GB2154516A - Baggage cart with stair climbing ability - Google Patents

Abstract

A baggage cart with two wheels 5 and three-stage extendable and retractable arms (1) has a pair of runners (6) pivotably connected to the arms (1), to make smooth the movement of the cart over stair steps. A strut 8 is releasably engaged with catches 9 or 10 on the arms to vary the position of the runners 6. <IMAGE>

Description

SPECIFICATION Baggage Cart The present invention relates to a baggage cart with two wheels used for carrying light baggage over flat places or up or down stairs, during traveling or on business.

Ordinary baggage carts are now widely used.

They are, however, often inconvenient to use; for example, when going up or down a stair, a person must bear his baggage cart in his arms, or otherwise must drag it, knocking it against the edges of the steps. Thus, although prior art baggage carts are indeed useful on flat places, they are rather cumbersome at airports or railway stations, for example, where there are usually many stairs.

Thus, an object of the present invention is to provide an improved baggage cart which permits easy transport of baggage even at stairs.

In order to achieve the object, the baggage cart according to the present invention essentially comprises: a pair of parallel extendable and retractable legs, each said leg comprising a series of three shafts connected together such that the first end shaft is slidable on the second intermediate shaft and said second intermediate shaft is slidable also on the third opposite end shaft, each said first shaft being connected with one of the wheels; a handle interconnecting said legs at said third shafts thereof; a pair of runners connected to said legs and pivotable about a first axis perpendicular to said legs; a strut structure connected to said pair of said runners and pivotable about a second axis perpendicular to said legs; and a plurality of pairs of catches provided on said legs, spaced apart from one another in the lengthwise direction of said legs, each said pair consisting of one catch on each leg and engageable with a free end of said strut structure, whereby the position of said strut structure and said runners can be adjusted with respect to said legs.

The runners each preferably have an inwardly bent free end, which will make smooth the movement of the cart drawn over successive stair steps.

The inwardly bent free ends of the runners are preferably arcuate in cross section.

Two pairs of the catches are sufficient for practical purposes.

The present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a prior art baggage cart; Figure 2 is a schematic diagram, in which a person is shown drawing the prior art baggage cart of Figure 1 over a series of stair steps; Figure 3 is a perspective view of an embodiment of the baggage cart according to the present invention; Figure 4 is a schematic diagram showing a typical position of the embodiment of the present invention relative to a person drawing it over a relatively gentle stair; Figure 5 is a schematic diagram showing another typical position of the embodiment of the present invention relative to a person drawing it over a steep stair; Figure 6 is a partial perspective view showing the runners of the embodiment of the present invention; and Figure 7 is a partial perspective view showing rollers or belts mounted to the runners.

Figure 1 shows a typical prior art baggage cart.

When a person carrys this cart up or down a stair, usually he must bear the cart in his arms, or otherwise must draw or drag it with a stoop, as shown in figure 2. Though light baggage will not cause any difficulties, it is a burden for a passenger to carry relatively heavy baggage with such a cart over stair steps. At stairs in airports or railway stations there are frequently seen passengers being troubled by their baggage carts.

The baggage cart according to the present invention as shown in Figures 3 to 7 has been devised in order to eliminate such trouble experienced in passing over stairs.

Referring now to Figure 3, there is shown a preferred embodiment of the invention. The cart essentially comprises a pair of parallel legs 1, a handle 2 interconnecting the legs 1, a carrier structure 3 mounted on the legs 1, a support 4 connected to the carrier 3, a pair of wheels 5 rotatably mounted to the legs 1, a pair of runners 6 pivotably mounted to the legs 1 and having inwardly bent free end portions 7, a strut structure 8 pivotably mounted to the runners 6, and two pairs of catches 9 and 10 provided on the legs 1 and engageable with the free end of the strut 8.

The legs 1 are of a telescopic extendable and retractable construction, and each consist of three shafts, though not particularly referenced. Each leg 1 is constructed such that the overall length of leg 1 is about 120 cm when it is fully extended, and about 90 cm when its one shaft is retracted; leg 1 can be further shortened by fully retracting its shafts. When a person goes up or down a stair drawing the cart, he normally has the legs 1 fully extended, and when going on flat floors or places he normally has the legs 1 partially retracted to the 90-cm position.

At the lower end of each leg 1 there is pivotably mounted a runner 6 which, when the cart is carried over a stair, can slide on the edges of the successive steps thereby making smooth the movement of the cart on the steps. The inclination 6 of the runners 6 with respect to the legs 1 can be adjusted by means of the strut 8 and the two pairs of catches 9 and 10 fixed on the legs 1 at a spacing therebetween, a shown. The strut can be caught in either of the catch pairs 9 or 10: pair 9 for relatively gentle slopes and pair 10 for relatively steep slopes. The runners 6 can be pivoted into side-by side relationship with respect to the legs 1, where the runners can be fixed.

The free end 7 of each runner 6 has an arcuate cross section of a relatively large radius of curvature, to provide for edges of steps which can otherwise catch it.

It has been proved by experiment that a baggage cart having an overall length of 90 cm (ordinary carts are of such a length) tends to have an inclination of 38 or so with respect to a person 165 cm tall who is drawing the cart by hand on a flat place, 35 or so with respect to a person 180 cm tall, and 43 with respect to a person 150 cm tall.

Thus, in almost all cases, the inclination of a baggage cart with respect to a person who is drawing it is within a range between 35 to 43o.

On the other hand, if a person stands on a tread and will draw up a cart on a tread one step below, then, to his inconvenience, the cart will tend to run against his legs. For this, a person will have to draw up his cart, standing on a tread two or three steps above the tread where the cart is. Then, however, the person must lean far over the cart to reach its handle. It is a much afflicting practice to lean over and draw up a baggage cart, and that particularly when the baggage is heavy. In this regard, it has been proved by experiment that a baggage cart having an overall length of about 120 cm, made 30 cm longer than when carried on flat places, permits a person to draw it over stair steps in relatively easy postures.Accordingly, the baggage cart of the present invention is of a telescopic extendable and retractable construction, such that it can be extended to an overall length of about 90 cm by extending its second shaft when used on flat places, and it can be further extended to an overall length of about 120 cm by further extending the third shaft when used at stairs. Such construction permits a person to carry the cart of the present invention up or down stairs in easy postures.

The baggage cart of the present invention is further characterized in that it permits easy and smooth transport over stairs without running of its body against the edges of steps. In order to achieve this, the baggage cart of the present invention is provided with the runners 6 mounted on its side to touch the steps, so that the cart can be slid over the steps.

There are various configurations of stair steps having different depths and heights, and different ratios of the former to the latter, according to conditions of location. Stair steps in principal railway stations also have various depth/height values, e.g. 34/17 cm and 31/31 cm, but generally have a ratio of depth to height equal to 2 which provides a slope of about 27 .

Figure 4 shows the cart of the present invention used at a gentle stair having a ratio of depth to height equal to 2. A person 165 cm tall usually has his hands at a height of about 70 cm as measured from his feet. Such a person is shown in Figure 4 going up the gentle stair drawing the cart at the handle 2, the overall length of the leg 1 of the cart then being 120 cm. A posture with the arms slightly tilted backward is then convenient. The runners must be longer than the spacing between successive edges of the steps (38 cm, for example), and the free end 7 of the runners are arcuate to avoid being caught by the edges of the steps. Typical values of l" 12, and R as shown in Figure 6 are: i1 = 38 cm, l2 = 8 cm, and R = 5 cm.

The inclination 0 of the runners with respect to the legs 1 should be adjusted in conformity with the slope of the stair; it is practically sufficient to provide an arrangement wherein the inclination 6 can be adjusted between two values in conformity with the slope. The value of inclination 6 for relatively gentle slopes is typically 35 , and the other value for relatively steep stairs of a ratio of depth to height equal to 1 is typically 30 , as shown in Figure 5.The adjustment of the inclination 6 can be made by means of the strut 8 and catches 9 and 10; if the free end of the strut 8 is caught in catches 9, the inclination is 35 , and if the free end of the strut is caught in catches 10, the inclination is 30 for the steep slope.

The runners 6 are made of a highly abrasion-resistant light alloy, and are constructed to be rigid so that they will not be deformed upon receipt of impacts.

The adjustment of the inclination 6 may be carried out using simple means other than the strut and catches as shown. For example, the strut 8 may be provided with hooks at the free end which can be engaged in corresponding recesses or openings formed in the legs 1.

A bag made of a synthetic leather may be positioned in the space between the legs 1 and the runners 6, which bag will be used to hold papers such as a passport, or other small articles.

The runners 6 can be pivoted into side-by-side relationship with respect to the legs 1, where they can be fixed. Thus, the cart can be folded into a compact form.

One or more arrays of elastic rollers or one or more elastic belts, made of rubber or a plastic, mounted to the runners 6 as shown in Figure 7, will make transport of the cart at stairs easier, and reduce friction against the cart.

As is apparent from the foregoing, the baggage cart of the present invention is provided with three-state extendable and retractable legs, runners for sliding over stair steps (the runners are adjustable in conformity with the slope of the stair), a strut and catches, etc., and thus can be conveniently used.

Further, as shown in Figure 3, a bag of rubber or a plastic may be positioned in the space between the runners 6 and the strut 8 caught by the catches 9 or 10, which bag will provide a convenience to hold articles. On the other hand a steel basket mounted on the carrier 3 will allow the cart to be used as an ordinary shopping cart.

While a preferred embodiment of the invention has been shown and described, it is to be understood that those skilled in the art may devise certain variations, modifications and/or substitution of the specific components as shown and described, without departing from the spirit and scope of the invention, as defined by the claims appended hereto.

Claims (6)

1. A baggage cart with two wheels including: a pair of parallel extendable and retractable legs, each said leg comprising a series of three shafts connected together such that the first end shaft is slidable on the second intermediate shaft and said second intermediate shaft is slidable also on the third opposite end shaft, each said first shaft being connected with one of said wheels; a handle interconnecting said legs at said third shafts thereof; a pair of runners connected to said legs and pivotable about a first axis perpendicular to said legs; a strut structure connected to said pair of said runners and pivotable about a second axis parallel with said first axis; and a plurality of pairs of catches provided on said legs, spaced apart from one another in the lengthwise direction of said legs, each said pair consisting of one catch on each leg and engageable with a free end of said strut structure, whereby the position of said strut structure and said runners can be adjusted with respect to said legs.

2. A baggage cart as claimed in claim 1, in which each said runner has inwardly bent free end.

3. A baggage cart as claimed in claim 2, in which said inwardly bent free end of each said runner is substantially arcuate in cross section.

4. A baggage cart as claimed in claim 1, in which two pairs of catches are provided.

5. A baggage cart as claimed in claim 1, 2, 3, or 4, in which said legs can be extended up to about 120 cm.

6. A baggage cart substantially as hereinbefore described with reference to Figures 3 to 7 of the accompanying drawings.