IE910101A1

IE910101A1 - A hand truck

Info

Publication number: IE910101A1
Application number: IE10191A
Authority: IE
Inventors: Henry Berrif Crawford
Original assignee: Henry Berrif Crawford
Priority date: 1991-01-11
Filing date: 1991-01-11
Publication date: 1992-07-15
Also published as: IE66045B1

Abstract

The invention provides an apparatus for a hand truck or trolley for carrying small loads that are too heavy to be carried. It comprises a primary frame (12) having a pair of ground engaging wheels (16, 17). A secondary frame includes two parallel side members (13, 14) each pivotally connected at an upper end to the primary frame. This secondary frame carries a load platform (27) (a tray or pan) which, incorporating abutment means (22, 23), can advance from a parallel position with the ground, forward of the wheels, to a substantially horizontal raised position (behind the wheels) by a turning movement of the primary frame. This results in no substantial tipping of the load. Further load restraining means can be incorporated to the aforesaid load platform by adjoining a flexible line, chain or rope attachable at each end to the primary and secondary frame.

Description

HENRY BERRIF CRAWFORD, a British Citizen of The Briars, St. Hilary Goldsithney, Penzance, Cornwall TR20 9DG, England. -1ό ό 0 4 5 - 1- *ς10 1 ν 1 A HAND TRUCK The present invention relates to a hand truck or trolley for carrying small loads which are too heavy or bulky to be carried.

Various different trucks or trolleys for transporting loads are known. One such known truck or trolley, the socalled sack-barrow, comprises a rigid L-shape frame with a pair of wheels pivoted at the intersection of two approximately orthogonal arms of the frame. The horizontal arm is very much shorter than the vertical arm and this latter has a pair of handles at the upper end, or a loop by which the barrow can be manipulated. Such barrows have the disadvantage that loading and unloading involves tipping the load in order to introduce the platform constituted by the horizontal arm of the L-shape frame. Further, the weight of the load is to a large extent carried by the operator through the handle, particularly if the frame is inclined at a substantial angle to the vertical in operation, and there is a risk that the load will tip and fall off if the load-bearing platform is placed on the ground, for example, to allow the operator to rest. A development of the sack-barrow is known from British Patent 566,932, which discloses a trolley having a pivoted sub-frame with arms for engagement under a raised floor of a special load.

FPES908476 *910101 A special load is also envisaged for another trolley described in French Patent 1,339,773. In this latter Patent a frame for a gas bottle can be engaged by a hook on a main frame to lift this into a tilted position for transport as is common with sack-barrows.

The present invention seeks to provide a hand truck which can be used as a load-bearing trolley or barrow and which will not suffer from the disadvantages of the known sackbarrow and at the same time will be simpler and more economical to manufacture than known four-wheeled trolleys; it has the unique features that it is designed to carry the load upright rather than in a tilted orientation like a sack-barrow, and can rest in a stable state on the ground and support the weight of the user without risk of rolling.

A hand truck for transporting a load, of the type comprising a primary frame having a pair of groundengaging wheels turnable about a first axis, and a secondary frame carrying a load platform pivotally attached to the primary frame and turnable with respect thereto about a second axis parallel to the said first axis and defining therewith a reference plane, first and second abutment means limiting the relative turning movement of the secondary frame with respect to the primary frame between first and second end positions in the first of which the load platform is orientated to lie parallel to the ground and in contact therewith and is X9 10 1 0 1 displaced forwardly of the said wheels, and in the second of which a part of the load platform of the secondary frame projects rearwardly beyond the said reference plane.

In such a truck the load is carried partly balanced about the first axis (of the ground wheels) and the leverage which is required to be applied by an operator is low making it possible to control even substantial loads on the platform, with this lying horizontally, without requiring the application of a very great force by the operator. The primary frame is preferably provided with operating handle means for manipulation of the truck.

It is a further feature of the present invention that relative movement between the primary frame and the secondary frame is limited by abutment stop means to determine the said first relative position of the secondary frame with respect to the primary frame. In this first relative position the load platform of the secondary frame can be placed in contact with the ground, in which case any attempt to move the primary frame further in the direction of displacement from the second relative position towards the first relative position is prevented by such abutment stops, and forces exerted on the primary frame are transferred to the ground through the secondary frame. In this position the line of action of a force on the handle passing through any point of the load platform exerts a turning moment about the said secondary axis -910101 urging the said secondary frame towards the said first relative position of the secondary frame with respect to the primary frame.

When the operator wishes, therefore, it is possible simply to lower the platform onto the ground and to allow the weight of the user's body to rest on the operating handle means without risk that the mechanism will roll on the wheels. For the elderly or infirm, who may require frequent rest periods, this is a considerable advantage since the mechanism can be used as a support to lean on at intervals during a passage from one place to another transporting a load.

The said secondary frame may include two parallel side members each pivotally connected at an upper end thereof to a respective side member of the primary frame, and the said first abutment means may comprise respective projections extending laterally from each of the said primary frame side members. The primary frame side members may be cranked at their lower ends, ie. L-shape, to displace the ground wheel axis forwardly of the second abutment stop means. Likewise it is preferred that the primary frame is composed of an upper frame part in the form of a handle loop, and a lower frame part, the two frame parts defining respective planes inclined at an angle to one another.

FPES908476 In a preferred embodiment of the invention the said load platform can be raised from the ground to a substantially horizontal raised position by relative turning movement of the primary frame with respect to the secondary frame about the said second pivot axis to move the said secondary frame to the said second relative position thereof with respect to the primary frame with the platform experiencing no substantial tipping from the substantially horizontal position in moving from the lowered to the raised positions.

The primary frame may include an axle member joining the two ground wheels of the primary frame, which axle member also constitutes the said second abutment against which the secondary frame engages to determine the said second relative position of the secondary frame with respect to the primary frame, the said axle member being generally ushape and having two parallel arms attached at their free ends to respective primary frame side members. The said load platform may be formed as a tray or pan attached to the secondary frame and projecting therefrom transversely of a plane joining its point of attachment to the primary frame with the said pivoted end thereof, the length of the said tray or pan, in the direction of projection thereof, being at least as great as the width thereof. There may further be provided load restraining means attached or attachable to the primary frame and/or to the secondary frame to restrain a load on the said load platform against tipping with respect to the load platform. Such load FPES908476 restraining means may for example comprise a chain or other flexible elongate member attached or releasably attachable at one or both ends thereof to the primary or secondary frame of the said mechanism.

According to another aspect the present invention provides a hand truck for transporting a load, of the type comprising a primary frame having at least two ground wheels mounted thereon so as to be turnable about a common first pivot axis, handle means for manipulating the primary frame, a substantially rigid secondary frame pivotally attached to the said primary frame and turnable about a second pivot axis substantially parallel to the said first pivot axis and defining therewith a reference plane, a load platform carried by the said secondary frame remote from the said second pivot axis, and first and second abutment means acting to limit the relative rotation of the said primary and secondary frames in first and second directions respectively to determine respective first and second relative orientations of the primary and secondary frames, in which in the said first relative orientation the platform is engageable on the ground with the wheels of the main frame substantially out of load-bearing contact with the ground, and in the said second relative orientation the platform can be held in a substantially horizontal orientation to which it can be raised from the ground without any substantial tipping from the substantially horizontal position in moving from the lowered to FPES908476 the raised positions, and in which the said second abutment means define a position in which the platform extends beyond the said reference plane defined by the said first and second pivot axes.

One embodiment of the present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which:Figure 1 is a perspective view of an embodiment of the invention constructed as a load-bearing trolley; Figure 2 is a side view of the embodiment of figure 1 in a first position; and figure 3 is a side view of the embodiment of the invention in a second position.

Referring now to the drawings, the trolley illustrated is generally indicated with the reference numeral 11 and comprises a generally U-shape primary frame 12 having side members 13, 14 joined at their free ends by an axle member 15 carrying two wheels 16, 17, one at each end. The axle member 15 is a shallow U-shape having a main bight portion 15a and two substantially parallel linbs 15b and 15c. The main bight portion 15a forms an abutment stop for purposes which will be described below. It will be appreciated, however, that the main bight portion 15a lies parallel to the axis of rotation of the two ground wheels 16, 17 and displaced somewhat rearwardly of this axis. The upper part of the primary frame 12, which is joined to the lower primary frame side linbs 13, 14 by elbows 19, 20, has an FPES908476 inverted U-shape with a bight portion 21 which constitutes the handle member by which the mechanism is manipulated by a user. Just below the elbows 19, 20 there are two pivotal mounts 22, 23 to which are pivoted the upper ends of two legs 24, 25 of a secondary frame 26 to the lower ends of which is secured a platform generally indicated 27 in the form of a shallow tray having a flat bottom and left and right sides 28, 29 and an upright back 30. The interconnection between the legs 24, 25 and the platform 27 is made by welding or bolting the lower ends of the legs 24, 25 to the side walls 28, 29 respectively in such a way that a rigid interconnection at a predetermined fixed angle between the plane of the platform bottom and the plane defined by the two legs 24, 25 is obtained.

Finally, the two pivotal mounts 22, 23 carried on the primary frame side members 13, 14 have flanged projections 30, 31 which serve as abutments to limit the pivotal movement of the secondary frame 26 about the pivot axis χχ with respect to the primary frame 12. Movement of the legs 24, 25 of the secondary frame 26 in the opposite direction is limited by abutment of the platform tray 27 or of the legs themselves, against the main part 15a of the secondary member 15. The effect of the limited articulation of the secondary frame 26 with respect to the Ushape main frame 12 will be described hereinbelow with reference to figures 2 and 3.

FPES908476 © Τί 0 1 0 1 Referring now to figure 2, the trolley is shown in a first position with the platform 27 flat on the ground. In this position the main frame 12 has been turned about the pivot axis x-x, in a clockwise direction as viewed in figure 2, to its maximum extent; the arms 13, 14 of the main frame 12 have turned about the pivot axis x-x until with the wheels 16, 17 still on the ground, the platform 27 now rests flat on the ground. The abutments 22, 23 have been brought to a position where they contact the legs 24, 25 of the secondary frame 26; no further turning of the main frame 12 clockwise can take place. Any downward load on the handle 21 will result in a clockwise moment on the secondary frame 12, either because of the diverging action of the lower side members 13, 14 and the secondary frame 26, in the case of a downward force the line of action of which passes behind the pivot axis x-x; or, in the case of a force the line of action of which passes forwardly of the axis x-x, because this also passes through the platform 27 thereby pressing this onto the ground and tending to turn the primary frame in a clockwise direction.

The position illustrated in figure 3 is achieved by pulling the handle 21 downwardly and to the left as viewed in figures 2 and 3, lifting the platform 26 from the ground. This has the effect of turning the main frame 12 about the pivot axis x-x until the axle 15 is brought into contact with the rear wall 30 of the load platform 27. In this position the wheels have moved forward to a position somewhat forward of the rear wall 30 of the platform 27 FPES908476 &ώ Ο 1 0 ί due to the crank members 15b, 15c, and further movement of the handle 21 then lifts the platform 27 to the position shown in figure 3. As will be appreciated, in passing from the position shown in figure 2 to the position shown in figure 3, the platform 27 experiences no substantial tipping motion.

Because the primary frame 12 is cranked at the elbows 19, the handle 21 is located a considerably greater distance from the vertical centre line through the wheels 16, 17 than the centre of gravity of a load on the platform 27. This leverage gives the operator a great mechanical advantage in handling the trolley, even with a heavy load on the platform 27.

The load may be retained securely in place by the provision of a restraining chain or like flexible linear member 28 as shown in broken outline in figure 3 in place around a notional load 29, also shown in broken outline. One end of the chain 28 can be releasably held by a clasp to aid fitting it round the load and adjusting it to size. As will be seen from figure 3 the load 29 can be carried entirely upright with its weight counterbalanced by the force applied to the handle 21. The weight of the load 29 is partly balanced on the wheels 16, 17 by the fact that the platform 27 extends some way behind the common axis of the wheels, thereby reducing the force required on the handle 21 by between one quarter and one third of that FPES908476 which would be required if the platform did not extend beyond the wheel axis, thereby enabling heavier loads to be handled more easily.

Claims

1. CLAIMS 9 10 10 1

1. A hand truck for transporting a load, of the type comprising a primary frame having a pair of groundengaging wheels turnable about a first axis, and a secondary frame carrying a load platform pivotally attached to the primary frame and turnable with respect thereto about a second axis parallel to the said first axis and defining therewith a reference plane, first and second abutment means limiting the relative turning movement of the secondary frame with respect to the primary frame between first and second end positions in the first of which the load platform is orientated to lie parallel to the ground and in contact therewith and is displaced forwardly of the said wheels, and in the second of which a part of the load platform of the secondary frame projects rearwardly beyond the said reference plane.

2. A hand truck according to claim 1 wherein the said primary frame has or incorporates handle means by which the said primary frame and therefore the truck as a whole can be manipulated.

3. A hand truck according to claim 2, wherein when the secondary frame is in the said first relative position thereof with respect to the said primary frame the line of action of a force on the said handle means passing through any point of the load platform exerts a turning movement ' '§ Η 1 Ο ί] about the said secondary axis urging the said secondary frame towards the said first relative position of the secondary frame with respect to the primary frame.

4. A hand truck according to any of claims 1 to 3, in which the said secondary frame includes two parallel side members each pivotally connected at an upper end thereof to a respective side member of the primary frame, and the said first abutment means comprise respective projections extending laterally from each of the said primary frame side members.

5. A hand truck according to any of claims 1 to 4, wherein the said load platform can be raised from the ground to a substantially horizontal raised position by relative turning movement of the primary frame with respect to the secondary frame about the said second pivot axis to move the said secondary frame to the said second relative position thereof with respect to the primary frame with the platform experiencing no substantial tipping from the substantially horizontal position in moving from the lowered to the raised positions.

6. A hand truck according to any of claims 1 to 5, wherein the primary frame includes an axle member joining the two ground wheels of the primary frame, which axle member also constitutes the said second abutment against FPES908476 which the secondary frame engages to determine the said second relative position of the secondary frame with respect to the primary frame, the said axle member being generally U-shape and having two parallel arms attached at their free ends to respective primary frame side members.

7. A hand truck according to my preceding claim, wherein the said load platform is formed as a tray or pan attached to the secondary frame and projecting therefrom transversely of a plane joining its point of attachment to the primary frame with the said pivoted end thereof, the length of the said tray or pan, in the direction of projection thereof, being at least as great as the width thereof .

8. A hand truck according to any preceding claim, wherein there are further provided load restraining means attached or attachable to the primary frame and/or to the secondary frame to restrain a load on the said load platform against tipping with respect to the load platform.

9. A hand truck according to claim 8, wherein the said load restraining means comprise a flexible line, chain, rope or the like attached or attachable at each end to the primary or secondary frame, at least one end being releasable from the said primary or secondary frame. FPES908476 il y OH

10. A hand truck according to any of claims 2 to 9 wherein the said handle means for manipulating the track comprises an integral loop of the said primary frame.

11. A hand truck for transporting a load, of the type comprising a primary frame having at least two ground wheels mounted thereon so as to be turnable about a common first pivot axis, handle means for manipulating the primary frame, a substantially rigid secondary frame pivotally attached to the said primary frame and turnable about a second pivot axis substantially parallel to the said first pivot axis and defining therewith a reference plane, a load platform carried by the said secondary frame remote from the said second pivot axis, and first and second abutment means acting to limit the relative rotation of the said primary and secondary frames in first and second directions respectively to determine respective first and second relative orientations of the primary and secondary frames, in which in the said first relative orientation the platform is engageable on the ground with the wheels of the main frame substantially out of load-bearing contact with the ground, and in the said second relative orientation the platform can be held in a substantially horizontal orientation to which it can be raised from the ground without any substantial tipping from the substantially horizontal position in moving from the lowered to FPES908476 the revised positions, and in which the said second abutment means define a position in which the platform extends beyond the said reference plane defined by the said first and second pivot axes.

12. A hand truck according to any preceding claim substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.