BACKGROUND OF THE INVENTION Double cylinder locks are well known, which may be locked and unlocked from opposite sides of a door or window. Such a lock, commonly referred to as a Euro profile cylinder, typically comprises two, separately actuable, axially aligned cylinders, each of which is connected to a cam located in a gap between the cylinders. A key may be inserted in either cylinder to throw the cam and actuate thereby a locking bolt or other locking mechanism.

Double cylinder locks may comprise a unitary body. However, since there is a large variety of door widths, a locksmith may need to maintain a large inventory of unitary-body double cylinder locks to fit all the widths. For this reason and others, some companies have developed double cylinder locks with adjustable lengths.

For example, US Patent 5,479, 801 to Keller describes a"web"-a piece used to adjust the length of a double cylinder lock. The double cylinder lock comprises two barrels in axial alignment on either side of the web. The web is engageable with internal end parts of the barrel elements. The web has a plurality of holes, which may be selectively aligned with mounting holes on the barrel elements and secured with fasteners.

SUMMARY OF THE INVENTION The present invention seeks to provide an improved and novel cylinder lock whose length may be extended or adjusted, as is described more in detail hereinbelow.

The cylinder lock of the present invention, which may be single or double, may be easily manufactured and assembled at significantly reduced cost compared to prior art locks.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which: Figs. 1 and 2 are simplified exploded and pictorial illustrations, respectively, of a cylinder lock, constructed and operative in accordance with an embodiment of the present invention; and Fig. 3 is simplified pictorial illustration of a connecting element for the cylinder lock of Figs. 1 and 2, constructed and operative in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Reference is now made to Figs. 1 and 2, which illustrate a cylinder lock 10, constructed and operative in accordance with an embodiment of the present invention.

Although the cylinder lock 10 will be described as a double lock, it is appreciated that the present invention may comprise a single or double cylinder lock.

Lock 10 preferably includes a first cylinder housing 12 in which a first pin tumbler 14 is rotatably disposed. Lock 10 preferably also includes a second cylinder housing 16 in which a second pin tumbler 18 is rotatably disposed. Each pin tumbler 14 or 18 may be rotated by insertion of a suitable key (not shown) in a key way 20.

Alternatively, instead of key-operated pin tumblers, rotors actuable by a turn-knob may be employed. The term"rotor"is used throughout the specification and claims to denote pin tumblers, knob-actuable rotors and any other suitable rotatable element.

Each pin tumbler 14 or 18 may be coupled to a central cam 22. For example, pin tumblers 14 and 18 may engage clutch elements, collectively designated by reference numeral 24, which in turn engage cam 22. As is known in the art, clutch elements 24 are designed such that upon insertion of a key in first pin tumbler 14, first pin tumbler 14 may be rotated together with its clutch elements 24 to rotate cam 22, while at the same time the clutch elements 24 of second pin tumbler 18 do not engage cam 22. Conversely, upon insertion of a key in second pin tumbler 18, second pin tumbler 18 may be rotated together with its clutch elements 24 to rotate cam 22, while at the same time the clutch elements 24 of first pin tumbler 14 do not engage cam 22.

First and second cylinder housings 12 and 16 may be attached to one another by means of a connecting element 26, which is also illustrated in Fig. 3. Connecting element 26 may comprise an elongate bar with a plurality of housing attachment holes 28 formed therein. The housing attachment holes 28 may be formed on opposite sides of a centerline 30 (Fig. 3) of connecting element 26. The housing attachment holes 28 may or may not be symmetric about centerline 30. The housing attachment holes 28 may or may not be equally spaced from one another. The housing attachment holes 28 may be of the same or different sizes. The housing attachment holes 28 may be through holes or may be blind holes, and they may or may not be threaded.

Connecting element 26 may comprise a hub 32 with a lock mounting hole 34 formed therein. Hub 32 may be centrally located on centerline 30. Lock mounting hole 34 may be used to mount cylinder lock 10 in a door or window with suitable fasteners (not shown). A profile element 36 may be snugly secured over hub 32, such as but not limited to, by means of a snap fit. For example, as seen in Fig. 3, profile element 36 may comprise one or more lugs 53 which snap fit into one or more recesses 55 formed in connecting element 26.

Profile element 36 may be used to give the assembled cylinder lock 10 the standard look of a Euro profile cylinder, although the invention is not limited to a Euro profile.

Ends of connecting element 26 may fit into mortises 38 formed in first and second cylinder housings 12 and 16. The housing attachment holes 28 may be aligned at a selected position with one or more mounting holes 40 formed in each of first and second cylinder housings 12 and 16. Fasteners 42, such as but not limited to, screws or rivets that pass through holes 40 and 28, may be used to secure connecting element 26 to first and second cylinder housings 12 and 16.

Any number of spacer elements 44, preferably shaped with the same or similar contour of first and second cylinder housings 12 and 16, may be positioned between cam 22 and first and second cylinder housings 12 and 16. The number and size of the spacer elements 44 depends on the desired finished length of the assembled cylinder lock 10.

Spacer elements 44 may be formed with mortises 46 to accommodate connecting element 26. Gap-filling elements 48 may be fitted in mortises 38 or 46, if needed. Gap-filling element 48 may be formed with a chamfer 56 that abuts a chamfer 58 formed on connecting element 26 (seen best in Fig. 1), which may help hold gap-filling element 48 in place.

Profile element 36 may comprise one or more protrusions 50 (seen best in Fig. 3) that fit into mortises 38 or 46, which may help form a snug assembly.

It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention includes both combinations and subcombinations of the features described hereinabove as well as modifications and variations thereof which would occur to a person of skill in the art upon reading the foregoing description and which are not in the prior art.