Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62B—HAND-PROPELLED VEHICLES, e.g. HAND CARTS OR PERAMBULATORS; SLEDGES
  • B62B5/00—Accessories or details specially adapted for hand carts
  • B62B5/02—Accessories or details specially adapted for hand carts providing for travelling up or down a flight of stairs
  • B62B5/026—Accessories or details specially adapted for hand carts providing for travelling up or down a flight of stairs with spiders or adapted wheels

Definitions

• the present invention relates to a stair climbing hand truck of the kind comprising a rotary holding means carrying supporting wheels arranged setwise in starlike configurations.
• the holding means which provide the starlike configurations at the positions previously being occupied by the supporting wheels comprise eccentric positionings of t ⁇ e carrying and rotary axes for the holding means, so that the rotary movement of the wheel configurations not is forced to take place than in case one or more of the foremost wheels belonging to the starlike configurations, due to being foremost in a chosen drive direction, hereby hit an obstacle such as a step of a stair case and due to the further movement of the truck are providing a rotary movement of the holding means resulting in positioning the next supporting wheel of the starlike configuration on the land area of the step of the stair case being present as the obstacle.
• This embodiment according to the state of the Art suffers under some drawbacks. Driving on a horizontal floor always take place with two wheels belonging to the single starlike configurations resting against the floor, and this naturally provides friction problems between the wheels and the floor when driving around sharp corners. Furthermore, the person using the hand truck himself mainly have to provide the power which is needed to turn the holding means when climbing stairs of a stair case.
• the holding means for a starlike configuration of supporting wheels is rotary positioned and may be rotated by means of a drive means which is either of the self-locking kind, as for instance a drive means comprising a worm gear, or is able to be locked, by means of a disengageable braking or locking mechanism in an attained position after a terminated rotary movement.
• a drive means which is either of the self-locking kind, as for instance a drive means comprising a worm gear, or is able to be locked, by means of a disengageable braking or locking mechanism in an attained position after a terminated rotary movement.
• the hand truck may thus be employed manually pushed or pulled on grounds or floors without obstacles.
• an obstacle such as a stair of a stair case
• the drive means manually or posssibly by means of a sensor becomes activated to drive the holding means forward so that a supporting wheel of the starlike configuration is brought to rest against the land area of the stair of the stair case, whereupon the drive means is brought to proceed some what further unto the supporting wheel is rotated upwards to be in level with the wheel resting against the land area of the stair of the stair case, after which the hand truck can be driven further on towards the next obstacle.
• the reverse action takes place in case an obstacle as the uppermost stair of a stair case leading below is going to be met from the upper end.
• the hand truck is stopped just before the downward leading stair case is met and the holding means is activated to rotate the holding means forward by means of the drive means which either is manually engaged or possibly is engaged by means of a sensor.
• the drive means is brought to proceed to a further supporting wheel rests against the land, and the hand truck is pushed forward to the nest obstacle, which may be either upwards leading or downwards leading.
• the drive means even perform the function of lifting or lowering the hand truck so that it only is necessary to push or pull the hand truck in horizontal direction or in slanting direction on grounds or floors being sufficiently smooth for the purpose.
• the present invention presents the advantage that by taking-up or delivering of goods with a hand truck, which for instance is constructed as a sack truck, the drive means may be used to lift or lower the sack truck end being thus the most heavy, as the drive means is brought to rotate clockwise or anti-clockwise, and due to the locking of the drive means or subsidiary of the holding means in the attained transportion position driving of the hand truck may take place on only two supporting wheels and not on the minimum which counts four wheels as it is the case at hand trucks constructed according to the state of the Art. In this way better drive performance around sharp corners is achieved.
• the hand truck may comprise driven supporting wheels. It is thus possible that the hand truck as well only comprises one supporting wheel - i.e. barrowlike - as comprises three or more supporting wheels which each could be constructed as a starlike configuration of wheels.
• a particular advantage of the construction compared to that of the state of the Art furthermore is that the hand truck equally well may be used at stairs of an open structure, i.e. stairs which only comprise horizontal land area means, as at stair cases of a more closed structure, i.e. comprising vertical connecting plates between the front range of the single plate shaped land area means and down to the rear range of the land area positioned underneath. Difficulties will be met when the known hand trucks are to be used as well for open structured stair cases as for stair cases where the mentioned connecting plate between the stairs has a position being displaced just somewhat more to the rear, as it will be difficult, if not impossible, to get the holding means turned into position for climbing the following of the stairs, etc. Further difficulties will also be met as mentioned when loading and unloading goods for transportation by means of a hand truck of the sack truck type, which type possibly, but not exclusively, should be of the preferred structure to be used according to the invention.
• FIG. 1 in the perspective illustrates a hand truck fitted as a sack truck according to the present invention
• Fig. 2 and 3 in two versions show longitudinal sections through the hand truck illustrated in Fig. 1
• Fig. 4 in the perspective illustrates a third version as according to Fig. 1
• Fig. 5 in the perspective shows a bottom plate for the embodiment according to Fig. 4, and
• FIG. 6 illustrates the lower half of the hand truck according to Fig. 4 seen from below and with a bottom plate as according to Fig. 5, being dismantled.
• a hand truck illustrated in Figure 1 and Figure 2 is constructed as a sack truck comprising side members 6, handles 7 and crossbars 15 between the side members 6 as well as a forward pointing sack lifting member 8.
• the truck is fitted with supporting wheels 1, 2 and 3 of which only the supporting wheels at one side of the truck are indexed with reference numerals.
• the supporting wheels 1, 2 and 3, i.e. the supporting wheels of both sides of the truck, are, in starlike configurations, held in position on the truck by means of a holding means 4 having a starlike configuration.
• the holding means 4 is held by a horizontal through-going shaft 5 carried by bearings in the side members 6 or by means of bearing pedestals, etc., on the side members.
• the shaft 5 carries a worm wheel 9 which by a worm 16, which is not shown in Figure 1, is driven by a shaft 10 directly or through a suitable gear, possibly a gear comprising possibility for changingbetween two or more gear ratios if such in particular cases should be wanted such as in case of transportation of very heavy and of very low weights of goods by means of the same hand truck, and where the shaft 10 is driven by for instance an electric motor 11 receiving energy supply from batteries in battery boxes 12 and 13.
• the elctric motor 11 can be brought to start or to stop and by means of the other handle respectively brought to rotate in one or other direction.
• the hand truck is used in the way that the motor is activated so that for instance the supporting wheels 3 and 4 simultaneously rest against the floor while the hand truck is slanted to a position in which the front end of the sack lifting member 8 touches the surface of the supporting means which carries sacks or other goods to be lifted by means of the hand truck. With two supporting wheels resting against the surface of this supporting means the lowest possible level of the platform body means of the sack truck is attained. In case the goods to be carried are positioned higher up the holding means 4 may be turned by means of the electric motor unto a suitable loading position for the hand truck is attained.
• the goods are loaded on the hand truck, whereby the electric motor 11 possibly might be activated for simultaneously rotating the holding means 4 so that the height level of the platform body of the hand truck becomes further increased.
• the sack truck is tilted back to a suitable slanting position to be used for the transportation whereby the electric motor 11 again may be activated to achieve this, preferably, a position of the hand truck may be used where only one pair of suuporting wheel rests against the floor, namely a pair of wheels with a wheel on each side of the sack truck which thus are resting against the floor.
• the sack truck is driven away from the loading spot, and if, as earlier explained, an obstacle as a stair case leading upwards or downwards is met, the electric motor 11 is activated to rotate the holding means so that changing of wheels takes place when climbing the single stairs.
• An embodiment of the hand truck could be contemplated where the supporting wheels are driven by a tooth wheel comprising, a drive belt comprising or a drive chain comprising drive means driven by a single drive motor or by drive motors being separately arranged in the hubs of the single wheels, etc. It is the aim by means of the embodiment according to the invention that it not should be necessary with a positive drive of the supporting wheels in case of hand trucks of small or medium size, just as it has been described above. In case of very heavy trucks such a drive means for the supporting wheels may be required.
• a hand truck for instance constructed as a sack truck, where behind the platform body, i.e. as a to the rear protruding prolongation of the sack lifting member 8, a stepping plate is provided.
• This stepping plate may be used when lifting especially one end of very heavy goods, such as the end of large rolls of paper, so that the hand truck, which in this case preferrably may be provided with a drive means for the rolling of it, may be used to push such particularly heavy objects along a supporting floor.
• the hand truck which in this case preferrably may be provided with a drive means for the rolling of it, may be used to push such particularly heavy objects along a supporting floor.
• the in starlike configurations on the holding means arranged supporting wheels possess different sizes, so that the most powerful set of wheels then can be located most closely to the heavy object to move.
• the holding means 4 may be thus constructed that it lends itself to be fixed, i.e. kept by locking in an attained position, whereby the drive mechanism for the rotating of the holding means for such purpose to avoid an expensive over-dimensioning of the components, to respond to such a heavy load, in practice is made inoperative during such a working operation, which occasionally may take place.
• the starlike configurations of the supporting wheels may be arranged to comprise only two wheels on each side of the hand truck as a cheaper version according to the invention.
• Configurations comprising more than three wheels shown in the Figures of the drawing might also be considered as an advantageous solution, as well as configurations of irregular kind, but though preferably equally configured in pairs with pair members on each side of the truck, might also be contemplated.
• Embodiments with wheel configurations on more than two sides of the truck may be contemplated in case of trucks which without turning shall be able to be driven in more than one direction, and in which case also the holding means 8 are positioned able to be lifted and lowered.
• Such an embodiment could also be provided in the way that the supporting wheels generally or singly are mounted able to be turned towards different directions, so that the hand truck, for instance at a stair case land area,is able to be driven further on in a direction sidewards to the direction of approach, along a next stair case, or in case the hand truck has to be driven to a congested location for being loaded or unloaded.
• a Seaable feature of the hand truck is that the hand truck according to the invention is able to climb stair cases and doorsteps and obstacles on the ground in the open field, such as kerbstones, at a larger velocity than the hand trucks belonging to the state of the Art are able to, and this is attained without a too large net weight of the truck.
• the moments of inertia of the rotary items or the moments of inertia of particularly the more fast rotating transmission elements are large subsidiary that they are furnished with a flywheel.
• the motor may be dimensioned to be less and have a lower weight in general and that the motor, in case it is an electric motor, may have a low current consumption at a given working voltage.
• a hand truck such as a sack truck
• a hand truck of such embodiments is capable of passing a stair case at a speed corresponding to that of walking at comfortable speed, whereas contrary hereto embodiments according to the state of the Art are operating more times more slowly and moreover, they are more difficult to handle.
• the hand truck is constructed also as a kind of sack truck comprising a detachable platform body 8 which easily can be exchanged with for instance a more projecting sack platform 8 for for instance transportation of beer cases, and the platform 8 may in a well known manner be hinged to the hand truck and be up-foldable.
• the sack platform 8 is mounted to the outer upper bottom surface 68 of a box with side members 72.
• the lower side of the box is open, but may be closed by means of a detachable bottom cover which is shown in Figure 5 and comprises as well an even plate portion 74 as a transversely projecting cover portion 73 serving to cover the wheel axis range as further described in the following.
• FIG 6 the box structure according to Figure 4 is shown, but seen from below.
• a battery 12 is mounted by means of an angular plate means 72 which holds the battery 12 to the bottom surface 68 of the box structure.
• the supporting bearings 61 may be bearings which for instance are dismantable in two halves so that all rotary items may be taken out at once when holding screws 69 which as well hold the drive means 61 to the bottom surface 68 as serve as chain tighteners for the transmission chain 79 also are removed. An easy service access to the internal items is thus achieved in this way.
• handles 7 at the vicinity of which preferably for instance control mode changing activating means for the control of the drive means 11 such as a reversing control means 76 and an on-off-switch 75 are located, a in proportion to the hand truck transversely orientated handle 77 is arranged. It makes a comfortable one-hand control of the hand truck possible.
• the handle 77 preferably comprises only an on-off-switch 75 which is arranged upwards projecting.
• the activating means 75, 76 should preferably be located on the external sides of these as it else, by a bodily push against the handles 7 with the purpose to move around a for instance particularly congested corner area in a corridor with the hand truck, may occur that the drive means 11 becomes wrongly operated.
• the activating means 75, 77 make a one-hand-operation of the hand truck possible. If, as hinted at, the cover means according to Figure 5 as described possesses a further projecting range to cover for instance the drive means 11 it is possible to employ a lesser box depth.
• the hand truck according to Figures 4, 5 and 6 besides exhibiting a higher reliability due to the covered means also has a structure which permits transportation of even rather heavy goods, just as it is an advantage that the heavy goods easily can be unloaded by sidewards pushing of the goods so that loading and unloading is possible within a larger heightrange than it is possible with a hand truck of the sack truck type as according to Figures 2 and 3.
• the hand truck is easily also capable of passing door steps, besides, as according to the purpose, to transport heavy goods upstairs and downstairs.
• a hand truck with a handle configuration is achieved being well suited for transportation of heavy goods exhibiting a centre of gravity which is located far from the surface where the goods rest against the hand truck.
• the drive means may be arranged at a low location within the truck and the hand truck is also well suited to serve as a stretcher, as a wheel chair and also for the transportation of equipment for disabled persons to which services the known trucks of this kind not easily may be converted and afterwards are not as easy to handle as the hand truck of the invention.
• the hand truck can during operation be used occupying an only very little slanting position being the case also when passing stair cases as when operated in an_even open field.

Applications Claiming Priority (2)

Publications (1)

Family

ID=8106119

Family Applications (1)

Country Status (4)

Cited By (25)

Citations (5)

• 1985
  • 1985-04-03 DK DK156585A patent/DK153818C/da not_active IP Right Cessation
• 1986
  • 1986-04-03 AU AU56973/86A patent/AU5697386A/en not_active Abandoned
  • 1986-04-03 WO PCT/DK1986/000028 patent/WO1986005752A1/en unknown
  • 1986-04-03 EP EP19860902344 patent/EP0216879A1/en not_active Withdrawn

Patent Citations (5)

Also Published As

Similar Documents

Legal Events