GB2217770A

GB2217770A - Anti-burglar lock

Info

Publication number: GB2217770A
Application number: GB8809546A
Authority: GB
Inventors: Tseng Tsai Yu
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-04-22
Filing date: 1988-04-22
Publication date: 1989-11-01
Anticipated expiration: 2008-04-22
Also published as: GB2217770B; GB8809546D0

Abstract

An anti-burglar lock in which the latch is designed to engage in an L-shaped slot in a door frame. The lock comprises a base plate 56 with a fowardly facing section with two apertures 2, 2', a latch 9, 9', movable forwardly through each aperture into a locking condition, each latch at its forward end having a laterally-protruding element, and guide slots to constrain each latch first to move forwardly through each aperture and then to move both forwardly and laterally. The lock may also include a conventional latch, which can be manually operated from outside the door only with a key. <IMAGE>

Description

AHTI-3URGLAR LOCT' The present invention relates to an anti-burglar lock.

In locks, conventionally a latch is moveable forwardly through an aperture in a forwardly-facing section of a base plate which is sunk within a door or window, the latch locating within a recess in the frame for the door or window. When the door is to be opened, the latch is drawn back out of the recess, usually by operation of a key. It is however often relatively simple for a burglar or other potential intruder to force the latch back, and then to enter the building.

It is an object of the present invention to avoid or reduce this disadvantage of the conventional lock. It is a further object of the present invention to provide an anti-hurglar lock which is of relatively simple construction, and easily installed in most types of doors. It is yet a further object to provide an anti-burglar lock which reduces the likelihood of malfunction, so thereby assuring effective release of the lock by an authorised user.

Thus according to one feature of the invention we provide à lock comprising a base plate with a forwardly facing section, an aperture in said forwardly facing section, a latch moveable forwardly through said aperture into a locking condition, the latch at its forward end having a laterally-protruding element, and guide slots in said base plate to constrain the latch first to move forwardly through the aperture and then to move both forwardly and laterally. Thus the latch can lock behind an L-shaped slot in the door frame. Preferably the lock includes a pair of latches, each latch having a laterally-protruding element, the elements facing away from each other. Usefully the lock also includes a conventional latch, which can be manually operated from outside the door only with a key.

The invention will be further described hy way of example with reference to the accompanying drawings in sshich:- Fig.1 is an exploded perspective view showing the structure of an anti-burglar lock in accordance with the present invention; Fig.2 is a further exploded view of the anti-burglar lock in accordance with the present invention; Fig.3 is a schematic section or view of the anti burglar lock in one operational position; Fig.4 is a further schematic sectional view of the anti-burglar lock in a second and intermediate operational position; Fig.5 is another schematic sectional view of the anti-burglar lock in a further operational position; and Fig.6 is a part perspective view of an anti-burglar lock in accordance with the present invention fitted into a door.

Referring now to the drawings, and particularly to Figs.1 and 2, there is shown a preferred embodiment of anti-burglar lock according to the present invention. The lock includes a base plate 56, having a forwardly facing section with two rectangular slots 2,2'. Towards each end of the forwardly-facing section there are respectively apertures 3,3' through which screws can he passed to secure the lock in a door. Rearwardly of the slots 2,2' are two pairs of respective slanting directive slots 4,4', as well as three protrusions of which only 5,5' are shown. Base plate 56 furthermore includes a slot 5, which is generally horizontal in its position of use, as well as a protruding element 7 for mounting a lid or cover 46.As shown in Fig.1, the two L-shaped latches 9,9' are in their locking position projecting forwardly through slots 2.2'; each latch at its forward end has a lateral projection, directed in opposite directions i.e. upwardly for latch 9 and dowmwardly for latch 9', and each latch 9,9' has side projections 10,10' which engage in directive slots 4,4'.

Between base plate 5 and cover 46 is positioned a locking core 27, which can be accessed through hole 25 in lid 46. Also between base 56 and cover 46 is a mechanism comprising a first plate 11 and a second plate 11', the plates 11,11' being joined by connectina element 12 to form a unit. At the forward end of the plates 11,11' are respective angled slots 13,13' to receive protrusions on the L-shaped latches 9,9' and of which 10',32' can be seen in Fig.2. Centrally of plates 11,11' are horizontal openings 14,14'. The plates 11,11' have upper recesses 19,19' and which in part define semi-circular slots 17,17' above slots 14,14'; the plates 11,11' also each have a lower recess below the slots 1a,14' and which in part define protruded pieces 15,15' and thus three locking slots 16,16'.The plates 11,11' are so formed in order to permit a multi-stage locking action.

Also between the base plate 5 and the cover 46 is a blocking unit comprising a blocking seat 21 urged downwardly as seen in Fig.1 and Fig.2, by spring 22 mounted against ledge 23 on base plate 55. At its lower end, blocking seat 21 is formed with an arch-shaped surface 211. At the mid portion of - the blocking seat 21 are lateral tags 212, together with a protrusion 213 of size to be received in slots 17,17'. Stub 214 at the upper end of the blocking seat locates spring 22.

The locking core 27 is of conventional design. When in use, a key (not shown) is placed into the locking hole 26 and so into the core 27, to rotate the disc-like structure 28, and the C-shaped element 29.

When assembled, the slot 21 of the blocking seat engages over protrusion 5, whereas horizontal slots 14,on" and slot 215 on the blocking seat engage over protrusion 5'. The protrusion 18 on plate 11' engages in the horizontal slot 34 of cover 46, whilst protrusion 20 on plate 11 engages in horizontal slot 8 on base plate 56. Therefore lid or cover 46 is positioned so that locking hole 27 is tightened around locking core 27. As mentioned above, by means of upwardly directed slots 21, 215 the blocking seat is mounted on the protrusions 5,5' of base plate 56, and the arch-shaped portion 211 is between the plates 11,11', whilst the protruded tags 212 are in contact with the inner surface of plate 11'.

Referring again to viz.1, inner handle 57 includes a rectangular bore 37, with a rotatable plate 38 for blocking the protruding portion 331. Slots are provided at the end of rectangular bore 37, so that handle 57 can be located on its mounting plate by a C-shaped ring; the handle 57 includes a spring 40.

Engaged with the handle 57 is a control rod 44, which is hollow so that flat rod 43 can he inserted therein. Rounded channels 45lea, 45M, 45A', and 45' are provided on the control rod 44. The flat rod 43 is received within hole 421 in a spring plate 42.

The conventional latch 4q is controlled by means of control rod 44, which is aligned with and mounted within circular hole 461 of external cover plate or lid 46, with the square hole 471 of external moving piece 47, with the square hole of fitting seat 48, with the square hole 551 of internal moving piece 55, and with the circular hole 562 of base plate 56; and finally with inner handle 57 which is coupled to control rod 44. Protrusions are provided on the internal and external moving pieces 47, 55 e.g. protrusion 472; rectangular protrusions are provided for the square hole 471, 551; and a circular protrusion is provided at the fitting seat 8 for connection with circular hole 461, 562 respectively of lid 46 and base plate 56.

Furthermore, at the latch controlling element, there is an operating rod 50 connected to a conventional latch 49, and passing through apertured stands 561 and 563 mounted on base plate 56. Thus the forward section of rod 50 passes through stand or connecting unit 551 and through the square end plate 51, between which is spring 53. At the rearward end of roi 50, spring 54 is provide between members 52 and 563. Ro 50 is movable forwardly by e.g. protrusion 472.

In fix.6, the lock is shown mounted in a door. Referring to Fig.2, in conjunction with Figs.3 - 5, the action of the lock will be further described. A key (not shown) is inserted through the locking hole 26 into locking core 27 and rotates the disc-like element 2Z in the counter-clockwise direction as seen in Fig.2.In the position of element 23 as seen in Fig.2, with the flat portion uppermost, spring 22 presses down arch-shaped portion 211, with peg 213 in the first recess 17,17' and locking peg 10,10' in the position shown in Fig.3. When the disc-like element 28 is rotated, the blocking plate is moved upwardly, as seen in Fig.2 to corapress spring 22, this movement being guided and limited by protrusions 5,5'.The edge of disc-like element 28 engages a doofnwardly directed protrusion 15,15' to move plates 11,11' to the left, taking with them L-shaped latches or locking elements ,9'; in this action, the protrusions or pes 10',32' etc are in the vertical section of slots 13' etc and are pushed thereby horizontally -along the horizontal section of directive slots a' etc. with further rotation of disc-like element 28, this action is repeated, through the Fig.4 position, to the Fig.5 position; the locking pegs, 10,10' are not only constrained to follow the directive slots 4,4', but also move along the rearwardly angled section of slots 13' etc.In the position shown in Fig.5, the latches 9,9' not only are received within a recess in the door frame, so preventing the door from being opened sicne.veys (into or out of the paper), but the laterally-protruding elements (upwardly for latch 9 and downwardly for latch 9') are engaged in corresponding slot in the door frame e.g. behind a metal plate affixed to the door frame and defining the opening, so that the latches 9,9' may not simply be forced back even when substantial force is applied.

Furthermore, protrusions 10', 32' etc are held e.g. in the rearwardly angled section of slots 13'etc, so that any attempt to force back the L-shaned latches 9,9' t-rill be resisted also by plates 11,11', and blocking seat 21.

Referring again to Fig.1, when the inner handle 57 is rotated, the flat rod a3 is also rotated. Furthermore, spring plate 42 applies an axial loading, to disengage the controlling square rod 44 from the external handle 36, whereby the circular slots 45A,45A',45B,45B' are no longer aligned with the square sections of inner and external handles 35, 57 etc.Thus the door cannot be opened by the controlling square rod 44, and closure of the door will secure latch 49, which cannot be opened by external handle 36 until a kev is inserted in lock 41. When such key is inserted in keyhole 41, flat rod 43 is rotated when the key is turned clockwise, to permit controlling rod 44 to move to a position in which a square face of controlling rod 44 is again in engagement with th-2 square vole of inner and external handle 36, 57, to permit the door to he opened.

It will be seen fro Figs.2-5 that the latch 9,9' engages a first directive slot, the first slot having a first section and a second section, and. also engages a second slot having a first section and a second section, the said first and second sections of each slot being angled one to the other, the respective first and second sections of the first and second slots being substantially at right angles to each other.

Claims

IV}IAT WE CLAIM IS : -

1. An anti-burglar lock comprising a base plate with a forwardly facing section, an aperture in said forwardly facing section, a latch moveable forwardly through said aperture into a locking condition, the latch at its forward end having a laterally protruding element, and guide slots in said base plate to constrain the latch first to move forwardly and then to move both forwardly and laterally.

2. An anti-burglar lock as claimed in Claim 1 in which the latch engages a first directive slot, the first slot having a first section and a second section, awnd also engages a second slot having a first section and a second section, the said first and second sections of each slot being angled one to the other, the respective first and second sections of the first and second slots being substantially at right angles to each other.

3. An anti-burglar lock comprising (a) a base plate having rectangular slot at one face, two sets of directive slots being provided on said plate and at the centre thereof, a locking hole for a locking core being provided, threo directive protrusions bein- formed on said haste plate; (b) a lid plate having slots corresponding to the slots of said. has plate in order to combine with said base plate; (c) two locking latches each having two perpendicular protruded elements which being troun,ec.1. within the corresponding directive slots of said base plate;; (d) a first and second plate which is mounted to each other by a connection piece, a horizontal slot being along the centre thereof, on the upper edge of horizontal slot, four circular slots being provided, below said horizontal slot, four circular slots being provided, below said horizontal slot, tvo protruded pieces being equally provided; (e) a blocking unit comprising of a blocking seat and a spring, an arch-shaped plate being formed on one end of a blocking plate, two edge plates being forned at the central region of said blocking plate and two directive slots being formed on the plate thereof;; locking core having a rotatable disc-like plate at t central region, an external handle in which a key hole being provided therein; an inner handle; a controlling square rod which is hollow in the centre and having circular channel on the rod thereof an internal plate and external plate respectively provided with circular hole for said rod.

4. An anti-burglar lock constructed and arranged substantially as described with reference to the accompanying drawings.

Amendments to the claims have been filed as follows 1. An anti-burglar lock comprising a base member with a forwardly facing section, an aperture in said forwardly facing section, a latch movable forwardly and rearwardly so that part of the latch moves through said aperture respectively into a locking and unlocking condition, first guide means in said base member to guide the latch in the forward and rearward operational directions, second guide means located on a locking member which is movable relative to the base member, said second guide means directing the latch forwardly if a forwardly-projecting portion of the latch is urged in a direction transverse to said operational directions.

2. An anti-burglar lock comprising a base member with a forwardly facing section, an aperture in said forwardly facing section, a latch movable forwardly and rearwardly through said aperture respectively into a locking and unlocking condition, the latch at its forward end having an element protruding laterally in one transverse direction, first guide means in said base member to constrain the latch to move also in a direction opposite to said one transverse direction as the latch is moved rearwardly through said aperture, second guide means located on a locking member which is movable relative to the base member, said second guide means directing the latch forwardly if the latch is urged in a direction opposite to said one transverse direction by way of said element.

3. An anti-burglar lock as claimed in Claim 1 or Claim 2 in which the base member comprises a base part and a cover part, the cover part being affixed to the base part, the base part including a perpendicular extension defining the forwardly facing section, the locking member being between the base part and the cover part.

4. An anti-burglar lock as claimed in any of Claims 1 to 3 in which there are two latches spaced apart in said transverse direction, each of the latches having an extension at its forward end, the said extensions projecting in opposite directions one away from the other.

5. An anti-burglar lock as claimed in Claim 3 or Claim 4 in which the first guide means is an opposed pair of guide slots respectively in the base part and in the cover part, each of the said guide slots having a first guide slot section and a second guide slot section with the first guide slot section at an angle to the second guide slot section, and in which the second guide means is an opposed pair of locking slots, each locking slot having a first locking slot section and a second locking slot section with each first locking slot section at an angle to the second locking slot section, the latch having corresponding pairs of opposed projections which respectively co-operate with the said guide slots and with the said locking slots.

6. An anti-burglar lock as claimed in Claim 5 in which the first guide slot section is substantially at rightangles to the second locking slot section, and in which the second guide slot section is substantially at rightangles to the first locking slot section, the first guide slot section being rearwards of the second guide section and the first locking slot section being rearwards of the second guide slot section.

7. An anti-burglar lock as claimed in Claim 6 in which there are two pairs of opposed guide slots and locking slots.

8. An anti-burglar lock as claimed in Claim 1 or Claim 2 in which the second guide means comprises a first plate and second plate connected to each other.

9. An anti-burglar lock as claimed in Claim 8 in which each of said first and second plates has in its central region a fore and aft extending slot.

10. An anti-burglar lock as claimed in Claim 9 in which in the normal position of use, above the fore and aft extending slot there are four part-circular recesses, and below said fore and aft extending slot there are two downwardly extending protrusions.

11. An anti-burglar lock as claimed in Claim 10 which includes a blocking unit comprising a blocking seat movable relative to the base member and spring compressed between the blocking seat and an abutment plate secured to the base member, the blocking seat having two vertically extending openings each of a width to receive a respective one of a pair of base member protrusions carried by the base member and adapted to inhibit movement of the blocking seat in the fore and aft direction, a pair of spacing tags to one side of the blocking seat, a blocking seat protrusion on said blocking seat at a position lower than said tags but extending in the same direction as the tags, as the abutment plate and as the base member protrusions, the blocking seat protrusion being adapted to engage in any one of said four part-circular slots to inhibit fore and aft movement of said plates.

12. An anti-burglar lock as claimed in Claim 11 in which said protrusion can be lifted out of the respective one of the four slots by means of a locking core rotatable from a first angular position to a second angular position, the locking core having an external cam surface.

13. An anti-burglar lock as claimed in Claim 12 in which rotation of the locking core from said first angular position to said second angular position can occur only after the core has been released following insertion of a key.

14. An anti-burglar lock as claimed in any preceding claim which includes a conventional latch operated upon partial rotation of an internal and external handle, the said internal and external handles being connected by an operating rod, the rotation of at least the external handle being controlled by a lock and key.

15. An anti-burglar lock constructed and arranged substantially as described with reference to the accompanying drawings.