GB2257024A

GB2257024A - Beam connector lock

Info

Publication number: GB2257024A
Application number: GB9113245A
Authority: GB
Inventors: Andrew Gleaves
Original assignee: BARRETT STORAGE SYSTEMS PLC
Current assignee: BARRETT STORAGE SYSTEMS PLC
Priority date: 1991-06-19
Filing date: 1991-06-19
Publication date: 1993-01-06
Anticipated expiration: 2011-06-19
Also published as: GB2257024B; GB9113245D0

Abstract

A lock 10 is used to lock a beam 11 in place in a pallet racking system. The lock comprises a block 50 which is mounted on a pin 51. The pin 51 comprises a front portion 52 and a rear portion 53. The block 50 is mounted eccentrically on the pin 51. The front portion 52 is much larger than the other components of the lock 10 and is formed into a flag. The block 50 is formed with the groove 90, the dimensions and positioning of which are chosen in order that the block will shear under a predetermined load. The pin 51 is formed from a weaker material than that of the block. <IMAGE>

Description

LOCK This invention relates to a lock and in particular, but not exclusively to a lock for use in adjustable pallet racking systems. An adjustable pallet racking system generally comprises the following: a frame made up of two or more uprights, adjacent uprights being joined together with structural braces; and beams comprising structural sections with handed connectors to each end which transmit the load from the beams to the frames.

A beam is connected to an upright by means of protrusions formed in the connector which engage with pre-formed holes in the upright.

Adjustable pallet racking systems are often used in warehouse environments. Forklift trucks are used to place, remove and replace pallet loads in predetermined positions.

As the pallet rackings systems may be relatively high, generally ranging from 2.4 metres to 10 metres, it is difficult to accurately position the fork of a truck relative to the racking system.

Careless fork truck driving and load positioning may cause the pallet loads to be uplifted such that they exert forces on the beam above the one on which they are to be supported.

The accidental uplifting of a beam potentially results in the beam becoming disconnected from the two uprights to which it is connected. If such disconnection were to occur, the beam would fall to the ground with possibly disastrous consequences.

In order to reduce the chances of this occuring, it is known to use beam connector locks.

Existing locks are designed to be placed in position through the interface between the upright and the connector. Known locks are generally of a pin type nature.

Disadvantages of these known locks are that they are easily removable. and not easily seen at high level. In addition, it is not easy to ascertain when a lock has sheared. This means that the beam may not in fact be securely locked.

A further disadvantage is that these known locks are frequently tampered with.

According to a first aspect of the invention there is provided a beam connector lock comprising: a pin having a front portion and a rear portion; and a block rotatably mounted on the pin between the front portion and the rear portion, characterised in that the block is eccentrically mounted on the pin.

In use, the block may be inserted through the pre-formed holes in the connector and the upright. The dimensions of the lock are such that when the front portion of the pin is flush against the surface of the connector, the block is positioned appropriately within the upright.

The front portion of the pin may then be rotated through 1800 The pre-formed hole is shaped such that the block cannot rotate whilst the pin rotates.

Due to the fact that the block is mounted eccentrically on the pin rotation of the pin by approximately 180 results in the rear portion locking behind lugs in the connector.

Once the lock has been moved into the locked position, it cannot be removed without first rotating the lock through 1800 again and pulling the assembly out of the pre-formed holes.

Thus, the lock according to the present invention is not easily removeable.

Preferably, the pin is made of a weaker material than the block. This means that should the block shear due to the load applied to the beam, the pin will shear as well. This means that the pin will fall to the floor on failure of the lock. The presence of a pin portion on the floor thus reveals that a lock has failed.

Preferably, the block comprises a groove the size of which groove determines the load under which the block will shear. The groove also determines the direction and manner in which the blocks will shear.

Preferably, the block is made fron a zinc alloy, and the pin is made from a thermoplastics material.

Advantageously, the front portion is formed into a flag, which is clearly visible from some distance. Conveniently, the front portion may be formed from a bright colour such as yellow to further enhance the visibility.

Advantageously, the rear portion of the pin is substantially the same size as the block. This means that the block may be inserted through a fairly small pre-formed hole in the connector and upright.

According to a second aspect of the invention there is provided a lock comprising a pin, and a block mounted on the pin. characterised in that the pin is formed from a weaker material than the block. The invention will now be further described by way of example only with reference to the accompanying drawings in which; Figure 1 is a schematic diagram of a pallet racking system in which a lock according to the invention may be used.

Figures 2 to 4 illustrate how the lock according to the invention is inserted into a connector and upright and moved into the locked position; Figures 5 and 6 illustrate the position of the block relative to the pin of the lock in the locked position; Figures 7 and 8 illustrate the position of the block and pin in the unlocked position; and Figures 9 to 12 show the lock according to the invention in more detail.

Referring to Figure 1, a portion of a pallet racking system is shown. The system comprises a frame 100 formed from uprights 110, and beams 120. The beams 120 are connected to the upright 110 by means of handed connectors 130.

Referring to Figures 2 to 4 a lock according to the present invention is designated generally by the reference numeral 10. The lock 10 is used to lock a beam 11 in place on an upright which beam and uprights form the pallet racking system shown in Figure 1. The beam 11 is joined to a connector or cleat 12. The beam 11 is connected to the upright by means of the protrusions 13 in the cleat which engage in pre-formed holes in the upright. The cleat 12 further comprises a pre-formed hole 14 in which the lock 10 may be inserted. The upright to which the beam 11 is connected is also formed with correspondingly positioned pre-formed holes in order that the locks may extend into the upright. As can be seen from the figures, a front portion 15 of the lock is rotated through approximately 1800 in order to move the lock into a locked position.

Turning now to Figures 5 and 6, the lock is shown in more detail. The lock comprises a block 50 which is mounted on a pin 51. The pin 51 comprises a front portion 52 and a rear portion 53. The block 50 is mounted eccentrically on the pin 51. In this example, the rear portion 53 has substantially the same shape as the block 50. In addition, the front portion 52 is much larger than the other components of the lock 10, and is formed into a flag. In the locked position, the rear portion 53 of the lock 10 engages with protrusion 54 of cleat 12. In this position, it is very difficult if not impossible to remove the beam from the upright.

Turning now to Figures 7 and 8, the lock 10 is shown in an unlocked position. In this position, the rear portion 53 of the pin and the block 50 are aligned with one another.

As can be seen from the figures, the block 50 is formed with a groove 90. The dimensions and positioning of the groove are chosen in order that the block will shear under a predetermined load. In addition, the block will shear in the direction of the groove. Thus the failure of the block is controlled.

The block in this example is made of a zinc alloy. The pin 51 is formed from a weaker material, for example a thermoplastics material.

In use, the lock 10 is inserted into the preformed holes in the connector 12 and the upright. The dimensions of the hole and of the lock 10 are such that the lock is appropriately positioned when the front portion 52 of the pin 51 is flush with thc surface of the connector 12. This position is shown in Figures 4 and 5.

The front portion 52 is then rotated through approximately 1800. The pre-formed hole is shaped such that the shear blocks cannot rotate whilst the front and rear portions 52, 53 are rotating.

The rear portion 53 of the pin 51 is shaped to be inserted into the pre-formed hole. However, due to the fact that the block 50 is eccentrically mounted on the pin 51, when the front portion 52 is rotated, the rear portion 53 locks behind a connector lug 54.

The lock 10 cannot now be removed without first rotating the lock through another 1800 and then pulling the lock 10 out using finger cavities which exist in the connector 12.

The block 50 is designed to withstand the necessary uplifting loads which may occur due to accidental pallet lift. If, however, loads are exceeded then the block will shear appropriately.

Once the lock 50 has sheared, the thermoplastic pin 51 on which the lock 50 is mounted will also shear*, as the pin 51 is made of a substantially weaker material than the lock 50. As the lock 10 shears, the front section 52 of the lock 10 will detach itself and fall from the rack usually to ground level.

This means that the finding of a front portion 52 detached indicates that a lock 10 has been accidentally uploaded.

Visual inspection from ground level can verify the position

Claims

CLAIMS 1. A beam connector lock comprising: a pin having a front portion and a rear portion; and a block rotatably mounted on the pin between the front portion and the rear portion, characterised in that the block is eccentrically mounted on the pin.
2. A beam connector lock according to claim 1 wherein the pin is made of a weaker material than that of the block.
3. A beam connector lock according to claim 1 or claim 2, wherein the block comprises a groove, the size of which groove determines the load under which the block will shear.
4. A beam connector lock according to any one of the proceeding claims wherein the block is made from a zinc alloy and the pin is made from a thermoplastics material.
5. A beam connector lock according to any one of the proceeding claims wherein the front portion is formed into a flag, which is clearly visible from a distance.
6. A beam connector lock according to any one of the proceeding claims wherein the front portion is formed from a material having a bright colour.
7. A beam connector lock according to any one of the proceeding claims wherein the pin is substantially the same size as the block.
8. A lock comprising a pin, and a block mounted on the pin, characterised in that the pin is formed from a weaker material than the block.
9. A lock substantially as hereinbefore described within reference to the accompanying drawings.