Burglary prevention kit for a door lock comprising a thumbturn cylinder

Abstract

Burglary prevention kit for a door lock arrangement comprising a thumbturn cylinder (110) having a thumbturn (117) and cam (115) that is rotatable from an interior side of the door via a shaft element (118). The kit comprises a rotary knob (250) that is adapted for fixation to the shaft element and a security cap (240) having a bore (241) adapted to be mounted over the shaft element; a flange part (242) adapted to be mounted against a housing element (112) and a cover part (245) that surrounds an outer surface of the rotary knob with a radial gap sufficient to enable a user to grasp the knob. At least a part of said outer surface is dimensioned to be larger than a diameter of the bore (141) such that the cap may be secured on the shaft element (118) in axial direction by the rotary knob.

Description

FIELD OF THE INVENTION

[0001] The invention is directed to the field of lock arrangements for a building door comprising a thumbturn cylinder which enables the door to be locked and unlocked from the inside via a rotary knob, and is more particularly directed to a solution for preventing a burglar from being able to operate the rotary knob from the outside.BACKGROUND ART

[0002] In order to comply with fire-safety regulations, a door lock comprising a thumbturn cylinder with a rotary knob is often prescribed, so that there is no need for a key to unlock the door from the inside. In situations where burglar-proof certification is desired or mandated, additional measures may be needed to prevent break-ins. For example, when the door is made of wood, it may be necessary to fit an anti-drill plate, so that a burglar cannot simply drill a hole through the door in order to gain access to the rotary knob. When the door has a letterbox, it may be necessary to fit a letterbox shield, so that a burglar cannot insert a wire loop or other manipulation tool for turning the knob and unlocking the door. Such measures are labour intensive to fit and can damage the door.

[0003] To provide extra security, it is possible to adapt the thumbturn cylinder such that the knob can be turned only when press-in buttons on the knob are depressed. Such a solution is known from EP 2559833. A person with arthritis in their fingers or other impairment might have difficulty in performing the necessary manipulation. Such a solution is therefore unsuitable in an environment such as a care home.

[0004] A further known solution is to mount a cover with a securable lid. The cover is mounted to the inside of the door, around the rotary knob, and has a lid that is released by pressing a button. Again, an additional action is required in order to gain access to the rotary knob, which is inconvenient in normal circumstances and potentially hazardous in emergency situations such as a fire when it is important to access the rotary knob immediately.

[0005] Consequently, there is room for improvement in terms of providing a secure solution that can be used in combination with standard thumbturn cylinders and which enables the rotary knob to remain directly accessible at all times, without the need for any manual manipulation other than grasping and turning.INVENTION SUMMARY

[0006] The present invention provides a burglary prevention kit for a door lock arrangement which includes a thumbturn cylinder having a thumbturn that is rotatable from an interior side of the door via a rotatable shaft element that forms part of the thumbturn or which is coupled thereto. Rotation of the shaft element actuates a cam of the thumbturn cylinder, which operates a deadbolt associated with the lock arrangement. The kit comprises a specially adapted rotary knob that is adapted for fixation to the rotatable shaft element, and a security cap. The security cap has a bore that is mountable over the shaft element and comprises a radially extending flange part and an axially extending cover part.

[0007] The security cap has a front side that faces towards a user and a rear side that is mounted against a housing element of the lock arrangement that protrudes from an interior side of the door. The cap is secured on the shaft element by the rotary knob, which is dimensioned such that an outer surface of knob is larger than a diameter of the bore through the cap. Furthermore, when the cap and the rotary knob are coaxially arranged in contact with each other, the cover part of the cap surrounds the outer surface of the knob with a radial gap G in between that is sufficient to enable a user's hand to grasp the knob.

[0008] In a preferred example, the rotary knob has an outer surface of circular geometry. The grasping surface is thus cylindrical. Furthermore, a front face of the knob is preferably flat, such that the portions of the knob which are accessible from the front side are free of any protrusions around which a wire or cord could be looped in order to turn the knob and unlock the door. The outer surface may additionally be executed as a smooth surface, to further reduce the risk that a manipulation tool might engage with the knob.

[0009] The knob is further protected from being accessed from the outside of the door, through the letterbox for example, by the cover part of the security cap which acts a shield. In some examples, the cover part has a cylindrical geometry. An oval, square or other polygonal geometry is also possible. The rotary knob and the cover part of the cap are preferably dimensioned such that in mounted condition, a front face of the rotary knob does not extend in axial direction beyond a front edge of the cover part, to prevent access to the knob from the side. In some examples, the front edge of the cover part extends beyond the front face of the rotary knob. This has the advantage of further enhancing the shielding effect.

[0010] In an advantageous development, the security cap is made of drill-resistant material. The flange part of the cap may thus serve the function of an anti-drill plate, but can be mounted without the need to change or adjust existing door fittings / furniture. Suitable materials for the security cap include hardened (sheet) metal and thermoplastic resins. A kit in accordance with the invention thus provides a burglar-proof solution that can be easily implemented on existing door lock arrangements comprising a standard thumbturn cylinder. The rotary knob remains visible and accessible at all times, thereby ensuring optimal safety as well as security.

[0011] This is particularly important in an environment such as a care home, where the resident may be infirm and needs to be able to unlock the door easily, without the need for additional actions such as described for the solutions known from the prior art. In situations where persons are in need of care, it can occur that the door to their residence is fitted with an electromechanical device that permits motorised rotation of the thumbturn and actuation of the cam. A care-giver is then able to unlock the door by e.g. using a smartphone app, which activates the motor.

[0012] Several such electromechanical devices are available on the market and typically comprise a lock shaft that can be coupled to the thumbturn of the thumbturn cylinder. The device has a housing that is mounted against the interior side of the door and may comprises a mechanism that can be coupled to and decoupled from the lock shaft, whereby in coupled condition the lock shaft is rotatable by the motor. One example of such an electromechanical device is described in US 10526813. The shaft element to which the rotary knob is fixed is then the lock shaft associated with the electromechanical device, and the resulting arrangement may be considered to comprise an electromechanical thumbturn cylinder. To comply with additional requirements for obtaining certification as regards burglar resistance, the arrangement may be fitted with a security cap and a rotary knob in accordance with the invention.

[0013] The security cap is mounted over the lock shaft, against a front side of the housing of the electromechanical device. Suitably, the flange part of the security cap comprises a correspondingly shaped recess, such that the cap fits over part of the device housing. This locates the cap in position and prevents rotation of the cap, which is secured on the lock shaft by the rotary knob as described above.

[0014] Such an electromechanical device is often fitted as a temporary measure during a period when home care is needed. It is therefore advantageous that the device and additionally required security features can be easily mounted and dismounted, without the need for modification of the door. The security cap and rotary knob of the invention are therefore particularly suitable for use in such a door lock arrangement comprising an electromechanical thumbturn cylinder.

[0015] The invention may also be implemented in combination with a purely mechanical thumbturn cylinder. The thumbturn is rotatable within a housing of the lock cylinder and has a shaft element that protrudes from the inside of the door, to which the rotary knob is fixed. In mounted condition, a front side of the housing also typically protrudes somewhat. In a further embodiment, the flange part of the security cap comprises a correspondingly shaped recess, such that the cap fits over the housing. Typically, the recess will have a europrofile shape. After the security cap is mounted over the shaft element and located in position over the cylinder housing, it is secured by the rotary knob.

[0016] A burglary prevention kit comprising a rotary knob and security cap in accordance with the invention may be provided together with a purely mechanical thumbturn cylinder or together with an electromechanical device that is adapted to be coupled to the thumbturn. The kit may also be retrofitted to an existing door lock arrangement comprising a purely mechanical or an electromechanical thumbturn cylinder. In either case, the kit provides a safe and secure solution that is easy to fit.

[0017] These and other aspects of the invention are apparent from and will be elucidated with reference to the embodiments described hereinafter and with reference to the accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Fig. 1ais a perspective front view of a door lock arrangement comprising an electromechanical thumbturn cylinder, fitted with a security cap and a rotary knob, which form main elements of a burglary prevention kit according to a first embodiment of the invention; Fig. 1bis a side view of part of the arrangement depicted in Fig. 1a, with a cutaway showing the main elements of the kit in cross-section; Fig. 1cis a perspective rear view of the security cap depicted in Figs 1a and 1b; Fig. 1dis a side view of the rotary knob depicted in Figs. 1a and 1b; Fig. 2ais a side view of a door lock arrangement comprising a mechanical thumbturn cylinder and a burglary prevention kit according to a further embodiment, with a cutaway showing the security cap and rotary knob in cross-section; Fig. 2bis a perspective rear view of the security cap depicted in Fig. 2a.

[0019] It should be noted that items which have the same reference numbers in different figures, have the same structural features and the same functions. Where the function and / or structure of such an item has been explained, there is no necessity for repeated explanation thereof in the detailed description.DETAILED DESCRIPTION OF EMBODIMENTS

[0020] A first example of a burglary prevention kit for a door lock arrangement comprising a thumbturn cylinder 110 is shown in Fig. 1a. As is known, a thumbturn cylinder comprises a cam 115 that is rotatable about an axis 113 so as to actuate a deadbolt associated with the door lock, whereby the cam 115 is operable from an interior side of the door via rotation of a thumbturn, and is operable from an exterior side via a key. In the depicted example, the arrangement comprises an electromechanical thumbturn cylinder for enabling motorized operation of the cam 115.

[0021] The arrangement includes an electromechanical device 120 having a device housing 122 in which a motor is arranged. In use, a rear side 125 of the housing 122 is mounted against the interior side of a door. A partially cut cross-sectional side view of the arrangement is shown in Fig. 1b. The arrangement comprises a lock shaft 130 that extends through a front side 126 of the device housing 122 and which is rotationally coupled to the thumbturn of the thumbturn cylinder 110. In one example, the electromechanical device includes a coupling bush (not visible) mounted around the lock shaft 130, and means for enabling the bush to be selectively coupled to and decoupled from the lock shaft. A gear wheel may be mounted around the coupling bush, which is drivable by a pinion gear mounted to an output shaft of the motor. When coupled, motor-driven rotation of the bush causes rotation of the lock shaft 130. After motorized operation, the bush is decoupled from the lock shaft 130 to permit manual operation of the cam 115 via thumbturn or key.

[0022] A locking arrangement as depicted in Figs 1a and 1b is suitable for use in care homes or sheltered housing complexes, in situations where it is desirable for e.g. a care-giver to be able to enter an apartment by entering an access code in an app that will activate the motor of the electromechanical device 120. Manual operation via the thumbturn always remains possible when the motor and gearwheel are decoupled from the lock shaft 130 and the security risks associated with thumbturn cylinders are likewise present.

[0023] To mitigate these risks, the arrangement is provided with a security cap 140, an example of which is depicted in perspective view in Fig. 1c. The cap has a central bore 141, a flange part 142 that extends in a radially outward direction, and a cover part 145 that extends in axial direction. In the depicted example, the security cap is made of a drill-resistant material such as hardened metal and one of its functions is to prevent drilling. The axially extending cover part 145 further acts as a shield for preventing access to a rotary knob that is fixed on the lock shaft, which will be described in more detail later.

[0024] Preferably, the flange part 142 of the cap comprises a recess 143 extending in axial direction that is shaped to receive part of the front side of the housing 122. A portion of the cap 140 therefore fits over the housing 122 in a form-fit manner which positions the cap and prevents rotation thereof. The cap 140 is secured in axial direction against the front side 126 of the housing via a specially adapted rotary knob 150, which a user may grasp so as turn the lock shaft. The rotary knob 150 fits over one axial end of the lock shaft 130 that protrudes through the front side of the housing 122. This end section of the lock shaft is suitably provided with a mounting hole 132 such as threaded bore. The knob 150 is likewise provided with a mounting hole 152 (refer Fig. 1d), and is secured to the lock shaft 130 via a suitable fastener 135 such as a hex screw. As shown in Fig. 1b, the cover part 145 of the cap may comprise an opening 147 for insertion of a tool, to facilitate fixation of the screw 135.

[0025] The rotary knob 150 is mounted and secured after the security cap 140 has been mounted against the front side 126 of the housing. Removal of the cap 140 is prevented, as the rotary knob has an outer surface 155, at least a portion of which has a diameter that is greater than the diameter of the bore 141 through the cap. The knob 150 therefore has an axially oriented surface 154 that forms a retaining surface for an opposing axially oriented surface of the flange part 142.

[0026] Suitably, a ring 158 made of sliding bearing material, having an axially oriented bearing surface, is arranged between the axially oriented rear surface 154 of the knob and the opposing surface of the flange 142, such that the cap is retained in axial direction in a manner that permits low-friction turning of the knob. In the depicted example, the ring 158 has an essentially L-shaped cross-section and additionally has a radially oriented bearing surface that is arranged between the central bore 141 of the cap and an opposing radially oriented surface 157 of the knob 150, which forms a seat for the bearing ring 158.

[0027] In the depicted example, a radially outer surface 155 of the knob, which is grasped by a user, has a circular geometry, such that there are no protrusions or angled parts around which an intruder could loop a cord or wire, via the letterbox, so as to turn the rotary knob. Furthermore, the cover part 145 of the security cap surrounds the radially outer surface 155 of the knob, shielding the knob from being accessed by manipulation devices. In the depicted example, the cover part 145 has a cylindrical geometry, although other shapes are also possible. To prevent the knob being accessed from the side, the knob 150 and the cap 140 are suitably dimensioned such that in mounted condition, a front face 156 of the knob does not protrude beyond a front edge 146 of the cap cover part 145. Preferably, to further enhance the shielding effect, the front edge 146 of the cover part 145 of the cap extends beyond the front face 156 of the knob 150. Using the front side 126 of the housing as a reference, the front edge 146 of the cap suitably extends in axial direction by an amount x 1 which is greater than an amount x 2 which represents the distance is axial direction between the front face 156 of the knob 150 and the front side 126 of the housing.

[0028] As will be understood, the cover part 145 of the cap surrounds the radially outer surface 155 of the knob with a radial gap G in between which is sufficient to permit a user's hand to grasp and operate the knob 150. The radial gap may be, for example, 2cm. In use, the knob remains visible and accessible so that in an emergency situation, a person can quickly and easily operate the knob in the normal manner.

[0029] In the embodiment depicted in Figures 1a and 1b, the lock shaft 130 of the electromechanical device 120 is coupled to the thumbturn of the thumbturn cylinder 110, for enabling motorized actuation of the cam 115. The security cap and rotary knob of the invention may also be used to prevent break-ins in door lock arrangements which comprise a purely mechanical thumbturn cylinder. An example of such an arrangement is shown in partially cut cross-sectional side view in Fig. 2a, whereby a rear perspective view of the associated security cap is depicted in Fig. 2b.

[0030] The arrangement comprises a thumbturn cylinder 110, which in the depicted example is a europrofile cylinder having a key slot 113 for key-operated actuation of the cam 115 from an exterior side of the door and a thumbturn 117 to enable rotation of the cam by hand from the interior side of the door. The thumb-turn 117 is rotatable within a housing 112 of the profile cylinder and has a shaft element 118 of relatively smaller diameter provided with a mounting hole 119 to enable attachment of a rotary knob 250. The arrangement is further provided with a security cap 240, which is preferably made of drill-resistant material. The cap has a central bore 241, a radially extending flange part 242 and an axially extending cover part 245. In mounted condition, a front side of the cylinder housing 112 protrudes somewhat from the interior side of the door. The flange part 242 of the security cap is mounted against the door and suitably comprises a recess 243 that is shaped to receive the front side of the housing 112, thereby locating the cap 240 and preventing rotation thereof.

[0031] The cap 240 is secured in axial direction by the rotary knob 250, which fits over the shaft section 118 of the thumb-turn 117 and is fixed thereto via a suitable fastener such as a hex screw that is screwed into the mounting hole 118. In the depicted example, a rear side of the knob 250 comprises a circular recess which serves as a seat for a ring 258 made of sliding bearing material, which bears against an opposing axially oriented surface of the flange part 242 of the cap. In other examples, a seat for the bearing ring 258 is provided on the flange part of the cap. The knob thus secures the cap and can be turned in a low-friction manner.

[0032] Advantageously, as explained with reference to the first embodiment, the rotary knob has a radially outer surface 255 of circular geometry and suitably has a flat front face 256, with no protrusions. The cover part 245 of the cap surrounds the knob with a radial gap that is sufficient to permit the knob to be grasped by a person's hand. Furthermore, the front edge 246 of the cylindrical part 245 extends further in axial direction than the front face 256 of the knob, to inhibit access to the knob via e.g. a manipulation tool inserted through a letterbox.

[0033] Examples, embodiments or optional features, whether indicated as non-limiting or not, are not to be understood as limiting the invention as claimed. It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims.

[0034] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.List of references and abbreviations

[0035] The following list of references and abbreviations is provided for facilitating the interpretation of the drawings and shall not be construed as limiting the claims. 110thumbturn cylinder 111rotation axis 112cylinder housing 113key slot 115cam 117thumbturn 118shaft element of thumbturn 119mounting bore in shaft element 120electromechanical device for permitting motorized operation of thumbturn 122device housing 125rear side of housing 126front side of housing 130lock shaft 132mounting hole in lock shaft 135screw fastener 140, 240security cap 141, 241central bore of cap 142, 242radially extending flange part 143,243shaped recess in flange part 145, 245axially extending cover part 146, 246front edge of cover part 150, 250rotary knob 152mounting hole in rotary knob 154axially oriented retention surface on knob for security cap 155, 255radially outer grasping surface of knob 156, 256front face of knob 157seat on knob for sliding bearing ring 158bearing ring

Claims

1. Burglary prevention kit for a door lock arrangement comprising a thumbturn cylinder (110) having a thumbturn (117) and cam (115) that is rotatable from an interior side of the door via a shaft element (118, 130) that forms part of the thumbturn or which is coupled thereto, the kit comprising a rotary knob (150, 250) that is adapted for fixation to the shaft element and a security cap (140, 240) having: • a bore (141, 241) adapted to be mounted over the shaft element; • a radially extending flange part (142, 242) adapted to be mounted against a housing element (112, 122) associated with the lock arrangement; and • an axially extending cover part (145, 245), wherein: - the rotary knob (150, 250) has an outer surface (155, 255) which is dimensioned to be larger than a diameter of the bore (141, 242) of the cap (140, 240), such that cap may be secured on the shaft element in axial direction by the rotary knob; and - when the cap and rotary knob are coaxially arranged in contact with each other, the cover part (145, 245) of the cap surrounds the outer surface (155) of the knob with a radial gap G in between that is sufficient to enable a user to grasp the knob.

2. The kit of claim 1, wherein the security cap (140, 240) and the rotary knob (150, 250) are dimensioned such that when coaxially arranged in contact with each other, a front face (156, 256) of the rotary knob does not extend in axial direction beyond a front edge (146, 246) of the cover part (145, 245) of the security cap.

3. The kit of claim 2, wherein the security cap (140, 240) and the rotary knob (150, 250) are dimensioned such that when coaxially arranged in contact with each other, the front edge (146, 246) of the cover part (145, 245) of the cap extends in axial direction beyond the front face (156, 256) of the rotary knob.

4. The kit of any of claims 1 to 3, wherein the security cap is adapted for mounting against a housing element (122) associated with an electromechanical device (120) for enabling motorised actuation of the cam (115), whereby the shaft element is formed by a lock shaft (130) that is coupled to the thumbturn (117) of the thumbturn cylinder (110).

5. The kit of any of claims 1 to 3, wherein the security cap is adapted for mounting against a housing element (112) of the thumbturn cylinder (110), whereby the shaft element (118) forms part of the thumbturn (117).

6. The kit of any preceding claim, wherein the flange part (142, 242) of the security cap comprises a recess (143, 243) that is shaped to at least partly receive a front side of the housing element (112, 122) against which the cap is adapted for mounting to.

7. The kit of any preceding claim, wherein the rotary knob (150, 250) or the flange part (142, 242) of the cap comprises a seat (157) for receiving a ring (158, 258) made of a sliding bearing material having at least an axially oriented bearing surface.

8. The kit of claim 7, further comprising a ring (157, 257) with at least an axially oriented bearing surface, which is adapted for arrangement between opposing axially oriented surfaces of the rotary knob and the flange part (142, 242) of the security cap.

9. The kit of any preceding claim, wherein the rotary knob (150, 250) has an outer surface (155, 255) of circular geometry.

10. The kit of any preceding claim, wherein the rotary knob (150, 250) has a flat front face (156, 256).

11. The kit of any preceding claim, wherein in the security cap (140, 240) is made of drill-resistant material.

12. A door lock arrangement comprising a thumbturn cylinder (110) having a thumbturn (117) and a cam (115) that is rotatable from an interior side of the door via a shaft element (130, 118) that forms part of the thumbturn or which is coupled the, the arrangement further comprising a burglary prevention kit according to any of the preceding claims, wherein the security cap (140, 240) is mounted against a housing element (112, 122) associated with the lock arrangement and is secured on the shaft element (118, 130) by the rotary knob (150, 250).

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