EP1764319B1

EP1764319B1 - Air track

Info

Publication number: EP1764319B1
Application number: EP06460031A
Authority: EP
Inventors: Maria Tabaszewska
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-09-16
Filing date: 2006-09-12
Publication date: 2011-05-04
Anticipated expiration: 2026-09-12
Also published as: DE602006021679D1; PL1764319T3; PL377105A1; ATE508083T1; EP1764319A1

Abstract

The subject of the invention is an air track of high load capacity comprised of a double aliminium pipe (1) placed above a long rigid support (2) and of a glider (4) fit with an element (5) of considerable mass if compared to the glider's mass. The double pipe (1) of the track is pressed down to the support (2) through the medium of springs (3).

Description

Field of technology

The subject of the invention is the air track, i.e. a device for lifting the bodies of known weights over the ground through the medium of compressed air.
The subject of the invention is intended to lift and transport the bodies of considerable weight with very low resistance to motion.
The subject of the invention may be used wherever a required information might come from an observation of motion of the bodies, not interfered by friction to the ground.

Prior art

The air tracks comprised of the pipe with aeration vents exhausting jets of compressed air lifting a glider are known. The pipes have various cross-sections: round, square, triangular, or rectangular. The glider's shape fits that of the pipe.
To prevent the pipes from dipping with their own weight and the glider's weight, these are fastened to the rigid, long metallic element.
The document of patent application FR-A-2 689 077 A1 discloses an air track made from the pipe of rectangular cross-section with at least two channels, or ducts, separated by one or more inner, vertical walls which both stiffen the pipe and make possible to provide compressed air to selected ducts. The glider hovers on the air cushion created between the glider and the air track by the jets of air exhausted through the orifices in the top surface of the air track. The glider is furnished with lateral, vertical stops preventing it from falling down from the track. The lateral gaps formed between the glider's vertical stops and adjacent vertical, lateral walls of the air pipe play minor role in creation of the air cushion, because compressed air is not directly supplied into these gaps. Therefore the lateral gaps dimensions, namely their height and width are not really important in FR-A-2 689 077 A1 . This document gives no suggestion on the lateral gaps width, and the gaps vertical dimension may be described only as "smaller" if compared to the air track width.
The patent documents US-A-4 714 155 and US-A-4 718 539 disclose the air tracks made of a pipe (double pipe in the document US-A-4 714 155 ) of rectangular cross-section fastened to the support. These air tracks have additional sets of orifices, or nozzles, pierced in the side walls of the air pipe. The jets of compressed air outflowing through these orifices contribute to the build-up of the air cushion between the glider and the air track, and increase stability of the glider's movement along the track. However these patent documents give no hint on the lateral gaps width either. One shall stress an impact the lateral gaps have on the glider movement's stability and uniformity, and on the efficiency of consumption of compressed air. If these gaps are too thin, the movement energy is lost by the air viscosity, and if the gaps are too wide, much of compressed air is lost. An optimum solution shall be elaborated.
Known air tracks are inconvenient in use because due to the difference in temperarures of the air supplied to the pipe and the air surrounding the stiffening support, the whole appliance bends which causes unintended movements of the gliders hovering over the track.
Attempts were made to prevent the tracks from bending caused by temperature differences, by mechanical separation of the track from the support. Patent document US-A-3 209 702 discloses resilient pads, and patent application DE-A-102 39 661 A1 discloses spring steels, both employed between a railway track and a support. These solutions, based on a concept of resilient elements pressed down toward the support mainly by the weight of the track itself, do not fully answer a necessity for immediate and accurate corrections in any direction, up- down- or sidewards, of the track position.
In known air tracks a thickness of the air-cushion below bottom-side surface of the glider is uniform and has to be considerable to diminish an influence of the air viscosity on slowing-down the glider's movement.
Another inconvenience in use of known air tracks is in that the weights hovering on the aircushion have to be relatively low because significant part of the air escapes from below of the glider through wide gaps.
In known air tracks the forces accelerating the gliders (particularly in collisions of the gliders) are applied to the point above the glicer's mass centre. An inconvenience in use of known air tracks consists in that the glider accelerated with the force applied to the point above its mass centre tilts over and grinds against the track.
Considerable inconvenience in use of known air tracks is also in that the gliders lifted on the aircushion created close to the longitudinal axis reel and grind against the track.

Substance of the invention

The substance of the invention is the air track consisting of double aliminium pipe with rectangular cross-section, long rigid support and the glider, fit with the springs that pull down the track pipe toward the support, which allows the track pipe to move with regard to the support.
In the air track according to an embodiment of the invention the height of lateral gaps formed between the glider and the track pipe and filled with compressed air is less than 0.25 of the air track width, and the width of each of lateral gaps filled with compressed air and formed between the glider and the track pipe is less than 0.2 mm.
In the air track according to another embodiment of the invention the glider is fit with the element of considerable mass if compared to the glider's mass and placed so that the glider's mass centre is above the track's surface.
In the air track according to another embodiment of the invention the orifices in the top surface of the pipe are placed close to the track pipe edges, and the track pipe central part which covers about 70% of the track pipe total top surface has no orifices, and the track pipe and support are made from double aliminium pipe of rectangular cross-section which is used for measuring staff with outer width of 90.5 mm and thickness of 18 mm.

Virtues of the invention

A virtue of the air track according to the invention is in a possibility for the track pipe to move above the support, then the track pipe reflects the support's shape and does not bend while influenced by a difference in temperatures of the air conducted from a compressor toward the track pipe and that of the air surrounding the support.
Another virtue of the air track according to the invention is in that the lateral gaps filled with compressed air and formed between the track pipe and the glider, because of their very low width, less than 0.2 mm each, they prevent the air from escaping from beneath the glider, which makes possible to burden the glider with additional weight, and slight height of lateral gaps, lesser than 0.25 of the track width, does not increase meaningfully the resistance to motion.
Yet another virtue of the air track according to the invention is in that the air which flows out of the orifices situated close to the track pipe edges, far from the track pipe longitudinal axis, lifts the glider and additionally prevents it from reeling and grinding against the track pipe.
Still another virtue of the air track according to the invention is in advantageous application of easily accessible, precisely manufactured double aluminium pipes of rectangular cross-section which are commonly used for measuring staff.

Preferred embodiment

Preferred embodiment of the invention is illustrated on the drawing where fig. 1 shows the lateral view of the air track, fig. 2 shows the cross-section of the air track without the glider, and fig. 3 shows the cross-section of the air track with the glider.
The air track consists of double aluminium pipe (1) of rectangular cross-section, long rigid support (2) and the glider (4) fit with the element (5) of considerable mass if compared to the glider's (4) mass and placed so that the glider's (4) mass centre is above the track's (1) surface. The springs (3) pull down the track pipe (1) toward the support (2). Lateral gaps filled with compressed air and formed between the glider (4) and the track pipe (1) are of height lesser than 0.25 of the track pipe (1) width, and the width of each of these lateral gaps is less than 0.2 mm. The orifices in the top surface of the track pipe (1) are placed close to the edges of the track pipe (1), and central part of the track pipe (1) which covers about 70% of the track pipe (1) total top surface has no orifices.
The track pipe (1) and the support (2) are advantageously made from double aliminium pipe of rectangular cross-section which is used for measuring staff, with outer width of 90.5 mm and thickness of 18 mm.

Claims

An air track consisting of a double aluminium track pipe (1) of rectangular cross-section, a support (2) and a glider (4) characterised in that the track pipe (1) is pulled down through the springs (3) toward the support (2) and said springs (3) enable said track pipe (1) to move with regard to said support (2).
The air track as in claim 1 wherein the lateral gaps formed between the glider (4) and the track pipe (1) are of height lesser than 0.25 of said track pipe (1) width and are filled with compressed air.
The air track as in claim 1 wherein the lateral gaps formed between the glider (4) and the track pipe (1) are of width lesser than 0.2 mm and are filled with compressed air.
The air track as in claim 1 wherein the glider (4) is fit with an element (5) of considerable mass if compared to said glider's (4) mass and placed so that said glider's (4) mass centre is above the surface of said track pipe (1).
The air track as in claim 1 wherein the top surface of the track pipe (1) has orifices placed close to the edges of said track pipe (1).
The air track as in claim 5 wherein a central part of the track pipe's (1) top surface, which covers about 70% of said track pipe's (1) total top surface, has no orifices.
The air track as in claim 1 wherein the track pipe (1) and the support (2) are made from double aluminium pipe of rectangular cross-section which is used for measuring staff, wherein the outer width of the double aluminium pipe is 90.5 mm and its thickness is 18 mm.