GB2030211A - Improvements in hinged doors - Google Patents

Abstract

A door 10 for closing off, for example, a brick kiln 11, is hinged at one edge for swinging movement on two hinges 14, 15 about a verticle hinge line and carries a jockey wheel 28 at the bottom of its opposite edge. When closed, the door rests on the ground and a pair of rams 25, 30 are provided for raising the door clear of the ground so that it may be swung open. One ram 25 is co-axial with the hinge line and the other 30 acts on the jockey wheel 28. The rams are operated by a manually- operated hydraulic pump 33. <IMAGE>

Description

SPECIFICATION Improvements in hinged doors The invention relates to hinged doors and provides a hinged door mounted on a fixed structure for pivotal movement about a generally vertical hinge line and comprising at least one hinge adapted to permit relative movement along the hinge line between the door and the fixed structure, a wheel or the like mounted on a part of the door remote from the hinge line and means for lifting the door between a lowered position in which the door rests on the ground or other support surface and a raised position in which the door is supported on the wheel clear of the ground and may be pivoted about the hinge line.

The lifting means may comprise at least one ram and preferably there are two rams, one acting between the fixed structure and the door to raise the door relative to the fixed structure and the other acting between the door and the wheel to lower the wheel relative to the door. The axis of the said one ram preferably coincides with the hinge line.

A suitable hydraulic circuit including a hand pump or the like may be provided for supplying fluid under pressure to the rams and preferably includes a restrictorvalve in series with the said other ram.

The hinged door described above is particularly suitable for closing off a kiln, such as the type of kiln used for firing bricks, which may comprise a number of firing chambers, which are fired independently one of the other.

Hitherto, in kilns of this type, the kiln doors have been free standing and when a kiln is to be utilized the doors are placed in position, across the entrance to the kiln chamber, by an operator using a fork lift truck.

Once in this position the doors are "wedged" shut with the aid of blocks of wood etc.

One of the disadvantages of such a system is that extra capital equipment, viz, the fork lift truck, is required with the attendant difficulties of maintenance, storage and the requirement of a driver therefore.

Another disadvantage is that the doors, once removed from their operative positions have to be stacked somewhere until required for further use and although the doors are fairly robust they are prone to extensive damage over a period of time thereby involving the cost of repair or replacement.

The door described above overcomes these disadvantages.

Further features and advantages of the invention will be apparent from the following description, by way of example, of a preferred embodiment of a hinged door according to the invention, the description being read with reference to the accompanying drawings, in which: Figure 1 is an elevation view of a hinged door according to the invention, and Figure 2 shows the hydraylic circuit of the rams of the door of Figure 1.

Referring first to Figure 1, there is shown a door 10 for closing off a kiln, parts of the structure 11 of which is shown in Figure 1. The kiln is a large furnace suitable for firing bricks and may be of the type described in British Patent Specifications 1490129 and 1490130.

The door 10 is a rectangular structure of a heat-resistant material reinforced by steel bars 13 fixed to its outer face. The door is pivoted on a part of the kiln structure 11 for swinging movement about a vertical hinge line by means of two hinges 14, 15, arranged at spaced locations of one of the shorter-edges of door 10. Each hinge 14, 15 consists of two hinge parts 17,18, one rigidly fixed to the kiln structure 11 and the other to the door 10.The hinge parts 17, 18 are in the form of angle bars with triangular strengthening webs and are connected together by a bolt 19 passing through one flange of each of the hinge parts 17, 18. Each bolt 19 has a nut 20 at each of its ends and is of a sufficient length to permit limited relative movement in the direction of the hinge line between the door 10 and the kiln structure 11.

The hinge parts 17 are welded to the web of a vertical l-beam 22 forming part of the kiln structure and which is shown in Figure 1 with its front flange removed for clarity.

Welded to the bottom of the web of the I-beam 22 is a support bracket 24 which rests on the floor and supports a hydraulic ram 25, the cylinder of which is fixed to the bracket 24 and which is arranged with its axis vertical. When actuated, the piston of the ram 25 acts on a flange 26 fixed to the door 10 to lift and support the hinged end of the door 10. The arrangement is such that the loading on the hinges and then the kilm frame is reduced to an acceptable level.

At the lower part of the free edge of the door 10 (that is, the edge opposite to the hinges 15, 16) there is provided a jockey wheel 28, pivoted on a U-bracket 29. The bracket 29 is supported by the piston of a ram 30, the cylinder of which is fixed to the door 10.

Fixed to the door 10 above the ram 3O is a horizontal support bracket 32 for a hand-pump 33 used to supply hydraulic fluid to the rams.

Referring now to Figure 2 as well as Figure 1,the pump 33 is connected by a hose 34 including a check valve 35 to a T-connector 36, the other arms of the connector 36 being joined by a hose 37 to the ram 25 and by a hose 38 to a restrictor valve 39 connected to ram 30. The use of the door 10 is as follows. When the kiln is in operation, the door 10 closes off the open front of the kiln as shown in Figure 1. In this positionm the door rests on the ground and is clamped in position sealing the kiln by clamps (not shown) spaced around the periphery of the door.

When firing of the bricks within the kiln is completed, the clamps are released and the pump 33 is placed in position as shown in Figure 1 and connected to hose 34 by a quick-release coupling.

The pump is then operated manually to extend both rams 25,30 and raise the door clear of the ground. During the pumping operation, the restrictor valve 39 ensures that, at each pumping stroke, hydraulic fluid is supplied first to ram 25 and then ram 30. This ensures that the door 190 is raised evenly at both ends. When the door has been raised clear of the ground, it is swung open through approximately 90 , the hinged end pivoting on ram 25 and the free end rolling on the wheel 28.

When the door is fully open, the pump 33 may be disconnected and used to open another similar door 10, the check valve 35 being closed by the action of disconnecting the pump 33 and ensuring that no hydraulic fluid is lost from the circuit and the door remains in its raised position.

When the fired bricks have been removed from the kiln and replaced by unfired bricks readyforfiring, the door 10 is again swung to its closed position. The pump 33 is replaced and the door is lowered by operating a relief valve on the pump which permits the hydraulic fluid to bleed back into a reservoir of the pump, the weight of the door forcing the fluid back into the reservoir. When the door is again in contact with the ground, it is clamped in position closing the kiln and the pump 33 is removed.

It will be appreciated that when the door 10 is open it may be left in either its raised or lowered position.

If left in its lowered position, the pump must be used to raise the door before it is swung into its closed position.

The invention is not limited to the preferred embodiment described above and various modifications may be made. For example, the door 10 may close off chambers other than kilns or furnaces.

Claims (9)

1. A hinged door mounted on a fixed structure for pivotal movement about a generally vertical hinge line and comprising at least one hinge adapted to permit relative movement along the hinge line between the door and the fixed structure, a wheel or the like mounted on a part of the door remote from the hinge line and means for lifting the door between a lowered position in which the door rests on the ground or other support surface and a raised position in which the door is supported on the wheel clear of the ground and may be pivoted about the hinge line.

2. A door as claimed in claim 1 in which the lifting means comprises at least one ram.

3. A door as claimed in claim 2 in which the lifting means comprises two rams, one acting between the fixed structure and the door to raise the door relative to the fixed structure and the other acting between the door and the wheel to lower the wheel relative to the door.

4. A door as claimed in claim 3 in which the axis of the said one ram coincides with the hinge line.

5. A door as claimed in claim 3 or claim 4 in which a hydraulic circuit is provided for conducting fluid under pressure from a pressure fluid source to the rams, the circuit including a restriction valve in series with the said other ram.

6. A door as claimed in claim 5 in which the pressure fluid source comprises a hand pump and the door includes a support bracket for the pump.

7. A hinged door substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

8. A chamber open at one side and including a hinged door as claimed in any one of the preceding claims pivoted on a part of the chamber.

9. A kiln comprising a chamber as claimed in claim 8.