US3576942A - Electric insulators with spigoting elements - Google Patents

Abstract

A method and apparatus for developing a column, which column comprises a plurality of substantially conical elements supporting one another in a spigoting arrangement, one seated in the other. The elements are connected to one another by a substance such as mortar. The walls of the elements are shaped such that when mortar is introduced in a controlled manner into one of the elements, there is a controlled discharge of the temporarily fluidized mortar along the ducts of prescribed contour constituted by the opposing wall surfaces of an adjacent interfitted element.

Description

References Cited UNITED STATES PATENTS 174/210X FOREIGN PATENTS 774,239 12/1967 174/150 174/210 174/209 174/210 1,093,479 4/1914 Sandford,Jr.................

643,523 5/1928 France........... 1,113,247 5/1968 GreatBritain..

253,896 7/1927 Primary Examiner-Laramie E. Askin Att0mey-Waters, Roditi, Schwartz & Nissen ABSTRACT: A method and apparatus for developing a column, which column comprises a plurality of substantially conical elements supporting one another in a spigoting ar-, rangement, one seated in the other. The elements are connected to one another by a substance such as mortar. The walls of the elements are shaped such that when mortar is introduced in a controlled manner into one of the elements, there is a controlled discharge of the temporarily fluidized mortar along the ducts of prescribed contour constituted by the opposing wall surfaces of an adjacent interfitted element.

a \t es n, as W Saint-Yorre, Allier, France [21] AppLNo 826,244

dlsolateursenverre Paris,France [32] Priority May22, 1968 1 1 1 1101b l7/66,1-101b 19/00 ThomasCaldor Mny20,l969 [45] Patented May 4,1971

France 152,792

ELEMENTS 6Clailm,4DrawingFigs.

United States Patent [72] Inventor [22] Filed [73] Assignee Soc1eteSediver,SocieteEuropeenne [541 ELECTRIC INSULATORS WITH SPIGOTING [50] Field INSUL'A'IORS WII'II SPIGO'I'ING ELEMENTS Already known are electric insulators consisting of elements spigoted into one another and rigidly united with one another and with end ferrules and possible intermediate elements by means of a hard-setting jointing substance, a notable example being a cement mortar, such insulator elements being made of an insulating material such as porcelain or glass.

It is one object of the present invention to simplify the machinery required for forming columns of such insulators, by dispensing with the stop means used to obtain correct equidistant spigoting and the usually constant appropriate thickness of the layer of setting substance between each element andan adjoining element.

Another object of the invention is to avoid, in such a column, the necessity to retract these stop means upon completion of fabrication, which means usually consist of stops pegs, rings, brackets or the like, depending on the fabrication facilities available, and have as their function solely to serve as abutment points for said insulator elements, such temporary abutment points being retained in position on frames, columns, bars or other movable means.

A further object of the invention is to avoid the necessity prior to each scaling, to accurately relocated such abutrnents individually and to then position the elements to be assembled, likewise individually, on said abutrnents.

It is yet another object of the invention to speed up the production rate, for although in the most commonly used types of prior apparatus there was only a minimum of such columns or the like for carrying the stop means, namely three, such columns being often adjustable, experience has shown that three-fourths'of the manufacturing time devoted to the sealing process is takenup for adjusting the stops and positioning the insulator elements thereon.

The invention accordingly relates to a method of assembling mutually spigoting insulator elements, including the steps of stacking said elements directly on top of one another after each element has received a dose of hardenable substance inside a spigot recess adapted to cooperate with a matching spigot on an asociatedelement, of subjecting the stack of elements while it is being formed to a temporary fluidim'ng treatmentof the hardenable substance, of checking the flow of said substance between the several elements, andof adjusting both the fluidization (by vibration in the case of a cement mortar) and the flow in order to automatically ensure a controlled movement towards one another, into substantially equidistant positions, of the several elements of an insulator column undergoing formation, without restraining said elements on external bearing means.

In one specific form of embodiment, flow control, for a given substance such as cement mortar chosen of a thixotropic nature, results from both the frequency and the amplitude of the vibration applied and, in all cases, from the variable profiling of flow ducts formed in the insulator elements, which ducts gradually constrict adjacent their outlets as the tightening together of the column elements is initiated, increases and tends towards a present limit.

The; present invention further embraces the insulator elements for performing the above-disclosed method, which elements are assembled for mutual spigoting to form chambers and controlled flow ducts for the hard-setting substance as the insulator column is being formed. Preferably, the insulator elements are fonned with a recess exhibiting successive steps the dimensions of which decrease towards an end face, each step having an internal profile matching an associated external profile, the intermediate shoulders having a more open conicity than the surfaces of the steps themselves, and the shoulder nearest the opening of said recess performing the function, jointly with the external shoulder of the adjacent insulator element, of a regulator for limiting the flow of hard-setting substance.

A feature of one form of embodiment of such insulator elements is that the head ofeach is formed externally with a solid protrusion .thelow height of which does not completely fill the corresponding recess in the adjoining element.

A further feature thereof is that the inner and outer surfaces of said steps are formed with transverse grooves preferably crossed by longitudinal ribs whereby to form, with the sealing substance, means for arresting accidental rotation of one insulator element relatively to its adjoining elements.

The present invention likewise relates to apparatus for perfonning the method hereinbefore disclosed, and most notably a sealing machine having an operator's station with which are associated an insulator element distributor and a vibrating member, a plurality of travelling sealing-towers cooperating in succession with this station to form the necessary stack of insulator elements upon contact with the vibrating member and to restrain this stack until the sealing substance has set.

Obviously, the forms of embodiment of such a machine may vary widely depending on the degree of automation considered necessary.

In one embodiment of the invention involving manual handling of the elements, the machine includes an operator's station with an elevating seat associated with a control console and a cement mortar store, the seat being caused to ascend opposite a rack having tiers for distributing insulator elements stored on the sloping bottoms thereof. The associated vibrating element is devised so as to be straddled by frames formed with guides, of which at least one can be retracted if necessary. The stacks are formed as required on these frames, and said guides do not at all form stop means for the insulator elements in the spigoting direction, which direction is preferably the vertical direction when the weight of the insulator element is used as the mutual tightening force.

Such arrangements make it possible to build up columnshaped insulators which, in addition to their intrinsic insulating capacity, possess high tensile, crushing, torsional and bending strength.

The description which follows with reference to the accompanying nonlimitative exemplary drawings will give a clear understanding of how the invention can be carried into practice.

In the drawings:

FIG. 1 shows a longitudinal section with partial cutaways of an insulating column according to the invention, shown upside down in the position it assumes in the course of its fabrication, with its lower part resting on an upper ferrule and its top formed by a bottom ferrule.

FIG. 2 shows in schematic side elevation a machine for fabricating such insulators.

FIG. 3 is a diagrammatic side view of an insulator element distributing rack.

FIG. 4 is a diagrammatic plan view of the manner of operation of the machine in FIG. 2.

In the form of embodiment shown in' FIG. 1, the insulator column consists of stacked insulator elements 1, and this stack is obtained by a mutual spigoting of conical elements, each conical element being fonned adjacent its base with an annular portion 2 (hereinafter referred to as skirt"). Each conical element is formed in reality by a plurality of cone frustums (numbering four in the exemplary embodiment illustrated) separated from one another by shoulders 3. Starting from skirt 2, the interior space of the element 1 comprises a first cone frustum 4 opening out via a stepped surface 5 atthe skirt end and terminating inwardly in a relativelyvery wide frustoconical shoulder 6 at the point of junction with a second cone frustum 7. The latter is in turn joined via a further shoulder 8 via a smooth shoulder 14 to a third cone frustum 15 connected in turn via a frustoconical shoulder 16 to an ultimate cone frustum 17, the exterior of which is formed with a substantially flat base 18.

The mean slopes imparted to the surfaces of internal shoulders 5, 6, 8 and external shoulders 12, 14 and 16 are substantially equal. The. substantially constant thickness imparted to thewall is such that upon spigoting into an adjoining insulator element 19, there remains, between the bottom a of the terminal recess of adjoining element 19 and the terminal spigot formed by surfaces 17 and 18 of element 1, a cavity 20 of fairly large volume and spaces 21 and 22 forming a clearance between the two elements. This clearance is reduced opposite the frustoconical shoulders.

v Naturally, the inner and outer surfaces of the inner (2, 7, 9) and outer (13, 15) spigoting cone frustums are formed with grooves 23 crossed by longitudinally directed ribs in order to create active anchoring surfaces to withstand both longitudinal stresses and torsional moments when assembly is completed and the bonding substance has set.

The assembly process is effected by lining the hollow part of an insulating element with a predetermined dose of a hardsetting substance and by driving the frustoconical body of an adjoining insulator element thereinto.

-In the course of such insertion the various clearances are filled and the filling substance, while still in the fluid state, has its flow suitably limited by successive throttling between the portions forming the fnistoconical shoulders.

More specifically, the sealing substance may be a cement mortar containing suitable proportions of cement, granular substance and water in order that it possess the required thixotropic properties such that it be fluid when subjected to vibration (such fluidity being controlled by the amplitude and frequency of the imposed vibratory motion) and such that this fluidity disappear and give way to solidification almost immediately after the vibration ceases.

There is thereby obtained a controlled spigoting insertion of insulator elements 1 into one another that ensures equidistance between the skirt 2 of the various identical elements during fabrication, such control being accomplished by gradually reducing the passageways offered to the fluid substance between the shoulders. As soon as the vibration ceases,

the degree of insertion reached at that point is maintained.

The column of insulator elements formed thus is so arranged as to exhibit excellent bending strength, since the successive spigotings produce generous surfaces for withstanding such loads.

In the case of twisting moments, the ribs directed along the generating lines and which cross said grooves represent reaction points.

The insulating elements are preferably made of toughened glass. This material permits very effective spigoting of the elements into one another with an interposed cement mortar and moreover ensures preservation of the spigotings in the event of accidental fracturing, for should such fracturing occur such material breaks up into fragments which swell and remain in position, whereby the portions spigoted into one another remain indissolubly bonded, the only apparent damage being the disappearance of the skirts from one or two possibly broken elements. This makes for great operational reliability with such columns, for the fracturing of an-element is immediately evident through the disappearance of its skirt; moreover, there is no urgency about replacing a damaged column since it can be relied upon to remain securely in position. There is consequently no need to fear accidental interruptions of service.

Clearly, however, provided that an increased hazard is acceptable, ceramics could be used instead of toughened glass.

Similarly, instead of a thixotropic cement and vibratory effects to achieve assembly, other materials and other processes could be used, notable examples being plastics and more specifically thermoplastic materials, since the spigoting could be obtained with controlled insertion by thermal treatment, the ensuing temperature rise permitting a limited spigoting eflect through gradual closure of the discharge ducts level with the shoulders, the process being arrested by subsequent cooling.

However, current prices and the present state of the art are vibratory treatment.

Referring still to FIG. 1, it will be seen that the fabrication of such columns of insulator elements involves the use of endpieces, to wit a base-forming ferrule 24 which, forthe purpose of fabrication, is placed at the top of the column, and a head 25 upon which the column rests during fabrication so that the bowl-shaped recesses which receive the mortar or like substance have their bottoms turned downwardly and their openings upwardly.

Regarding the narrowest frustoconical portion bounded by end-face 18, its height is such that it stops well short of the bottom of the cavity into which it penetrates, thereby to limit its mechanical advantage and moment of inertia when it is subjected to a bending force.

Such insulator elements may be assembled for fabrication of an insulator column in economical fashion by means of the apparatus schematically illustrated in FIGS. 2 to 4.

An operator's station consists of an elevating platform 26 mounted on a jack 27 (of which only that part located above the floor is shown) and this platform supports an operator's seat 2%, a control console 29 and a mortar tank 30. To one side of this station may be disposed a rack 31 whose sloping supporting shelves 32 form slideways for the elements 1. The floors 22 of the tiered compartments are provided up to the maximum height of the columns to be fabricated, and whenever the operator removes an insulator element from the compartment, the reserve elements which come after it descend along a sloping bottom 32 until they abut against an associated catch 33 located at the entrance end. A rack of this kind is preferably mounted on wheels 34 in order to facilitate supply operations by allowing a full rack to be substituted for an emptied one whenever necessary.

On the opposite side to control console 29, said station may cooperate with forked carts 35 having a member mounted on wheels 3%. The frame of each such cart 35 comprises a lower plate 37 bearing a bowl 38, and this plate is capable of cooperating with the active head 39 of a vibrator 40 placed in a fixed position in front of the station. The uprights 40a of the cart rest on bottom girders 41 carrying the wheels 36, and

these girders carry .on their ends forming the fork of the cart, magnetic members 42 capable of restraining the cart on positioning and restraining stops 43.

At the top of uprights 40a is disposed a platform 44 into which are fitted guides 45 for the vertical columns 46. One at least of said columns is slidably mounted in a guide 45 and, responsively to a steel rope 47 and a which 48, can be lifted out of contact with plate 37 in order to release a stack of elements it as soon as the latter have been mutually spigoted and bonded together to form an insulator column, as described with reference to H6. 1.

Preferably, three columns such as the column 46 are used in order to form a space inside which the stacked elements 1 of circular section inscribed in the triangle formed by said columns can be suitably restrained and guided without the need to provide supporting abutrnents which, in the prior art, would be required to ensure equidistant assembly of the elements 1 in a column thereof.

Slidably mounted at the top of the columns is an upper plate as which is biased upwardly by tie means and a counterweight 5i), and mounted on one of the adjacent uprights is a contactor 51 for stopping and starting the vibrator 40.

The apparatus described hereinabove functions in the following manner:

An empty cart 35 is moved up to the work station as shown in HQ. a From his seat 2ft, an operator removes elements 1 in succession from the appropriate level, each element being then coated with an accurately proportioned quantity of cement mortar which the operator removes with a proportioning ladle from the tank 30. The elements 1 are stacked upon one another, the bottommost one on the ferrule 25 on plate 37, the vibrator 40 being caused to operate continuously during this such as to cause the generally recognized qualities of cement stacking process.

.When the number of elements 1 corresponding to a given column has been reached, the operator caps the elements with an outer ferrule 24 fixed beforehand to plate 49, which plate descends under gravity on to the stack.

The vibration is maintained and a controlled flow of the cement mortar takes place, and the settling process of the corresponding column is .followed by the plate 49 which, when it reaches contact switch 51, stops the vibration. The vertical position of the switch is naturally adjustable and corresponds to. a constant, fixed height for the fabricated insulator columns.

As soon as the vibration ceases, the cement mortar stops flowing. Oozing is negligible because of the accurate closing with a ladle referred to precedingly. The'active cart 35 can then be withdrawn, as shown in FIG. 4, with the help notably of the gentle slope imparted to the part of the floor used to support the cart in-the vicinity of the operator's station. The cart, complete with its insulator columns, is then left to stand in a suitable location, at controlled temperature and humidity if necessary, in order to ensure proper setting and hardening of the cement mortar. This cart can then be replaced by another forked cart 35 at the operator's station.

Obviously, the embodiment hereinbefore described is by no means the only possible one, it being possible to introduce changes according to the degree of automation required, such I automatic distribution of the elements 1,

automatic distribution of the doses of cement mortar, automatic handling of the carts, storing racks, and the like,

as construction of the piles proceeds.

Once the cement mortar has set, a column insulator built up in this way can be disengaged by means of the winch 48, which hoists the relevant column 46 and opens the guiding system laterally.

It should be noted that such columns lend themselves well to a form of structure that would comprise, in a given column,

a plurality of successive types of variously dimensioned elements like the elements 1. A design of this kind would be suitable for very tall columns in which the upper elements may be of smaller size than the bottom elements.

In such a design, naturally, insulating or noninsulating joints may be inserted between sections of the column and could consist notably of special transition insulating elements.

Further, in the case of certain head ferrules such as the ferrule 25 in FIG. 1, it would be preferable to reduce their size, in

. which case an insulator element lb may-comprise, instead of an ultimate cone frustum 17 like the ordinary elements, only a bottom 18b, which may then lie very close to the end-section 18 of the immediately adjacent ordinary element, since in such adesign the ultimate'frustoconical element would in no way help to impart structural strength.

It goes without saying that, without departing from the scope of the invention, other changes still may be made to the forms of embodiment of the insulator elements, to the apparatus for fabricating the insulator columns and to the steps involved in the method which have been described herein.

Thus, the counterweight 50, the winch 48 and the cable 47 could be replaced by an electric hoist mounted at the top of the cart and capable of travelling horizontally along a beam running in the direction of travel of the cart.

I claim:

1. A column comprising a plurality of insulator elements supporting one another in a mutual spigoting arrangement, said elements including walls shaped for mutual spigoting and constituting chambers containing a hard-setting and temporarily fluidizable cementitious substance, said walls having inner and outer surfaces, the inner surface of one of said walls cooperating with the outer surface of an adjacent wall for constituting ducts, said ducts including means for controlling the discharge of said temporarily fluidized substance from respective chambers.

2. A colurrm as claimed in claim 1, wherein said walls constituting said chambers and ducts have internally provided recesses formed with successive steps of size decreasing in one direction cooperating with identical steps externally provided on an adjacent element, said walls including intermediate matching shoulders which separate and bound said steps and constitute together with said steps said means for controlling the discharge of said temporarily fluidizable substance.

3. A column as claimed in claim 2, wherein said walls are frustoconical walls, and said shoulders are inclined at wide apex angles.

4. A column as claimed in claim 3, wherein said elements include an ultimate wall stage constituted by an external male projection and an internal female receptacle, the male projection of one element extending into the female receptacle of an adjacent element, the length of the male projection being substantially less than the depth of the female receptacle.

5. A column as claimed in claim 3, wherein the surfaces of the various steps which cooperate with the hard-setting substance are formed with raised portions and with grooves having both transverse and longitudinal configurations.

6. A column as claimed in claim 2, wherein the steps on the spigoting surfaces number at least three, whereby a dual spigoting, involving three elements, is effected at all levels on the column of said elements.

Claims (6)

1. A column comprising a plurality of insulator elements supporting one another in a mutual spigoting arrangement, said elements including walls shaped for mutual spigoting and constituting chambers containing a hard-setting and temporarily fluidizable cementitious substance, said walls having inner and outer surfaces, the inner surface of one of said walls cooperating with the outer surface of an adjacent wall for constituting ducts, said ducts including means for controlling the discharge of said temporarily fluidized substance from respective chambers.

2. A column as claimed in claim 1, wherein said walls constituting said chambers and ducts have internally provided recesses formed with successive steps of size decreasing in one direction cooperating with identical steps externally provided on an adjacent element, said walls including intermediate matching shoulders which separate and bound said steps and constitute together with said steps said means for controlling the discharge of said temporarily fluidizable substance.

3. A column as claimed in claim 2, wherein said walls are frustoconical walls, and said shoulders are inclined at wide apex angles.

4. A column as claimed in claim 3, wherein said elements include an ultimate wall stage constituted by an external male projection and an internal female receptacle, the male projection of one element extending into the female receptacle of an adjacent element, the length of the male projection being substantially less than the depth of the female receptacle.

5. A column as claimed in claim 3, wherein the surfaces of the various steps which cooperate with the hard-setting substance are formed with raised portions and with grooves having both transverse and longitudinal configurations.

6. A column as claimed in claim 2, wherein the steps on the spigoting surfaces number at least three, whereby a dual spigoting, involving three elements, is effected at all levels on the column of said elements.

Images