GB2449756A

GB2449756A - Mechanism controlling the closing of a door for a temperature controlled room

Info

Publication number: GB2449756A
Application number: GB0809560A
Authority: GB
Inventors: Sew Hing Woo
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-05-26
Filing date: 2008-05-27
Publication date: 2008-12-03
Also published as: GB2449636A; GB0710146D0; GB0809560D0

Abstract

A mechanism arranged to control the position of a door 10 to a cold room such as a walk-in refrigerator where the energy inputted into the mechanism for opening the door is used to power the closing of the door. The door may be closed by a weight 22 attached to the door 10 by cable 14; upon opening the door the weight is raised, and upon release of the door the potential energy in the raised mass closes the door. The door may be closed by the force of compression spring 32 positioned between the door and frame which is compressed at the door open position and applies a force on the door in the closing direction. A coil spring 12 may be attached to the door and connected to a cable 14 fixed to the wall of the room; upon opening of the door the helical spring is compressed and applies a force on the cable to close the door. The door may be retained in the open position for example by a suction cup 42 with a pressure relief valve which allows air into the suction cup to release the door after a predetermined time delay; additionally a separate timer may be provided in conjunction with the pressure relief valve of the suction cup.

Description

1 2449756

IMPROVED MECHANISM FOR A TEMPERATURE CONTROLLED ROOM DOOR

This invention relates to apparatus for closing a door to a room that has its temperature controlled.

Temperature controlled rooms are used in many places to store chilled and frozen products.

The room has a door that is opened when a person wants to place products in the room or take products out of the room. Often doors are left open, as they can be heavy and unwieldy. Due to the temperature difference between ambient air and the air within the room leaving the door open allows warmer ambient air to enter the room and the temperature of air within the room to increase. Additionally, at the same time, moisture within ambient air also enters the room.

To reduce the temperature in and remove excess moisture from the room requires energy.

Closing the door to the room soon after it has been opened minimises the increase in temperature and moisture within the room. Therefore, it is advantageous to keep the time * ... * that the door is open to a minimum. * *. *.** * . * *.*

: * One possible mechanism for opening and closing a door to a temperature controlled room is a...

described in International Patent Application No. WO 99/22105. International Patent Application No. Wa 99/22105 describes the use of a motor to open and close a door. A * positioning system allows the acceleration and deceleration of the door to be controlled. a..

However, such a mechanism requires the use of a motor, and therefore energy, negating any energy savings from the reduction in energy needed to cool the air within the room.

According to a first aspect of the invention there is provided a mechanism arranged to control the position of a door to a temperature controlled room, the door being adapted to moved between an open position and a closed position, the mechanism having an active configuration where the mechanism causes a force to be exerted on the door and a rest configuration, the mechanism connected to the door in such a manner that when the door is in the open position the mechanism is in the active configuration and when the door is in the closed position the mechanism is in the rest position, the force exerted by the mechanism on the door is directed to cause the door to move into the closed position. The mechanism thereby allows the potential energy created by the opening of the door to be used to close the door ensuring that the door is fully closed.

The mechanism may comprise a compression spring fixed, at one end, to the door and, at the other end, to a wall of the temperature controlled room, compression spring being compressed when the door is in the open position. The compression spring tends towards its rest position and, when no opposing force is exerted on the door, will push against the door to return itto its closed position. * * * *..

: ** Alternatively, the mechanism may comprise a coil spring attached to the door and connected to one end of a cable, the other end of the cable being attached to a fixed point, the active : configuration comprising the helical spring being compressed and exerting a force on the *** * * cable to move the door to a closed position. The spring is arranged so that when it returns to *..

the rest position it pulls the cable towards it thereby moving the door towards the end of the cable that is fixed and towards a controlled position.

The end of the cable that is fixed may be attached to a wall of the temperature controlled room or, alternatively, to a bracket fixed to a slider along which the door is configured to slide.

The cable may be arranged to pass over a roller to ensure that there are no sharp turns in the cable. The roller may be attached to the door or, alternatively, it may be attached to a wall of the temperature controlled room.

In a further embodiment the mechanism may comprises a cable attached to the door at one end and to a weight at the other end, the cable being arranged to run over a fixed roller, the active configuration comprising the weight being raised above the level of the floor. The opening of the door raising the weight up and the force of gravity moving the weight down causing a force to be exerted onto the door through the cable to return the door to a closed position.

The mechanism may also include means configured to retain the mechanism in the active configuration. This may be, for example, a suction cup. The suction cup may be attached to * ** *. a bracket on a wall of the temperature controlled room such that a side of the door contacts **..

* ** the suction cup when the door is in the open position. Alternatively, the suction cup is * S * *S*S *20 attached to a side of the door and is arranged to contact a projection from the temperature controlled room such that the suction cup contacts the projection when the door is in the * ** * * S *** S * open position. S..

Additionally, the mechanism further includes timing means configured to cause the means configured to retain the door to allow the door to return to the closed position after a specified amount of time. This timing means may be a pressure relief valve configured to allow air to enter the suction cup at a predetermined rate. Alternatively, the timing means may include timer and a pressure relief valve the timer configured to cause the pressure relief valve to allow air to enter the suction cup after a specified time period has elapsed.

According to a second aspect of the present invention there is provided a temperature controlled room including a door configured to slide between an open and a closed position and a mechanism arranged to control the position of a door to a temperature controlled room, the door being adapted to moved between an open position and a closed position, the mechanism having an active configuration where a force is exerted on the door and a rest configuration, the mechanism connected to the door in such a manner that when the door is in the open position the mechanism is in the active configuration and when the door is in the closed position the mechanism is in the rest position, the force exerted by the mechanism on the door is directed to cause the door to move into the closed position.

Other aspects and features of the present invention will become apparent to those ordinarily * *. skilled in the art upon review of the following description of specific embodiments of the * *.

invention in conjunction with the accompanying figures. *S*. * ** * * * *S*.

*O Figure la illustrates a door in accordance with a first embodiment of the present invention in a closed position; * ** * * * S.. S * Figure lb illustrates a door in accordance with a first embodiment of the present invention in S.. *

an open position; Figure 2a illustrates a door in accordance with a second embodiment of the present invention in a closed position; Figure 2b illustrates a door in accordance with a second embodiment of the present invention in an open position; Figure 3a illustrates a door in accordance with a third embodiment of the present invention in a closed position; Figure 3b illustrates a door in accordance with a third embodiment of the present invention in an open position; and Figure 4a illustrates the first embodiment of the present invention including a suction cup to maintain an open position; and Figure 4b illustrates the first embodiment of the present invention including a suction cup to maintain an open position and damping means.

A first embodiment of the present invention is illustrated in Figures Ia and lb. In Figure 1 a door 10 to a room that is temperature controlled (not shown) is opened and closed by substantially horizontal motion along a slider (not shown). The door 10 has a coil spring 12 attached to it. A cable 14 is connected, at one end, to the coil spring 12 and at the other end to a fixed point on a wall of the room. The fixed point may be, for example, a bracket 16, or *:*::* any other suitable attachment means. Preferably the cable 14 passes over two rollers 18 *. that act to maintain the cable's position and thereby allow free movement of the cable 14. * ** * * * *S*.

*20 When the door 10 is moved from the closed position, illustrated in Figure Ia, to the open position, illustrated in Figure ib, the coil spring 12 on the door 10 moves away from the fixed * point 16 on the wall where the cable 14 is attached. As the coil spring 12 moves away from *S.

S

the fixed point 16 the cable 14 acts to compress the coil spring 12. In this manner the energy used to open the door 10 can be stored. When the door 10 is released the coil spring 12 returns to its rest position as there is no longer any force maintaining it in a compressed position. The coil spring 12 returning to its rest position pulls the cable 14 over the rollers 18 and restores the door to its closed position.

In this way the time that the door 10 is open is reduced and it can be ensured that the door 10 is provided with sufficient force to fully close. Hence, the amount of energy required to cool the temperature controlled room can be reduced.

As will be understood by the skilled person the cable 14 may be attached to any suitable fixed point. For example it may be attached to a fixed bracket on the slider along which the door moves.

Any number of rollers may be used to help guide the rope. Additionally, one or more rollers may be situated in any suitable position, for example, a roller may be attached to the door, to a fixed point on the wall of the temperature controlled room or to a fixed point on the slider along which the door moves. Further the rollers may be used in pairs and positioned adjacent to each other with the cable running between, and in contact with both of, the * *. rollers. * * * * *S S... * . * S5*

* *, In another embodiment, illustrated in Figures 2a and 2b, the cable 14 is fixed at one end 20 * S * *S..

*0 to the door 10. The other end of the cable 14 is connected to a dead weight 22 that can be raised and lowered. The cable 18 is arranged to pass over at least one roller 18 fixed on the * wall. The roller 18 facilitates movement of the cable 14. **S

In the second embodiment, when the door 10 is moved from the closed position, illustrated in Figure 2a, to the open position, illustrated in Figure 2b, the cable 14 passes over the roller 18 and the dead weight 22 is raised from its rest position. When the door 10 is released the dead weight 22 lowers to the floor pulling the cable 14 over the roller 18 and thereby exerting a horizontal force on the fixed point 20 of the door 10, moving the door 10 to the closed position.

In a third embodiment, illustrated in Figures 3a and 3b, one edge 30 of the door 10 is in communication with a compression spring 32 that is attached to a wall of the room (not shown). The compression spring 32 may be attached to the wall using any suitable means, for example, a bracket. When the door is moved from the closed position, illustrated in Figure 3a, to the open position, illustrated in Figure 3b, the spring 32 is compressed from its normal rest configuration. This means that when the door 10 is released the spring exerts a force onto the edge 30 of the door 10 until it returns to its rest position. The force exerted on the edge 30 or the door 10 causes the door 10 to return to the closed position.

Optionally, temperature controlled room may be provided with means for holding the door open in order that, for example, if many products are to be placed within the room the door .. does not have to be opened multiple times. An example of this is illustrated in Figure 4 * *.

*. where the wall is provided with a bracket 40 that is attached to a suction cup 42 arranged to **S.

* *. contact the door 10 when the door 10 is fully open. When the door 10 is moved to the open * * S *S..

*0 position it presses against the suction cup 42, pushing the air out of the suction cup 42 : causing the door 10 to be held against the suction cup 42 by a pressure differential. *** I

I *I.

I

To close the door 10 air is released into the suction cup 42, for example, using a pressure release valve (not shown). The entry of air reduces the pressure differential until the suction cup 42 no longer holds the door 10 in the open position allowing the door 10 to return to the closed position.

As will be understood by the skilled person any suitable means, such as a latch, can be used to hold the door in the open position.

Preferably, to minimise the amount of warm air entering the room, the door is only held open for a specified period of time. In the embodiment illustrated in Figure 4a this may be achieved by fitting the suction cup 42 with a pressure release valve (not shown) that allows a gradual ingress of air into the suction cup 42. This gradual ingress of air means that after a predetermined amount of time the suction cup 42 will no longer hold the door 10 in the open position and the door will return to the closed position. Preferably, the rate of ingress of air is variable so that the time that the door 10 is held in the open position can be varied. Any other means for varying the time that the doorl 0 is open can be used, for example, a timer may be used to automatically release a latch holding the door open or to open the pressure relief valve after a specified amount of time. * S. * * . * *.

*. Optionally, damping means 44 (as illustrated in Figure 4b) may be provided to slow the ***.

* *, speed at which the door 10 approaches the suction cup 42 in order to prevent the speed of * S * *.*S the door 10 being too great for suction to occur between the suction cup 42 and the door 10.

: Any suitable damping means, such as a compression spring, may be used to decelerate the S.. * * door 10. As will be understood by one skilled in the art the damping means may be situated S..

S

in any suitable position to enable damping to occur.

As will be understood by one skilled in the art, although Figure 4 illustrates the suction cup being attached to the wall using a bracket attached to the wall, any suitable means may be used to attach a suction cup to the wall. Additionally, the suction cup may attached to the door, rather than to the wall, and arranged to contact a flat surface that projects from the wall. Any other suitable arrangement may be used.

The cable may be made of any suitable material, for example, it may be made from steel. * I. * * * * S. * . * *. * . S S...

S * .. * S 5 ** * *..

Claims

1. A mechanism arranged to control the position of a door to a temperature controlled room, the door being adapted to moved between an open position and a closed position, the mechanism having an active configuration where a force is exerted on the door and a rest configuration, the mechanism connected to the door in such a manner that when the door is in the open position the mechanism is in the active configuration and when the door is in the closed position the mechanism is in the rest position, the force exerted by the mechanism on the door is directed to cause the door to move into the closed position.

2. The mechanism as recited in Claim I wherein the mechanism comprises a compression spring fixed, at one end, to the door and, at the other end, to a wall of the temperature controlled room, compression spring being compressed when the door is in the open position.

*...*

3. The mechanism as recited in Claim I wherein the mechanism comprises a coil spring * ** * * attached to the door and connected to one end of a cable, the other end of the cable **.* being attached to a fixed point, the active configuration comprising the helical spring e * * S...

being compressed and exerting a force on the cable to move the door to a closed position. *.. . **.

4. The mechanism as recited in Claim 3 wherein the other end of the cable is attached to the wall

5. The mechanism as recited in Claim 3 wherein the other end of the cable is attached to a bracket fixed to a slider along which the door is configured to slide.

6. The mechanism as recited in any one of Claims 3 to 5 wherein the cable is arranged to pass over a roller.

7. The mechanism as recited in Claim 6 wherein the roller is attached to the door.

8. The mechanism as recited in Claim 6 wherein the roller is attached to a wall of the temperature controlled room.

9. The mechanism as recited in Claim I wherein the mechanism comprises a cable attached to the door at one end and to a weight at the other end, the cable being arranged to run over a fixed roller, the active configuration comprising the weight being raised above the level of the floor.

10. The mechanism as recited in any preceding claim further including means configured * S. . to retain the mechanism in the active configuration. * I * S...

*0

11. The mechanism as recited in Claim 10 wherein the means configured to retain the mechanism in the active configuration comprises a suction cup. *** *5s

S

12. The mechanism as recited in Claim 11 wherein the suction cup is attached to a bracket on a wall of the temperature controlled room such that a side of the door contacts the suction cup when the door is in the open position.

13. The mechanism as recited in Claim 11 wherein the suction cup is attached to a side of the door and is arranged to contact a projection from the temperature controlled room such that the suction cup contacts the projection when the door is in the open position.

14. The mechanism as recited in any of Claims 10 to 13 wherein the mechanism further includes timing means configured to cause the means configured to retain the door to allow the door to return to the closed position after a specified amount of time.

15. The mechanism as recited in Claim 14 when dependent upon any of Claims 11 to 13 wherein the timing means includes a pressure relief valve configured to allow air to enter the suction cup at a predetermined rate.

16. The mechanism as recited in Claim 14 when dependent upon any of Claims 11 to 13 wherein the timing means includes timer and a pressure relief valve the timer configured to cause the pressure relief valve to allow air to enter the suction cup after * a specified time period has elapsed. * .* *. . *

:.20

17. A temperature controlled room including: a) a door configured to slide between an open and a closed position * b) a mechanism as recited in any of Claims I to 16. S..

18. A mechanism substantially as herein described with reference to and as shown in any combination of the accompanying drawings.

19. A temperature controlled room substantially as herein described with reference to and as shown in any combination of the accompanying drawings. * ** * S S * SS S... * S * S* * . .

S 5. * S. * . S 55.

S

SSS

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