Combination locking device

A combination locking device is disclosed. The device includes a spindle which is axially movable, has recesses in it and locking protrusion on it. Around the spindle are annular dials with markers on the outside and associated recesses on the inside. Between each dial and the spindle are gate wheels which have apertures extending radially from the spindle to the dial. The gate wheels also have recesses matching the locking protrusions and when the protrusions and recesses are aligned and the spindle moved axially the gate wheels are rotatably fixed to the spindle. A plurality of locking balls is located within the apertures. Axial movement of the spindle selects device conditions including a code change condition where the locking balls are able to enter the spindle recesses freeing them from the dial recesses and allowing the dials to move around the gate wheels.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of GB Patent Application No. 1520045.4, filed on Nov. 13, 2015. The disclosure of the above application is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a combination locking device and relates particularly, but not exclusively, to a combination padlock.

BACKGROUND

The use of combination locks, such as padlocks, is well known and it is particularly desirable to have a lock which an operator can change the combination code when they wish to. An example of such a combination lock is disclosed in our earlier European patent application published under the number EP1837466. The combination lock disclosed therein uses clutch wheels, associated with each dial, to allow the combination to be changed. In a code change condition the clutch wheels are fixed and the dials can be moved over the clutch wheels so that a new code becomes associated with the unlocking position for the padlock. However, in order to ensure that the padlock does not become accidentally recoded it is necessary that the force required to move the dials relative to the clutch wheels is quite high and it is therefore necessary to use a tool to apply sufficient force to the dial. Although the tool required is simply a small rod, the rod supplied with the padlock or another suitable tool may not be conveniently available when the operator wishes to change the code.

In order to ensure correct alignment of the clutch wheel and dial the external surface of the former and internal surface of the latter are provided with a series of ridges and associated grooves, one for each number on the dial, which should be aligned with each other. However, it is possible, in principle, for the ridges and grooves to be incorrectly aligned when the dials are recoded. In this instance when an operator comes to try and unlock the padlock using the code they had intended the padlock will not unlock.

BRIEF SUMMARY

The present invention is directed to a combination locking device comprising: a housing; a spindle axially movable within said housing and having a plurality of recesses formed therein; a plurality of annular dials accessible through said housing for manipulation by an operator, the dials having a plurality of markers visible on an external surface thereof and having a plurality of recesses, associated with said markers, on an internal surface; a plurality of gate wheels each having at least one aperture extending therethrough providing a pathway between said spindle and said internal surface of said dials; a plurality of first locking members for allowing and preventing rotation of said spindle relative to said wheels; and a plurality of second locking members located within said apertures for allowing and preventing rotation of said wheels relative to said dials. The spindle is movable to produce a plurality of device conditions including a locked condition wherein said wheels are rotatable around said spindle and said apertures are not aligned with said spindle recesses so that said wheels are locked to said dials by said second locking members and a code change condition wherein said wheels are locked to said spindle by said first locking members and said apertures are aligned with said spindle recesses so that said second locking members can move thereby allowing said dials to move relative to said wheels.

DETAILED DESCRIPTION

By providing a combination locking device as set out above, the advantage is provided that the code of the locking device can be changed without the use of a tool. In particular, the interference fit between the clutch wheel and the dial in the prior art is removed with the second locking members providing a precise locked or unlocked condition between the gate wheel and the dial in the present invention. As a result, in the present invention, when in the code change condition the dial can freely rotate relative to the gate wheel. Furthermore, by having a dial recess associated with each marker on the dial ensures correct alignment between the gate wheels and dials therefore preventing an operator accidentally recoding the lock between two dial markers. In particular, the spindle is unable to move from the recode condition if the dial is not correctly aligned because the second locking member will not be able to move back into a recess in the dial until the dial is correctly aligned with the aperture in the gate wheel.

In a preferred embodiment the first locking members are fixed to said spindle.

In another preferred embodiment the first locking members comprise protrusions extending from said spindle which engage wheel recesses formed in said gate wheels to prevent said spindle rotating relative to said wheels in said code change condition.

By forming the first locking members as protrusions extending from the spindle the advantages provided that the spindle precisely determines the locked condition. Furthermore, this allows the unlock and recode positions to be the same.

The second locking members may comprise at least one sphere. The second locking members may also comprise a plurality of said spheres.

Forming the second locking members from one or more spheres provides the advantage that these locking members move very easily within the aperture and can easily move in and out of the recesses in the spindle and the dials.

In a preferred embodiment the second locking members comprise a non-magnetic metallic material.

By forming the second locking members from a non-magnetic metallic material the advantage is provided that a magnet cannot be used to determine the position of the aperture in the gate wheel which may assist an unauthorized person from determining the unlocking code.

In another preferred embodiment the spindle is movable between at least three positions including a locked position with said device in said locked condition, a code change position with said device in said code change condition and an unlocked position with said device in an unlocked condition.

By having three positions for the spindle to move between, and in particular having separate positions for the unlock and recode conditions, provides the advantage that the chances of accidentally recoding the lock whilst the devices unlocked are significantly reduced.

In a further preferred embodiment when said spindle is in said code change condition said device is also in an unlocked condition.

This provides the advantage that the mechanism for the lock having the unlock and code change conditions in the same spindle position is simpler.

Referring to the figures, a combination locking device10is shown. This example of a combination locking device is typically used for locking bicycles and referred to as a D or U lock. The mechanism of the combination locking device of the present invention is suitable for other combination locking devices including, but not limited to, padlocks and locking bolts.

The locking device10has a housing12and a U shaped shackle14. The locking mechanism16is contained substantially within the housing12, although parts of some of the components are visible and manipulatable through the housing. The components of the locking mechanism16include a spindle18which has an axis20. Spindle18is movable axially within the housing12and is maneuvered by manipulation by an operator of a handle22which extends through the housing12. The spindle18has a series (in this example four) recesses formed therein and generally labelled as24and the individual recesses specifically as24A,24B,24C and24D. Spindle18also has a series of first locking members, generally labelled as26, which are formed as pairs of protrusions26A and26A′,26B and26B′,26C and26C′,26D and26D′.

The locking device10also has a plurality of substantially annular dials which are generally labelled28and the individual dials specifically labelled28A,28B,28C and28D which are accessible through the housing12(seeFIG. 1) for manipulation by an operator. The dials28have a plurality of markers which are visible on an external surface30of each of the dials. In this example, and as is common practice, the dials28are marked with the reference numerals0to9making a total of 10 markers. An internal surface32of annular dial28is provided with a plurality of dial recesses34. Each dial has a recess34associated with each marker and as a result there are 10 recesses on the internal surface32of each dial28.

The dials28are, in use, positioned coaxially with spindle18and located between the dials28and the spindle18are a plurality of gate wheels which are generally labelled36and the individual gate wheels specifically labelled36A,36B,36C and36D. Each gate wheel36has at least one, and in the embodiments shown two, aperture is38and40extending therethrough perpendicular to the spindle axis20. When the gate wheels36are in use and located between the dials28and spindle18the apertures provide a pathway between the spindle and the internal surface32of the dials. Located within the apertures38and40are second locking members, in the form of locking balls42. The main purpose of the locking balls42is to selectively allow and prevent rotation of said wheels relative to said dials. In the embodiment shown a pair of locking balls42is located in each aperture38and40and the sum of the diameters of the pair of locking balls42is greater than the radial distance from an inner surface44of gate wheel36to an outer surface46of gate wheel36. In other words, the pair of locking balls42does not fit entirely within the aperture38or40and must extend partially either radially inward or radially outward of the inner and outer surfaces44and46of gate wheel36.

Also formed in the gate wheels36are pairs of recesses which are generally referred to by reference numeral48. These gate wheel recesses are associated with the protrusions/first locking members26in the spindle18and the gate wheel recesses48are specifically labelled48A and48A′,48B and48B′,48C and48C′ and48D and48D′. The association between the protrusions26and the recesses48(for each pairing labelled with the suffix A, B, C and D) are such that in one rotational position around axis20the protrusions26and recesses48are aligned so that the spindle18can move axially with the protrusions26entering the recesses48. The protrusions26and recesses48are positioned so as not to be opposite each other around axis20and this rotational asymmetry ensures that there is only one correct position in which the spindle18can move relative to the gate wheel36. The protrusions26and recesses48need not be in the same position for each gate wheel. However in the interests of simple manufacture it is preferable that they are identical.

Operation of the locking device10will now be described. The spindle18is axially movable relative to the housing12by a sliding motion under the control of handle22. A guide rod50which is located in a guide slot52in housing12ensures linear movement of the spindle and also prevents its rotation. The spindle18is able to move between at least two positions, those shown inFIGS. 6 to 8andFIGS. 9 to 11. The device10has three operating conditions namely a locked condition, an unlocked condition and a recode condition. These conditions are selected by movement of the spindle18and the position of the spindle may relate to one or more conditions. For example, in the position illustrated inFIGS. 6 to 8, hereinafter referred to as the first position, the device is in the locked condition. In the position illustrated inFIGS. 9 to 11, hereinafter referred to as the second position, the device is in both the unlocked and recode conditions.

In the first position, locked condition, as illustrated inFIGS. 6 to 8, the locking balls42are located within the apertures38and40and the outermost locking balls extend into two of the dial recesses34. The inner locking balls engage the spindle18and do so on a portion of the spindle18that does not include a spindle recess24or a protrusion26. This portion of the spindle provides an annular surface for the inner locking ball to abut and is most clearly seen as the portions of the spindle18immediately to the right of each dial28as seen inFIG. 9. With the locking balls42pressed into engagement in the dial recesses34the gate wheel36is locked to the dial28and these pairs of components must rotate together around the spindle18.

Also in the first position, the protrusions26are located to the left of their dials28, that is protrusions26A and26A′ are located to the left of dial28A and protrusions26B and26B′ are located to the left of dial28B etc. As can be seen fromFIG. 7the protrusions28are not aligned with the wheel recesses48and as a result any attempt to move the spindle18to the right (as shown inFIGS. 6 and 8) is prevented by the protrusions26engaging the gate wheels36. If each gate wheel36is rotated so that both the protrusions26are aligned with the gate wheel recesses48, by rotation of each dial24to the correct marker numeral, then the spindle can move to the right so that the protrusions26enter the gate wheel recesses48. The end of spindle18adjacent the guide rod50acts on a release mechanism (not shown) which releases the shackle14allowing the locking device10to be opened. Details of the workings of the shackle release mechanism do not form part of the invention and will be familiar to persons skilled in the art.

With the spindle18now moved to the right the device is in the second position, as illustrated inFIGS. 9 to 11. With the protrusions26located within the gate wheel recesses48the gate wheels36are unable to rotate around the spindle18. However, when the protrusions26are within the gate wheel recesses48the apertures38and40become aligned with the spindle recesses24. As a result, the locking balls42are able to move radially inwards into the spindle recesses24. Because the spindle recesses24are a similar depth to the dial recesses34the locking balls42are able to move from the dial recesses thereby unlocking the dials28from fixed engagement with the gate wheels36. The dials28can therefore be rotated around the gate wheels36and this recodes the locking device10. Once each of the dials28has been positioned to the new desired code the handle22can be moved back in a leftwards direction returning the device to the first position and locked condition and the new code has been set. If the dial recesses34are not correctly aligned with the apertures38and40the spindle18will not be able to move leftwards as the locking balls42abut the internal surface32of the dial28and will not be able to move radially outwards from the spindle recess24.

If the dial recesses34are correctly aligned with the apertures38and40and the spindle18is moved in a leftwards direction, the spindle recesses24will no longer be in alignment with the apertures38and40the gate wheels. The curved cam surface of the spindle recess24pushes the innermost locking balls42in a radially outward direction which pushes the outermost locking balls in the same direction causing them to re-enter the dial recesses34. The spindle18prevents radially inward movement of locking balls and therefore the gate wheels36are locked to the dials28. It is desirable that the spindle18is biased towards the first position by biasing means, in the form of a suitable spring (not shown).

In an alternative embodiment the spindle18may be moved between three positions with each position relating to a different locked condition. For example, a central position may relate to a locked condition with movement of the spindle in one direction moving to an unlocked condition (assuming the dials are correctly aligned to the locking device code) and movement in the other direction moving the spindle to a recode condition (also assuming the dials are correctly aligned with the locking device code).

It will be appreciated by persons skilled in the art that the above embodiments have been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departure from the scope of the protection which is defined by the appended claims. For example, the pair of locking balls42could be replaced by a single locking ball by varying the size of the locking ball and/or the radial thickness of the gate wheel36as measured from the inner surface44to the outer surface46. Furthermore, the locking ball could be replaced with an alternative second locking member in the form of a non-spherical locking member, such as a rod, which is able to slide in the aperture is38and40in the gate wheel. The thickness of the locking member or combined thickness of locking members sitting within an aperture should be slightly larger than the radial thickness of the gate wheel and should be approximately equal to the radial thickness of the gate wheel plus the depth of one of the dial recesses and the spindle recesses. It is also the case that number of protrusions and associated gate wheel recesses can be varied from two. One is possible and three or more can be used as long as they are positioned with rotational asymmetry around the spindle.

Furthermore, the locking member described above can be used on other locking devices including padlocks and locking bolts. By way of example, the mechanism could be incorporated into a device similar to that disclosed in our previously mentioned publication EP1837466, details of which are hereby incorporated by reference. The mechanism of that padlock can be amended by replacing the spindle, digit clutch wheels, clutches and dials with a similar spindle but with recesses, gate wheels, locking balls and dials described above.