GB1576190A

GB1576190A - Tool for removing locking keys from members

Info

Publication number: GB1576190A
Application number: GB1587178A
Authority: GB
Original assignee: Coal Industry Patents Ltd
Current assignee: Coal Industry Patents Ltd
Priority date: 1978-04-21
Filing date: 1978-04-21
Publication date: 1980-10-01

Description

(54) TOOL FOR REMOVING LOCKING KEYS FROM MEMBERS (71) We, COAL INDUSTRY (PA TENTS) LIMITED, a company organised in accordance with the laws of Great Britain of Hobart House, Grosvenor Place, London, S.W.1X 7AE England, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to door opening tools, and in particular, but not exclusively, to tools for use in the opening of access doors in scraper chain conveyors.

A scraper chain conveyor comprises a series of line pans joined together to present a surface over which a material may be conveyed. The material is usually granular and is often a mineral such as coal. Each line pan comprises a pair of parallel opposed side sections which are substantially E or sigma-shaped in cross section. A deck plate is fixed between the centre projections of the side sections and forms the surface for conveying. Scraper bars are hauled over the deck plate in a direction parallel to the length of the conveyor by chains. In a double chain scraper conveyor, on a working run the chains move in the recesses of the side sections above the deck plate, and on a return run in the recesses below the deck plate.

In an installation, for instance in a coal mine, there may be up to three hundred line pans joined together to form the conveyor.

It is in these cases necessary to be able to gain access to the recesses below the deck plate at intervals along the conveyor so that should a break in the chain run below the deck plate occur it is possible to repair the chain without having to dismantle the whole conveyor. Also it is possible to carry out necessary maintenance. Presently access is gained through an access door provided in the deck plate of every fifth line pan (although not necessarily in every fifth line pan).

Originally the access doors and line pans were made of steel plate. The doors were joggled by forging to fit into frames which were fabricated into the deck plates. The doors did not fit very well into the frames in the deck plates. This had the advantage that the doors were easy to remove.' For instance in many cases one operative could stand on one end of the door and this would cause it to move enough for another operative to get a good grip on the door or to insert a lever whereby the door could be moved. However these doors also had the disadvantage that they could snag the scraper bars and possibly break the chain. Therefore nowadays the access doors and the line pans are machined. This gives a flush fit of the doors in the frames. However although this removes the danger of snagging and chain breaking, it also removes the advantage of easy opening.

Generally access doors as presently used have in them a pair of opposed slots each of which leads to a hole which is adapted to be aligned with a complementary hole in the frame. The door is then held in place by inserting a key into each hole and complementary hole, through the respective slots.

It is an object of the present invention to provide a tool that will facilitate the opening of machined access doors in line pans.

According to the present invention there is provided a tool to be used to move a key in a guideway formed in at least one of two members held in a set relationship by the key, the tool comprising a shaft having a pivoting end, and a key engaging device pivotally mounted on the shaft, the tool being adapted, in use, to be located with the pivoting end against an abutment on one of the members and the key engaging device engaged with the key, which, in use, is moved in the guideway by pivotal movement of the shaft.

Preferably the key engaging device is a hook. The key is normally rectangular in section with one end turned up to form a head which is provided to be engaged, in use, with the key engaging device. The key may also be a two or multi-pronged key, for instance a U-shaped key.

Preferably the key engaging device is mountable in one of a plurality of positions on the shaft in order to accommodate possible variations in the spacing of the key and the abutment. This may bc achieved by providing a channel in the shaft into which the key engaging device fits, the channel being provided with a series of grooves into which the key engaging device may fit and in which the device may pivot.

Preferably the tool also includes a member engaging device on or towards the other end of the shaft, whereby the two members may be moved relative to one another.

Conveniently the member engaging device comprises a curved end of the shaft having fixed onto it a plate which may be jammed into a slot on one of the members. Conveniently the slot comprises part of the abutment. A convenient jammable plate is square or rectangular in plan and has a parallelogram-shaped cross-section. The perpendicular distance between the two shorter sides of the parallelogram is less than the width of the slot, but the length of the longer sides of the parallelogram is greater than this width. The length of the shorter sides is shorter than the depth of the slot. Thus the plate may be inserted into the slot if the shorter sides are parallel to the sides of the slot and the longer sides are across the width of the slot. If the shaft is then rotated, the plate is jammed into the slot and the member may be moved.

The member engaging device may comprise any suitable means, for instance a hook engageable with an eye on one of the members, or an asymmetric flange engageable by rotation of the shaft in slits formed in the sides of a slot in one of the members.

In use, the tool operates in the following fashion to move members relative to one another. The pivoting end of the tool is placed against the abutment and the key engaging device is engaged with the key which is in its guideway. The tool is then pivoted in the appropriate direction, causing the key to be removed from its guideway, thereby freeing the members for relative movement. The member engaging device, if present, may then be engaged with one of the members and be used to cause relative movement between the members. The tool may be used in the opposite fashion to replace the members and to reinsert the key into the guideway.

It is envisaged that the tool according to the invention will be of particular, but not exclusive, use in the removal and replacing of doors in deck plates of line pans of a scraper chain conveyor installation. In this case the guideway is comprised of a slot and its respective hole and complementary hole.

The slot is also used to accommodate the member engaging device. In this case the tool will have to be used twice to remove the two keys from the door before it can be moved.

The tool may also be used for instance in ships where bulkhead door or hold doors are held in place by keys, or for manhole covers held in place by keys. The tool may also be used to remove lynch pins from hinges.

The invention will now be described by way of example only with reference to the accompanying drawings, in which: Figure 1 shows a side view of a tool according to the invention; Figure 2 shows a plan view of the tool of Figure 1; Figure 3 shows a scrap side view of the tool of Figure 1 in a position to extract a key from a line pan door; Figure 4 shows a scrap plan view of a line pan with the tool in a position to move the door; and Figure 5 shows a side view along line A-A of Figure 4.

Referring now to Figures 1 and 2, the tool according to the invention comprises a rectangular cross section shaft 1 having an enlarged end 2 which tapers to a point 3. A channel 4 is formed in the enlarged end 2, and has in it three grooves 5. A hook 6 comprising a flat metal member having a slit 7 in one end and bent into a hook shape at its other end is welded onto a circular section bar 8 which passes through the channel 4. The bar 8 has a diameter slightly less than that of the grooves 5. The bar 8 is engageable in the grooves 5 and the hook 6 may pivot about the bar 8 in the grooves 5.

At its other end, the shaft 1 is curved and has welded onto it a plate 9 having a parallelogram-shaped cross section.

The use of the tool will be described now with reference also to Figures 3 to 5. A door 10 is to be removed from a frame 11 (comprising the bottom plate of a line pan, the central projection 20 of which is seen in Figure 3). The door 10 has in it a pair of opposed slots 12, leading to holes 13. In use the holes 13 are aligned with complementary holes 14 in the frame 11. The frame 11 and door 10 around their edges are formed into complementary tongues 15, 16, except around the region of the slots 12 where they are flush fitted so that the holes 13 and 14 may be aligned. Each slot 12, and its respective hole 13 and complementary hole 14 comprise a guideway for a key 17.

The door 10 is held in place in the frame 11 by passing the key 17 through each set of holes 13, 14 and slot 12. The key 17 has a tapered end 18 and is bent at its other end 19 so as to form a part engageable with the hook 6.

To remove the key 17, the pointed pivoting end 3 of the shaft 1 is placed in the left hand slot 12 (as seen in Figure 3) and the shaft 1 is moved until the hook 6 is engaged with the key 17 as shown in full lines in Figure 3. (If the hook 6 cannot be so engaged with the bar 8 in the groove 5 as shown, the bar 8 may be relocated into another groove 5 to enable the hook 6 to engage with the key 17). The shaft 1 is then pivoted in an anticlockwise direction (as seen in Figure 3) to the position shown in chain lines, wherein the key 17 is extracted from the holes 13, 14, and may be removed from the slot 12 manually.

A similar procedure is then carried out to remove the key (not shown) in the left hand slot 12 of the door 10. With the keys 17 removed the door may be opened by inserting the plate 9 into one of the grooves 12 as shown in Figures 4 and 5.

The dimension a of the plate 9 is less than the width b of the slots 12. The dimension c of the plate 9 is less than the depth d of the slots 12. However the length e of the plate 9 is greater than the width b of the slots 12.

Therefore when the shaft 1 is rotated in an anticlockwise sense as seen in Figure 5 the plate 9 is jammed into the slot 12. The door 10 may then be opened by lifting the shaft 1.

Thus the present invention provides a useful tool for use with line pans whereby operatives can easily remove flush fitting access doors to carry out repairs or mainte nance.

WHAT WE CLAIM IS: 1. A tool to be used to move a key in a guideway formed in at least one of two members held in a set relatonship by the key, the tool comprising a shaft having a pivoting end, and a key engaging device pivotally mounted on the shaft, the tool being adapted, in use, to be located with the pivoting end against an abutment on one of the members and the key engaging device engaged with the key, which, in use, is movable in the guideway by pivotal movement of the shaft.

2. A tool according to claim 1, in which the key engaging device is a hook.

3. A tool according to either one of claims 1 and 2, in which the key engaging device is mountable in one of a plurality of positions.

4. A tool according to claim 3, in which a channel having a plurality of grooves provides the plurality of mounting positions for the key engaging device.

5. A tool according to any one of the preceding caims, and including a member engaging device.

6. A tool according to claim 5, in which the member engaging device comprises a plate fixed on the other end of the shaft, which end is curved, the member being jammable in a slot in one of the members by rotation of the shaft.

7. A tool substantially as herein before described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

14 comprise a guideway for a key 17.

The door 10 is held in place in the frame 11 by passing the key 17 through each set of holes 13, 14 and slot 12. The key 17 has a tapered end 18 and is bent at its other end 19 so as to form a part engageable with the hook 6.

To remove the key 17, the pointed pivoting end 3 of the shaft 1 is placed in the left hand slot 12 (as seen in Figure 3) and the shaft 1 is moved until the hook 6 is engaged with the key 17 as shown in full lines in Figure 3. (If the hook 6 cannot be so engaged with the bar 8 in the groove 5 as shown, the bar 8 may be relocated into another groove 5 to enable the hook 6 to engage with the key 17). The shaft 1 is then pivoted in an anticlockwise direction (as seen in Figure 3) to the position shown in chain lines, wherein the key 17 is extracted from the holes 13, 14, and may be removed from the slot 12 manually.

A similar procedure is then carried out to remove the key (not shown) in the left hand slot 12 of the door 10. With the keys 17 removed the door may be opened by inserting the plate 9 into one of the grooves 12 as shown in Figures 4 and 5.

The dimension a of the plate 9 is less than the width b of the slots 12. The dimension c of the plate 9 is less than the depth d of the slots 12. However the length e of the plate 9 is greater than the width b of the slots 12.

Therefore when the shaft 1 is rotated in an anticlockwise sense as seen in Figure 5 the plate 9 is jammed into the slot 12. The door 10 may then be opened by lifting the shaft 1.

Thus the present invention provides a useful tool for use with line pans whereby operatives can easily remove flush fitting access doors to carry out repairs or mainte nance.

WHAT WE CLAIM IS: 1. A tool to be used to move a key in a guideway formed in at least one of two members held in a set relatonship by the key, the tool comprising a shaft having a pivoting end, and a key engaging device pivotally mounted on the shaft, the tool being adapted, in use, to be located with the pivoting end against an abutment on one of the members and the key engaging device engaged with the key, which, in use, is movable in the guideway by pivotal movement of the shaft.
2. A tool according to claim 1, in which the key engaging device is a hook.
3. A tool according to either one of claims 1 and 2, in which the key engaging device is mountable in one of a plurality of positions.
4. A tool according to claim 3, in which a channel having a plurality of grooves provides the plurality of mounting positions for the key engaging device.
5. A tool according to any one of the preceding caims, and including a member engaging device.
6. A tool according to claim 5, in which the member engaging device comprises a plate fixed on the other end of the shaft, which end is curved, the member being jammable in a slot in one of the members by rotation of the shaft.
7. A tool substantially as herein before described with reference to the accompanying drawings.