WO1996000674A1

WO1996000674A1 - Track transport system

Info

Publication number: WO1996000674A1
Application number: PCT/FI1995/000376
Authority: WO
Inventors: Markus Roschier
Original assignee: Markus Roschier
Priority date: 1994-06-29
Filing date: 1995-06-29
Publication date: 1996-01-11
Also published as: FI96193B; FI96193C; AU2794395A; FI943132A; FI943132A0

Abstract

A rail transport system, comprising a travelling crab (1) with a traction motor (2) and a guiding rail (3) affixed to a stationary structure, such as a building, the travelling crab being disposed to run in support and guidance of said guiding rail, driven by the traction motor, for transporting a load along the transport track, and the guiding rail (3) comprising two rolling surfaces (4, 5) facing away from each other and which are located on opposite sides of the guiding rail, facing away from each other, and the travelling crab (1) comprising a pair of wheels (6, 7), its wheels (6, 7) disposed on opposite sides of the guiding rail for resting against the rolling surfaces so that the guiding rail lies between the wheels. The configurations of the rolling surfaces (4, 5) and wheels (6, 7) in cooperation with each other are disposed to produce tangential, punctiform contacts between the rolling surfaces and the wheels.

Description

TRACK TRANSPORT SYSTEM

The present invention concerns a rail transport system as defined in the preamble to Claim 1.

In prior art, through the reference FI 74433, a system is known, comprising a travelling crab provided with a traction motor, and a guiding rail fixed to a stationary structure, such as a building, carried and directed by which said travelling crab has been arranged to move, driven by said traction motor, in order to transport a load suspended from the crab, along the transport track defined by the guiding rail. The guiding rail comprises two rolling surfaces facing away from each other, provided on opposite sides of the guiding rail facing away from each other. The travelling crab comprises a pair of wheels, its wheels being disposed on opposite sides of the guiding rail for running on said rolling surfaces in such manner that the guiding rail lies between the wheels. In the system of prior art, the guiding rail presents two surfaces enclosing an angle with each other and the traction surfaces of the wheels have been given a corresponding angular shape. Since the configurations of the contact surfaces of wheel and guiding rail are complementarily equal in shape, lineal contact is established between guiding rail and wheel. The line of contact lies in a plane transversal to the longitudinal direction of the rail, and in one plane with the wheel's axis of rotation. (See Figs 1 and 2.)

A specific application where systems like this are employed is in connection with taking care of real estate, where the transport system is used to suspend movable service platforms, hanging cages, hanging ladders, etc. equipment. Using such equipment one is enabled to maintain and service outside and inside facades, inside and outside surfaces of roofs of buildings, e.g. to wash roof surfaces of glass, to install facade elements, to replace broken windows, etc. The sectional rail on which the travelling crab moves together with the equipment thereto affixed, may be mounted to run the whole circuit of the building in that at the angles it has been curved to match the configuration of the building. When the point of application arising from the weight of the load lies beside the wheels and the rail, the guiding rail may equally deviate from horizontal, with upward or downward inclination, or be vertical, and the travelling crab provided with drive and brake means may negotiate the uphill and downhill stretches thus produced, as well as in vertical direction along the guiding rail.

The problem embarrassing the system known through the reference FI 74433 is that the distance from the wheel's axis of rotation of the point of contact is different at different points of the line of contact, the peripheral velocity of the wheel's point of contact being lower at a point of the line of contact lying closer to the axis of rotation than at such a point of the line of contact where the distance from the wheel's axis of rotation is greater. These different peripheral velocities on the length of the line of contact give rise to friction between wheel and rail, as well as shear stresses parallelling the surface of the guiding rail, by effect of the friction forces between wheel and rail. Continuously repeated, these cause attrition and fatigue of the surface, and matter tends to be detached from the rail surface. The friction forces moreover impede the motion of the travelling crab. It has been found that a travelling crab of prior art runs better if the rail is made slippery, whereby the friction between rail and wheel is reduced. Rendering the rail slippery is not expedient, however. As the material of the guiding rail is usually aluminium, material may be detached from the surface of the guiding rail in the form of elongated flakes. Even though detachment of material from the rolling surface might not significantly reduce the strength of the guiding rail, it is highly objectionable, especially when the system is employed in interior spaces, where thus aluminium dust and flakes would fall down on the floor and upon persons at work in the respective space and on their desks.

The object of the invention is to eliminate the drawbacks mentioned. The transport system of the invention is characterized by that which is stated in Claim 1.

The rail transport system of the invention comprises a travelling crab, comprising a traction motor, and a guiding rail fixed to a stationary structure such as a building, the travelling crab being disposed, carried and guided by said rail, to move, driven by the traction motor, for transporting a load suspended from the travelling crab, along the transport track defined by the guiding rail, and the guiding rail of the system comprising two rolling surfaces facing away from each other, and which are located on opposite sides of the guiding rail, facing away from each other, and the travelling crab comprises a pair of wheels, its wheels disposed on opposite sides of the guiding rail, for resting on the rolling surfaces in such way that the guiding rail lies between the wheels.

As taught by the invention, the configurations of the rolling surfaces and of the wheels cooperating with them have been disposed to produce tangential, punctiform contacts between rolling surfaces and wheels.

The invention affords the advantage that by means of punctiform contact an accurately defined point of contact is obtained between guiding rail and wheel, whereby no so-called internal friction will be incurred between wheel and rail as is the case with lineal contact conforming to the state of art. At the point of contact, the rail is subject mainly to pressure at right angles against the surface, not so much to shear parallelling the surface nor to friction, by reason of which the wheel shows no tendency of wearing down the surface of the guiding rail or of detaching material therefrom.

Other favourable features, and advantages, of the invention will be apparent from the detailed description of the invention following below, referring to the attached drawing, wherein

Fig. 1 presents, schematically and partly sectioned, a system conforming to technology of prior art,

Fig. 2 presents, schematically and in elevational view, the guiding rail and pair of wheels in the system of Fig. 1,

Fig. 3 presents, schematically and partly sectioned an embodiment of the system of the invention.

Fig. 4 presents, schematically and in elevational view, the guiding rail and pair of wheels in the system of Fig. 3,

Fig. 5 presents a detail of the guiding rail and wheel in the system of Figs 3 and 4,

Fig. 6 presents a detailed diagram of the guiding rail and wheel in another embodiment of the system of the invention, and

Fig. 7 presents a detailed diagram of the guiding rail and wheel in a third embodiment of the system of the invention. In Fig. 1 is depicted a rail transport system previously known through the reference FI 74433, comprising a travelling crab 1 with traction motor 2 and a guiding rail 3 to be fixed to a stationary structure such as a building, the travelling crab running carried and guided by said guiding rail and driven by the traction motor 2. The guiding rail 3 advantageously consists of an extruded section beam of aluminium. From the travelling crab 1 a load can be suspended, which moves along with the travelling crab, following the transport track defined by the guiding rail. The guiding rail 3 has two rolling surfaces 4,5 facing away from each other, and which lie on different sides of the guiding rail facing away from each other. The travelling crab 1 comprises a pair of wheels 6,7, its wheels 6,7 being disposed on different sides of the guiding rail so that they can rest on the rolling surfaces 4,5 in such manner that the guiding rail lies between the wheels 6,7. As can be seen in Fig. 1, the rolling surface 4,5 of the guiding rail 3 of prior art consists of two planar surfaces at an angle against each other, and the traction surfaces of the wheels 6,7 in contact with these planar surfaces have been given a corresponding angular configuration.

In Fig. 2 the lineal contact produced in the system of prior art has been sketched with an interrupted line B, this contact being established between a guiding rail 3 and a wheel 6,7 of the kind above described, and giving rise to the problems described in the general part of the disclosure.

Fig. 3 depicts an embodiment of the rail transport system of the invention, also comprising a travelling crab 1 with traction motors 2 and a guiding rail 3 affixed to a stationary structure, such as a building, the travelling crab 1 running in support and guidance of said guiding rail, driven by the traction motors 2. There are two traction motors 2 in this embodiment, one for each wheel. From the travelling crab 1 a load or burden can be suspended, which travels with the travelling crab along the transport track defined by the guiding rail 3. The guiding rail 3 presents two rolling surfaces 4,5 facing away from each other and which are located on opposite sides of the guiding rail, facing away from each other. The travelling crab 1 comprises a pair of wheels 6,7, its wheels 6,7 being disposed on opposite sides of the guiding rail to rest against the rolling surfaces 4,5, so that the guiding rail 3 lies between the wheels 6,7.

As can be seen in Fig. 4, the configurations of the rolling surfaces 4,5 and the wheels 6,7 have been disposed to be different so that they produce tangential, punctiform contacts between the rolling surfaces and the wheels. This punctiform contact has been illustrated by dots B in Fig. 4. As a result of such substantially punctiform tangential contact, the wheel will roll on the rolling surface of the guiding rail 3 along a closely defined path, and no friction causing attrition will occur between the mating surfaces of the guiding rail 3.

It is obvious that tangential punctiform contact can be implemented by numerous different configurations of guiding rail and wheels. Figs 5-7 show a few examples.

In Fig. 5 the rolling surface 4,5 of the guiding rail 3 is convexly round. The cross section of the rolling surface of the guiding rail has the shape of a circular arc, i.e., the surface is a cylindrical surface. The wheel 6,7 rolling upon the rolling surface of the rail comprises two conical surfaces 8,9 placed at an angle relative to each other and tapering towards the central part of the wheel so that they constitute a groove. The conical surfaces 8,9 serve as contact surfaces against the convex rolling surface 4,5 of the guiding rail 3. Two punctiform contacts are established between the conical surfaces and the convex rolling surface, symmetrically on either side of the vertical axis of the rail. In Fig. 6 the rolling surface 4,5 of the guiding rail is convexly round. The wheel 6,7 comprises two convex surfaces 10,11 serving as contact surfaces against the convex rolling surface of the guiding rail. Punctiform contact is established between the two convex surfaces. In Fig. 7 the rolling surface 4,5 of the guiding rail comprises two planar surfaces 12,13 placed at an angle with reference to each other. The wheel comprises two convex surfaces 14,15, and these are the contact surfaces against the planar surfaces 12,13 of the guiding rail. Punctiform contact is established between the planar surface and the convex surface.

The invention is not exclusively delimited to concern the embodiment examples presented in the foregoing: numerous modifications are feasible within the scope of the inventive idea defined by the claims.

Claims

1. A rail transport system, comprising a travelling crab (1) with a traction motor (2) and a guiding rail (3) affixed to a stationary structure, such as a building, the travelling crab being disposed to run in support and guidance of said guiding rail, driven by the traction motor, for transporting a load suspended to be carried by the travelling crab, along the transport track defined by the guiding rail, and the guiding rail (3) comprising two rolling surfaces (4,5) facing away from each other and which are located on opposite sides of the guiding rail, facing away from each other, and the travelling crab (1) comprising a pair of wheels (6,7), its wheels (6,7) disposed on opposite sides of the guiding rail for resting against the rolling surfaces so that the guiding rail lies between the wheels, characterized in that the configurations of the rolling surfaces (4,5) and of the wheels (6,7) in cooperation with them are disposed to produce tangential, punctiform contacts between the rolling surfaces and the wheels.

2. Rail transport system according to claim 1, characterized in that the rolling surface (4,5) of the guiding rail is convexly round, and the wheel (6,7) comprises two conical surfaces (8,9) at an angle to each other, which constitute the contact surfaces against the convex rolling surface of the guiding rail.

3. Rail transport system according to claim 1, characterized in that the rolling surface (4,5) of the guiding rail is convexly round, and the wheel comprises two convex surfaces (10,11), which constitute the contact surfaces against the convex rolling surface of the guiding rail.

4. Rail transport system according to claim 1, characterized in that the rolling surface (4,5) of the guiding rail comprises two planar surfaces (12,13) at an angle with reference to each other, and the wheel (6,7) comprises two convex surfaces (14,15), which constitute the contact surfaces against the planar surfaces of the guiding rail.