FR2745880A1 - Chain link system for process conveyors - Google Patents

Abstract

The transmission chain of a conveyor can be reduced in the course of its way, of its length in one or several of its considered sections. An accompanying reduction in the speed mechanism is obtained without reducing the drive speed or that of the part where the sections are not reduced. At a preselected point on its way there is a recovery in the length of the sections back to their original lengths with a simultaneous recovery of its speed to its original level.

Description

The object of the present invention, within a global mechanical system and this on the same chain used for the transmission of a movement, for transport, for handling or for other uses, is to modulate the average speed of translation of certain sections thereof relative to certain others while conferring on this chain, at its fastest section, known as "stretched section", a proper linear speed, known as a "constant or variable base speed", continuous or sequential, but which may not have identical repercussions on other sections which may be animated either with a linear speed equal to the basic speed or with an average speed slowed down compared to the average speed of the stretched stretch.

This differentiation of average speeds is particularly useful when the chain must confer, along its route and depending on the sectors covered, different speeds without the overall training cycle being affected.

This is the case, in particular, of a parts handling chain undergoing, during their cycle, successive specific treatments such as, for example, varnishing followed by drying in the oven and then their extraction from the chain, requiring progressions at different speeds or even sometimes continuous progression (varnishing and drying) then alternative interspersed with short stops, in particular at the level of their extraction in order to facilitate it.

The differentiation of equidistances between the axes of two consecutive links is also of major interest in certain cases. It makes it possible, on certain sections, to pile up, for example, transported parts, thereby reducing the space occupied by them during a particular treatment in a limited enclosure and, on others, to move them away from one another in view of different treatment requiring their respective distance.

To achieve these functions of "differential speed" and at the same time of "variable equidistance" the chain consists of links which, when it is normally stretched, fully transmit the movement which is impelled to them - by sprockets, jacks or other - like a classic chain.

It will be enough, on the sections of chain selected for this purpose, to transform part of the translation impulsed with the stretched section into a movement of folding of the links towards each other putting the section considered in "retraction", to locally subtract this " retraction length "of the" useful length "of the chain then, in another section, to cause again the" deployment "of the links thus restoring to the chain, by this instantaneous additional movement, its initial tension therefore its original useful length .

By this alternative game of localized SUBTRACTION of two movements followed by their reciprocal ADDITION at another point in the chain's path, we give this one, although driven at its basic speed, average speeds differentiated on specific sections by addition algebraic, of two movements therefore of variable average speeds in the manner of what a classical system of differential gears could achieve.

In order to allow a chain to fill this office it is necessary, on the one hand, to make possible by the configuration of its links, the folding of these towards each other, transforming their linearity into a succession of "V "which can follow one another and, on the other hand, block these successive folds of a link on its contiguous links at an angle of a predetermined value by using" blocking means "stabilizing these successive angles at the end of the fold at the same opening.

Thus, once the retraction of the chain has been completed on the planned section, and all of the successive "V" s thus stabilized, a compact "accordion" block, incompressible, will be formed, composed of a number of links at least equal to two but generally much higher, constantly'Véalimenté "upstream by incipient" V "and" désalimenté "at the same rate downstream by the re-extension in linear position of the links occurring successively at the exit of the aforementioned incompressible compact block, and thus right now.

The system will be completed by a "priming device" for the folding of the chain, itself, in principle stretched between two drive discs, the disc located downstream of the retracted section contributing by traction to the linear re-extension of the links.

Finally, a "stacking means" will participate, pulse after pulse, in the folding of the last "V" during training and in the progression, step by step, of the incompressible compact block.

It will suffice to fix on the assembly axes of the appropriate links the "support pieces" responsible for driving the moving parts so that the latter, accompanying the links at all points of their journey at their current speed, move section by section at the different average speeds programmed and separated on each of the sections at different speed, by a length or "equidistance" different from one section to another.

Figure 1 shows the diagram of the entire system described.

The example which follows illustrates, by the description of an embodiment (FIG. 7) for particular use, the operation of the system which is the subject of the patent.
Or a machine for producing by bi-orientation / blowing a plastic bottle from a preform or preform with a diameter close to 2.5 to 3.5 cm. called to transform into a bottle with a diameter almost 3 times greater. The equidistance of the supporting parts, vertical fingers in this case, may be only 5 cm. at the level of the preforms but will have to pass to a dimension four times more important at the time of the transformation of the preform into bottle, transformation which will take place in a mold "M" in two half-shells after that, by heating in an oven with infrared elements, the preforms have been brought to their softening temperature (Figure 2).

Two sections are therefore to be built on the passage of the chain - the heating section "1C '' with low equidistance of the fingers for an optimization of the length of the oven and at low average speed in order to extend the duration of heating, -and the molding section "TM" at three times the equidistance and at an accelerated average speed in order to increase the molding rates for better profitability.

The chain (fig. 3-4) carries two in two links, in the extension of their connecting axis, a "support finger" terminated ("P") by a "guide pin", one link in two being equipped with a "lug" constituting the locking means called to delimit the "V" angle formed by two consecutive links on the retracted section.

Another pawn "P" 'equips the axes not carrying fingers.

The chain is driven by two drive discs slaved to each other and to the opening of the mold, discs here being "stars", whose movement is of the sequential type, each sequence of their rotation having the amplitude of two links and the device for initiating the withdrawal of the chain is formed by two "grooves" "G" and "G" 'parallel to each other after they have diverged from a common crossroads held by a "selector" "S" operating in the manner of a switch alternately sending the even and odd guide pins of the same link in a different groove which initiates the setting in "V" of two consecutive links. (Figures 5 and 6)

Claims (8)

CLAIMS. 1. Chain used for the transmission of a movement, for transport, handling or other uses, having the option of seeing its length over one or more of its sections reduced during its course, this reduction resulting in the section (s) considered, a concomitant reduction in its average speed without, however, modifying the drive speed communicated to it or its speed on sections of non-reduced length and which also have the option, once its reduced length, to find at a preselected point of its course, an extension making it regain its original length and, simultaneously, its initial course speed. 2. Qlaine according to claim 1 likely to see evolve, on various sections of its course, the amplitude of its reduction in length and its rmllongage and being able therefore to undergo, on successive course areas, modulations of its speed average according to different values between them. 3. Chain according to claims 1 or 2 in which the shortening is obtained by the folding "accordion" of several consecutive links settling towards each other in a geometry formed by successive "V" and the reciprocal elongation is achieved by the total or partial redeployment of these aillos by the subsequent opening of the angle at the top of these "V" in angles of higher value which can go up to 1800 and thus giving the chain a linear geometry (Figure 1). 4. Chain according to claim 3 in which certain links or all of them are (is) provided with (ée) stops either fixed or adjustable, limiting the closing angle of the geometries in "Y" to one (des) predetermined value (s).  5. Chain according to claim 4 equipped with one or more  thrust members forming by folding the successive "V" then the  advancing through contact with those who preceded them in  this new structure, by impulses reverberating on  the whole stack consisting of these consecutive "V" s  joined together, set rigidly incompressible by play  stops object of claim 4.  6. Chain according to claim 4 provided, at the outlet of a section  retraction lesson, of a rotary circular member meshing with  it, and that may be one of the drive wheels of it,  pulling on the links located immediately  its upstream at a speed higher than the average speed of these  last which has the effect of deploying the "V" they formed  between them, giving back down a greater useful length  at the chain, generating a speed higher than that of the tron  lesson that preceded it.  7. Chain according to claim 5, provided with an associated device  to the thrust member, having the function of initiating under the impulse of the latter, the successive formation of "V" by guiding for this purpose the axes of the links concerned on two differentiated tracks, this guidance being operated by grooves, rails or the like (G and G ') traversed alternately by rollers or "guide pins" (P and P') positioned in alignment with the connecting axes of the links between them. 8. Chain according to claim 7, equipped with a selector (S) having the function, by periodic oscillations coordinated with the advancement of the latter, to distribute alternately on the differentiated tracks the guide pins succeeding each other at its height .