GB2228291A - Striker plate - Google Patents

Abstract

A striker plate has a body of channel form with a rectangular opening (16) therein adjacent one longitudinal edge of the body which is a front edge when the body is fitted to a door frame, in use. At the opening is fitted a pivotable element (17) which has front and rear flat surfaces (19, 21) respectively, the front surface (21) substantially closing the opening in one position of the element and lying flush with a front surface of the body, the rear surface (21) in another position of the element lying below the level of the front surface of the body and terminating short of a longitudinal front edge of the opening to define a recess for a latch bolt of a door secured to the door frame, in use. A thumb-wheel (35) is manually operable at the front surface of the body to pivot the element (17) between said two positions, and a spring plate (37) at the rear of the body acts to oppose such movement of the element. The latch bolt cannot lock the door when the element (17) is in said one position. <IMAGE>

Description

STRIKER PLATE This invention relates to a striker plate which is intended to be secured to a surface of a frame for a hingedly mounted wing, so that when the wing is in its closed position and contained within the frame a spring loaded bolt carried by the wing extends through an aperture in the striker plate to hold the wing closed, until the bolt is retracted by operation of a handle at one or either side of the wing. The term 'striker plate' includes all equivalent members, such as those known as staples, keeps etc.

It is common practice to provide a wing, such as a door, with such a spring loaded bolt, normally called a latch bolt, which can be manually retracted from inside by means of a lever or knob on the latch case, but which can only be retracted from the outside by a suitable key.

With such an arrangement a snib is often provided, this being a button adjacent the lever or knob for retracting the bolt, the button being slidable, when the lever or knob is turned, to retain the bolt in its retracted position i.e. withdrawn into the edge of the door.

With either a front or rear door of a house, this snib facility is useful in that an occupier can leave the house for a short time without having to bother to take a key for the front or rear door, as even if the door closes whilst the occupier is outside, it will not lock, as the latch bolt is held withdrawn by the snib.

However it is possible that a violent slamming of such a door, for example by a gust of wind when another door in the house is opened, or a continuing movement of the door against its frame caused by less violent wind, could loosen the snib, with the result that the latch bolt is released and the door locks.

It is an object of the invention to provide a striker plate which can provide the same effect as a snib, but which overcomes the above mentioned disadvantage.

According to the invention there is provided a striker plate comprising a body, an opening in the body, and an element at the opening movable, in use, between one position in which a recess for a latch bolt is defined, and another position in which the opening is blocked to prevent reception of said latch bolt.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a front view of a striker plate of the invention, with a component thereof in a first, blocking position, Figure 2 is a rear view of the striker plate of Figure 1, Figure 3 is a view of one end of said component, Figure 4 is a cross-section on the line 4-4 of Figure 1, Figure 5 is a view of one end of a plate spring of the striker plate, and Figure 6 is a schematic, fragmentary view, similar to Figure 1, showing said component in a second latch receiving position.

The striker plate of Figures 1 and 2 has an extruded aluminium body 10 of channel form, the channel base defining a front, flat surface 11 and a rear flat surface 12, one of the channel sides 13 being shorter than the other channel side 14. Three countersunk holes are provided at both ends and the centre of the body respectively, these holes being aligned with unthreaded bores in respective blocks held in the channel. In use the body is secured in or at a rebate in a door frame with the side 13 being at the side of the frame towards which a spring loaded latch bolt of the door swings when the door is closing, in use. Respective screws pass through the blocks and engage with the frame, heads of the screws being received in the countersunk holes respectively.

A pair of rectangular apertures 15, 16 respectively are provided in the body, being equally spaced at opposite sides of the centre of the body. The longer sides of each aperture are parallel to the channel sides. The lower aperture 15 is empty, but the upper aperture 16 receives an angularly movable member 17. Just below the bottom of the aperture 16 is a small rectangular aperture 18.

The member 17 is of brass and has a central body portion whose transverse cross-section is as shown in Figure 4.

It has a flat surface 19 and a shorter flat surface 20 at o 90 thereto. An angled flat surface 21 extends from the surface 20 upwardly and outwardly to meet a flat surface 22 parallel to the surface 19. Finally an upwardly and outwardly directed short flat surface 23 joins surfaces 22 and 19. At its ends the central body portion has respective walls 24, 25, each of which continues the surfaces 19 and 20, but which extends downwardly beyond surface 22 to form a radiussed lower surface 26 and a sloping flat surface 27, the surface 27 continuing surface 23.

The surface 19 of member 17 is just shorter than the length of the aperture 16 and is somewhat less wide than the width of aperture 16, as shown in Figures 1 and 2.

Extending outwardly from the wall 24 is a cam portion 28 and a cylindrical end hub 29. The cam portion 28 has a flat surface 30 below the surface 19 and at a slight angle thereto. It could alternatively be parallel thereto. It then has a radiussed part 31 generally facing the radiussed end wall surface 26 and connected to a further flat surface 32 generally parallel to surfaces 23, 27. The surfaces 30, 32 are connected by a short, radiussed portion 33. The hub 29 is disposed inwards of the portion 33 which, as will be described, acts as a pivot for the member 17. The flat surfaces 30, 32 are effectively tangential to the hub 29.

At the other wall 25, a further cam portion 34, of identical form to cam portion 28, extends outwardly and terminates at a knurled thumb-wheel 35, at the other side of which is a further cylindrical end hub 36, identical to hub 29, and positioned relative to cam portion 34 in the same manner as hub 29 to cam portion 28.

Finally, the striker plate has a plate spring 37, of generally U-shape in plan, secured to its rear surface 12, as shown in Figure 2, by a pair of nut and bolt arrangements. At the end of each arm of the spring 37, the plate is bent into a raised, generally semicylindrical portion 38 to receive the hubs 29, 36 respectively. Instead of the nut and bolt arrangements, countersunk rivets could instead be used.

The member 17 is thus fitted to the body 10 with its central body portion aligned and partly within the aperture 16, with its hubs 29, 36 in the portions 38 respectively of the spring plate. The thumb-wheel 35 partly projects through the aperture 18.

The member is angularly movable between two extreme, stable positions.

The first position is that shown in Figures 1 and 2 where the surface 19 is flush or substantially flush with the front surface 11. In this state the surfaces 30 of the cam portions respectively are against or substantially against the rear surface 12 and the edge between surfaces 19 and 20 of member 17 abuts the longitudinal front edge of aperture 16. The hubs 29, 36 are disposed against the surface 12. As can be seen from Figure 1, the surface 19 substantially fills the aperture 16, there being merely a small longitudinal gap 39 at the rear longitudinal edge of the aperture 16.

If the thumb-wheel 35 is now turned clockwise, as viewed in Figure 1, the member 17 turns in the aperture 16 and the radiussed portions 33 of the cam portions 28, 34 respectively move angularly into engagement with the rear surface 12. This causes a lifting or pivoting of the hubs 29, 36 off the surface 12, which is resisted by the portions 38 of the spring 37. However if turning of the thumb-wheel is continued the spring force is overcome and the flat surface 32 of each cam portion moves angularly to engage against the rear surface 12, with the hubs 29, 36 also returning to engage the surface 12. Thus the spring prevents the member 17 moving between its extreme position unless there is a positive force applied to it.

As the thumb-wheel is turned as described, the member 17 rotates in the aperture until the position shown in Figure 6 is reached, where surface 23 is flush or substantially flush with the surface 11 at the rear longitudinal edge of aperture 16 and the surfaces 21, 22 form a recess within the aperture, together with a longitudinal gap 40 at the front longitudinal edge of the aperture, larger than gap 39 in the other extreme position. The edge between surfaces 19 and 23 can engage the rear longitudinal edge of the aperture 16 additionally to form a stop.

In use, the striker plate is fitted to a door frame so that when the door is closed, the normal spring loaded latch bolt engages against the surface 11 adjacent the front longitudinal edge of aperture 16 and is retracted against its spring until it moves clear of the surface 11, whereupon it enters the recess defined by the member 17 in the aperture 16 when in its second position as described. The leading angled or curved face of the bolt engages the surfaces 21, 22 whilst the trailing latch bolt face engages against the front longitudinal edge of the aperture 16, the bolt itself extending into the gap 40. With the member 17 held in this position by the bias of spring 37, the door can be opened and closed conventionally using the latch bolt.The lower aperture 15 is provided to receive a dead bolt arranged at the door edge, the frame having a rebate behind the aperture 15 into which the dead bolt can extend when thrown by key operation.

If however an occupier wishes to leave the house for a short time, without wanting to bother to take the key to operate the latch bolt from the outside, whilst at the same time wanting to be sure that the door will not slam and lock, all that is necessary is that before leaving the occupier turns the thumb-wheel anti-clockwise so as to move the member 17 to its first, blocking position, where it is held by spring 37. In this state the door cannot lock since the latch bolt cannot enter the aperture 16. If the door swings into its frame all that happens is that the latch bolt engages the surface 12 and the surface 19 and is retracted against its spring. The door thus remains unlocked and can merely be pushed open from outside. Accordingly no snib is necessary at the latch bolt casing, the snib function instead now being at the frame and being totally reliable against accidental snib disengagement.

The invention is applicable to any type of frame and wing where a spring loaded bolt normally engages with a striker plate to cause a locking of the wing which requires a key to open the wing from outside.

For a door of opposite hand, the striker plate would be inverted and the components 17 and 37 arranged in the other, now upper, aperture. Instead of the plate accommodating both a latch bolt and a dead bolt, there could of course be two separate plates, since the striker plate snib function is of course unrelated to the dead bolt operation.

Claims (14)

1. A striker plate comprising a body, an opening in the body, and an element at the opening movable, in use, between one position in which a recess for a latch bolt is defined, and another position in which the opening is blocked to prevent reception of said latch bolt.

2. A striker plate as claimed in Claim 1, wherein said element is pivotally mounted for movement between said two positions.

3. A striker plate as claimed in Claim 2, wherein said element has a flat surface which in said another position is flush or substantially flush with at least a front, flat surface of the body at a front of the opening.

4. A striker plate as claimed in Claim 3, wherein said element has a further flat surface which in said one position is disposed below said front flat surface of the body at said front of the opening to define, with a front edge of the opening, said recess for a latch bolt.

5. A striker plate as claimed in Claim 4, wherein extending from an end wall of the element is a cam portion having two mutually angularly inclined flat surfaces therearound separated by a cam surface which engages a rear surface of the body, in use, as said element is pivotally moved between said two positions, in which said flat surfaces of the cam portion respectively engage said rear surface.

6. A striker plate as claimed in Claim 5, wherein outwardly of the cam portion is a hub which in said two positions of said element is against said rear surface of the body and closely covered by a generally semicylindrical portion of a plate spring, pivotal movement of said element between said two positions being opposed by said spring plate when said cam surface engages said rear surface and causes movement of the hub and thus the semi-cylindrical portion away from the rear surface.

7. A striker plate as claimed in Claim 6, wherein both a cam portion and a hub are provided at respective end walls at opposite ends of the element.

8. A striker plate as claimed in Claim 7, wherein between a cam portion and a hub at one end wall is a manually operable thumb-wheel to move the element pivotally between its two positions, the thumb-wheel being accessible at said front surface of the body.

9. A striker plate as claimed in Claim 8, wherein the thumb-wheel extends outwardly through a slot through the body from said rear surface to said front surface so as to be accessible thereat.

10. A striker plate as claimed in any one of Claims 7 to 9, wherein the plate spring is of U-shape being secured to said rear surface of the body, and has the respective free extremities of its arms bent into raised, generally semi-cylindrical portions which extend closely around the hubs respectively.

11. A striker plate as claimed in any one of Claims 3 to 10, wherein when said element is in said another position, a longitudinal edge of said flat surface is disposed alongside a longitudinal front edge of the opening.

12. A striker plate as claimed in Claim 11, when appended to Claim 4, wherein when said element is in said one position, said longitudinal edge of said flat surface is disposed alongside a longitudinal rear edge of the opening, and a longitudinal edge of said further flat surface is spaced from said longitudinal front edge of the opening.

13. A striker plate as claimed in any one of the preceding claims, wherein the body has a further opening therein identical to said opening for the element to receive, in use, a dead bolt.

14. A striker plate substantially as hereinbefore described, with reference to, and as shown in the accompanying drawings.