US2516789A

US2516789A - Device for forming insulating parts on electric conductors

Info

Publication number: US2516789A
Application number: US732522A
Authority: US
Inventors: Montoriol Charles Emil Antoine; Sabine Maurice
Original assignee: Lignes Telegraphiques et Telephoniques LTT SA
Current assignee: Lignes Telegraphiques et Telephoniques LTT SA
Priority date: 1946-10-21
Filing date: 1947-03-05
Publication date: 1950-07-25
Anticipated expiration: 1967-07-25

Description

July 25, 1950 c. E. A. MoNToRlol. Erm. 2,515,789

DEVICE FOR FORMING INSULATING PARTS oN ELECTRIC coNDucToRs Filed March 5, 1947 ons..

m wd @WJ W wvo mi w hamm fm W w 10J WIM@ lll Patented July '25, 1950 3- TDEVICE FOR FORMING iNsULAfrING PARTS oN ELECTRIC ooNpUoroas pany of France Application March 5, 1947, Serial No. 732,522 In France October 21, 1946 1 claim. (o1. 12a- 30) The invention has for its object an improved device for the manufacture of discontinuously insulated electric conductors. n y

Devices have been known'for a long time which enable washers of insulating material to be fitted on wires; some enable prefabricated split washers to be tted to the conductor, others enable washers to be directly moulded on the conductor which is fed with an intermittent movrnent through the moulding machine, but these methods have numerous drawbacks; the first method, in particular requires delicate machines and furthermore the stability of the split washers on the conductor is not satisfactory; the second method is slow and discontinuous.

The device according to the present invention obviates the drawbacks inherent in these methods by permitting of a quick and continuous manufacture of insulated wires which makes it possible, immediately after they come out of the device, to cover them with the return conductors or other usual protections for electric cables, thereby avoiding having to store wires provided with the sulating parts but without a covering, which has considerable drawbacks as regards their preservation and their dielectric properties.

The device according to the invention is essen-- tially characterised by the fact that it comprises a number of movable moulds leach formed by two separate half-moulds which are adapted to bear against one another so that the conductor, which moves at the same speed as said moulds, is located in the axis of the mould at the instant when the feed passage for said conductor comes opposite the nozzle of an extruding machine which then injects plastic material into the mould, the two parts of which are separated again when the insulatng material has set on the conductor.

Other characteristics and advantages of the present invention will become apparent from the ensuing -description made with reference to the accompanying drawing which shows, diagrammatically and merely by way of example, a particularly advantageous embodiment of the invention.

In this drawing:

Fig. 1 is a transverse sectional view of an embodiment of the device according to the invention.

Fig. 2 is a side view thereof, in part section.

Fig. 3 is a detail view on a larger scale.

According to the embodiment which has been shown by way of example in the drawing, the extruding machine essentially comprises a tubular cylindrical body 5 which is heated and inside which can rotate, about its longitudinal axis, a

propelling screw t.' Said screw feeds the plastic material, which has been inserted in the body 5 through the opening 'i and has been made malleable bythe heat, towards a nozzle 8 which is xed tothe end of the cylindrical body and which is adapted to iit into a head 9 provided with a screw tightening device I0 which enables the links I I of the two endless chains I to be pressed against one another when said chains pass through the head 9 by the action of toothed drums Izwhich drive them with aiuniform motion at the same speed and in the same `direction as the conductor 4.

Each link I I (see Figs. 1 and 3) carries a halfmould E3 comprising a shell of appropriate shape, for example semi-cylindrical, whichfis extended by a ktransverse groove i4. When the links pass throughthe head 9, they press against one another in such a manner that the two half-moulds fit one ontop of the other round the conducting wire 4, the two transverse grooves I4 then forming a supply passage for the plastic material. When said passage lcomes opposite the outlet of the nozzle 8, the plastic material which is in a malleable state owing to the heat evolved by the cylindrical body 5 and is compressed by the screw 6, lls the cavity of the mould and surrounds the conducting wire 4 which passes tlirougih'the axisl of said cavity.

When, owing to its movement, the supply pas-j sage is no longer opposite the outlet of ther nozzle, said nozzle is closed by the side faces'of the two links II until the instant when a fresh supply passage comes opposite said outlet. It will be apparent from Fig. 3 that the link blocks II in which are fitted the sections of the moulds I3 are of such width along the longitudinal line of the conveyors that, when the blocks I I are registered together on the inner runs of the endless conveyors I, the ends of the blocks will be in contiguous or contacting relation thus presenting an unborken continuous wall closing the mouth of the plastic discharge nozzle 8 until such time as a mould orice I4 arrives in registry with the nozzle; whereupon, due to the fact that the plastic is contained in the chamber 5 under pressure of the screw or other device 6, there will be automatic injection of the plastic into the mould cavity I3. As soon as this mould orifice I4 moves away from the nozzle discharge mouth such mouth Will be closed by the blank wall of the link blocks II. In this manner the two conveyors may be continuously driven to provide continuous and uninterrupted production.

During the period of time which elapses between two injectionsl of plastic material. said material remains compressed in the cylindrical body 5 and the nozzle 8. This enables successive injections of insulating material to be made into the cavities which pass in front of the nozzle, While having a continuous supply of insulating material.

After having passed through the head 9 and passed opposite the nozzle, the twochainsI I, as can be seen in Fig. 2, move away from one another so as to release the discs 3 which have been moulded on the conductor Il and which have reached a sunicient consistency owing to cooling. This result may be obtained in' any desirable way, one form of which is shown in Figure 2 of the drawing in which the pressure head 9 is situated intermediately between the receiving and discharge pairs of the conveyor rollers l2 with the centers of the rollers at the discharge ends of the conveyors being displaced in a vertical sense or direction a greater distance than that between they centers of the two companion rollers I2 at the' inlet or induction ends of the conveyors. The pressure head 9 being situated intermediate the pairs oiinduction and discharge rollers and the conveyors being of a ilexible nature, the innerl runs .will therefor be required to progressively diverge from the pressure head 9 to the discharge rollers I 2.

It will be seen that the device according to the invention oiers the great advantage of being able tobe used directly in the chain of manufacture of a machine for manufacturing coaxial cable, operating in a continuous manner.

On the other hand, this same device can also be used for moulding small objects of plastic material; in this case, no conductor is provided and the'moulds have the shapeof the objects to be moulded.

Itis moreover-obvious that the invention has onlybeen described and illustrated in a purely explanatory and in no way limitative manner and that modifications of detail may be made therein in accordance with its spirit.

We claim:

A molding machine comprising two continuously driven endless iiexible conveyors arranged side by side, rollers at each end of the conveyors over which said conveyors pass, mold-carrying blocks continuously movable with said conveyors, said conveyors and rollers at the beginning of 4 the inner runs of said :conveyors positioned to move said blocks together, said blocks being of such length longitudinally of the conveyors as to nt in close contact with one another when brought together on the inner runs of the conveyors whereby to provide a blank side wall, complemental mold sections carried by said blocks and moved into mating accurate relationship when the blocks are brought together on the inner runs of the conveyors, said blank wall of the blocks: having mold orifices communicating with the cavities of saidA mold sections, a container for plastic material, means for maintaining the plastic material in said container under heat and pressure', a discharge nozzle for said container hai/ings,v continuously open mouth in contacting engagement with the blank continuous side wall of said blocks and in alignment with said mold orifices whereby to automatically charge the mold cavities with plas-tic material when the orices register with the mouth of said' nozzle, a pressure head located intermediately the ends of the con veyors and in position to receive therethrough the inner runs of the conveyors and for urging the mold blocks andthe entrained mold sections together, said pressure head positioned remote from the discharge end of the inner runs of the conveyors, the rollers at the discharge end of the inner runs of the two'conveyors having a gap therebetween wider than the sumv of the thicknesses of the twc conveyors and blocks passing therethrough to permit a separation of the adjacent surfaces of the conveyors and blocks and to require such inner surfaces of the two conveyors to follow progressively divergent paths from the pressure head to the discharge end of the inner runs'o'fthe conveyors'.

CHARLES EMLE ANTOINE MONTORIOL. MAURICE SABINE.

REFERENCESV CITED Thefollowing` refer-ences are of record in the le of, this patent:

UNITEDY STATES PATENTS Number Name Date 2,074,368 Corner Mar. 23, 1937 2,197,968 DeMattia Apr. 23J 1940 2,248,580" Morin et al July 8, 1941 2,288,899 Gits July'7', 1942