US3357404A

US3357404A - Installation for coating the inside of metal tubes

Info

Publication number: US3357404A
Application number: US326500A
Authority: US
Inventors: Zollinger Hans
Original assignee: AUTOCALORA SA
Current assignee: AUTOCALORA SA
Priority date: 1962-12-21
Filing date: 1963-11-27
Publication date: 1967-12-12
Anticipated expiration: 1984-12-12
Also published as: CH381608A

Description

1967 H. ZOLLINGER 335K404 INSTALLATION FOR COATING THE INSIDE OF METAL TUBES Filed Nov. 27, 1963 7 Sheets-Sheet 1 a? E k I N I Q A w C C) b C: 0 q q I i \C g 1 E! If ISL/ BL; I c :51 Q o o Dec. 12, 1967 H. ZOLLINGER 3,357,404

TALLATION FOR COATING THE INSIDE OF METAL TUBES INS '7 Sheets-Sheet 2 Filed Nov. 27 1963 Dec. 12, 1967 H. ZOLLINGER 3,357,.404

INSTALLATION FOR COATING THE INSIDE OF METAL TUBES Filed NOV. 27, 1965 '7 Sheets-Sheet I5 3,35'YAQ4 Dec. 12, 1967 H. ZOLLINGER INSTALLATION FOR COATING THE INSIDE OF METAL TUBES '7 Sheets-Sheet 4 Filed Nov. 27, 1963 Dec. 12, 1967 H. ZOLLINGER 3,357,494;

INSTALLATION FOR COATING THE INSIDE OF METAL TUBES Filed Nov. 27, 1963 '7 Sheets-Sheet 5) Dec. 12, 1967 H. ZOLLINGER INSTALLATION FOR COATING THE INSIDE OF METAL TUBES 7 Sheets-Sheet 6 Filed Nov. 27, 1963 FIG. IO.

INVENTOR HANS ZOLLINGER ATTORNEY.

1957 H. ZOLLINGER 3,35'ZAQ l- INSTALLATION FOR COATING THE INSIDE OF METAL TUBES Filed Nov. 2'7, 1963 '7 Sheets-Sheet '7 INVENTOR HANS ZOLLINGER ATTORNEY.

United States Patent 3,357,404 INSTALLATION FOR COATING THE INSIDE OF METAL TUBES Hans Zollinger, Lausanne, Vaud, Switzerland, assignor to Autocalora S.A., Vevey, Switzerland, a corporation of Switzerland Filed Nov. 27, 1963, Ser. No. 326,500 Claims priority, application Switzerland, Dec. 21, 1962,

15,041/ 62; Aug. 31, 1963, 10,740/63 11 Claims. (Cl. 118--642) The present invention relates to an installation for coating the inside of metal tubes.

Separate devices have previously been used for the various operations associated with glazing the inside of metal packing tubes, such as annealing the tube metal, glazing, and polymerization of the finished glaze. This procedure has made any form of automation impossible.

It is an object of the present invention to obviate this disadvantage, and the present invention accordingly relates to an installation for coating the inside of metal packaging tubes or other tubular articles with a polymerized glaze, with a View to automating these various operations.

The installation according to the present invention comprises an endless chain conveyor having supports for supporting the tubes and having disposed consecutively along its path: a device for loading tubes for glazing into the supports; an oven for annealing the metal of the tubes; at least one device for glazing the interior of the tubes; a glaze polymerization oven; and a device for unloading the glazed tubes; driving means provide a continuous advance of the conveyor; the glazing device is adapted to move between two positions spaced out along the path of the conveyor; and coupling means periodically connect the glazing device to the conveyor for movement thereby between the said two positions, return means being provided to return the glazing device to the upstream position upon release of the said coupling means.

With these and other objects in view which will become apparent in the following detailed description, the present invention will be clearly understood in connection with the accompanying drawings, wherein:

FIGURE 1 is a general plan view of the installation;

FIGS. 2 and 3 are partial views, in elevation and plan, respectively, of an endless-chain conveyor, with partial sections taken, in FIG. 2, along the lines 2-2 of FIG. 3, and in FIG. 3 along the lines 33 of FIG. 2;

FIGS. 4 and 5 are sections taken along the lines 4-4 and 55 respectively of FIG. 1, to an enlarged scale;

FIG. 6 is a section taken along the lines 6-6 of FIG. 3, to an enlarged scale;

FIG. 7 is a plan view of a coupling mechanism, the view being to an enlarged scale and looking in the direction of an arrow 7 in FIG. 5;

FIG. 8 illustrates a device for unloading tubes, the device being shown in various consecutive operative position;

FIG. 9 is a profile view of the device illustrated in FIG. 8 and looking in the direction of arrows 9 therein;

FIG. 10 is a perspective front view of the glazing device; and

FIG. 11 is a perspective front view of the loading and unloading device.

Referring now to the drawings, and in particular to FIG. 1, the installation is for coating the inside of metal packing tubes with a polymerized glaze. The installation comprises an endless-chain conveyor 1, which has arranged consecutively along its pathin the direction of conveyor movement as indicated by an arrow A-a loading device 2 for loading tubes for glazing into supports borne by the conveyor, a furnace or oven 3 for annealing the tube metal, a glazing device 4 for glazing the inside of the tubes carried along by the conveyor, a furnace or oven 5 for polymerizing the glaze, and an unloading device 6 for unloading the glazed tubes from the conveyor 1.

The conveyor 1, details of which are given in FIGS. 2 and 3, comprises identical carriages 7 articulated to one another by vertical pivot pins 8. The carriages 7 each have a hollow bottom part or base part 9 receiving running elements, which take the form for each carriage of two wheels 10 and a ball 11. At a considerable height above the running plane of the

running elements

10 and 11, the carriage has a horizontal disc or tray or plate or the like 12 which is connected to the carriage base part 9 by a central foot 13. The base part 9 and the plate 12 are of substantially the same width, but the foot 13 is much narrower. Edges 14 of the plates 12 are straight and parallel and form carriage guide rails in a manner which will be described hereinafter.

The installation comprises a rigid frame 15 having four parallel longitudinal members 16 which extend over its whole length (FIG. 1). The two ovens 3 and 5 rest on the members 16 and have plane bases 17 and 18, respec tively, which form running surfaces for the

carriage running members

10 and 11. The conveyor is guided by rotating guide posts 19 borne by the oven bases 17 and 18 and the path of the conveyor comprises, between the furnaces, two straight parts 20 and 21 bordered by rows of support rollers 22.

The rollers 22 are pivoted to blocks borne in each row by a longitudinal member 23 secured to the nearby longitudinal member 16 by cross-pieces 24. In the outer rows, the blocks 25 bearing the rollers are secured to the longitudinal member 23, while in the inner rows the blocks 26 hearing the rollers can move and can slide perpendicularly to the conveyor in stirrups 27 secured to the longitu dinal member 23 (FIG. 5 and 6). The moving blocks 26 have lateral ribs received in grooves 28 in the stirrups and each compnse a rod 29 extending through the stirrup and bearing an abutment 30 (FIG. 6). Resilient washers 31 threaded on the rod 29 and placed between the stirrup 27 and the block 26 tend to force the associated roller 22 towards the conveyor 1.

The rollers 22 are formed with a peripheral groove 32 of V-shaped cross-section, and the side edges 14 of the carriage plates or the like 12 are bevelled, as indicated by the numeral 33 in FIG. 6. I

As they leave the oven 3, and as can be seen in FIGS. 2 and 3, the edges 14 of the plate 12 of the carriages 7 engage between the two rows of rollers 22 bordering the path of the conveyor 1, the plate edges 14 therefore forming guide rails which co-operate with the rotating rollers 22 to support and guide the conveyor over the straight part 20 of its path. Similar considerations apply to the straight part 21 of the conveyor path.

The carriages 7 are supported and guided between the two furnaces 3 and 5 just by the rollers 22, there being no running surface in these parts of the conveyor path for the running

elements

10 and 11 at the bottom of the carriages. Rollers 34 in FIGS. 2 and 3 facilitate the engagement of the plate 12 between the rollers 22, and the same are near enough together for each plate 12 always to be in engagement with at least two rollers 22; the rollers 22 therefore oppose any longitudinal and transverse tilting of the carriages 7.

The plate 12 of each carriage has spindles 35 rotatably mounted in sleeves 36 rigidly secured to the plate 12; at their top end they have a basket 37 adapted to support a tube 38 placed vertically above the conveyor 1, in the position in FIG. 4.

The annealing oven 3 comprises a heating tunnel 39 having in its top part three heating members 40 in the form of electric resistors, with gaps between them through which the tube baskets can pass. Protective means are provided between the heating members 40 and the carriage chain to protect the same from the heat radiating from the top of the oven, and comprise two rows of 'bafiies 41 and 42 at different levels. The top row 41 comprises a central horizontal bafiie 41a suspended between the two rows of baskets, and two side horizontal baffles 41b, 410 secured to the tunnel side walls, the gap between the central bafiie and each lateral bafiie being just enough for the vertical spindles 35 to pass through. The bottom row 42 is formed by two lateral baffles 42a, 42b separated by a gap narrower. than the plate or the like 12 and the carriage base part 9, through which gap the central foot 13 connecting the plate 12 to the base part 9 can pass.

The polymerization oven comprises a heating tunnel 43 similarly devised to the tunnel 39 but with a number of resistors which can be varied to suit the required polymerization temperature.

The installation comprises a driving motor 44 which provides a continuous advance of the conveyor 1 (FIG. 1). The motor 44 drives via a speed reducer 46 a gear 45 having a double toothed ring. Disposed between the gear 45 and an identical reversing wheel 47 is an endless chain 48 whose runs extend parallel with the nearby part of the conveyor 1. The links of the chain 48 comprise parallel spindles 48a (FIG. 5) and lateral abutments 49 which project beyond the side surface of the carriagebasepart 9 in the path of the spindles 48a, so that the carriages 7 which are opposite the chain 48 are driven thereby, so that the chain 48 advances the conveyor 1 continuously in the direction indicated by the arrow A in FIG. 1.

The glazing device 4 can be moved between two positions spaced out along the straight part 20 of the conveyor path, and coupling means shown in FIGS. 7 and connect the device 4 to the conveyor periodically for movement thereby between the two positions, return means being provided to return the glazing device 4 to its upstream position upon release of the coupling means.

For its displacement the glazing device 4 is mounted by way of feet 50 on a movable solepiece 51 slidable on two circular cross-section guide rods 52 (FIGS. 7 and 10). The aforesaid coupling means comprise a coupling lever 53 articulated by a pivot 54 to the solepiece 51 and tending to be maintained by a spring 55 in the advanced angular position illustrated in FIG. 7, in which position the lever 53 abuts at its rear end a pin 56, While its hook-shaped front end 57 is in the path of pins 58 rigidly secured to the plates 12 of the carriages 7. A locking lever 59 articulated by a pivot 60 to the solepiece 51 and ten-ding to be maintained by a spring 61 in engagement with a pin 62, maintains the lever 53 in the angular position shown in FIG. 7, in which position the moving solepiece 51 is coupled with the conveyor carriage 7. The solepiece 51 moves with the conveyor 1 in the direction indicated by an arrow B in FIGS. 7 and 10 against the force of a return spring 63 secured at one end to a foot (not shown) below the solepiece 51 and at the other end to a bridge-piece 64 rigidly secured to the rods 52.

As the solepiece 51 moves to the right, the outer end 65 of the locking lever 59 abuts an adjustable stop 66 secured by bolts or the like to a longitudinal member 67 of the frame of the installation. The stop 66 causes the lever 59 to pivot against the force of the spring 61, so that its end '68 rotates anticlockwise (FIGS. 7 and 10) and releases the coupling lever 53. Because of the lateral position of the book 57 relatively tothe pivot 54, and because of the resistance to advance offered by the return spring 63, the lever 53 disengages from the pin 58 and the solepiece 51 is returned abruptly in the direction of the bridge 64 by the return spring 63, while the conveyor 1 continues to move to the right. Once the coupling lever 53 has disengaged from the pin 58, the spring 55 returns it to the advanced angular position illustrated in FIGS. 7 and 10', and the 4 locking lever 59 is returned to the locked position by the spring 61.

The reummeoentn rt v The return movement of the solepiece 51 is interrupted when the coupling lever 53 strikes the following pin 58a, the solepiece 51 therefore moving with the conveyor from an upstream position, determined by the position of the pin 58 with which the coupling lever 53 hooks up, to a downstream position determined by the abutment 66. The travel of the solepiece 51 is not always constant and can adapt itself as required to variations in the spacings between the pins 58 and 58a.

The device 6 for unloading the glazed tubes can also move between two positions spaced out along the straight part 21 of the conveyor path. To this end, the device 6 is borne by a moving solepiece 51' (FIG. 11) the same as the solepiece 51 of the glazing device; an unloading coupling means 51" (comprising springs, levers, etc.), the same as the coupling means for the glazing device (and therefore not described in detail), periodically connects the solepiece 51' of the unloading device 6 to the conveyor 12, resilient return means 63 (the same as that for the return of the glazing device), being provided to re turn the unloading device to its upstream position upon release of the coupling.

The unloading device 6, which is illustrated in FIGS. 8, 9 and 11, comprises,-on a stationary frame 69 having a slide 70 parallel with the conveyor path, a moving slideway 71 connected by an arm 71a, part of which is shown in FIG. 9, to the moving solepiece 51' of the device 6. The slideway 71 bears a cylinder 72 pivotally mounted on pivots 73 and receiving a piston 74. A rod 75 of the latter has at its bottom end a gripper 76 adapted to seize the tube disposed in the tube basket 37 of a support. The gripper 76 comprises a mandrel 76a disposed in the tube end, and a moving part controlled by an electromagnet 86.

The coupling device is so devised that the slideway 71 moves past a moving basket 37 between an upstream position and a downstream position, in which position the axis C of the cylinder 72 respectively, takes up the positions illustrated by the axes I and V in FIG. 8.

In position I, the piston 74 is maintained in its top position by a spring 77, and the gripper 76 is open and is in the top position represented by the axis 1. In this up stream position, the chamber formed above the piston in the top part of the cylinder 72 communicates, through a duct 78 in one of the pivots of the cylinder and through a duct 79 in the slideway 71, with an exhaust port 80 pierced in the slide 70. When the slideway 71 moves to the right (FIG. 8), such movement occurring opposite a tube basket 37, the orifice of the duct 79 comes opposite a supply port 81 in the slide 70 and compressed air enters the cylinder 72 to force the piston 74 downwards against the force of the spring .77. The piston 74 then descends gradually, as denoted by II, and the gripper 76 engages over. the tube end, as denoted by the reference III. In this position, a contact 82 at the top of the cylinder engages with a stationary contact strip 83 to close an electric circuit to energise an electromagnet 84 which operates the gripper 76 to close the same on the tube edge. Shortly after position III, the air duct 79 comes opposite a second exhaust port 85 in the slide 70 and the air escapes from the cylinder 72 so that the gripper 76 which is closed on the tube returns to the top position denoted by the reference IV and removes the tube from the basket 37.

From position I to position IV, the axis C of the cylinder 72 is in a vertical position, and a roller 86. rigidly secured to an arm 87 disposed on the side of the cylinder rests on a first flat part 88 of a cam 89 secured to the frame 69, while a spring 90 which is compressed between the base of the slideway 71 and the top end of the cylinder 72 keeps the roller 86 forced against the cam 89. When the cylinder 72 moves slightly past the position IV, the roller 86 reaches a part 91 near the end of the flat part 88 of the cam 89. As the advancing movement continues, the

roller 86 engages with a second part 92 of the cam, such part being inclined to the rear, so that the cylinder 72 pivots on its pivots 73 and is inclined to the rear, as illustrated in FIG. 9, by the spring 90. This tilting movement disengages the contact 82 from the strip 83, so that the gripper 76 opens and releases the tube which can drop into a stationary receptacle 93 above which the tube has been brought. In its rapid return movement the cylinder 72 does not have time to fill up completely, and it returns to position I opposite the next tube basket 37.

The bases 17 and 18 of the annealing oven 3 and polymerisation oven 5 comprise, on parts on the conveyor path corresponding inter alia to the heating tunnels 39 and 43 zones 94 where the sheet metal is pierced with a number of apertures communicating with an air distribution duct 95 (FIGS. 1 and 4) disposed below such bases. The duct or trunking 95 acn be supplied with fresh air by a fan 96, shown in FIG. 1, whose motor 97 is supplied via a switch disposed in a casing 98; such switch is closed when the main driving motor 44 is energised and is driving the conveyor 1. It remains closed when the main motor 44 is stopped and must be opened individually for stopping the fan 96.

The cooling air supplied by the fan 96 and exhausting through the apertures in the zones 94 is injected into the hollow base parts 9 of the carriage 7, which are substantially open at the bottom, and the distributing means thus formed ensure that the cooling air continues to be distributed automatically should the conveyor 1 stop. This cooling of the carriages 7 means that the same can withstand a stoppage in the hottest part of their path without the need to switch off the heating current to the heating tunnels.

Some of the advantages of the installation disclosed are as follows:

In the annealing and polymerization ovens, the carriages of the endless conveyor run on running elements placed at the bottom of the carriages very far away from the heating members, whereas in the loading, glazing and unloading stations, the carriages are guided and maintained via the edges of their plates or the like 12and much nearer the tube baskets 37by rotating stationary elements which do not have to withstand the great heat of the ovens.

Because these two different guiding systems are used each on a part of the path of the conveyor, the same can pass inside the ovens and the tube baskets can be maintained in a predetermined position in the working stations where it is necessary for the tubes to be positioned fairly accurately. There is therefore no disadvantage if the running elements at the bottom of the carriages are relatively inaccurate, for they can still operates correctly even in the absence of effective lubrication. Also, since protective bafiles are provided in the heating tunnels of the ovens, the chain can pas therethrough without overheating. The tubes borne by the conveyor can therefore be moved from one station to another and be processed in the various ways described automatically and without any waste of time.

As a variant, the installation can comprise more than one annealing oven and more than one polymerization oven.

Since the glazing and unloading devices are driven by coupling means which periodically couple their respective devices to the endless conveyor, movements can be satisfactorily synchronised notwithstanding variations in conveyor speed or in the gaps between the carriages 7. Good synchronisation is very important for the glazing station where glaze guns 4' (FIG. descend into the moving tubes, and at the unloading station where, as already described, a gripper seizes the tubes.

As a variant, the grippers can be formed by extinsible mandrels which are adapted to move vertically and which enter the tube insides very accurately to be secured in the tube necks.

Of course, the loading device can if required by adapted by a coupling means 51" to move along the conveyor path for movement thereby, for instance, in the same manner as the unloading device (FIG. 11). A final feature is that the installation disclosed is also of use for glazing articles other than packing tubes, for instance, metal boxes, covers or the like, just by a simple change of shape of the tube baskets, herein such being generally termed tubular articles or more briefly tubes.

While I have disclosed one embodiment of the present invention, it is to be understood that this embodiment is given by example only and not in a limiting sense, the

scope of the present invention being determined by the objects and the claims.

I claim:

1. Installation for coating the inside of tubular articles with a polymerized glaze comprising an endless-chain conveyor consisting of carriages; roller members disposed on the base of said carriages; articulation means connecting said carriages, supports on said carriages for supporting tubes disposed consecutively along the path of said conveyor at the upper parts thereof so as to support tubes standing vertically above said conveyor; lateral guide rails for said carriages; a track for said conveyor along part of its path formed by a running surface for said roller members and over another part by rotatable support members on either side of the path engageable by the carriage lateral guide rails; at least one device for glazing the interior of the tubes; a glaze polymerization oven; an annealing oven, and a device for loading and unloading the tubes; driving means providing a continuous advance of said conveyor; said glazing device being adapted to move between two positions spaced out along the path of said conveyor; coupling means periodically connecting said glazing device to said conveyor for movement thereby between said two positions; and return means to return said glazing device to the upstream position upon release of said coupling means.

2. The installation, as set forth in claim 1, wherein the oven comprises; plane bases forming running surfaces for said carriage roller members; said tube loading, glazing and unloading devices being disposed on straight parts of the conveyor paths; and said rotatable support members being engageable by lateral guide rails bordering the straight parts of the conveyor path.

3. The installation, as set forth in claim 1, wherein said rotatable support members oppose any lengthwise or transverse tilting of said carriages, whose rails are in engagement with such elements.

4. The installation, as set forth in claim 1, wherein said carriages comprise; a hollow 'base part receiving said roller members; a horizontal plate disposed at a considerable height'above the running plane of the roller members, the lateral edges of such plate forming the said carriage guide rails; and a central foot which is much narrower than said plate and than the carriage base part connecting said plate to said hollow base part.

5. The installation, as set forth in claim 1, wherein said carriages comprise; a hollow base part receiving said roller members; a horizontal plate disposed at a considerable height above the running plane of the running elements, the lateral edges of said plate forming said carriage guide rails; and a central foot which is much narrower than said plate and than the carriage base part connecting said plate to said hollow base part, and wherein the bases of said ovens are formed to define perforations through which cooling air can be injected into said hollow base part of said carriages when the same are in said ovens; and the cooling air is distributed automatically by distributing means in the event of the conveyor stopping.

6. Installation for coating the inside of tubular articles with a polymerized glaze, comprising an endless chain conveyor consisting of carriages; roller members disposed on the base of said carriages; articulation means connecting said carriages, supports on said carriages for supporting tubes disposed consecutively along the path of said conveyor at the upper parts thereof, so as to support tubes standing vertically above said conveyor; lateral guide rails for said carriages; a track for said conveyor along part of its path formed by a running surface for said roller members and over another part by rotatable support members on either side of the path engageable by the carriage lateral guide rails; at least one device for glazing the interior of the tubes; a glaze polymerization oven; an annealing ovenand a device for unloading the glazed tubes; driving means provide a continuous advance of said conveyor; said glazing device being adapted to move between two positions spaced along the path of said conveyor; coupling means periodically connecting said glazing device to said conveyor for movement thereby between the said two positions; and return means to return said glazing device to the upstream position upon release of said coupling means, wherein the annealing and polymerization ovens comprise heating members disposed in the top part of heating tunnels in said ovens; and protective means provided between said heating members and said carriages to protect the same from the heat radiating from the top par-t of the tunnels.

7. The installation, as set forth in claim 6, wherein the protective means comprise baflies having surfaces which reflect the heat upwards into the top part of the heating tunnels.

8. The installation for coating the inside of tubular articles with a polymerized glaze, comprising an endless chain conveyor consisting of carriages; roller members disposed on the base of said carriages; articulation means connecting said carriages, supports on said carriages for supporting tubes disposed consecutively along the path of said conveyor at the upper parts thereof, so as to support tubes standing vertically above said conveyor; lateral guide rails for said carriages; a track for said conveyor along part of its path formed by a running surface for said roller members and over another part by rotatable support members on either side of the path engageable by the carriage lateral guide rails; at least one device for glazing the interior of the tubes; a glaze polymerization oven; an annealing oven, and a device for unloading the glazed tubes; driving means providing a continuous advance of said conveyor; said glazing device being adapted to move between two positions spaced along the path of said conveyor; coupling means periodically connecting said glazing device to said conveyor for movement thereby between said two positions; and return means to return said glazing device to the upstream position upon release of said coupling means, wherein said annealing and polymerization ovens comprise heating members disposed in the top part of heating tunnels in said ovens; and protective means provided between said heating members "and said carriages to protect the same from the heat radiating from the top part of the tunnels, wherein said carriages comprise; a hollow base part receiving said roller members; a horizontal plate disposed at a considerable height above the running plane of the running elements, the lateral edges of such plate forming said carriage guide rails; and a central foot which is much narrower than said plate and than said carriage base part connecting said plate to said hollow base part.

9. The installation, as set'forth in claim 8, wherein said tunnels have lateral bafiies which are disposed opposite one another and which are separated from One another by a gap narrower than said plates and the conveyor carriage base parts, such gap serving as a passage for the central foot which connects said carriage base parts to said plates.

10. The installation, as set forth in claim 8, wherein each conveyor carriage plate has at least two rows of article supports; and a central horizontal bafiie is suspended between such rows and two horizontal lateral baffles are secured to the tunnel side walls, the distance between said central bafile and each lateral bafiie being just enough to allow vertical rods which bear said supports to pass through.

11. Installation for coating the inside of tubular articles with a polymerized glaze, comprising; an endless chain conveyor; supports for supporting tubes disposed consecutively along the path of said conveyor; a device for loading tubes for glazing into said supports; an oven for annealing the metal of the tubes; at least one device for glazing the interior of said tubes; a glaze polymerization oven; a device for unloading the glazed tubes; driving means for providing a continuous advance of said conveyor; said glazing device being adapted to move between two glazing positions spaced out along the path of said conveyor; glazing coupling means periodically connecting said glazing device to said conveyor for movement thereby between said two glazing positions; and return means to return said glazing device to the upstream position upon release of the said glazing coupling means; said device for unloading the glazed tubes adapted to be moved between two unloading positions spaced out along the path of said conveyor and comprising; unloading coupling means periodically connecting said unloading device to said conveyor for movement thereby between said two unloading positions; and return means to return said unloading device into the upstream position upon release of said unloading coupling means.

References Cited UNITED STATES PATENTS 1,055,320 3/1913 Claussen et a1. 118-317 X 1,271,027 7/1918 Gail 1l8-58 2,069,845 2/1937 Paasche.

2,333,557 11/1943 Fischer.

2,547,884 4/1951 Paasche 1l8-32l X 2,611,493 9/ 1952 Nordquist.

2,660,978 12/1953 Dyne et a1 1l83 17 X 2,676,895 4/1954 Russel 1l83l8 X 2,781,738 2/1957 Paasche l1832l X DANIEL BLUM, Primary Examiner.

Claims

1. INSTALLATION FOR COATING THE INSIDE OF TUBULAR ARTICLES WITH A POLYMERIZED GLAZE COMPRISING AN ENDLESS-CHAIN CONVEYOR CONSISTING OF CARRIAGES; ROLLER MEMBERS DISPOSED ON THE BASE OF SAID CARRIAGES; ARTICULATION MEANS CONNECTING SAID CARRIAGES, SUPPORTS ON SAID CARRIAGES FOR SUPPORTING TUBES DISPOSED CONSECUTIVELY ALONG THE PATH OF SAID CONVEYOR AT THE UPPER PARTS THEROF SO AS TO SUPPORT TUBES STANDING VERTICALLY ABOVE SAID CONVEYOR; LATERAL GUIDE RAILS FOR SAID CARRIAGES; A TRACK FOR SAID CONVEYOR ALONG PART OF ITS PATH FORMED BY A RUNNING SURFACE FOR SAID ROLLER MEMBERS AND OVER ANOTHER PART BY ROTATABLE SUPPORT MEMBERS ON EITHER SIDE OF THE PATH BY ENGAGEABLE BY THE CARRIAGE LATERAL GUIDE RAILS; AT LEAST ONE DEVICE FOR GLAZING THE INTERIOR OF THE TUBES; A GLAZE POLYMERIZATION OVERN; AN ANNEALING OVEN, AND A DEVICE FOR LOADING AND UNLOADING THE TUBES; DRIVING MEANS PROVIDING A CONTINUOUS ADVANCE OF SAID CONVEYOR; SAID GLAZING DEVICE BEING ADAPTED TO MOVE BETWEEN TWO POSITIONS SPACED OUT ALONG THE PATH OF SAID CONVEYOR; COUPLING MEANS PERIODICALLY CONNECTING SAID GLAZING DEVICE TO SAID CONVEYOR FOR MOVEMENT THEREBY BETWEEN SAID TWO POSITIONS, AND RETURN MEANS TO RETURN SAID GLAZING DEVICE TO THE UPSTREAM POSTIONS UPON RELEASE OF SAID COUPLING MEANS.