GB2173137A

GB2173137A - Apparatus for conveying can bodies

Info

Publication number: GB2173137A
Application number: GB08605485A
Authority: GB
Inventors: Siegfried Frei
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-03-06
Filing date: 1986-03-05
Publication date: 1986-10-08
Also published as: IT1190216B; DE3607272A1; ES8701566A1; IT8647714A0; GB8605485D0; GB2173137B; ES552991A0; CH667255A5

Abstract

The conveyor belt (25) conducts the can bodies (3), which have their longitudinal seams welded in a welding machine (1), before such bodies pass into the welding plane (E) and until such bodies are completely welded and has a velocity which corresponds with the welding speed. The section (31) of the belt (25) which passes through the calibrating roller assembly has a concave configuration and is about twice as long as the height (h) of the lowest can body (3) processed on the welding machine. <IMAGE>

Description

SPECIFICATION Apparatus for conveying can bodies The present invention relates to a device for conveying can bodies whilst the longitudinal seam is being welded in a can welding machine, such apparatus including a sizing or calibrating roller assembly, which is substantially disposed in the welding plane and comprises a plurality of diabolo or like rollers, a conveyor system which conducts the can bodies into the welding plane, and a driven conveyor belt which passes over two rollers for discharging the welded can bodies from the welding plane.

It is known to conduct to the welding plane, defined by the plane in which lie the axes of rotation of welding rollers or like means, of a can welding machine the can bodies which, at such time are still unwelded and to conduct such can bodies in a cylindrical cage formed from parallel bars or a plurality of small rollers. A supporting or calibrating roller assembly is used in the welding plane for guiding the can body in an extremely precise manner during the operation of welding the longitudinal seam, generally by means of a pair of welding rollers. Downstream of the welding plane when viewed in the conveying direction, a small conveyor belt which passes over two rollers is responsible for advancing the can body emerging at the welding plane until it is then conducted to an additional conveyor system for further processing.

During the operation of welding the longitudinal seams of squat can bodies, i.e. can bodies whose height is less than their diameter, there is always the danger, with known conveyor devices, that the can bodies will tilt or twist because such can bodies, as they pass through the calibrating roller assembly, are either rammed from behind and retained in the clamping gap of the welding rollers or, alternatively, they are actually grasped by the conveyor belt downstream of the welding plane and are also additionally retained by the welding rollers. In any event, the points of contact with the can body are always diagonally situated, so that it is possible for the can body to be deflected from the axis of rotation when there are slight differences in the speeds of the welding rollers and the conveyor systems, even, for example, in the event of speed differences caused by slippage.This deflection may result in defective welding operations and, consequently, in waste and shutdowns.

The invention now seeks to provide apparatus for conveying can bodies in the region of the welding plane, such a device overcoming or minimising the disadvantages of known systems and generally always conducting the can bodies in a coaxial po- sition relative to the precise, geometric conveyor axis.

According to the present invention there is provided apparatus for conveying can bodies whilst the longitudinal seam is being welded in a can welding machine, such apparatus including a sizing or calibrating roller assembly, which is substantially disposed in the welding plane and comprises a plurality of diabolo or like rollers, a conveyor system which conducts the can bodies into the welding plane, and a driven conveyor belt which passes over two rollers for discharging the welded can bodies from the welding plane, characterised in that, when viewed in the conveying direction of the can bodies, the two rollers over which the driven conveyor belt passes comprise a first roller disposed at the inlet end of the conveyor belt and upstream of the welding plane, and a second roller disposed at the outlet end of the conveyor belt downstream of the welding plane, and in that the upper run or section of said driven conveyor belt extends parallel to and in abutment with the can bodies and turns at a velocity which corresponds to the welding speed.

It is now possible to advance the can bodies by a single conveyor means throughout the whole of the seam welding operation, whilst simultaneously supporting the can bodies over the whole length or height of the body, so that there is no possibility of any tilting or twisting.

Additional advantageous embodiments of the invention are described in the dependent claims.

The diabolo rollers, which are disposed on both sides of the conveyor belt, prevent the can bodies from becoming laterally displaced on the belt.

The can bodies lie in the concavely-shaped or disposed surface of the conveyor belt in a laminar or of sheet-like manner and are kept embedded in said surface.

Excellent supporting or sizing, i.e. calibration of the can bodies may be advantageously ensured because of the diabolo roller which is disposed beneath the conveyor belt in the welding plane.

The curved surface of the belt can be easily produced by concavely-shaped guide rollers, i.e. the diabolo roller.

In the case of very low can bodies, e.g. for fish preserves, it is advantageous to provide a plurality of conveyor belts adjacent one another which retain the can bodies on all sides.

Utilisation of a conveyor belt with an upper run of a length which is greater than twice the diameter of the can bodies permits precise guidance to be ensured throughout the entire welding process.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic, partial elevational view of a machine for welding can seams; Figure 2 is a cross-sectional view through the welding plane taken along the line Il-Il of Figure 1; and Figure 3 is a cross-sectional view through a conveyor belt.

A welding machine 1 for welding the longitudinal seam of can bodies 3 has a guide cage 7 for guiding the unwelded can bodies 3 which are conveyed from a rounding device (not shown) by means of a first conveyor system 5, e.g. a chain with cams. The guide cage 7 includes a plurality of cylindrically disposed guide bars 9 although may, alternatively, comprise a plurality of small guide rollers (not shown) which are arranged to form a cylindrical tube. The welding of the can bodies 3 is effected between two spring-loaded, driven welding rollers 11 and 13. The welding roller 13 is situated inside the can body 3 and is secured to a welding arm 15.A positioning or calibrating roller assembly 17, illustrated in Figure 2, is disposed in the welding plane E, which is formed by the plane extending through the rotational axes of the welding rollers 11 and 13; said assembly 17 being provided with a plurality of diabolo rollers 19 which calibrate the can bodies 3 during the welding process.

When viewed in the conveying direction, the welded can bodies 3 are received downstream of the welding plane E by a conveyor system 21 and conducted to a subsequent processing station.

In the region of the welding plane E itself, the can bodies 3 are conveyed by a device 23 which is independent of the conveyor systems 5 and 21.

The device 23 includes a conveyor belt 25 which passes around two rollers 27 and 30. A conveyor chain may, alternatively, be used instead of a belt 25. At least one of the rollers 27 and 30 is driven and drives the belt 25 at a velocity V which corresponds to the welding velocity speed Vs and, consequently, corresponds also to the speed which can bodies 3 pass the welding plane E.

In the region traversed by the belt 25, the calibrating roller assembly 17 may have a diabolo roller 29 with a radius which is reduced by an amount corresponding to the thickness of a belt 25, so that the surface of the belt 25 in contact with the can body 3 substantially lies in the circular aperture formed by the diabolo rollers 19. Alternatively, the belt 25 may pass through the welding plane E without any support.

A profiled belt 25 as shown in Figure 3 may be used instead of a thin belt 25, which adapts to the surfaces of the diabolo roller 29 and/or rollers 27 and 30 or can body 3; the surface of such a profiled belt 25 of Figure 3 being curved in a concave manner. One cylindrical supporting roller would, of course, be sufficient in the case of a profiled belt 25.

The upper run or section of the conveyor belt 25 will be supported so as to be disposed presenting a concave surface or the belt 25 will be profiled, as in Figure 3, to have a concave outer facing surface; either of said concave surfaces preferably having a radius of curvature substantially corresponding to the radius of the can bodies 3.

The length of the upper run or section 31 of the belt 25 conducting the can bodies 3 is preferably twice the height h of the lowest can body 3 welded on the machine 1.

The distance between the rotational axis of the roller 27 and the welding plane E may be slightly shorter than the spacing of the roller 30 therefrom, because the can bodies 3 continue to be retained behind by a Z-shaped rail (not visible) as they pass into the welding rollers 11 and 13.

For most applications, the use of a belt 25 which supports the can bodies 3 opposite the welding seam 33 is sufficient. In the case of extremely squat can bodies 3 whose height h is substantially smaller than their diameter D or in the case of those can bodies which are formed from very thin sheet metal, it may be advantageous to use two or more such belts 25.

Claims

1. Apparatus for conveying can bodies whilst the longitudinal seam is being welded in a can welding machine, such apparatus including a sizing or calibrating roller assembly, which is substantially disposed in the welding plane and comprises a plurality of diabolo or like rollers, a conveyor system which conducts the can bodies into the welding plane, and a driven conveyor belt which passes over two rollers for discharging the welded can bodies from the welding plane, characterised in that, when viewed in the conveying direction of the can bodies, the two rollers over which the driven conveyor belt passes comprise a first roller disposed at the inlet end of the conveyor belt and upstream of the welding plane, and a second roller disposed at the outlet end of the conveyor belt downstream of the welding plane, and in that the upper run or section of the said driven conveyor belt extends parallel to and in abutment with the can bodies and turns at a velocity which corresponds to the welding speed.

2. Apparatus as claimed in claim 1, in which the upper run or section of said conveyor belt passes through the welding plane between two diabolo rollers.

3. Apparatus as claimed in claim 1, in which the side of the upper run or section of the conveyor belt facing the can body is curved in a concave manner, and the radius of curvature substantially corresponds to the radius (D/2) of the can bodies.

4. Apparatus as claimed in claim 2 or 3, in which the upper run or section of said conveyor belt passes through the welding plane resting on a roller.

5. Apparatus as claimed in claim 4, in which the belt is curved in a concave manner by the surface of the roller.

6. Apparatus as claimed in any of claims 1 to 5, in which two or more conveyor belts are disposed in the region of the welding plane, and their sections partially define or enclose a cylindrical face.

7. Apparatus as claimed in any of claims 1 to 6, in which the length of the upper run or section of the conveyor corresponds approximately to twice the height (2h) of the can bodies.

8. Apparatus as claimed in any of claims 1 to 7, in which the axis of rotation of said roller is situated nearer the welding plane than the axis of rotation of said second roller.

9. Apparatus for conveying can bodies substantially as herein described with reference to the accompanying drawings.