Lockout device

Abstract

A lockout device (200) for disabling chain hoists, the device comprising: a housing (202) arranged to receive two chains (102a, 102b) of the chain hoist; an immobilising device (204) configured to restrain the received two chains; and a lock (213) arranged to prevent access to the immobilising device in use.

Description

[0001] LOCKOUT DEVICE

[0002] FIELD

[0003] The present invention relates to a lockout device for a chain hoist and a related method.

[0004] BACKGROUND

[0005] A chain hoist is a device used for lifting or lowering a load by means of a series of gears and pulleys. Chain hoists generally have a first looped chain wrapped around a first pulley and a second looped chain wrapped around a second pulley; the first and second pulleys are joined by a suitable system of gears and levers in order to increase the mechanical work done. In general, the first looped chain (sometimes referred to as a hand chain) is arranged for a user to pull on and the second looped chain (sometimes referred to as a load chain) is arranged to be secured to a load to be lifted by the chain hoist. In a simple device, an operator will pull down on one side of the first looped chain which will turn the first pulley in the chain hoist housing. The turning of this first pulley causes the second pulley to turn via the suitable system of gears and levers which increases the mechanical work exerted by the operator. In this way, heavy loads may be lifted manually by an operator.

[0006] Chain hoists can be used in industrial environments to lift heavy loads such as machinery or raw materials etc. Sometimes, it is necessary to secure the chain hoist to prevent accidental or unintended movement of the hoist. For example, a piece of machinery may have to be lifted clear of a working area to allow workers access to a space under the machinery. In this situation, it is clear that the chain hoist must be secured to prevent the machinery being lowered or otherwise accidentally moved when workers are near or underneath the hoist.

[0007] Traditionally, chain hoists are secured using a simple padlock placed through two or more individual links of the first and / or second looped chains thereby preventing an operator from pulling on the chain. Such locks may be left on for several days, weeks or months.

[0008] Keys for padlocks can often be misplaced in an industrial setting and thus sometimes it is necessary to cut the padlock from the chains using bolt cutters or an angle grinder to allow the chain hoist to be used again. This is dangerous as an operator may inadvertently damage the chain when cutting the padlock. Such damage may not be immediately obvious to an operators eye. Therefore, there is a requirement for an improved lockout device for chain hoists.

[0009] SUMMARY

[0010] According to an aspect of the present invention, there is provided a lockout device for a chain hoist comprising: a housing arranged to receive two chains of the chain hoist; an immobilising device configured to restrain the received two chains; and a lock arranged to prevent access to the immobilising device in use.

[0011] The lockout device prevents operation of the chain hoist by restraining the chains of the chain hoist using the immobilising device i.e. preventing relative movement between one and other. In this way, a user is unable to move the first or second looped chain thereby disabling the device. The lock prevents access to the immobilising device such that accidental operation of the chain hoist is prevented. Furthermore, the lock prevents unauthorised use of the chain hoist.

[0012] It will be understood that the two chains of the chain hoist may be two portions of a single chain loop, i.e. the first and second sides of the first or second loop as described above or alternatively may be two portions of different chain loops i.e. a first side of the first chain loop and a first side of the second chain loop. Advantageously, any configuration of restraining the chain loops relative to each other will prevent operation of the chain hoist.

[0013] The housing may partially wrap around the received chains or may completely enclose the received chains. The housing may be substantially cuboid in shape although it will be appreciated that any appropriate shape and / or dimension of housing will be apparent to the skilled person. The housing may be brightly coloured, e.g. luminescent, such that operators my quickly identify that a chain hoist has been disabled by the lockout device. Advantageously, the housing may provide physical protection against accidental damage to the received chains. The housing may be arranged protect the received chains against intentional damage to the lock. For example, even if the lock is intentionally cut by an operator e.g. using bolt cutters, the housing is arranged to shield the received chains thereby preventing damage to the received chains themselves. Damage to the chains from devices such as bolt cutters may cause the chain to weaken or fail which may be especially dangerous if a load is suspended by the chain hoist.

[0014] The lock may be any suitable type lock which prevents access to the immobilising device. The lock may prevent the housing from being opened. For example, the lock may be a padlock, a knob lock, deadbolt lock, cam lock, mortise lock, smart lock or keypad lock. When the lock is a padlock, the housing may comprise one or more flanges with corresponding holes to allow the padlock to be placed through the holes in the flange to secure the housing thereby preventing access to the immobilising device.

[0015] There may be provided more than one lock. For example, there may be provided two locks. In arrangements where there is provided more than one lock, the respective keys may be held by different operators. Such an arrangement provides redundancy and lends itself to the two-man lock out principle which prevents any one single operator from unlocking the device. When a plurality of locks are provided, the locks may be of the same or different types.

[0016] In one arrangement, the housing comprises: a first portion; and a second portion; wherein the first portion and second portion are arranged to mate such that the received chains are contained within the housing between the first and second portions. In this arrangement, the first and second portions may correspond to two halves of a box. The first and second portion may be physically joined. For example, the first and second portion may be joined by a hinge or a flexible piece of material. Preferably the first and second portions are joined by a hinge.

[0017] In one arrangement, the first and second portions are arranged to mate to form an enclosure and wherein optionally the first and / or second portions comprise an aperture for the received chains to enter the enclosure. In this way, the immobilising device may be completely shielded from access thereby preventing tampering with the immobilising device. This arrangement may be advantageous in dirty industrial environments as the immobilising device can be protected from fouling and / or contaminants. The first and second portions may comprise one or more apertures to allow the received chains to enter and exit the lockout device. For example, the first portion may comprise two apertures on a first side wall of the housing and a further two apertures on an opposite second side wall of the housing to allow the received chains to be laid straight through the lockout device. In an alternative arrangement, the first and second portions may comprise apertures which are aligned such that when the first and second portions are brought together to form an enclosure, the apertures match to form a single aperture.

[0018] In one arrangement, the immobilising device comprises a first stud for the first chain and a second stud for the second chain; wherein the first and second studs are integral with the housing; such that in use, the links of the received two chains are restrained by the studs. A stud is a geometry integral to the housing capable of inserting through the link of a chain such that the chain cannot slip from the stud. As such, the length of the first and second stud must be such that the stud cannot be removed from the link of the respective chains. For example, the stud length may be equal to or marginally less than the depth of the first and second portion of the housing. It will be appreciated that the minimum length of the first and second stud will be the depth of the first and second portion of the housing minus the diameter of the chain link. In this way, once the housing is closed, the respective chains are effectively ‘pinned’ by the studs within the housing and cannot slip from the studs.

[0019] In one arrangement, the first and second studs are tack welded to the housing although in other arrangements, they may be mechanically or chemically joined to the housing. In one arrangement, the first and second studs may be made from a threaded bar. In an alternative arrangement, the first and second studs may be formed as one piece with the housing, for example, cast from a single mould, vacuum extruded or manufactured using additive manufacturing techniques. There may be provided a plurality of studs for each received chain. In this way, the chain may be aligned with the housing.

[0020] The studs may be located on the first portion or the second portion or both portions of the housing. For example, the first stud for the first chain may be integral with the first portion and the second stud for the second chain may be integral with the second housing although it will be appreciated that any number of combinations of studs and their positioning are possible on the portions of the housing without departing from the scope of the invention. In some arrangements, the housing further comprises a receiving female geometry for the first and second studs. It will be appreciated that the receiving female geometry will be on the opposite housing portion to that of the studs. For example, if the first stud is located on the first housing, the receiving female geometry will be located on the second portion of the housing. In this way, the first and second studs may be received into a cooperative female geometry thereby further strengthening the lockout device in the closed position. Further, the chance of a chain link slipping from the stud is further reduced.

[0021] In one arrangement, the immobilising device comprises a geometry corresponding to a female geometry of the received two chains. In this way, the received chains may be restrained by the cooperative female geometry of the immobilising device. The geometry may be provided as an insert for the housing or may alternatively be formed as one piece with the housing e.g. casted, vacuum moulded as has been described above with respect to the studs. Where the housing comprises a first and second portion, there may be provided a respective first and second portion of a cooperative female geometry for the immobilising device.

[0022] In an alternative arrangement, the immobilising device comprises a moveable pin arranged to insert into links of the received chains. The moveable pin may comprise a cylindrical shank section. The moveable pin may be arranged to be inserted through the housing or alternatively may be completely enclosed within the housing. Where the moveable pin is arranged to be inserted through the housing, the housing may comprise one or more holes in the side wall of the housing to receive the moveable pin. The moveable pin may comprise a head at one end of the cylindrical shank section in order to abut against the housing. The moveable pin may comprise one or more through holes in order to receive a padlock or similar.

[0023] In one arrangement, the moveable pin is configured to be inserted into the links of the received chains by the lock. For example, the lock may be a turn key lock which when moved to the locked position, causes the moveable pin to translate through the links of the received chains thereby restraining the received chains. In one example, the device is made from a metal, metal alloy or plastic. Preferably the device is made from metal, more preferably steel.

[0024] According to a second aspect, there is provided a system comprising: the lockout device according to the first aspect; and a chain hoist comprising at least two chains.

[0025] According to a third aspect, there is provided a method of locking out a chain hoist comprising; receiving two chains of a chain hoist into a housing of the locking device according to the first aspect; restraining the received chains using the immobilising device and locking the device.

[0026] BRIEF DESCRIPTION OF THE FIGURES

[0027] Embodiments of the invention will now be described by way of example only with reference to the figures, in which:

[0028] Figure 1 shows an example of a chain hoist of the prior art;

[0029] Figure 2 shows an example arrangement of the lockout device in the open position;

[0030] Figure 3 shows the lockout device of Figure 2 in the closed position;

[0031] Figure 4 shows an alternative arrangement of the lockout device in the open position;

[0032] Figure 5 shows an alternative arrangement of the lockout device in the open position; and

[0033] Figure 6 shows an example flow diagram of a method of operating the lockout device.

[0034] DETAILED DESCRIPTION

[0035] Example embodiments are described below in sufficient detail to enable those of ordinary skill in the art to embody and implement the systems and processes herein described. It is important to understand that embodiments can be provided in many alternate forms and should not be construed as limited to the examples set forth herein.

[0036] Accordingly, while embodiments can be modified in various ways and take on various alternative forms, specific embodiments thereof are shown in the drawings and described in detail below as examples. There is no intent to limit to the particular forms disclosed. On the contrary, all modifications, equivalents, and alternatives falling within the scope of the appended claims should be included. Elements of the example embodiments are consistently denoted by the same reference numerals throughout the drawings and detailed description where appropriate.

[0037] The terminology used herein to describe embodiments is not intended to limit the scope. The articles “a,” “an,” and “the” are singular in that they have a single referent, however the use of the singular form in the present document should not preclude the presence of more than one referent. In other words, elements referred to in the singular can number one or more, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes,” and / or “including,” when used herein, specify the presence of stated features, items, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, items, steps, operations, elements, components, and / or groups thereof.

[0038] Unless otherwise defined, all terms (including technical and scientific terms) used herein are to be interpreted as is customary in the art. It will be further understood that terms in common usage should also be interpreted as is customary in the relevant art and not in an idealized or overly formal sense unless expressly so defined herein.

[0039] Figure 1 shows an example of a chain hoist 100 of the prior art. The chain hoist comprises a first looped chain 102 and a second looped chain 104. The first looped chain 102 is arranged to be operated by a user by pulling down on one side 102a 102b of the chain. The second looped chain 104 is arranged to be secured to a load 106 by a bottom hook assembly 105. The first looped chain is wrapped around a first pulley 108 and the second looped chain is wrapped around a second pulley 1 10. The first and second pulleys 108 1 10 are connected by a suitable system of gears and levers (not shown) which are arranged to increase the mechanical work done by a user pulling on the first looped chain 102. The first 108 and second 1 10 pulleys are housed in a cover 1 12. The cover may comprise a top hook assembly 1 14 arranged to be suspended from height.

[0040] As has been described before, sometimes it is necessary to secure the chain hoist 100 between lifting operations to prevent use of the chain hoist 100.

[0041] Figure 2 shows an example arrangement of the lockout device 200. In this arrangement, the device comprises a housing 202 comprising a first portion 202a and a second portion 202b arranged to receive two chains 102 of the chain hoist (not shown). The first portion 202a and second potion 202b of the housing are joined by a hinge 203 and are arranged to mate to form an enclosure. In this arrangement the two chains are the first 102a and second 102b sides of the first looped chain 102. The second portion 202b of the housing comprises an immobilising device 204 in the form of a first stud 206a for the first chain 102a and a second stud 206b for the second chain 102b. The stud is integral to the housing 202 and in use, is configured to be inserted through links 102c 102d of the received chains. In this arrangement there is shown a further two studs 206c, 206d. Their function is the same as studs 206a 206b and shall not be repeated here for brevity. In this arrangement, there is provided a receiving female geometry 208a 208 b located on the first portion 202a of the housing for the first 206a and second 206b studs. In this arrangement there is shown a further two receiving female geometry 208c 208d. Their function is the same as receiving female geometry 208a 208b and shall not be repeated here for brevity.

[0042] The first 202a and second 202b portions of the housing 202 comprise apertures 210a-d for the received chains 102 to enter the housing 202. In this arrangement, the first portion 202a and second portion 202b each comprise two apertures 210a 210b on a first side wall of the housing 202 and a further two apertures 210c 21 Od on an opposite second side wall. The apertures 210a-d are in the form of semi-circular cut outs in the side walls of the housing 202 such that when the first 202a and second 202b portions of the housing 202 are brought together to form an enclosure, apertures 210a and 210c and apertures 210b and 21 Od form a circular opening in the housing 202.

[0043] In this arrangement, the first 202a and second 202b portions of the housing 202 each comprise a flange 212a 212b with corresponding holes to allow a lock (not shown) to be inserted through the holes thereby preventing access to the immobilising device 204 in use. Such a configuration is shown in Figure 3 where the lockout device 200 is in the closed and locked position wherein a lock 213 is inserted through flanges 212a 212b. For ease of reference, the housing 202 and chains 102 are as described in Figure 2 and their function will not be repeated here for brevity.

[0044] Figure 4 shows an alternative arrangement of the lockout device 400. In this arrangement the lockout device 400 comprises a housing 402 comprising a first portion 402a, second portion 402b, apertures 41 Oa-d and flanges 412a 412b are arranged to mate as described in relation to Figure 2. In this alternative arrangement, the immobilising device comprises an insert 404a 404b corresponding to a female geometry cooperative with the received two chains 102a 102b. In other words, the female geometry is arranged to immobilise the received chains 102 such that there is no free movement of the chains when the housing 402 is closed. In this arrangement, the insert 404a 404b is made from plastic and is separable from the housing 402.

[0045] Figure 5 shows another alternative arrangement of the lockout device 500. In this arrangement, the housing 502, chains 102, apertures 51 Oa-d are as described in relation to Figure 2. In this arrangement, the immobilising device 504 comprises two moveable pins 514a 514b which are arranged to be inserted through the housing 502 via holes 516a-d located in the side wall of the housing 502. Each of the moveable pins 514a 514b comprises a cylindrical shank section 518 comprising a through hole 520 at one end and a head 522 at the opposite end. In use, the moveable pins 514a 514b are threaded through the holes located in the side wall of the housing 502, through the links 102c 102d of the received chains 102 and through the opposite holes in the sidewall of the housing 502. A padlock or similar lock may be placed through the through hole 520 of each moveable pin 514a 514b to prevent removal of the pins from the housing thereby restraining movement of the received chains 102. Whilst two moveable pins 514a 514b are shown in this arrangement, there may be provided a single pin or more than two pins although it will be appreciated that using a single pin must be threaded through the links of both received chains to prevent movement relative to one and other. Figure 6 shows an example method flow diagram 600 of using the lockout device as herein described comprising the steps of;

[0046] 602: receiving two chains of a chain hoist into a housing of the locking device as herein described; 604: restraining the received chains using the immobilising device; and

[0047] 606: locking the device.

[0048] The preceding description has been provided to enable others skilled in the art to best utilise various aspects of the exemplary embodiments disclosed herein. This exemplary description is not intended to be exhaustive or to be limited to any precise form disclosed. Many modifications and variations are possible without departing from the spirit and scope of the instant disclosure. The embodiments disclosed herein should be considered in all respects illustrative and not restrictive. Reference should be made to the appended claims and their equivalents in determining the scope of the instant disclosure.

Claims

CLAIMS1 . A lockout device (200) for a chain hoist comprising: a housing (202) arranged to receive two chains (102a 102b) of the chain hoist; an immobilising device (204) configured to restrain the received two chains; and a lock (213) arranged to prevent access to the immobilising device in use.

2. The lockout device according to claim 1 wherein the housing comprises: a first portion (202a); and a second portion (202b); wherein the first portion and second portion are arranged to mate such that the received chains are contained within the housing between the first and second portions.

3. The lockout device according to claim 2 wherein the first and second portions are arranged to mate to form an enclosure and optionally wherein the first and / or second portions comprise an aperture (210a-d) for the received chains to enter the enclosure.

4. The lockout device according to claim 3 wherein the immobilising device comprises a first stud (206a) for the first chain (102a) and a second stud (206b) for the second chain (102b); wherein the first and second studs are integral with the housing (202); such that in use, the links (102c 102d) of the received chains are restrained by the studs.

5. The lockout device according to claim 4 wherein the housing further comprises a receiving female geometry (208a 208b) for the first and second studs.

6. The lockout device according to any preceding claim wherein the immobilising device comprises a geometry (404a) corresponding to a female geometry of the received two chains.

7. The lockout device according to any preceding claim wherein the immobilising device comprises a moveable pin (514a) arranged to insert into the link of the received chains.

8. The lockout device according to claim 7 wherein the moveable pin is configured to be inserted into the link of the received chains by the lock.

9. The lockout device according to any preceding claim wherein the device is made from a metal, metal alloy or plastic.

10. A system comprising: the lockout device (200) according to any previous claim; and a chain hoist (100) comprising at least two chains (102 104).

11. A method (600) of locking out a chain hoist comprising; receiving two chains of a chain hoist into a housing of the locking device according to claims 1 to 9; restraining the received chains using the immobilising device and locking the device.

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