GB2403266A

GB2403266A - A device for holding a door open

Info

Publication number: GB2403266A
Application number: GB0314988A
Authority: GB
Inventors: Andrew Kevin Clingan
Original assignee: Freeman & Pardoe Ltd
Current assignee: Freeman & Pardoe Ltd
Priority date: 2003-06-27
Filing date: 2003-06-27
Publication date: 2004-12-29
Anticipated expiration: 2023-06-27
Also published as: GB0314988D0; GB2403266B

Abstract

A device comprises a cylindrical socket 23 into which an engagement member 41 is axially slid. The engagement member 41 is held in place in the socket 23 by a plurality of retaining members 27, 28 located around the socket which are radially pressed into corresponding recesses 43 on the engagement member 41 when the controlling member 30 is operated by the solenoid 35. The assembly is used to hold open a door when activated but sufficient force on the door can be used to manually override the opener if required. Deactivation of the solenoid will allow the door to close.

Description

Title: Device for Holding a Door Open

Description of Invention

This invention relates to a device for holding a door open.

A device in accordance with the invention is able to be operated electrically, the holding open of the door requiring the supply of electrical power to the device and the door being released so as to be able to be closed when the supply of electrical power to the device is cut off. Devices working in this manner are well known, being required for doors which might be held open in normal circumstances but which are required to be closed in an emergency, for example if a fire alarm is operated in the premises having the doors.

Operation of a fire alarm may cause the supply of electrical power to the hold open devices of the doors to be cut off, so that the doors are free to be closed by door closets, e.g. of the spring operated hydraulicallydamped type.

It is known that a door-holding-open device operable as above described can be provided in association with a door closer, avoiding the need for a separate holding-open device to be provided at another part of the door.

However, such known holding-open devices have been complex and expensive to manufacture.

It is broadly the object of the present invention to provide an improved electrically operable device for holding a door open, which may be provided in association with a door closer and which is versatile and relatively simple in construction and operation, and hence economical in manufacture.

According to one aspect of the invention, we provide a device for holding a door open, comprising an engagement member, and a holding means cooperable with the engagement member to hold the latter when the door is open, wherein the holding means comprises a receiving member affording a socket formation having an axis in the direction of which it receives the engagement member; a number of catch elements spaced about said axis and movable radially relative to said receiving member; a control member movable axially relative to the receiving member and having cam means cooperable with the catch elements for moving the latter radially inwardly relative to the receiving member by an axial movement of the control member; the catch elements when thus moved being engageable with the engagement member to hold the latter in the socket formation; and an electromagnetic device operable on or in relation to the control member to achieve or permit said axial lO movement thereof.

Conversely an opposite movement of the control member will permit the catch elements to move outwardly and release the engagement member.

Preferably the engagement member is adapted to be connected to a door to move therewith as the door is opened and closed, and the holding means will then be provided on a member or structure e.g. part of a building structure, relative to which the door is movable.

The electro-magnetic device is preferably operable on the control member to cause the axial movement thereof, in the direction which causes it move the catch elements radially inwardly, when it is supplied with the electrical power, and releases the control member for opposite movement thereof under the influence of spring means when the electrical power supply is cut off: The receiving member may comprise a sleeve affording a generally cylindrical socket for receiving the engagement member. The catch elements may comprise balls, which may be movable in respective apertures extending radially through the receiving member.

The control member may comprise a sleeve movable axially on an exterior surface of the receiving member, and having in its interior an annular recess having an annular cam surface engageable with the balls to move them inwardly when the control member is moved axially by the electromagnetic device. Axial movement of the control member may be assisted by engagement of the control member by the engagement member.

The engagement member may comprise a generally cylindrical spigot having on its exterior an annular groove with which the catch elements are engageable. Where the catch elements are balls, the annular groove may have a cross-sectional shape which is part-circular, substantially corresponding to the radius of each of the balls. The engagement member preferably has a tapering nose portion which first enters the socket formation in the receiving member.

The configuration of the catch elements and the control member with its cam means may be such that the exertion of sufficient force radially outwardly against the catch elements will cause axial displacement of the control member against the force exerted on it by the electro-magnetic device. With suitable configuration of the catch elements and the catch formation with which they engage on the engagement member, e.g. the balls and part-circular section annular groove as aforesaid, even if the engagement member is held by the catch elements when the electro-magnetic device is energised, the exertion of sufficient force on the engagement member can release it from being held.

Thus if a door is being held open by the device, pulling the door sufficiently strongly can release it to be free to close. This will, of course, require more force to be exerted on the door than can be exerted by a spring door closer on the door.

Also, if the door is closed it can be opened and the holding-open device engaged to hold it open until it is required to be closed as referred to immediately above, or until the electrical supply to the holding-open device is cut off if a fire alann is operated, immediately freeing the door to close.

The electro-magnetic device may comprise a solenoid coil operable directly on the control member which is of a suitable magnetically- attractable material. The coil is preferably disposed at the end of the receiving member opposite that from which the receiving member is entered by the engagement member.

A holding device in accordance with the invention may be provided in association with a door closer, e.g. of the spring operated hydraulicallydamped type. For this, the engagement member may be movable along an axis in relation to a guide means, and adapted to be connected the door closer in such a way as to undergo such movement as the door is opened and closed, and the holding means may then be fixed or adapted to be fixed in relation to the guide means so as to cooperate with the engagement member to hold the latter in a position relative to the guide means corresponding to the door being open. It may be provided in a slide track fitted to a part of a frame relative to which a door is pivotably movable, the engagement member being connected to a slide member which is movable along the track and is connected at one end of an arm whose other end is fixed to the angularly movable spindle of a door closer mounted on the door.

Alternatively, a device in accordance with the invention could be provided on or in the body of the door closer unit which incorporates its _ operating spring and damping means. Such door closer units commonly incorporate a rack and pinion mechanism by which axial movement of a piston member within the body is transmitted to the spindle of the closer. In accordance with the invention, the engagement member may be provided on the piston, and the receiving member and its associated parts may then be provided on the body within which the piston is movable.

The invention will now be described by way of example with reference to the accompanying drawings, of which: Figure 1 is a diagrammatic view of part of a door having a door closer, to which the invention may be applied; Figures 2 and 3 are diagrammatic sections through a holding device in accordance with the invention, in different operative conditions; s Figure 3a is an enlargement of part of Figure 3; Figures 4 and 5 are diagrammatic sections showing a possible alternative application of a device in accordance with the invention; Figure 6 is a section corresponding to Figure 2, through part of a modified embodiment of the invention.

Referring firstly to Figure 1 of the drawings, this illustrates part of a door 10 openable by pivoting relative to a fixed frame having a jamb 11 and lintel 12. A spring powered hydraulically-damped door closer 13 is fitted to the face of the door adjacent its top edge, the door closer haying an output spindle 14 to which is secured an arm 15. The other end of the arm 15 is pivotally connected to a slide block 16 movable along a guide track 17 fitted to the lintel 12.

Figure 2 shows the block 16 within the track 17. The track may be an extrusion whose cross-sectional shape includes an opening on one side, through which a part extends to provide a connection to the arm 15. A holding device is provided for holding the block 16 at a position within the track corresponding to the door being open.

The holding device comprises a holding means 20 cooperable with an engagement member 21 fixed to the block 16. The holding means comprises a receiving member 22 in the form of a cylindrical sleeve affording a cylindrical socket 23 whose central longitudinal axis 24 is the direction along which the block 16 is movable within the track 17. The receiving member 22 is provided with a number of circumferentially spaced radially extending apertures, of which two diametrically opposed ones are shown in Figure 2 at 25, 26. There may be four such apertures equally spaced about the receiving member, or possibly a larger number, e.g. six. The apertures as 25, 26 accommodate respective catch elements in the form of balls as indicated at 27, 28 and the balls are radially movable through the apertures, the extent of inwards movement thereof being limited by lips (as indicated at 29 for the aperture 25) at the innermost end of the apertures.

Axially slidable on the exterior of the receiving member 22 is a control member 30 of hollow cylindrical form, having in its interior an outwardly extending annular recess 31 into which outermost parts of the balls as 27, 28 are movable. When the balls are in this position, as shown in Figure 2, they are clear of the interior socket 23 of the receiving member. At the end of the recess 31 nearest the end of the receiving member 22 from which the engagement member 21 can enter the receiving member, the control member has in its interior an inclined (frusto-conical) cam surface as indicated at 32 and shown in greater detail in Figure 3a.

The receiving member 22 is secured to an electrically energisable solenoid coil indicated generally at 35, by a bolt 36. Wires for supplying electrical power to the coil 35 are indicated at 37.

Although not shown in Figures 2 and 3, there is fixing means enabling the holding means 20 to be fixed relative to the track 17 in a position corresponding to the desired held-open position of the door 10. The holding means is able to be adjusted along the track 17, and fixed in the required adjusted position.

The engagement member 21 comprises a base 40 fixed to the block 16 and a spigot 41 extending axially therefrom. The spigot 41 ends in a tapered nose portion 42. Adjacent the nose portion 42 the external surface of the spigot has an annular catch formation 43 therein, in the form of a groove of part circular cross-sectional shape corresponding to the balls 27, 28.

The control member 30 is retained on the receiving member 22 by a circlip 45 adjacent the open free end of the latter. The control member is of magnetic material so as to be magnetically attracted to the coil 35 when the latter is electrically energised. As the control member 30 approaches the coil 35, the cam surface 32 within the control member engages the balls as 27, 28, and causes the latter to be moved radially inwardly through their apertures 25, 26 to a limiting position determined by the lips as 29, in which the balls protrude inwardly into the socket formation 23 so as to be able to enter the groove 43 in the engagement member when the engagenent member is present within the socket formation of the receiving member.

Figure 3 of the drawings illustrates the device in the condition wherein the engagement member has entered the receiving member as aforesaid, and the catch elements in the form of the balls have engaged with the groove 43. In this condition, as long as the coil 35 remains electrically energised, the engagement member is held within the receiving member so that the door can be held open despite the closing force exerted on the door (i.e. the force on the block 16 trying to pull it away from the holding means 20) by the door closer 13.

As clearly shown in the Figure 3a, when the control member has reached the limit of its movement and is contacting the coil 35 (Figure 3) the relationship between the cam surface 32 and the balls 21, 28 is such that if sufficient radially outwardly directed force is applied to the balls they can move the control member away from the coil 35, overcoming the force of its magnetic attraction to the coil. Thus even though the coil may be energised to hold the door open, the door can still be closed if sufficient force is exerted on it by a person wishing to close it. When the balls have moved sufficiently far outwardly to clear the groove 43 in the engagement member, the engagement member can be released from the receiving member 22.

When the coil 35 is no longer electrically energised, the control member is moved on the receiving member 22 away from the coil under the influence of a spring, so very little force has to be exerted on the balls to move them outwardly. The force exerted on the block 16 by operation of the door closer 13 will then be sufficient to cause the disengagement of the engaging member from the receiving member, permitting the door to close.

A light spring is operatively interposed between the control member 30 and coil 35 for such releasing movement of the control member when the coil is not energised. A further possibility is that a spacing member of nonmagnetic material, e.g. a plastics material or a non-ferrous metal, may be interposed between the control member and coil, to provide an air gap even when the control member has reached its limiting position adjacent the coil, to ensure that any residual magnetic attraction is minimal.

Referring now to Figures 4 and 5 of the drawings, these show that a holding means in accordance with the invention may be provided in association with the door closer 13 rather than with the guide track 17.

These figures show the door closer 13 which, as referred to above, may be of the spring operated hydraulically-damped type. The closer comprises a body 50 defining an internal cylinder 51 within which is axially movable a piston assembly 52. The piston assembly includes a rack formation 53 engaging with a pinion (not shown) carried by the spindle 14 of the closer, so that angular movement of the spindle as the door is opened and closed moves the piston assembly axially within the cylinder. A spring (not shown) is provided for biasing the piston towards one end of the cylinder. At the other end of the cylinder an engagement member 54 is connected to the piston assembly, the engagement member passing through a cylinder end cap 55, the end cap having a seal 56 which engages the external surface of the engagement member to prevent leakage of damping oil where the engagement member emerges.

To the exterior of the cylinder end cap 55 there is secured a holding means 60 which is as described above in relation to the holding means 20 in the embodiment of Figures 2 and 3. The holding means 60 can cooperate with the engagement member 54 to hold the latter, in exactly the same manner as above described, when the piston assembly 52 is at its position corresponding to the maximum required for opening of the door in which the door is to be held, as shown in Figure 5.

Referring finally now to Figure 6 of the drawings, this shows part of an embodiment corresponding to that shown, and in the operative condition shown, in Figure 2, but incorporating certain modifications in respect of the configuration of the receiving member 22 and control member 30. Other parts are as shown in Figure 2 and will not be described again, being identified by the same reference numerals previously used.

In Figure 6, the receiving member 22 has a portion 22_ of reduced external diameter adjacent the coil 3S. The control member 30 has, at its end closest to the coil 35, an internal recess 30_ facing the part 22_ of the receiving member, and ending in an inwardly extending annular wall 30_ which also forms the end of the annular recess 31 inside the control member. The wall 30_ cooperates with the end of the part 22_ of the receiving member, to limit the IS distance by which the control member can move away from the coil 35, as shown in Figure 6. A light helical spring may be disposed between the coil 35 and wall 30_ to urge the control member to its position in which it is shown in Figure 6. When in this position, a part 30_ at the end of The control member remote from the coil 35 extends beyond the end of the receiving member 22, and this part of the control member is engageable by the base 40 of the engagement member as the door approaches its fully open position. This moves the control member towards the coil, reducing the air gap therebetween and ensuring that the force which can be exerted on the control member by the coil when supplied with electrical power is sufficient to overcome the force exerted in the opposite direction by the spring. When the door has reached a position in which the balls as 27 enter the groove on the exterior of the engagement member and the control member contacts and is held in contact with the energised coil, the door is held in that position until the electrical power supply to the coil is cut off and the control member returns to its position shown in Figure 6.

In the present specification "comprises" means "includes or consists of" and "comprising" means "including or consisting of".

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1. A device for holding a door open, comprising an engagement member; and a holding means cooperable with the engagement member to hold the latter when the door is open; wherein the holding means comprises a receiving member affording a socket formation having an axis in the direction of which it receives the engagement member; a number of catch elements spaced about said axis and movable radially relative to the receiving member; a control member movable axially relative to the receiving member and having cam means cooperable with the catch elements for moving the latter radially inwardly relative to the receiving member by an axial movement of the control member; the catch elements when thus moved being engageable with the engagement member to hold the latter in the socket formation; and an electro- magnetic device operable on or in relation to the control member to achieve or permit said axial movement thereof.

2. A device according to Claim 1 wherein the electro-magnetic device is operable on the control member to cause said axial movement thereof to move the catch elements radially inwardly when it is energised with electrical power, and releases the control member for opposite movement thereof when the electrical power is cut off.

3. A device according to Claim 2 wherein the opposite movement of the control member is effected under the influence of spring means.

4. A device according to Claim 3 wherein the axial movement of the control member is assisted by engagement thereof with the engagement member.

5. A device according to any of Claims 1 to 3 wherein the engagement member is adapted to be connected to a door and the holding means to a member or structure relative to which the door is openable.

6. A device according to any one of the preceding claims wherein the receiving member comprises a sleeve affording a generally cylindrical socket for receiving the engagement member.

lO

7. A device according to Claim 6 wherein the catch elements are movable in respective apertures extending radially through the receiving member.

8. A device according to any one of the preceding claims wherein the catch elements comprise balls.

9. A device according to any one of the preceding claims wherein the control member comprises a sleeve movable axially on an exterior surface of the receiving member.

lO. A device according to Claim 9 wherein the control member has in its interior an annular recess having an annular cam surface engageable with the catch elements to move them inwardly upon axial movement of the control member.

11. A device according to Claim lO wherein said cam surface is frustoconical.

12. A device according to any one of the preceding claims wherein the engagement member comprises a generally cylindrical spigot having on its exterior an annular groove with which the catch elements are engageable.

13. A device according to Claim 12 as appendant directly or indirectly to Claim 8 wherein the annular groove has a cross-sectional shape which is part circular, substantially corresponding to the radius of each of the balls.

14. A device according to Claim 12 or 13 wherein the engagement member has a tapering nose portion which first enters the socket formation in the receiving member.

15. A device according to any one of the preceding claims wherein the configuration of the catch element, control member and cam means is such that exertion of sufficient force radially outwardly against the catch elements will cause axial displacement of the control member against any force exerted on it by the electro-magnetic device.

16. A device according to any one of the preceding claims wherein the electro-magnetic device comprises a coil operable directly on the control member, which is of suitable magnetically attractable material.

17. A device according to Claim 16 wherein the coil is disposed at an end of the receiving member opposite that from which the receiving member is entered by the engagement member.

18. A device according to any one of the preceding claims provided in association with a door closer.

19. A device according to any one of the preceding claims wherein the engagement member is movable along an axis in relation to a guide means and adapted to be connected to a door so as to undergo such movement by opening and closing the door, and the holding means is fixed or adapted to be fixed in relation to the guide means for holding the engagement member in a position relative to the guide means corresponding to the door being opened.

20. A device according to Claims 18 and 19, provided in a slide track adapted to be fitted to part of a frame relative to which a door is pivotally movable, the engagement member being connected to a slide member which is movable along the track and is connected to one end of an arm whose other end is fixed to an angularly movable spindle of a door closer adapted to be mounted on a door.

2 1. A device according to Claims 18 and 19 provided on or in a body of the door closer.

22. A device according to Claim 21 wherein the door closer is a spring powered hydraulically-damped device, and the engagement member is provided on a damping piston and the receiving member and associated parts are provided on a body within which the piston is movable.

23. A device for holding a door open substantially as herein described with reference to and/or as shown in the accompanying drawings.

24. A door fitted with a holding-open device according to any one of the preceding claims.

25. Any novel feature or novel combination of features described herein and/or in the accompanying drawings.