GB2553080A

GB2553080A - Load handling apparatus

Info

Publication number: GB2553080A
Application number: GB1609618.2A
Authority: GB
Inventors: Lawrence Fletcher Neil
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-06-02
Filing date: 2016-06-02
Publication date: 2018-02-28
Anticipated expiration: 2036-06-02
Also published as: GB2553080B; GB201609618D0

Abstract

Load handling apparatus or hand truck 101 comprises a wheeled support structure 102 having a frame 103, a platform element 104 providing a load platform and a platform element positioning mechanism by means of which the load platform is movable in a raising direction R and in a lowering direction L. The platform element positioning mechanism comprises a lead screw 111 supported by the frame 103, the lead screw 111 having a male buttress thread and at least one half nut 112, 113 supported by the platform element 104, the or each half nut 112, 113 having a female thread co-operable with the male buttress thread of the lead screw 111. The platform element (104) is tiltable relative to the lead screw 111 to selectively disengage and engage the or each half nut 112, 113 from the lead screw 111 to allow the platform element 104 to slide along the lead screw 111. A handle 115 may facilitate the tilting of the platform element 104. The lead screw 111 may be motorised for rotation. A foot operable rear stand 119 may be provided. An elongate guard element 121 forwardly of the lead screw 111 may prevent a load on the load platform from contacting the lead screw 111.

Description

(71) Applicant(s):

Neil Lawrence Fletcher

Fieldfare, West End, NORTHLEACH, Gloucestershire, GL54 3HF, United Kingdom (72) Inventor(s):

Neil Lawrence Fletcher (51) INT CL:

B66F 9/20 (2006.01) B62B 1/12 (2006.01) F16H 25/20 (2006.01) (56) Documents Cited:

GB 2362372 A US 8556280 B1

US 20080203688 A1 (58) Field of Search:

INT CL B62B, B66F, F16H Other: WPI, EPODOC (74) Agent and/or Address for Service:

Bryers LLP

Gay Street, BATH, BA1 2PH, United Kingdom (54) Title of the Invention: Load handling apparatus

Abstract Title: Hand truck with adjustable height load platform (57) Load handling apparatus or hand truck 101 comprises a wheeled support structure 102 having a frame 103, a platform element 104 providing a load platform and a platform element positioning mechanism by means of which the load platform is movable in a raising direction R and in a lowering direction L. The platform element positioning mechanism comprises a lead screw 111 supported by the frame 103, the lead screw 111 having a male buttress thread and at least one half nut 112, 113 supported by the platform element 104, the or each half nut 112, 113 having a female thread co-operable with the male buttress thread of the lead screw 111. The platform element (104) is tiltable relative to the lead screw 111 to selectively disengage and engage the or each half nut 112, 113 from the lead screw 111 to allow the platform element 104 to slide along the lead screw 111. A handle 115 may facilitate the tilting of the platform element 104. The lead screw 111 may be motorised for rotation. Afoot operable rear stand 119 may be provided. An elongate guard element 121 forwardly of the lead screw 111 may prevent a load on the load platform from contacting the lead screw 111.

102

109

101

/

101

At least one drawing originally filed was informal and the print reproduced here is taken from a later filed formal copy.

01 18

01 18

mm

Λ

5mm Pitch

-,5mm Rad

01 18

Low Voltage D.C. Motor

01 18

38mm Dural Lead Screw

LOAD HANDLING APPARATUS

Field of the Invention

The present invention relates to load handling apparatus, in particular to manually propellable wheeled load handing apparatus comprising a movable load platform, and more particularly to a hand truck comprising an adjustable height load platform.

Background of the Invention

A known type of load handling apparatus is a hand truck. A known type of hand truck comprises an L-shaped frame with wheels at a lower end thereof and a handle at an upper end thereof, the L-shaped frame comprising a back rest and a ledge extending perpendicularly forwardly of the back rest. The L-shaped frame is pivotable about the wheels between a standing position of the hand truck, in which the back rest is upright and the ledge rests on the floor to stabilise the hand truck, and an inclined position of the hand truck in which the back rest is rearwardly tilted and a load on the ledge is raised over the wheels to facilitate transportation of the load.

Another known type of hand truck comprises an ‘adjustable height platform’ that is movable with respect to the back rest and selectively locatable at one of a plurality of positions corresponding to lower or higher elevations above the ledge when the hand truck is in the standing position. The adjustable height platform allows loads to be received on the platform, and discharged from the platform, at different heights above ground level. UK Patent Publication No. GB 2 353 770 discloses a hand truck comprising a wheeled support structure, a load supporting platform slidably engaged with the wheeled support structure and a raising mechanism that is operated in response to movement of the wheeled support structure in one direction along the ground and by means of which the load supporting platform is raised, and also by means of which the load supporting platform is lowered.

The present invention provides an improved hand truck with an adjustable height load platform.

I

Summary of the Invention

The present invention provides load handling apparatus comprising a wheeled support structure. In an embodiment, the load handling apparatus is a hand truck. The wheeled support structure comprises a frame providing a back rest and a ledge extending substantially perpendicularly to and forwardly of the back rest, a platform element providing a load platform, and a platform element positioning mechanism by means of which the load platform is movable relative to the back rest in a raising direction and in a lowering direction. A wheel arrangement is provided towards a lower end of the back rest and a handle arrangement is provided towards an upper end of the back rest. The frame is pivotable about an axle of the wheel arrangement between a standing position and rearwardly inclined position.

The platform element positioning mechanism comprises a lead screw supported by the frame, the lead screw having a male buttress thread, and at least one half nut supported by the platform element, the or each half nut having a female thread cooperable with the male buttress thread of the lead screw. When the platform element is in threaded engagement with the lead screw, rotation of the lead screw causes the platform element to move along the lead screw to move the load platform in the raising or the lowering direction. The platform element is tiltable relative to the lead screw to selectively disengage the half nut from the lead screw. When the platform element is not in threaded engagement with the lead screw, the platform element is slidable along the lead screw to reposition the platform element along the lead screw and move the load platform in the raising or the lowering direction.

The lead screw with buttress thread and the half nut allows controlled advancement of the platform element along the lead screw, such as when the load platform is supporting a load, and allows more rapid shifting of the platform element along the lead screw, such as when the load platform is not supporting a load.

In an embodiment, the lead screw is motorised, such that rotation of the lead screw is electrically powered. The motor may be configured to enable a user to rotate the lead screw in both a clockwise direction and an anti-clockwise direction. In an embodiment, the platform element is provided with a handle to facilitate tilting of the platform element to disengage the half nut from the lead screw and subsequent repositioning of the platform element along the lead screw.

In an embodiment, the back rest may comprise a pair of spaced-apart side frame members. The back rest may further comprise cross-members that extend between the spaced-apart side frame members and that define a load supporting profile of the back rest. The back rest may have a flat or a curved load supporting profile.

The handle arrangement may comprise a horizontal loop handle, a vertical loop handle, a single grip handle, a double grip handle, a ‘P-shaped’ handle, a double loop handle or a combination of handle types.

In an embodiment, a lead screw motor activation device is located in the vicinity of the handle arrangement.

The load platform may be solid or define one or more apertures therein. The load platform may be foldable between a use position and a stowage position. The load platform may be configured to allow extensions to be mounted thereto.

The wheel arrangement may comprise on or more wheels or rollers. In an embodiment, the wheel arrangement comprises a pair of spaced-apart wheels. The wheels may have solid or pneumatic tyres. The wheel arrangement may comprise a brake.

The wheeled support structure may comprise stair climb or stair glide features.

The wheeled support structure may comprise a rear stand movable between a stabilising position and a stowage position. The rear stand may be foot operable.

The rear stand and the wheel arrangement may be configured such that the wheel or wheels of the wheel arrangement are raised above the ground as the rear stand is moved into the stabilising position.

The load handling apparatus and components thereof may have any suitable dimensions. The load handling apparatus and components thereof may be fabricated from any suitable material or materials, and may be manufactured using any suitable process, method, technique or combination thereof. The load handling apparatus may have any desired aesthetic appearance.

Different aspects and embodiments of the invention may be used separately or together.

Brief Description of the Drawings

The present invention will now be more particularly described, with reference to the accompanying drawings, in which:

Figure I shows a load handling apparatus according to the present invention; Figure 2 shows details of the platform element positioning mechanism of the load handling apparatus of Figure I in further detail;

Figure 3 shows a feature of the platform element positioning mechanism of the load handling apparatus of Figure I in further detail; and

Figure 4 is a schematic of a partial side view of the load handling apparatus of

Figure I.

Description

Example embodiments are described below in sufficient detail to enable those of ordinary skill in the art to embody and implement the invention described herein. 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.

A load handling apparatus 101 is shown in Figure I. According to this illustrated embodiment, the load handling apparatus is a hand truck 101. The hand truck comprises a manually propellable wheeled support structure 102.

The wheeled support structure 102 comprises a frame 103, a platform element 104 and a platform element positioning mechanism. The frame 103 provides a back rest, indicated at 105, and a ledge 106 extending substantially perpendicularly to and forwardly of the back rest 105. The platform element 104 provides a load platform 107. In the shown arrangement, the load platform 107 also extends substantially perpendicularly to and forwardly of the back rest 105 and is substantially parallel to the ledge 106.

A wheel arrangement 108 is provided towards a lower end of the back rest 105 and a handle arrangement 109 is provided towards an upper end of the back rest 105. The frame 103 is pivotable about an axle I 10 of the wheel arrangement 108 between a standing position and rearwardly inclined position. The wheel arrangement 108 acts as a fulcrum with the handle arrangement 109 on one side and the ledge 106 on the other side.

In this Figure, the hand truck 101 is shown in the standing position, in which the back rest 105 is upright and the ledge 106 rests on the floor to stabilise the hand truck 101. When the hand truck 101 is in an inclined position the back rest 105 is rearwardly tilted and a load on the load platform 107 is raised over the wheeled arrangement 108 to facilitate transportation of the load.

The back rest 105 has a height direction H and the platform element positioning mechanism allows the position of the load platform 107 relative to the back rest 105 to be moved in a raising direction R and in a lowering direction L.

The platform element positioning mechanism comprises a lead screw I I I supported by the frame 103, the lead screw I I I having a male buttress thread. The platform element positioning mechanism further comprises a plurality of half nuts, such as half nuts 112, 113, supported by the platform element 104, each half nut having a female thread co-operable with the male buttress thread of the lead screw I I I.

In this embodiment, the platform element 104 is normally in threaded engagement with the lead screw I I I. When the platform element 104 is in threaded engagement with the lead screw I I I, rotation of the lead screw I I I causes the platform element 104 to move along the lead screw I I I, in turn causing the load platform 107 to move in the raising direction R or the lowering direction L, depending on the direction of rotation of the lead screw I I I. This arrangement provides for controlled advancement of the platform element 104 along the lead screw III. In this embodiment, the lead screw I I I is rotatable in both a clockwise and an anticlockwise direction. Thus, the threaded engagement between the platform element 104 and the lead screw I I I provides for controlled movement of the load platform 107 in the raising direction R, upwards towards the handle arrangement 109, and in the lowering direction L, downwards towards to the wheel arrangement 108.

Advantageously, the threaded engagement between the platform element 104 and the lead screw III is selectively releasable, to allow the platform element 104 to be moved along the lead screw I I I without utilising the rotation to linear motion provided by the co-operating engagement of the half nuts 112, 113 with the lead screw.

In this embodiment, the platform element 104 is tiltable relative to the lead screw I I I to selectively disengage the female thread of the half nuts 112, 113 from the male buttress thread of the lead screw III. When the platform element 104 is not in threaded engagement with the lead screw III, the platform element 104 is slidable along the lead screw I I I to reposition the platform element 104 along the lead screw I I I and in turn move the load platform 107 in the raising direction R or the lowering direction L.

The load handling apparatus 101 thus allows a user to raise or lower the load platform 107 in a first mode of positioning, in which the platform element 104 and lead screw

I I I are in threaded engagement, and also in a second mode of positioning, in which the platform element 104 and lead screw I I I are not in threaded engagement.

For example, a user may choose to raise or lower the load platform 107 in the first mode when the load platform 107 is supporting a load and to raise or lower the load platform 107 in the second mode when the load platform 107 is not supporting a load. In the second mode, the load platform 107 may be moved between two positions more quickly than in the first mode. This beneficially allows a user to, for example, quickly locate the load platform 107 at a first desired height relative to ground level in before placing a load on the load platform from a first surface at a first height, and then to raise or lower the supported load on the load platform 107 to a second different desired height relative to ground level for unloading the load onto a second surface at a second height.

In this embodiment, the lead screw I I I is motorised, such that rotation of the lead screw I I I is electrically powered. In this embodiment, rotation of the lead screw I I I is effected by motor I 14, which is operable in both a forward and a reverse direction to enable powered rotation of the lead screw I I I in both the clockwise and anticlockwise directions. The motor may be any suitable motor. In an example, the motor is a low voltage DC motor.

In an embodiment, the platform element is provided with a handle I 15 to facilitate tilting of the platform element 104 to disengage the half nuts 112, 113 from the lead screw I I I and also subsequent repositioning of the platform element 104 along the lead screw III. The handle 115 may be any suitable type of handle. In this embodiment, the handle I 15 extends in the opposite direction to the load platform 107. The lead screw I I I acts as a fulcrum with the handle I 15 of the platform element 104 on one side and the load platform 107 on the other side.

The handle arrangement 109 may comprise any suitable type of type of handle or handles. In this embodiment, the handle arrangement 109 comprises a ‘P-shaped’ handle I 16. Preferably, and in this embodiment, a hand-operable motor activation arrangement 120 is provided in the vicinity of the handle arrangement 109 and positioned to allow an operative to conveniently operate the motor I 14 to adjust the height of the load platform 107 when using a handle of the handle arrangement 109. The hand-operable motor activation arrangement 120 may comprise any suitable arrangement of one or more suitable activation devices, for example, a button, a lever, a switch, a dial.

The wheel arrangement 108 may comprise any suitable arrangement of one or more wheels or rollers. In this embodiment, the wheel arrangement 108 comprises a pair of spaced-apart wheels 117, 118 between which axle I 10 extends.

In this embodiment, the hand truck 101 comprises a rear stand, indicated at 119, which is movable between a use position and a stowage position. In this embodiment also, the read stand I 19 and the wheel arrangement 108 are configured such that the wheels 1107, 118 are raised above the ground as the rear stand I 19 is moved into the use position. Preferably, and in this embodiment, the rear stand I 19 is foot-operable.

In this shown embodiment, the hand truck 101 comprises an elongate guard element 121 located forwardly of the lead screw III to prevent a supported load from contacting the lead screw I I I, to protect both the buttress thread of the lead screw I I I from the load and the load from the leads screw III. Further, in this shown embodiment, the elongate guard element 121 extends through an aperture (not shown) in the load platform 107 of the platform element 104.

Figure 2 shows a hand 201 manipulating the handle I 15 of the platform element 104 to tilt the platform element 104 relative to the lead screw III in preparation for repositioning the platform element 104 along the lead screw I I I and in turn adjusting the height of the load platform 104 above the ledge 106. In order to tilt the platform element 104 to disengage the half nuts I 12 of the platform element 104 from the buttress thread 202 of the lead screw I I I, the handle I 15 is rotated in the direction indicated by arrow B. With the platform element 104 tilted rearwardly and not in threaded engagement with the lead screw III, the platform element 104 may be moved manually along the lead screw I I I in the raising direction R or the lowering direction L to a desired position, after which the handle I 15 may be returned to its original position to engage the half nuts I 12 of the platform element 104 with the buttress thread 202 of the lead screw I I I. It is to be appreciated that the weight of the load platform 107 biases the platform element 104 towards threaded engagement with the lead screw I I I. The platform element 104 is then maintained at that desired position by the threaded engagement with the lead screw I I I unless either the lead screw III is rotated (movement of load platform 107 in mode one as described above) or the platform element 104 is manually moved again (movement of load platform 107 in mode two as described above).

A further advantageous feature of the shown platform element positioning mechanism is evident when the load platform 107 is moved downwards towards the ledge 106 under mode one (in which the platform element 104 is in threaded engagement with the lead screw I I I and the lead screw I I I is rotated). As the load platform 107 reaches the end of travel down the lead screw I I I and adjacent the ledge 106, continued rotation of the lead screw I I I causes the platform element 104 to tilt rearwardly and in turn causes the load platform 107 to also be tilted to prevent trapping between the load platform 107 and the ledge 106. Thus, the platform element positioning mechanism provides a trapping hazard prevention feature to improve user safety.

Figure 3 shows the male buttress thread 202 of the lead screw I I I in further detail. The buttress thread 202 is oriented with the flat surface 301 uppermost and the inclined surface 302 extending inwardly and downwardly from a corner 303 between the flat and inclined surfaces 301, 303. In a specific example, the buttress thread 202 has a diameter of 38 mm and a pitch of 5 mm, the corner 303 has a radius of 0.5 mm and the inclined surface 302 has an inclination of 45 degrees.

Figure 4 is a schematic of a partial side view of hand truck 101. At A, the platform element 104 is shown being maintained at a first position along lead screw III, with the half nuts I 12, 401 of the platform element 104 in threaded engagement with the lead screw I I I and with the load platform 107 at a first height above ledge 106. At B, the platform element 104 is shown tilted at a second, lower position along lead screw III, with the half nuts I 12, 401 of the platform element 104 no longer in threaded engagement with the lead screw I I I and with the load platform 107 at a second height above ledge 106. In this embodiment, the buttress thread of the lead screw I I I defines the different height positions at which the platform element 104 can be brought into threaded engagement with the lead screw I I I.

In an example, the lead screw is fabricated from a polytetrafluoroethylene coated aluminium alloy. In a specific example, the lead screw is fabricated from Teflon ™ coated Duralumin ™. In an example, the half nuts of the platform element are fabricated from a synthetic polymer. In a specific example, the half nuts of the platform element are fabricated from nylon. In an example, the frame is fabricated from a metal material, such as steel. It is to be appreciated that any suitable materials may be used;

however the materials of the afore-mentioned specific examples satisfy criteria relating to physical properties (weight), performance characteristics (wear, heat, noise) and cost.

The present invention provides load handling apparatus with an adjustable height load platform, the load handling apparatus having improved height adjustability of the load platform and having improved user safety.

Although illustrative embodiments of the invention have been disclosed in detail herein, with reference to the accompanying drawings, it is understood that the invention is not limited to the precise embodiments shown and that various changes and modifications can be effected therein by one skilled in the art without departing from the scope of the invention.

Claims

Claims

31 05 17

1. Load handling apparatus comprising: a wheeled support structure, comprising:

5 a frame providing a back rest and a ledge extending substantially perpendicularly to and forwardly of the back rest, a platform element providing a load platform, a platform element positioning mechanism by means of which the load platform is movable relative to the back rest in a raising direction and in a lowering direction,

10 a wheel arrangement provided towards a lower end of the back rest, and a handle arrangement provided towards an upper end of the back rest; the frame pivotable about an axle of the wheel arrangement between a standing position and a rearwardly inclined position; wherein the platform element positioning mechanism comprises:

15 a lead screw supported by the frame, the lead screw having a male buttress thread, and at least one half nut supported by the platform element, the or each half nut having a female thread co-operable with the male buttress thread of the lead screw; and the platform element is tiltable relative to the lead screw to selectively disengage and engage the or each half nut from the lead screw;

20 when the platform element is in threaded engagement with the lead screw, rotation of the lead screw causes the platform element to move along the lead screw to move the load platform in the raising or the lowering direction, and when the platform element is not in threaded engagement with the lead screw, the platform element is slidable along the lead screw to reposition the platform element along

25 the lead screw and move the load platform in the raising or the lowering direction.
2. Load handling apparatus as claimed in claim I, wherein the platform element is provided with a handle to facilitate tilting of the platform element to disengage the half nut from the lead screw and subsequent repositioning of the platform element along the lead

30 screw.
3. Load handling apparatus as claimed in claim 2, wherein the handle extends in the opposite direction to the load platform.

II

31 05 17
4. Load handling apparatus as claimed in claim I, wherein the lead screw is motorised, such that rotation of the lead screw is electrically powered by a motor.
5 5. Load handling apparatus as claimed in claim 3, wherein the lead screw is rotatable in both a clockwise direction and an anti-clockwise direction.
6. Load handling apparatus as claimed in claim 4 or claim 5, wherein the motor is a low voltage DC motor.

IO
7. Load handling apparatus as claimed in any of claims 4 to 6, wherein a handoperable lead screw motor activation device is located in the vicinity of the handle arrangement.

15
8. Load handling apparatus as claimed in claim 7, wherein the hand-operable lead screw motor activation device comprises one of: a button, a lever, a switch, a dial.
9. Load handling apparatus as claimed in any preceding claim, wherein the handle arrangement comprises one of: a horizontal loop handle, a vertical loop handle, a single grip

20 handle, a double grip handle, a ‘P-shaped’ handle, a double loop handle or a combination of handle types.
10. Load handling apparatus as claimed in any preceding claim, wherein the back rest comprises a pair of spaced-apart side frame members and cross-members that extend

25 between the spaced-apart side frame members, the cross-members defining a load supporting profile of the back rest.

I I. Load handling apparatus as claimed in claim 10, wherein the back rest has one of: a flat load supporting profile, a curved load supporting profile.

I 2. Load handling apparatus as claimed in any preceding claim, wherein the load platform defines one or more apertures therein.

I2

31 05 17

I 3. Load handling apparatus as claimed in any preceding claim, wherein the load platform is foldable between a use position and a stowage position.

14. Load handling apparatus as claimed in any preceding claim, wherein the wheel 5 arrangement comprises one or more wheels.

I 5. Load handling apparatus as claimed in claim 14, wherein the wheel arrangement comprises a pair of spaced-apart wheels between which said axle extends.

IO 16. Load handling apparatus as claimed in claim 15, wherein the wheels have one of:

solid tyres, pneumatic tyres.

I 7. Load handling apparatus as claimed in any preceding claim, wherein the wheel arrangement comprises a brake.

18. Load handling apparatus as claimed in any preceding claim, wherein the wheeled support structure comprises a rear stand movable between a stabilising position and a stowage position.

20 19. Load handling apparatus as claimed in claim 18, wherein the rear stand is foot operable.

20. Load handling apparatus as claimed in claims 14 and 18, wherein the rear stand and the wheel arrangement are configured such that the wheel or wheels of the wheel

25 arrangement are raised above the ground as the rear stand is moved into the stabilising position.

21. Load handling apparatus as claimed in any preceding claim, further comprising an elongate guard element located forwardly of the lead screw to prevent a load supported on

30 the load platform from contacting the lead screw.

22. Load handling apparatus as claimed in any preceding claim, wherein the lead screw is fabricated from a polytetrafluoroethylene coated aluminium alloy.

23. Load handling apparatus as claimed in any preceding claim, wherein the or each half nut of the platform element is fabricated from a synthetic polymer.

5 24. Load handling apparatus as claimed in any preceding claim, wherein the frame is fabricated from metal.

25. Load handling apparatus as claimed in any preceding claim, wherein the load handling apparatus is a hand truck.

31 05 17

I4

Intellectual

Property

Office

Mr Karl Whitfield
13 November 2017

GB1609618.2

1 to 25