3 and the axial width E of the ring. The bearing surfaces and end faces determining the lengths L1, L2 and machined by different tools, and so the manufacture of these items to close tolerances requires the use of accurate machines with careful setting-up and many inspections.

In the lock according to the invention, shown in FIG. 2, a cylinder 11 rotatable in a bore 12 of a lock casing 13 is located axially therein by a resilient ring 14 received in cooperating facing grooves 15 and 16 in the casing 13 and cylinder 11 respectively (FIG. 3). The two grooves 15 and 16 have, with allowance for a very slight clearance, the same axial width B as the resilient ring 14. The grooves 15 and 16 and the ring 14 are all rectangular in cross-section.

Each of the two grooves 15 and 16 can be machined by means of a cutting tool which forms the two opposite side surfaces of the groove simultaneously, with the result that the groove has the same axial width as the tool. Grooves of exactly the required width can therefore be readily made, with the result that the cylinder engages axially in the casing without excessive axial play, although no costly tooling is involved.

As can be seen in FIG. 3, the grooves 15 and 16 are disposed at the base of matching frustoconical bearing surfaces 17 and 18 of the bore and of the cylinder.

As FIG. 4 shows, the maximum diameter D of the bearing surface 17 which forms a frustoconical entry part of the bore is slightly larger than the outer diameter D1 of the resilient ring 14 when the same is in an unstressed state. The inner diameter d1 of the ring 14 is approximately equal to the diameter of the cylinder, and so the ring 14 can readily be threaded thereon.

When the cylinder with the ring on it is introduced into the bore, the ring extends into the conical entry part 17, to be compressed thereby to a smaller diameter in proportion as the cylinder is advanced through the bore. After having passed over the conical part 17 (FIG. 5), the temporarily compressed ring 14 drops into groove 15 and, because of its resilience, expands into the groove 15. However, the diameter D2 of the bottom of the groove 15 is smaller than the external diameter D of the ring when the same is in its unstressed condition so that the radially inner part of the ring stays engaged in the groove 16. The cylinder is therefore retained in the lock casing by the now inaccessible resilient ring 14.

In the embodiment shown in FIG. 8, a resilient ring 21 which is approximately square in cross section is first placed in a groove 22 in a conical entry 23 of a lock casing bore. A cylinder 24 is then introduced into the ring 21, then pushed into the bore in the casing so that a conical part 25 of cylinder 24 opens the ring 21, the latter engaging in a groove 26 in the cylinder so as to locate the same axially. In this embodiment the major diameter D3 of the matching complementary parts is greater than the external diameter of the ring when the same is in its unstressed condition, and the minor diameter d3 of the conical parts is smaller than the internal diameter of the ring when the same is in its unstressed condition to facilitate introduction of the ring into the casing and of the cylinder into the ring.

FIGS. 6 and 6a are diagrammatic views showing how the lock is made using cutting tools 30 and 31 to turn the grooves 15 and 16 in the casing 13 and cylinder 11. Apart from tool Width, which must be accurate, no accuracy is required in these operations and the axial position of the grooves can readily vary within wide tolerances.

The apertures for receiving the locking pins are drilled subsequently in the manner shown diagrammatically in FIGS. 7 and 7a. The casing 13 and the cylinder 11 are disposed on drilling jigs having projections N which engage in the previously formed grooves 15 or 16. Consequently, the holes drilled via apertures 34 in the drilling jigs are accurately located axially relatively to the grooves 15 and 16 which are disposed facing one another in the assembled lock.

Axial location of the cylinder is therefore the result of very simple steps, and the grooves can be machined independently of article length, which may vary. The same drilling jigs can therefore be used to manufacture cylinders of various lengths.

The resilient ring is e.g. a steel ring split radially by a saw cut. Alternatively, the resilient ring can be a loop of spring wire or any other element adapted to engage simultaneously in the two facing grooves.

In a variant, the cylinder can be formed with slots for I claim:

1. A cylinder lock comprising a lock casing having a bore therein and a plurality of radial holes,

a cylinder rotatably mounted in said bore,

a plurality of cylindrical locking pins carried by said cylinder and engaged in corresponding of said radial holes in said bore when said cylinder is in a locked position, said locking pins and radial holes having the sam diameters,

said casing 'nd said cylinder having cooperating facing grooves, and

a resilient ring received in said cooperating facing grooves, said resilient ring being of the same axial width as that of said facing grooves and exclusively locating said cylinder in said bore in an accurate axial position, so that said locking pins are properly positioned in said corresponding radial holes in said bore,

said bore of said casing and said cylinder defining complementary frustoconical surfaces, and

said cooperating facing grooves being in said frustoconical surfaces.

2. The cylinder lock, as set forth in claim 1, wherein said metallic resilient ring is massive and its outer diameter and inner diameter in the unstressed state thereof are smaller and larger, respectively, than the largest and smallest diameters, respectively, of said frustoconical surfaces.

References Cited UNITED STATES PATENTS 1,741,093 12/1929 Briggs 70367 1,772,747 8/ 1930 Croning 70-252 2,020,260 11/1935 Larsson 70-370 2,111,511 3/1938 Lowe et al. 70221 2,761,111 8/1956 Klostermann 33992 3,316,742 5/ 1967 Wellekens 70-379 MARVIN A. CHAMPION, Primary Examiner R. L. WOLFE, Assistant Examiner US. Cl. X.R. 70 3s1, 451

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