GB2363366A

GB2363366A - A trolley convertible into a height adjustable worktable

Info

Publication number: GB2363366A
Application number: GB0016413A
Authority: GB
Inventors: John Leslie Blackford
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-07-05
Filing date: 2000-07-05
Publication date: 2001-12-19
Also published as: GB0016413D0

Abstract

The trolley comprises a platform (1), the height of which is infinitely adjustable. To convert the trolley into a worktable the user operates the levers (8) which releases friction clamps from engagement with rods connected to each leg (2). This allows the platform (1) to be lifted and locked at the required height. Lifting of the platform (1) also raises the trolley wheels (4) so that they are no longer in contact with the ground. In trolley mode, a handle (6) can be placed in a socket to allow the trolley to be easily moved.

Description

AUTOMATIC INFINITELY ADJUSTABLE 2363366 HEIGHT TROLLEY/WORKTABLE This

invention relates to a hand trolley which exclusively converts into a worktable of infinitely variable height. The purpose of this trolley development is to enable the use of the trolley to load his/her goods, equipment, tools etc., onto the trolley. Propel the trolley to the place of work. Unload the trolley, then by picking up the platform of the trolley can have instantly at any height desired by the user a worktable on which all manner of work can be carried out. On completion of the task, the platform can be lowered to the floor converting itself automatically into a trolley again. During operation there is no need to turn the trolley over, make any fittings of legs or individual adjustments for heights of legs. All operations are automatic simply by picking up or lowering the trolley platform. A major benefit is that the wheels which can be soiled by their travelling, (mud etc.) are left at low level when the trolley is in its worktable mode and do not have to be detached for any reason including the user remaining clean.

The trolley will stay at whatever height the user determines. This is accomplished by the trolley wheels being strategically positioned and attached to four legs which fold scissor fashion underneath the trolley. Height locking handles are operated on the underside of the trolley platform by the user when picking up or lowering the platform. They are released when the desired height is reached. At approximately half the potential height the wheels automatically leave the floor leaving the trolley standing on the four legs. Height adjustments can be made simply by holding the trolley platform and height adjusting handles, readjusting the height and releasing the height adjusting handles. The trolley is propelled by pushing or pulling a handle made of metal or other materials which is fitted into sockets on the rear legs and is removable when the trolley is being used as a worktable. The handle can be stored on the underside of the trolley on the legs which have the handle sockets.

The height adjusting handles are two hand operated levers which operate clamps on two friction rods, each rod controls two fore or aft legs. The levers are positioned on the underside of the platform so that when the platform is held to adjust the height, the user hand operates the levers at the same time. The levers are spring loaded so that when closed towards the underside of the platform the grip on the friction rods is released and the platform can be raised or lowered. When released, the levers spring back and grip the friction rods holding the platform at the desired height. An important feature is that when the platform is adjusted for height it never goes out of level. At the end of the use as a worktable the platform is operated as previously described and lowered to the floor. The wheels automatically reposition themselves to give mobility to the trolley. The propelling handle is repositioned in the sockets in the rear legs of the trolley which can then be pushed or pulled to a new location. Brakes on the trolley wheels can be fitted if so desired. When the trolley has to be transported by vehicle it can be made smaller or lighter by partial dismantling it. The propelling handle as previously described can be removed. The bottom section of each leg can be removed complete with one wheel. The wheel section is attached to the main leg by the fact that the leg and bottom section are constructed of tubular metal or other material whose cross section measurements allow the bottom section of the main leg to slide inside or outside the top of the lower leg section. Location and correct position are maintained by the insertion of a removable pin by holes drilled through both the lower leg section and the bottom of the main leg.

I When the holes all line up the pin is passed through all four holes and is held in position by a spring or other means.

The top of the upper legs are connected to the underside of the trolley platform by slides or tracks which allow the top of the upper leg to swivel and travel longitudinally. Each leg has its own slide or track. The length of slide or track is limited but of sufficient length to allow the legs to fold scissor fashion to an almost flat profile against the underside of the trolley platform.

The tops of the legs are connected in pairs to the two friction locks described earlier. Each friction lock allows one pair of fore or aft legs to travel in the slides or tracks when the sprung height-adjusting handle is depressed. When the legs travel in one direction the platform lowers. When they travel in the opposite direction the platform rises.

The fore and aft legs are pivoted at a crucial position along their length to allow the correct height of the platform to be achieved with the appropriate length of travel of the top of the legs in their slides or tracks. An axle of tubular metal or other material connects each pair of legs transversely with the other pair on the other side of the platform. The legs swivel about this axle allowing the platform to rise or lower.

The wheels can be made of plastic, metal, rubber or synthetic material or any combination of these materials. The diameter of these wheels can be any size suitable for the terrain to be travelled over. Preferably two or four wheels have a castor action allowing the trolley to be steered. The wheels can be sprung or not as the user requires. The top surface of the platform has a no slip or smooth finish depending on the needs of the user. It can be made of wood, metal, plastic, fibreglass or other material or any combination of any or all these materials. Preferably the edge of the platform is protected from damage by a protective strip of plastic, metal, rubber, or other material or any combination of any of these or other materials and also have a groove or lip incorporated into the cross section design of this protective strip in which tools, restraining straps, or other equipment can be hooked or attached to the trolley.

2 To Commence with the Assembly of the Trolley.

The trolley platform (1) is positioned on edge or on its back. The lower leg sections with wheels attached (3) and (3a) are slid onto or into the upper leg sections (2) and secured with a sprung pin (5) through the four locating holes in each leg. The trolley is then positioned with its wheels on the floor and the propelling handle (6) is located into the sockets on the rear legs (3a). The trolley can then be wheeled to its destination. Cross-braces (19) of metal, plastic, or other materials are fitted to each pair of fore and aft legs to give stability.

Method of Operation On arrival at the destination with the trolley in the low position the propelling handle (6) is removed from sockets on the rear legs (3a). The trolley platform (1) is gripped by the user on the two long edges positioning their hands to also grip their height adjustment handles (8) at the same time as lifting the platform the height adjusting handles (8) are closed towards the underside of the platform. This releases the grip of the height locking bar clamps (12) on the height locking bars (11). The user picks up the platform to the required height. This action allows the legs to drop in a scissor action pivoting around the axle (7). The tops of the legs slide in or on their tracks or slides (14) until the desired height is reached. When the legs slide in their slides or tracks the top of the legs are connected in fore and aft pairs by the locking bar axles (13) which pull and push the locking bar (11) through the locking bar clamps (12). The locking bar swivels at its connection with the locking bar axle (13), this prevents the jamming of the locking bar (11) into the locking bar clamp (12) and allows the bar to run smoothly through the clamp. When the desired height is reached the user releases the two height-adjusting handles (8). This makes the torsion springs (9) return the handles to the grip position allowing the height locking clamps (12) to grip the height locking bars (11). This prevents the platform returning to ground level. A gas strut (20) can be fitted to the axle (7) as an aid in the lifting of the trolley platform, if so desired. By the strategic positioning of the wheels (4) on the lower legs (3) and (3a), the wheels leave the floor and the ends of the lower legs (3) and (3a), connect with the floor. At very low heights the wheels still connect with the floor but are aligned in such a manner to still give the platform stability without undue movement. At extreme heights or when the platform is lowered to the ground the track or slide stops (15) prevent the legs running off the track or slide. They can be removed if necessary to allow the leg to be removed from the track or slide.

To prevent distortion of the height-locking handles, two blocks of hard material e.g. metal, plastic etc. (10), with the handles passing through them are fixed to the underside of the trolley keeping the two handles in the correct position.

When the user wants to return the worktable to its trolley position, the long edges of the platform (1) are held along with the height-adjusting handles (8). The handles are closed toward the underside of the platform. The platform is then lowered to the floor where the wheels reconnect with the floor level. The platform edge and and the height-adjusting handles are released and the propelling handle (6) returned to the sockets on the rear legs (3a). The trolley is now ready to be propelled on its wheels.

During usage, if the platform is deemed not large enough for the job at hand, a platform extension (17) can be attached to the front of the platform and supported by a pull-out slide support (16). This extension can be detached or left on as desired.

3 Method of Operation continued...

The long edges of the platform (1) have protective metal moulding (18) which incorporate a groove or lip into its sectional design which allow tools, restraining straps, chains or other equipment to be hooked or attached to the trolley.

Most trolleys available do not covert into worktables and those that do are of a fixed height in the worktable mode and have the wheels at worktable level which means the user must either remove the wheels or be soiled by them. Very few trolleys can be adjusted for height, this can only be done by adjusting each individual leg by use of a turn button on each leg. This can be time consuming and not very accurate unless two people are involved, one to assess the table height and the other adjusting the legs while kneeling on the floor in unknown conditions (muddy field etc.). The wheels then still have to be dealt with.

4 AUTOMATIC INFINITELY ADJUSTABLE HEIGHT TROLLEY/WORKTABLE

Claims

1. A hand propelled trolley which converts to a worktable or platform of infinite height required by the user.

2. A trolley as claimed in claim (1) which leaves the trolley wheels at low level when in the worktable mode and does not require the removal of said wheels (to keep the user clean).

3. A trolley as claimed in claim (1) and (2) where the height adjustment of the trolley is controlled by two friction rods and friction rod clamps operated by the user to achieve the desired height.

4. A trolley as claimed in claim (3) where the trolley does not have to be turned on its side or upside down or have any attachments or equipment or appliances, to carry out the conversion to a worktable. The only act is to pick up the trolley platforin to the users desired height. It will stay there until the height has to be adjusted or the worktable converted back to a trolley in which case the platform is then lowered tot he ground where the wheels automatically make contact with the ground and the platform reverts back to trolley mode.

A-mended claims have been filed as follows REVISED CLAIMS 1. A hand propelled flat platform trolley which converts to a worktable or platform of acquired height infinitely adjustable by the user. The height adjustment is carried out by the manual use of two height locking bars (friction rods), each with a height blocking clamp (catchplate). The operation of which is described in detail in the General Desription. The use of two rods and catchplates (each operating on a pair of fore or aft legs) gives several advantages.

a) It allows the trolley platform length to be much shorter for a given maximum working height which for general use must be around 900 - 100 mm. This is important because the trolley has got to be capable to be transported by a small car with the consequent limited boot size.

b) It has got to be light in weight enabling people of limited strength, as well as more able-bodied people to lift, transport and operate the trolley. E.g. transporting and showing of dogs and other animals.

c) Because both the fore and aft legs in pairs contribute to the height adjustment equally, it means the travel of each pair of legs in or on their tracks is much shorter (by 50%), than if only one pair of legs for this purpose. This gives a lot more space on the underside of the trolley for other purposes or mechanisms.

d) By using two friction rods and catchplates it halves the loading on each rod and catchplate, thus making the platform in use more stable and safer.

4. A trolley as claimed in claim (3) where the trolley does not have to be turned on its side or upside down or have any attachments or equipment or appliances, to carry out the conversion to a worktable. The only act is to pick up the trolley platform to the users desired height. It will stay there until the height has to be adjusted or the worktable converted back to a trolley in which case the platform is then lowered tot he ground where the wheels automatically make contact with the ground and the platforni reverts back to trolley mode.

1 CI

5. A trolley as claimed in claims I - 4. Where the trolley is required to be transported by a vehicle of limited space, the wheels, complete with the lower half of each leg, can be removed by the simple removal of a spring pin. The individual wheel can then be removed from the trolley by holding the bottom leg section not the wheel. This tops touching the dirty wheels with the hands. All wheels can then be put into a bag to stop the vehicle being soiled. The result of this is the trolley is lighter and smaller (the trolley is now only 60 mm thick). The length of the trolley in its collapsed state is now no longer than the platform enabling the easier lifting and storage (see claim I (b)). The legs when necessary along with the wheels, can be reattached easily by sliding the lower leg section onto or into the upper leg and insert the spring pin into its locating hole. The trolley is now ready for use.

6. A trolley/worktable as substantially described with reference to the accompanying drawings.