STRAP AND HANDLE ASSEMBLY
This invention relates to an improved strap and handle assembly of the kind used for portermg items of different dimensions.
Such assemblies are known from CN UM 202035658 and from GB 2378936. A principle object of the present invention is to improve upon these proposals by providing an assembly in which (a) the strap cannot be accidentally disengaged from the handle when it is carrying a load and (b) the strap can be wound onto its spool and then locked using the same hand which is carrying the handle.
In accordance with the invention there is provided a strap and handle assembly for portering items of miscellaneous dimensions, the assembly, comprising a handle, a pair of anchorage points for a strap in spaced relation on the handle, at least one of said points allowing passage of the strap therethrough to adjust the length of the strap which extends between the anchorage points and means for releasably locking the strap relative to said one anchorage point when a chosen length of the strap extends between the anchorage points, characterised in that the strap has a free end which is releasably engageable with the other of said anchorage points by means of a tab having side lugs which engage in respective slots in the handle adjacent said other anchorage point and each opening upwardly of the handle, the lugs and slots having respective shapes such that when the tab is rotated so that the strap extends away from the handle the lugs cannot be disengaged from the slots. Each lug is preferably formed with at least one flat side and the associated slot will accommodate said lug in the greater part of its length only when the latter is rotated to a position in which the tab aligns with the slo said slot having a blind end remote from the open end of said slot which is enlarged relative to said greater part of its length such that when the associated lug is in the enlarged part of the associated slot said lug can be freely rotated.
A spool is preferably mounted on or in the handle associated with said one anchorage point to store the length of the strap which does not extend between the anchorage points.
In this arrangement the handle may be provided by a hollow casing in which the spool is rotatably mounted in separated relation to said other anchorage point and the strap can pass around and between the spool and said other anchorage point and has a leading end which emerges from the casing and is connectable to the casing, means being provided to tension a loop of the strap thus formed around an item to be carried and to then lock the strap against emergence from the casing. Means is preferably provided for rotating said at least one spool to retract the strap into the casing. Said rotating means may comprise a wheel accessible for manual operation externally of the casing. Said wheel preferably rotates the spool through a planetary gear system which rotates the spool more slowly than said wheel.
Said rotating means preferably comprises a clock spring.
The spool is preferably integral with a ratchet which cooperates with a pawl to permit movement of the strap only into and not out of the casing wherein the pawl is spring urged into contact with the ratchet and wherein said manual disengagement means permits a loop of the strap to be formed and retained prior to being passed around an item to be carried.
The pawl is preferably manually disengageable from the ratchet to permit withdrawal of the strap from the casing. Preferably the pawl is spring urged into contact with the ratchet and said manual disengagement means permits a loop of the strap to be formed and retained prior to being passed around an item to be carried.
A preferred embodiment of the invention will now be described by way of non-limitative example with reference to the accompanying drawings, in which:
Figure 1 is a front perspective view from above and one side of an assembly in accordance with the present invention,
Figure 2 is a sectional view taken on the line Π-Π of Figure 1,
Figure 3 is an exploded view showing the mechanism by which the ratchets associated with the spool are engaged and disengaged, and
Figure 4 is an enlarged view of the tab which terminates the free end of the strap.
The device illustrated comprises a handle assembly 10 in which a spool 11 is rotatably mounted. The spool is flanked on either side by similar ratchet wheels 12. Wound onto the spool 11 is a strap 13 which emerges from the underside of the handle assembly 10 after passing around a fixed pin 14. The free end of the strap 13 terminates in a tab 15 shown in more detail in Figure 4. The tab has side lugs 16', 16" which will engage in slots 17 near the end of the handle assembly 10 remote from the spool 11. As seen most clearly in Figure 2 the slots 17 open upwardly of the handle assembly and have enlarged blind ends 1 T. Referring to Figure 4 the lugs 16', 16" have flats enabling the tab 15 to pass down the slots 17 when the tab 15 is at right angles to the longitudinal axis of the handle assembly 10. However when rotated into a downward, load-bearing position, which becomes possible when the lugs 16', 16" are in the enlarged, blind ends 17' of the slots 17, the tab cannot re-emerge from the slots 17. This is a safety feature to ensure that the tab 15 cannot be disengaged from the handle assembly 10 when the strap 13 surrounds an item to be carried.
The ratchet wheels 12 are engageable by a plate 18 urged into contact with the ratchet wheels by a spring 23 (Figure 3). With the ratchet wheels 12 engaged by the plate 18 the spool 11 can be rotated to wind the strap 13 onto the spool but cannot counter-rotate to release the strap from the spool. The spool 11 is manually rotated by a thumb-wheel 19 accessible on one side of the handle assembly 10. Optionally a planetary gear system (not shown) is interposed between the thumb-wheel 19 and the spool 11 to provide a mechanical advantage to the thumb wheel 19 so that the strap 13 can be tensioned with less force.
By pulling the strap 13 away from the handle assembly 10 the spool 1 1 is manually rotated against the action of a clock spring (not shown) which tends to rotate the spool 11 in a direction to wind the strap 13 onto the spool. To release the strap 13 sufficiently to surround an item to be carried the plate 18 is pressed down against the action of the torsion spring 22 sufficiently to clear the junction between the rebates 20 and 2 land then pulled back into the rebate 21 sufficiently to clear the ratchets 12. With the plate 18 held in this position against the action of the compression spring 23 tending to bring it back into engagement with the ratchets 12 it is possible to unwind the strap 13 to form a loop of the strap sufficient to surround an item to be carried, all the time holding the plate 18 with the thumb of the same hand which is holding the handle 10. With a loop of the strap sufficient to surround the item drawn from the spool the plate 18 is released and is brought back into the rebate 20 by the bias of springs 22 and 23. In this position the plate engages the ratchets 12 temporarily to maintain the loop of strap so that an item to be carried can easily be surrounded by said loop. To tighten the strap 13 about the item to be carried the thumb -wheel 19 is rotated such that the ratchets 12 force the plate 18 out of rebate 20, the plate riding over the teeth of the ratchets 12 against the action of the spring forcing the plate into contact with the ratchets. When the thumb-wheel 19 is released the spring bias of the plate 18 keeps it in contact with the ratchets 12 so that the latter cannot counter-rotate to release the item. When the item is carried the resulting increased tension on the strap applies a corresponding pressure to the edge of plate 18 in contact with ratchets 12 such that the plate 18 is forced into rebate 20 where it cannot move or be accidentally released. When the item being carried has reached its destination it is released from the strap 13 by withdrawing the plate 18 from the ratchets, allowing the strap to be pulled out of the handle assembly and then if desired releasing the tab 15 from the slots 17.