The present application claims priority to United Kingdom Patent Application No. 2218134.1, filed Dec. 2, 2022. The entirety of the aforementioned priority application is incorporated herein by reference in its entirety.
The present invention relates to a combination locking mechanism and relates particularly, but not exclusively, to a strap lock that is secured via a rotary combination dial mechanism.
Rotary combination dial locks are widely used for securing lock mechanisms such as a strap locks, padlocks or lock boxes. Combination locks are in general a lightweight but reliable method to secure items without the need for keys.
An example of this is using a combination lock connected to a strap for securing a bike to a bike rack. As a combination dial can contain vast numbers of numerical combination variations the user can be assured that their bike should be safe. However, there are a number of individuals who can unlock the strap lock without knowing the combination by understanding how the lock sounds or feels when a digit is correctly entered. This decreases the level of security of the lock and increases the level of uncertainty a user may feel when they are wanting to secure their personal possessions.
Preferred embodiments of the present invention seek to overcome or alleviate the above-described disadvantages of the prior art.
According to an aspect of the present invention there is provided a lock mechanism comprising a clasp and a clasp receiver for engaging and locking with each other, the clasp receiver comprising: a body; a latch member biased in a first direction by a first biasing member, wherein a boundary between said latch member and the body defines a shear line and one of the latch member and the clasp having at least one protrusion for selectively engaging the other of the latch member and the clasp in locking engagement; a plurality of first pins biased in a second direction transverse to the first direction by respective second biasing members, wherein the pins move between a locked condition, wherein the pins straddle the shear line, and an unlocked condition, wherein the pins do not straddle the shear line; and a plurality of combination dials at least partially contained in the body, the combination dials comprising a digit portion and a pin receiver portion, wherein each said combination dial has an unlocked rotational position in which the pin engages a first recess in the pin receiver moving the pin to the unlocked condition.
By providing a combination lock which utilizes pins straddling a shear line and connects a clasp to a clasp receiver, the advantage is provided a loop lock, such as a strap lock, chain lock or padlock, can be provided with an improved combination lock utilizing pins straddling the shear line. This type of combination lock, because it works differently from standard combination locks, is harder to overcome and presents different challenges to anyone attempting to interfere or open the lock without knowing the combination.
In a preferred embodiment the pin receiver portion further comprises a first aperture and at least one fixing device extending through the first aperture for securing the digit portion to the pin receiver portion. Having a fixing device for securing every clasp receiver to the digit portion increases the level of security for the combination device as all the fixing devices would have to be damaged or forcefully removed.
In another preferred embodiment the clasp receiver further comprises a blocking device biased in a third direction by a third biasing member, wherein when all the first pins are in the unlocked condition the blocking device is movable to allow access to the digit portion and enable manipulation of the fixing device and release the digit portion from the pin receiver portion thereby allowing the combination of the lock to be changed.
Unlike other combination dial locks this blocking device prevents access to the fixing member such as a screw when in a locked condition. This prevents any unlawful tampering with the fixing member and therefore avoids someone, other than the owner, changing the combination or unlocking the device. The blocking device also acts as a barrier to stop moisture or rain getting into the mechanism from the underside preventing rust build up around the fixing member and other moving parts such as the latch member which could cause it to get stiff or unusable.
In a further preferred embodiment at least one second pin is biased by a fourth biasing member in a fourth direction towards said combination dial wherein said combination dial comprises at least one second recess corresponding to each digit of said digit portion for engaging said second pin and said fourth biasing members act on said second pins with greater force than said second biasing members on the first pins.
Having a second pin acting on the digit portion for every turn of the digit portion masks the feeling and the sound of the first pin moving into place in the pin receiver. This provides an extra security feature and would deter someone tampering with the combination lock because it is more difficult to feel or hear the movement of the first pin. The recesses also act as an additional grip for the user when they are turning the digit portion.
In another preferred embodiment the second recesses are located on the digit portion. In an additional preferred embodiment, the first pins are split pins. In a preferred embodiment a pushing member is used to control the position of the latch member to release the clasp when all the pins are in an unlocked condition.
According to another aspect of the present invention there is provided a lock comprising: a mechanism as set out above; and a flexible connector connecting between the clasp and the clasp receiver, wherein the flexible connector comprises a strap.
In a further aspect of the present invention there is provided a lock mechanism comprising: a body; a latch member biased in a first direction by a first biasing member, wherein a boundary between the latch member and the body defines a shear line; a plurality of first pins biased in a second direction transverse to the first direction by respective second biasing members, wherein the first pins move between a locked condition, wherein the first pins straddle the shear line, and an unlocked condition, wherein the first pins do not straddle the shear line; a plurality of combination dials at least partially contained in the body, the combination dials comprising a digit portion and a pin receiver portion having a first aperture, wherein cach combination dial has an unlocked rotational position in which the first pin engages with the pin receiver moving the first pin to the unlocked condition; at least one fixing device extending through the first aperture for rotationally securing the pin receiver portion to the digit portion; and a blocking device, wherein when all the pins are in an unlocked condition the blocking device is movable to allow the second aperture to align with the first aperture of the pin receiver portion and enable manipulation of the fixing device to release the digit portion from the pin receiver portion thereby allowing the combination of the lock to be changed.
By providing fixing devices for each of the combination dials and a blocking device the advantage is provided that the lock can only be changed by accessing them through the space created by the movement of the blocking device. Thus, a very secure mechanism, utilizing materials such as hardened steel for the blocking device, can be provided to prevent interference with the dials.
In a preferred embodiment the blocking device is biased in a third direction. In a preferred embodiment of the present invention the pins comprise split pins. In another preferred embodiment of the present invention a pushing member is used to control the position of the latch member to release the clasp when all the pins are in an unlocked condition.
In a further aspect of the present invention there is provided A lock mechanism comprising: a body; a latch member biased in a first direction by a first biasing member, wherein a boundary between the latch member and the body defines a shear line; a plurality of pins biased in a second direction transverse to the first direction by respective second biasing members, wherein the pins move between a locked condition, wherein the pins straddle the shear line, and an unlocked condition, wherein the pins do not straddle the shear line; a plurality of combination dials at least partially contained in the body, the combination dials comprising a digit portion and a pin receiver portion having a first aperture, wherein each the combination dial has an unlocked rotational position in which the first pin engages with a first recess of the pin receiver moving the first pin to the unlocked condition; and at least one second pin biased by a fourth biasing member in a fourth direction towards the combination dial wherein the combination dial comprises at least one second recess corresponding to each digit of the digit portion for engaging the second pin.
The fourth pins are used to prevent there being a perceivable difference in the feeling of the first pins engaging the correct position in the dial. In a preferred embodiment of the present invention the fourth biasing member acts on the second pin with a greater force than the second biasing member on the first pin. In another preferred embodiment of the present invention the at least one second recess is located on the digit portion. In a further preferred embodiment of the present invention the first and second pins comprise split pins.
Preferred embodiments of the present invention will now be described, by way of example only, and not in any limitative sense with reference to the accompanying drawings in which:
Initially referring to
Even though the button 36 is an integral part of the latch member 22 in the above embodiment, it could be a replaced by a separate button that would act indirectly with the latch member. This could be achieved via levers attached to the button and latch member 22. Once the button is pressed it would indirectly move the latch member 22 via these levers.
Located at the boundary between the latch member 22, and the body 20 are a plurality of first split pins 38 being biased by a second biasing member 48 in the form of a helical spring in a second direction D2. The first split pins 38 have a first left portion 40 and first right portion 42, forming a first coupling joint 44 when together. When in an unlocked condition the first right portion 42 is located within a first pin recess 46 within the latch 22 and the first left portion 40 is located within a first pin aperture 47 within the body 20. Furthermore, the first pins 38 do not straddle the shear line 26 and the coupling join 44 is in line with the shear line, allowing the latch 22 to move when the button 36 is pressed. When in a locked condition the first split pins 38 straddle the shear line 26, therefore the coupling join 44 is not in line with the shear line and the latch cannot move when the button 36 is pressed. When in a locked condition a proportion of the first left portion 40 crosses the shear line 26 thereby stopping the latch 22 from being moved when the button 36 is pressed. It is noted that in the above example split pins have been described. However, non-split pins with a longer biasing member that engages the end of the non-split pin could be used. In this instance, the shear line would be defined by the join between the non-split pin and the biasing member (spring).
Contained within the body 20 are a plurality of combination dials 50, in
The blocking device 68 is made from a hardened steel and biased in a third direction D3 by third biasing members 74 in the form of a helical springs towards the latch member 22. It should be noted that even though D3 is parallel to D2 (although acting in the opposite direction), if the shape of the body was different or larger the springs could act on the blocking device transversely or at an angle relative to D2. The blocking device 68 also includes a series of finger recesses 74, with each finger recess corresponding to a single first aperture 58 on the pin receiver portion 54. That is, the transverse distance between each of the finger recesses 74 is the same as the transverse distance between each of the first apertures 58. This ensures that when the finger recesses 74 and first apertures are lined up, with the first apertures 58 above the finger recesses 74, they create unrestricted access between the base of the blocking device and the first apertures 58 to the grub screws 60. In between each finger recess 74 is a finger protrusion 76. These finger protrusions 76 are inserted part way into the third biasing members 72 so to move the blocking device 68 smoothly when in an unlocked condition. When in a locked condition the blocking device 68 is prevented from movement by the clasp 16. In particular, a blocking device extension 69, which is fixed to the blocking device 68, engages with the clasp 16 when the clasp 16 to prevent any movement of the blocking device until the mechanism 10 is unlocked and the clasp has been removed.
To allow the user access to the blocking device 68 there is a third aperture 78 at the base of the housing 24 that aligns with the finger recesses 74 of the blocking device when in an unlocked condition. When not in use this aperture 78 is concealed by a plug 79 that is removable.
The digit portion 52 also engages a second split pin 80. This second split pin 80 also includes a second right and left portion also forming a second coupling joint 82 when together. The second right portion 84 is adjacent a fourth biasing member 88 in the form of a spring located with the latch 22, biasing the second split pin 80 in a fourth direction D4 towards the digit portion 52. The second left portion 86 has a head that fits the shape of the third recess 70 of the digit portion 52. When the head of second split pin 80 engages the third recess 70, the second split pin does not straddle the shear line 26, between the latch 22 and the body 20, allowing the second coupling joint 82 to align with the shear line 26. With every turn of the digit portion 52 from one number to the next the head of the second split pin 80 will always have a recess to engage and therefore the second coupling joint 82 will align with the shear line 26. When the digit portion is moved in between two numbers (that is, the head of the second split pin is not engaging a third recess 70) the second coupling joint 82 will not be aligned with the shear line 26. Therefore, the second split pin 80 will be straddling the shear line preventing the latch 22 from moving.
These second split pins 80 are used as decoy split pins and are not important for locking the locking mechanism. The fourth biasing members 88 are stronger acting helical springs compared to the second biasing members 48 acting on the first split pins. When the digit portions 52 are turned from one number to the next, regardless of whether the combination is right the second split pins will always enter into a third recess 70, masking the sound and feel of the first split pins 38 entering into the first recess 56 of the pin receiver portion 54.
It should again be noted that even though D4 is in the same planar direction as D2 in the embodiment the second split pin could also be rotated or extend from another part of the body. For example, if the body 20 was slightly larger or a different shape, the second split pin 80 could be located transverse to the digit portion.
Referring again to
Operation of the locking mechanism will now be described. It should be noted that in
Once the combination 1-2-3-4 is entered into the combination dials 50 the first split pins 38 will no longer be straddling the shear line 26. Allowing movement of the latch 22 and therefore the release of the clasp 16 from the clasp receiver 18.
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, although the above embodiment is being described as a strap lock it could be used in other situations such as a locking seatbelt or pram. The combination dial could be connected to a separate strap as opposed to being connected to the strap and the clasp receiver.
A further example is the biasing members are in the form of springs and more specifically helical springs, but they could be replaced by opposing magnets, or other type of springs such as a conical disk spring.
Another example is the strap could be replaced by a cable or chain.
A further example is the material of the blocking device is made from. It does not necessarily need to be made from a hardened steel, it could equally be made from a normal steel material or other such metal or plastic.
An additional example is the shape of the blocking device. As described in the embodiment above, the blocking device it has a series of finger protrusions and finger recesses however it would also work if the blocking device had a single recess, a series of apertures or had no recess or apertures but a single block of steel being removed from the locking mechanism or moved aside to allow access.
Another example could be replacing the blocking device and plug with a cam lock requiring a key to remove and therefore access the grub screw within the pin receiver.
Number | Date | Country | Kind |
---|---|---|---|
2218134.1 | Dec 2022 | GB | national |