GB2363598A

GB2363598A - A load strap retracting and tensioning means

Info

Publication number: GB2363598A
Application number: GB0104481A
Authority: GB
Inventors: Hugh David Facey; Brian Edward Shawcross; John Makin
Original assignee: Gripple Ltd
Current assignee: Gripple Ltd
Priority date: 2000-06-16
Filing date: 2001-02-23
Publication date: 2002-01-02
Anticipated expiration: 2021-02-23
Also published as: AU2001242591A1; WO2001096204A8; WO2001096204A1; GB0014658D0; GB2363598B; GB0104481D0

Abstract

A storage unit 14 for a retractable strap 15 comprises a housing 23, 24 with an opening 26 for the strap to emerge, a crosshead 27 slidable along guides 25 towards and away from the opening, crossbars 28, 29, 30 of graduated diameters in the crosshead, a fixed array of crossbars 31, 32 adjacent to the opening with the smallest diameter crossbars nearest each other, the strap having one end secured to one of the small diameter crossbars 28 and lapped in multi-purchase array round the other smallest diameter crossbar 31 and each successively larger crossbar 29, 32, 30 in turn before emerging from the opening, spring means (33, Fig. 7) to urge the crosshead away from the fixed array, attachment means 18 on the free end of the strap, stop means 34 for limiting the extent to which the attachment means can be drawn into the housing and means 35 to tension the strap. The strap is tensioned by operating a handle 37 which turns slotted crossbar 39 to form an S shape in the strap. Preferably the unit is used to secure a load onto a pallet where one or more units may be fitted to a cap, lid or spider. The attachment means may comprise a hook with two prongs 19.

Description

2363598 LOAD HANDLING PALLETS AND LOAD STRAPPING MEANS This invention

relates to load handling pallets and load strapping means.

It is known to provide a reel unit for incorporation in a load handling pallet, e g, a 4-way pallet, comprising a housing, a shaft rotatably mounted within the housing, a drum mounted on and rotatable with the shaft, a strap wound on the drum, an opening in the housing through which the strap emerges, attachment means on the free end of the strap for securing the strap to a load on a pallet or for securing to anchorage means on a pallet after passing the strap over a load on the pallet, a rewind spring coiled round the shaft alongside the drum, stop means preventing the attachment means being drawn through the opening into the housing by the action of the rewind spring, a ratchet concentric with the drum and rotatable with the drum and shaft, with a pawl for engaging teeth on the ratchet to stop or prevent pulling of the strap from the drum, means for effecting engagement of the pawl with the ratchet, and manuallyoperable means is provided for tensioning the strap when the pawl has been engaged with a tooth on the ratchet.

A pallet is described in EP-A-0 585 832 with reel units secured alongside spacer blocks below one side of the load receiving platform of the pallet, and the attachment means are loops for engagement with ski-tensioner type anchorage means in housings secured alongside spacer blocks below the opposite side of the platform Alternatively, tensioning devices could be incorporated in the straps, or in the reel units, one form of the latter having a second ratchet concentric with the drum and rotatable with the drum and shaft, with a second pawl for engaging the teeth of the second ratchet to prevent rewind of the strap, a manually-operable change-over means being provided for selectively rendering one or other of the pawls inoperative, and tension being applied to the belt by a lever operated drive pinion engaged with a driven gearwheel secured on the shaft.

Another pallet is described in JP-A-10167267 with reel units secured one in a corresponding outer side of each of four corner spacers moulded integrally with a load receiving platform, and the attachment means are loops while the anchorage means are hooks within the outer sides of the corner spacers not occupied by the reel housings, which housings also carry lever mechanisms for tensioning the straps when the pawls are engaged with the ratchets.

The complexity and bulk of these prior art reel units adds very appreciably to the cost of the pallets, and their tensioning mechanisms are also prone to damage, in the case of EP-A-0 585 832 because of being located where contact can take place with the forks of fork-lift trucks, and in the case of JP-A-1 0167267 because of exposure of the lever mechanisms at all four sides of the pallet Furthermore, the length of strap that can be accommodated is limited by the diameter of drum that can be accommodated alongside or within the corner spacers.

One object of the present invention is, therefore, the provision of a unit for a retractable strap for use with a pallet saving both on cost and risk of damage and of such compact construction as to be accommodated other than within or alongside the spacer blocks of pallets.

According to the present invention, a unit for a retractable strap, e g for use with a load handling pallet, comprises a housing, parallel guides longitudinally of the housing, an opening adjacent one end of the housing for emergence of a strap stored within the housing; a crosshead slidable along the guides towards and away from the opening, the crosshead being principally constituted by crossbars of graduated diameters; a fixed array of graduated crossbars adjacent the opposite end of the housing from the crosshead, the axes of the crossbars in the crosshead and in the fixed array all being parallel and in a common plane with the smallest diameter crossbars being the nearest to each other; a strap having one end secured to one of the smallest diameter crossbars and lapped in multi-purchase array round the other smallest diameter crossbar and each successively greater diameter crossbar in the crosshead and the fixed array in turn and with the final lap emerging from the opening in the housing; spring means to urge the crosshead away from the fixed array; attachment means on the free end of the strap for securing to anchorage means on a load on a pallet or on a spider, cap or lid for securing a load on a pallet, or for securing to anchorage means on a pallet after passing the strap over a load on the pallet, or after drawing the strap down from a spider, cap or lid on a load on a pallet; stop means for limiting the extent to which the attachment means can be drawn into the housing by the action of the spring means urging the crosshead away from the fixed array; and manually-operable means for tensioning the strap between the housing and the attachment means after the strap has been disposed for securing a load on a pallet.

The total length of strap that can be accommodated in the unit is principally dependent on the number and lengths of laps between the crosshead and the fixed array, the number of laps being determined by the number of crossbars in the crosshead and in the fixed array (e g three crossbars in one and two in the other giving five laps), so the diameters of the crossbars can be but a few millimetres each consistent with being strong enough to carry the loads in the strap generated by the spring means Thus the housing can be of the nature of a fiat cassette of overall thickness (or 'thinness') such that it can be accommodated within a pallet, e g within the thickness of the platform of a pallet or within a spider, cap or lid for use in conjunction with a pallet to secure a load thereon, the total length of strap thus also being commensurate with the length of the housing from end to end.

The crossbars, in both the crosshead and in the fixed array, other than that smallest one to which the strap is secured, may be rollers rotatable with respect to side cheeks of the crosshead slidable along the guides or side cheeks secured to or integral with one end of the housing; or some or all of them may be non-rotatable and provided with low friction surfaces.

The guides may be channels along which slide wings on the crosshead and accommodating coil compression springs Alternatively the guides may be bars passing through the crosshead and encircled by coil compression springs.

Alternatively, the spring means may be a tension spring or springs.

The tensioning means may be a lever mechanism with an over-centre locking action, or with a rotational device within the housing adjacent the opening with a push- lock action or spring catch.

The attachment means on the free end of the strap may be a rigid loop for securing to anchorage means on a pallet consisting of a bollard within a recess in one of the spacers of a pallet or on a spider, cap or lid, or it may be (preferably) a hook to engage a load or the underside of the platform of a pallet, e g a two- pronged hook having prongs spaced apart by at least the width of a middle spacer of a pallet, so that the prongs can engage the underside of the platform one to each side of the spacer.

The stop means for preventing the attachment means being drawn through the opening into the housing may be afforded by making the attachment means, whether a loop or a hook, wider than the opening, and the latter is preferably recessed within the housing end (or within the edge of the platform of a pallet or a cap or lid for use therein within which the unit is incorporated) so that the attachment means will not project significantly therefrom when the strap is fully retracted Alternatively a recess may be provided in the underside of the platform or of a cap or lid for engagement by the hook The invention also comprises pallets, spiders and caps or lids with units as defined above incorporated therein in various possible numbers and arrays.

For example, the platform of a pallet may incorporate a single unit and be provided with bollards in recesses in its spacers (particularly middle spacers) enabling the strap to be passed over a load on the pallet (or over a lid on the load) from the unit to and around a bollard on another side then over the load (or lid) to and around a bollard on a third side and finally again over the load (or lid) to engage with a bollard on the fourth side (which may be the one from which the strap emerged).

Again, a spider or a cap or lid for use with a pallet may incorporate at least two units back-to-back with their openings for the straps at the remote ends of the units, but preferably incorporating four reel units in cruciform array, each attachment means conveniently being a two-pronged hook to engage the platform of an existing pallet without any modification of the latter being necessary.

A preferred embodiment of the invention will now be descried, by way of example only, with reference to the accompanying drawings, in which:Figure 1 is a perspective view of a cap (or lid) incorporating a pair of units in accordance with the invention; Figure 2 is a perspective view showing the cap of Figure 1 in use securing a load on a pallet; Figure 3 is a plan view of a cap (or lid) incorporating four units in accordance with the invention; Figure 4 is a fragmentary perspective view of part of Figure 1 to a larger scale; Figure 5 is a fragmentary perspective view of the same part of Figure 1 to a larger scale and with the top part of the housing of the unit removed; Figure 6 is a fragmentary perspective view of the same part as seen in Figure 2 to a larger scale and again with the top part of the housing removed; Figure 7 is a fragmentary perspective view of the other end of the unit with the top part of the housing removed and the exposed parts of the mechanism in positions corresponding to Figures 1, 4 and 5; Figure 8 is a similar view to Figure 7 but showing the exposed parts in positions corresponding to Figures 2 and 6; Figure 9 is a longitudinal vertical section through both ends of the unit with the parts of the mechanism in positions corresponding to Figures 1, 4 and 5; and Figure 10 is a similar view to Figure 9 but showing only the outer end of the unit with the parts of the mechanism in positions corresponding to Figures 2 and 6.

In Figure 1 a rectangular cap (or lid) 11 having flanges 12 along all four sides has a recess 13 accommodating two units 14 for retractable straps 15 (only one being visible) for use with a pallet 16, see Figure 2, for securing a load 17 thereon, each strap having at a free end thereof attachment means in the form of a two- pronged hook ( 18) having its prongs 19 spaced apart by at least the width of a middle spacer 20 of the pallet so as to be able to engage anchorage means 21 constituted by the underside of the platform 22 of the pallet with a prong to each side of the spacer.

In Figure 3 a cap (or lid) 11 X has three recesses 13 X, 13 Y, 13 Z accommodating four units 14 for retractable straps(none being visible) for use with a pallet (not shown) in similar manner to that shown in Figure 2 but affording greater secureness of a load on the pallet.

The construction of a unit 14 and its mechanisms for tensioning its strap 15, and also for retracting its strap, will now be described in detail with reference to Figures 4 to 10.

The unit 14 comprises a housing formed by separable parts, a lower part 23 and an upper part 24, parallel guides 25 longitudinally of the housing, an opening 26 adjacent one end of the housing for emergence of the strap 15 stored within the housing; a crosshead 27 slidable along the guides towards and away from the opening, the crosshead being principally constituted by crossbars 28, 29, 30 of graduated diameters; a fixed array of graduated crossbars 31, 32 adjacent the opposite end of the housing from the crosshead (i e adjacent the opening 26), the axes of the crossbars in the crosshead and in the fixed array all being parallel and in a common plane with the smaller diameter crossbars 28, 31 being the nearest to each other; the strap 15 having its end remote from the attachment means 18 secured to the smallest diameter crossbar 28 of the crosshead 27 and being lapped in multi-purchase array round the other smallest crossbar 31 and each successively greater diameter crossbar, 29, 32, in the crosshead and the fixed array in turn and with the final lap emerging from the opening 26 in the housing 23, 24 and being secured to the hook 18; spring means constituted by coil compression springs 33 to urge the crosshead 27 away from the fixed array of crossbars 31, 32; stop means 34 for limiting the extent to which the attachment means(i e, the hook 18) can be drawn into the housing by the action of the spring means urging the crosshead away from the fixed array; and manually- operable means 35 (to be described in detail presently) for tensioning the strap 15 between the housing and the attachment means after the strap has been disposed for securing a load on a pallet, as shown in Figure 2.

The manually-operable tensioning means 35 comprises a cross-pin 36 fixedly mounted parallel to the fixed array of crossbars 31, 32 and between that array and the opening 26, a U-shaped lever 37 on an axis 38 parallel to the cross-pin and mounted between that cross-pin and the opening 26, and a slotted crossbar 39 between the arms of the lever extending parallel to the cross-pin and adapted to be swung, by movement of the lever from an inoperative position (see Figures 1, 2, 4, 5 and 9) to a locking position (see Figures 6 and 10), from a position remote from the cross-pin (see particularly Figure 9) to a position closely adjacent the cross-pin (see particularly Figure 10), the slot 40 in the crossbar 39 being of a width and disposed such that when the crossbar 39 is in its position remote from the cross-pin 36 the strap 15 passes freely through the slot (as shown in Figure 9) and whereby as the crossbar 39 is being swung towards its position closely adjacent the cross-pin (by swinging of the lever 37 from the inoperative position to locking position) the strap 15 is tensioned by being wrapped round the crossbar 39 into an S-shape and partially round the cross-pin 36 as the crossbar 39 approaches the cross-pin (as shown in Figure 10).

The throw of the lever 37 is about 180 and will suffice to apply considerable tension to the strap 15 after the hook 18 has been engaged with a pallet and slack in the strap has been taken up by the spring means 33 urging the crosshead 27 away from the fixed array 31, 32.

Spring or detent means may be provided to retain the lever 37 in locking position, but friction between the strap 15 and the cross-pin 36 may be sufficient to retain the lever in locking position, especially if a nipping of the strap 15 between the crossbar 39 and the cross-pin 36 results from the closeness of approach of the crossbar 39 to the cross-pin.

Swinging of the lever 37 is effected by grasping the handlebar 41 between the arms 42 of the lever In the inoperative position the lever is protected from accidental contact by a pair of cheeks 43 which are extended downwardly to provide protection also for the hook 18 A pair of slots 44 in the upper part 24 of the housing accommodates the arms 42 of the lever as they swing from inoperative position to locking position, in which latter position the handlebar 41 of the lever is accommodated in a groove 45 between the slots 44 thus protecting it from accidental contact.

The coil compression springs 33 are shown encircling rigid strips 46 extending the full length of the lower part 23 of the housing, merely to hold the springs 33 in place during assembly, as slight pre-compression in the springs would otherwise cause them to bow and spring out.

Claims

1 A unit for a retractable strap comprising housing, parallel guides longitudinally of the housing, an opening adjacent one end of the housing for emergence of a strap stored within the housing; a crosshead slidable along the guides towards and away from the opening, the crosshead being principally constituted by crossbars of graduated diameters; a fixed array of graduated crossbars adjacent the opposite end of the housing from the crosshead, the axes of the crossbars in the crosshead and in the fixed array all being parallel and in a common plane with the smallest diameter crossbars being the nearest to each other; the strap having one end secured to one of the smallest diameter crossbars and lapped in multipurchase array round the other smallest diameter crossbar and each successively greater diameter crossbar in the crosshead and the fixed array in turn and with the final lap emerging from the opening in the housing; spring means to urge the crosshead away from the fixed array; attachment means on the free end of the strap for securing to anchorage means on a load on a pallet or on a spider, cap or lid for securing a load on a pallet, or for securing to anchorage means on a pallet after passing the strap over a load on the pallet, or after drawing the strap down from a spider, cap or lid on a load on a pallet; stop means for limiting the extent to which the attachment means can be drawn into the housing by the action of the spring means urging the crosshead away from the fixed array; and manually-operable means for tensioning the strap between the housing and the attachment means after the strap has been disposed for securing a load on a pallet.

2 A unit for a retractable strap as in Claim 1, wherein the housing is of the nature of a flat cassette of overall thickness such that it can be accommodated within a pallet or within a spider, cap or lid for use in conjunction with a pallet to secure a load thereon, the total length of strap thus also being commensurate with the length of the housing from end to end.

3 A unit for a retractable strap as in Claim 2, wherein the overall thickness of the housing is such that it can be accommodated within the thickness of the platform of a pallet

4 A unit for a retractable strap as in any one of Claims 1 to 3, wherein the crossbars in both the crosshead and the fixed array, other than that smallest one to which the strap is secured, are rotatable rollers.

A unit for a retractable strap as in any one of Claims 1 to 3, wherein some or all of the crossbars in both the crosshead and the fixed array are non- rotatable and provided with low friction surfaces.

6 A unit for a retractable strap as in any one of Claims 1 to 5, wherein the guides are channels along which slide wings on the crosshead and accommodating coil compression springs.

7 A unit for a retractable strap as in any one of Claims 1 to 5, wherein the guides are bars passing through the crosshead and encircled by coil compression springs.

8 A unit for a retractable strap as in any one of Claims 1 to 5, wherein the spring means is a tension spring or springs.

9 A unit for a retractable strap as in any one of Claims 1 to 8, wherein the tensioning means is a lever mechanism with an over-centre locking action.

A unit for a retractable strap as in any one of Claims 1 to 8, wherein the tensioning means is a lever mechanism with a rotational device within the housing adjacent the opening with a push-lock action or spring catch.

11 A unit for a retractable strap as in any one of Claims 1 to 10, wherein the attachment means on the free end of the strap is a rigid loop for securing to anchorage means on a pallet consisting of a bollard within a recess in one of the spacers of a pallet or on a spider, cap or lid.

12 A unit for a retractable strap as in any one of Claims 1 to 10, wherein the attachment means on the free end of the strap is a hook to engage a load or the underside of the platform of a pallet.

13 A unit for a retractable strap as in Claim 12, wherein the attachment means on the free end of the strap is a two-pronged hook having prongs spaced apart by at least the width of a middle spacer of a pallet so that the prongs can engage the underside of the platform one to each side of the spacer.

14 A unit as in any one of Claims 11 to 13, wherein the stop means for preventing the attachment means being drawn through the opening into the housing is afforded by making the attachment means, whether a loop or a hook, wider than the opening.

A unit as in Claim 14, wherein the opening into the housing is recessed within the housing end so that the attachment means will not project significantly therefrom when the strap is fully retracted.

6 16 A pallet having incorporated in its platform a single unit as defined in any a one of Claims 1 to

15.

" ' 17 A pallet having incorporated in its platform four strap units as defined in any one of Claims 1 to 15 in cruciform array ' 18 A unit incorporating a retractable strap substantially as hereinbefore described with reference to the accompanying drawings.

14 A unit for a retractable strap as in any one of Claims 11 to 13, wherein the stop means for preventing the attachment means being drawn through the opening into the housing is afforded by making the attachment means, whether a loop or a hook, wider than the opening.

A unit for a retractable strap as in Claim 14, wherein the opening into the housing is recessed within the housing end so that the attachment means will not project significantly therefrom when the strap is fully retracted.

16 A unit for a retractable strap as in Claim 14, wherein a recess is provided in the underside of the platform or of a cap or lid for engagement by the hook.

17 Pallets, spiders and caps or lids incorporating one or more units for retractable straps as in any one of Claims 1 to

16.

18 A pallet having incorporated in its platform a single unit for a retractable strap as in any one of Claims 1 to 16, wherein the pallet is provided with bollards in its spacers enabling the strap to be passed over a load on the pallet from the unit to and round a bollard on another side then over the load to and around a bollard on a third side and finally again over the load to engage with a bollard on the fourth side.

19 A spider or a cap or lid for use with a pallet, the spider or cap or lid incorporating at least two units as in any one of Claims 1 to 16 back-to- back with their openings for the straps at the remote ends of the units each attachment means being a two-pronged hook to engage the platform of an existing pallet without any modification of the latter being necessary.

A spider or a cap or lid for use with a pallet to secure a load as in Claim 19, wherein four reel units are incorporated in cruciform array.

21 A unit for a retractable strap substantially as hereinbefore described with reference to the accompanying drawings.

22 A cap or lid for use with a pallet to secure a load substantially as hereinbefore described with reference to the accompanying drawings.

Amendments to the claims have been filed as follows 1 A unit incorporating a retractable strap comprising a housing, parallel guides longitudinally of the housing, an opening adjacent one end of the housing for emergence of a strap stored within the housing; a crosshead slidable along the guides towards and away from the opening, the crosshead being principally constituted by crossbars of graduated diameters; a fixed array of graduated crossbars adjacent the opposite end of the housing from the crosshead, the axes of the crossbars in the rosshead and in the fixed array all being parallel and in a common plane with tne smallest diameter crossbars being the nearest to each other; the strap having one end 103 secured to one of the smallest diameter crossbars and lapped in multipurchase array round the other smallest diameter crossbar and each successively greater diameter crossbar in the crosshead and the fixed array in turn and with the final lap emerging C from the opening in the housing; spring means to urge the crosshead away from the ,, fixed array; attachment means on the free end of the strap, to enable the strap to be disposed to secure a load on a pallet; stop means for limiting the extent to which the attachment means can be drawn into the housing by the action of the spring means urging the crosshead away from the fixed array; and manually-operable means for tensioning the strap between the housing and the attachment means after the strap has been disposed for securing a load on a pallet.

2 A unit as in Claim 1, wherein the housing is of the nature of a flat cassette of overall thickness such that it can be accommodated within a pallet, or within a spider, cap or lid for use in conjunction with a pallet to secure a load thereon.

3 A unit as in Claim 2, wherein the overall thickness of the housing is such that it can be accommodated within the thickness of the platform of a pallet 1 v 4 A unit as in any one of Claims 1 to 3, wherein the crossbars in both the crosshead and the fixed array, other than that smallest one to which the strap is secured, are rotatable rollers.

A unit as in any one of Claims 1 to 3, wherein some or all of the crossbars in both the crosshead and the fixed array are non-rotatable and provided with low friction surfaces.

6 A unit as in any one of Claims 1 to 5, wherein the guides are channels along which slide wings on the crosshead and accommodating coil compression springs.

" 7 A unit as in any one of Claims 1 to 5, wherein the guides are bars passing r Q through the crosshead and encircled by coil compression springs.

^ 8 A unit as in any one of Claims 1 to 5, wherein the spring means is a tension spring or springs.

9 A unit as in any one of Claims 1 to 8, wherein the tensioning means is a lever mechanism with an over-centre locking action.

10 A unit as in any one of Claims 1 to 8, wherein the tensioning means is a lever mechanism with a rotational device within the housing adjacent the opening with a push-lock action or spring catch.

11 A unit as in any one of Claims 1 to 10, wherein the attachment means on the free end of the strap is a rigid loop.

12 A unit as in any one of Claims 1 to 10, wherein the attachment means on the free end of the strap is a hook for engagement with a load or the underside of the platform of a pallet.

13 A unit as in Claim 12, wherein the attachment means on the free end of the strap is a two-pronged hook having prongs spaced apart by at least the width of a lo middle spacer of a pallet so that the prongs can engage the underside of the platform one to each side of the spacer.