Patent Application
20130241177
The present invention relates to a dolly for transporting goods and in more particular a coupling device for connecting a dolly to another dolly or a tractor unit.
Known dollies of this type are known in the art and they are used for various applications, e.g. for carrying articles in industrial environments, especially in food industry and car industry and for carrying baggage in train or airport stations or airport or any place wherein transportation of goods on wheels is needed.
A dolly of this kind usually comprises a draw bar provided at one end of the dolly and a hook or similar device for connecting to the draw bar at the opposite end of the trolley. The goods carrying platform of the dolly is often constructed of lengths of steel profiles welded together. This carrying platform forms the body of the dolly. On this body, at its corners is mounted four wheels of which two are swivel wheels and two fixed, the swivel wheels being at the front end of the dolly to allow guiding the dolly to a desired direction. Sometimes also four swivel wheels are used for increased agility.
A towing unit may be any motorised or non-motorised which provides the fraction for the dolly. Most often the tractor unit is another dolly situated immediately in front of the line of dollies.
In known dollies the drawbar is generally in the form of a longitudinal element mounted in an articulated manner about the transverse axis of the trolley and provided on its front part a ring capable of co-operating with a hook on the towing unit.
U.S. Pat. No. 6,874,807 discloses a coupling device for a handling trolley, comprising a drawbar mounted at the front of the trolley and designed to co-operate with a hook mounted on the rear of a towing unit such the two such equipped trolleys may be connected together. The drawbar of one coupling device has a longitudinal slot in which the hook of another coupling device is able to slide so that the hook an slide in the longitudinal slot such the two trolleys may be connected together by the drawbar. The drawbar is connected to the front of the trolley by articulation means defining an articulation axis in such a way that as to pivot between a coupling position, in which the drawbar extends substantially horizontally in order to co-operate with the hook and a lifted position, in which the drawbar is in a raised position and is disengaged from the hook.
The problem related to the known coupling systems is that very often the coupling means are at least partially under the body of the dolly, whereby it is difficult the see the relative positions of the coupling hook and the slot. Because of this, the person handling the dollies must usually bend down to floor level and guide the draw bar and dollies to be coupled by hand, which is quite difficult, especially when dollies are loaded with heavy load. The working position is awkward and even mentally irritating. In the device described in U.S. Pat. No. 6,874,807 this problem is solved by positioning the connecting hook little bit outside the outer reach of the rear surface of the trolley. Now it is clearly easier to position the draw bar and connect the trolleys. However, the hook is protected by the body of the trolley and it may hit goods, people or any obstacle on the floor or even stuck to clothing of the personnel. In such case damage to the trolleys or other goods placed on the floor may occur or even human injuries happen.
The invention is intended to provide a coupling means that can be connected without exact guidance by the user.
The invention is based on having a female connecting part and a male connecting part, the male connecting part comprising a draw bar and a connecting peg and the female part comprises a sliding area, that is larger than the largest cross section of the connecting peg for easy positioning of the connecting peg and a guide surface at least partially surrounding the sliding area for guiding the connecting peg when pulled towards the guide surface, and a hole on the sliding surface dimensioned to contact with the connection peg and positioned in connection with the guide surface so that the peg can be directed to the hole by the guide surface.
According to one particular embodiment of the invention, the female part comprises an at least partially closed recess having an area limited by at least partially closed wall having a height and comprising at least a concave guiding part and a ceiling positioned to form the at least partially closed recess with the wall, and a hole in the ceiling at the tip of the concave part of the wall and dimensioned to receive the connecting peg.
According to one preferred embodiment of the invention, the at least partially closed wall comprises a V-shaped part with rounded tip and two parallel extensions extending from the arm of the V-shape.
Further, according to one embodiment, the connecting peg comprises a cylindrical body connected to the draw bar at one end and having a knob at the opposite end, the knob being shaped to extend at least partially over the diameter of the cylindrical body.
According to one feature of the invention, the ceiling has a stopping tongue extending away from the ceiling and towards the tip of the concave part of the at least partially closed wall and it has preferably a thickness less than the distance of the draw bar and the knob of the connecting peg.
According to one embodiment of the invention, the female connecting part is made of two metal plates that are welded together.
Further, according to one feature of the invention, the draw bar is attached to the dolly through a sliding connection.
More specifically, the invention is characterized by what is stated in the independent Claims.
Preferred embodiments of the invention are characterized by what is stated in the characterizing portions of the dependent Claims.
Considerable advantages are gained with the aid of the invention.
The invention comprises a sliding and guiding area against which a connection peg of a draw bar can be easily placed either by hand or guiding with leg. After that, the guide area directs the connection peg to its place to a connecting hole or similar receiving element automatically when the dollies are pulled away from each other. The sliding area is relatively large, especially larger than the diameter of the connection peg, so that the peg can be positioned against the area without difficulty not having to position it precisely.
Of the invention is that the draw bar can be connected to the female connecting part of another dolly without using hands or seeing the connecting parts. The female connecting part can be arranged wholly under the frame or body of the dolly, whereby it is always protected from damage. The assembly according to the invention has minimum of protruding parts, only the draw bar extends over the perimeter of the body of the dolly when the draw bar is turned to a connection position. In the lifted position the draw bar may be contained within the perimeter of the dolly in sideways direction. Thus any danger for entanglement with clothes or collision with other equipment or goods is prevented. The draw bar can be operated from a standing position simply by pushing the bar with foot. In a standing position pushing the dollies loaded with goods is more easy than in a kneeling position for example, since standing position provides often best leverage.
The female locking part can be manufactured advantageously from a single piece of sheet metal by punching a hole on a metal plate and using the separated part for forming the ceiling of the locking part by welding it over the punched hole.
In the following, the invention is examined with the aid of examples and with reference to the accompanying drawings.
In
The structure of the female connection part is shown in
The top plate 13 is preferably the part of the base plate that is cut away from it during making of the hole 14. It has the same shape as the hole 14 except that the concave part is now convex to outwards and has a straight edged groove 20 formed at the tip of the convex part. This groove 20 is formed by cutting away some of the material of the top plate 13 and bending the rest towards the base plate as a stopping tongue 21. The top plate 13 is positioned on the base plate so that the convex edge 19 is somewhat over the concave shape of the hole 14 of the base plate 12. Now the top plate 13 can be attached to the base plate 12 along the straight edges 17 and along the convex part 19. If the plates are made of steel, one suitable joining method is welding, otherwise any joining method suitable for the material to be used should be chosen. Now, as can be seen from
The assembly operates as shown on
To operate the draw bar to lock and release the dollies, it can be pushed in horizontal position for locking by foot or hand and, for release; small push downwards is enough to push the knob 11 off the opening 24.
The invention may be varied in several ways. The female part comprising an at least partially closed recess may be closed or open. The closed embodiment gives guidance in all directions. The draw bar may be attached to the dolly by a slidable telescopic connection to allow dollies to be pushed together. This embodiment is somewhat more difficult to operate since in some positions the draw bar must be drawn by hand under the dolly. The positions of the female and male connecting part may be interchanged. Regarding materials, steel is preferable as well as the plate configuration described above, but any reasonable strong construction material is feasible as well as any manufacturing method.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/FI2010/050987 | 12/1/2010 | WO | 00 | 5/31/2013 |
