IMPROVEMENTS TO POLYMER SHEET BUTT WELDING EQUIPMENT FIELD OF THE APPLICATION

This application for patent of invention consists of an evolutionary solution that is capable of providing a remarkable benefit to companies with demand for manufacture of products presenting an essential need for bonding component parts made of polymer material sheets, mainly polypropylene (PP) and polyethylene (PE) sheets, among others.

As an example of application, it is important to mention the operations of seams and reuse of polymer sheets. Within this context the construction of tanks tubular walls manufactured from polymer sheets. DEMAND OF THE INVENTION

The inventor, an expert in the technology involving sheets welding identified a clear need for providing greater productivity to the operation of polymer sheets welding in the most varied forms of execution.

However, it is also important that this increased productivity is associated with a guaranteed quality welding, so that the use of the bonded parts can provide total security to the final product when it is exposed to diverse types of conditions, especially those involving tension forces, buckling and expansion.

In addition, it was also identified the explicit need to provide better ergonomics working condition to welding equipment operator, mainly in the heating phase of the polymer sheet butts being bonded together, since in this operation the operator is obliged to perform lifting and lowering movements regarding the heating bar. This operational condition is properly described in the welding operation critical analysis on the subsequent chapter about the technique principles.

Still within the scope of the need to improve operating ergonomics, the inventor evinces the need to improve the condition of ergonomics to obtain parallels from the butts that will receive polymer sheets welding.

PARADIGM OF THE INVENTION

In brief, the present invention applies to polymer sheet butt welding equipment, specifically in equipment that performs sheet butt to butt welding, 90° sheets welding and also tubular walls, in which conventional equipment will be used. REQUIREMENTS OF THE INVENTION

In line with the demand and paradigm of the invention, the applicant created "improvements to polymer sheet butt welding equipment", provided with innovation and creativity capacity, since it does not descend in an obvious way from other known solutions in the state of the art for this type of equipment.

In addition, the "invention" has industrial applicability, being economically viable and, therefore, it meets the stringency of the patentability requirements, notably as patent of invention, according to the dictates of articles 8 and 13 of Law No. 9,279.

TECHNIQUE PRINCIPLES

In order to provide veracity and consolidate the context explained in the introduction chapters, an explanation will be presented on the state of the art dictated by solutions developed and widely used for welding of polymer material sheets, in which after critical analysis of these, once exposed to professionals with expertise in the field of plastic welding, it will be possible to identify limiting aspects, thus consolidating the identification of new requirements to the conventional polymer sheet butt welding equipment.

a. Plastic welding principle: based on a process of thermo fusion of two polymer sheet butts with immediate bond between those butts whose cure of the bond area occurs by natural cooling.

b. Constructive concept of conventional plastic welding equipment: provided with the following main modules: - Structural module (ml): consists of a metallic structure, which has the function to give support to all operation modules;

- Table module (m2): formed of two steel sheets that are separated from each other by a gap, which has the function to provide support to polymer sheets that will be arranged butt to butt, parallel between each other. In addition, one of the steel sheets describes the horizontal movement of approximation or recoil in relation to the other sheet, which, in turn, is always in the same position. For the displacement movement of the mobile sheet it is foreseen a car type mechanism applied to each one of these, which are triggered by a crank.

- Module fixation of polymer sheets

(m3):

formed of a pair of linear bars, whose ends feature accommodation to receive stay bolts, which are mounted on the side and upper edges of the structural module in order to allow radial movement, and the stay bolts are essentially composed by a partially or completely threaded screw which receives a fastening nut. In this way, once the polymeric sheets are positioned, the operator just have to lift the stay bolts so that their body is within the side openings of the linear bars, and the compression of this on the polymeric sheets will occur by threading the fastening nuts.

' - Polymer sheets welding module (m4): formed mainly by a linear heating bar preferably made of aluminum, whose interior receives a resistance. This linear bar is fixed to the structural module, more specifically; it is mounted in the region of the gap between the steel sheets of the table module (m2) and is arranged in parallel to the butt of these sheets. In addition it is foreseen a lifting and lowering device of the heating bar on the occasion of the setup of polymer sheets on the table sheets, this is in downward position to guarantee a total liberty for handling and positioning the polymeric sheets.

During the butt to butt welding operation, the operator performs the lifting movement of the heating bar so that its walls are perpendicularly positioned in relation to the steel sheets butt of the table module (m2). This lifting /retraction of the heating bar is done using a lever mounted on one end of the heating bar.

In addition to this lifting/lowering device of the heating bar, it is also foreseen a device for longitudinal move that is able to provide the distance of this bar from the butt of the polymer sheet that is fixed to the metal sheet fixed to the base module (2).

Finally, it is foreseen a locking device such as a butterfly twist lock to ensure the heating bar support in operational height or even its fully retraction during the setup of the sheets to be bonded.

- Operation control module (m5):

formed of electro electronic components that enable digital or non-digital control of operating variables such as temperature and heating time of the heating bar, thus controlling its heating or cooling, which is defined in accordance with the specifications of the melting point of the polymer material of the sheets to be welded.

In addition to this module it is also foreseen the control of welding pressure, which acts directly on the displacement cars of the base module (2) , where its operation follows an adjustment scaling from welding pressure.

These are the main modules included in the welding equipment, and enough to the good understanding of the field of application and further understanding of the problems to be solved.

c. Identification of problems: a careful analysis of the architecture of current conventional plastic welding equipment allows the identification of the negative aspects in relation to the ergonomics of the equipment operation, which is more evident in the following operational aspects:

c.1 Sheets welding setup: in particular, the positioning of the butts that will be welded between the polymer sheets must obey a technical condition of perfect parallelism between each other, where only in this condition it is possible to ensure the expected result of a homogeneous welding and quality throughout the sheets bond.

However, careful observation of the set up for positioning of polymeric sheets reveals that the action of positioning on the tables is done empirically, depending on the visual acuity and precision of the operator to obtain a condition of parallelism between the butts of those sheets.

According to the evidenced in the previous paragraph as a result of this technical difficulty, we can also say that the process of set up is time-consuming, thus jeopardizing the overall throughput of the welding equipment.

c.2 Handling of the heating bar: especially when the operator is carrying out the lifting or lowering of the resistance bar, although this procedure is simple, it also requires effort to hold it up that is directly pro- portional to the weight of the bar. Considering the repeatability of that movement, daily, as time goes by, the operator feels the effects of the inevitable physical fatigue of the muscles of his arms, as he is permanently "holding" that weight, which ceases only when the bar is locked at the desired height by means of a locking device such as a butterfly twist lock.

d. The causes of the problems:

d.1 Sheets welding set up:

the cause of the difficulty in obtaining the parallel alignment of the polymer sheets butts lies in the fact that there is no effective form of control and adjustment proven to be precise for the parallel positioning of these butts; and

d.2 Handling of the heating bar: We can say that the cause of the problem lies in the high weight of the aforementioned bar due to the form of installation of the same, which fully transfers its weight to the lifting/retraction knob, which affects its operation. PROPOSAL OF THE INVENTION

a. Objective proposed: the present invention has the purpose of solving the problems identified, i.e. generally aims at providing the plastic welding equipment maximum operating ergonomics, and in particular it is possible to define as a paradigm of development the following proce- dures:

a.1 Sheets welding set up - make the polymer sheets set up operation in such a way that guarantees that their butts will be aligned and parallel before the bond operation by plastic welding;

- make the polymer sheets set up oper- ation quicker, providing optimization of the equipment productivity;

a.2. Handling of the heating bar:

- make the handling of the operation bar resistance (heating) quicker to minimize the effort made by the operator.

b. Distinctive feature:

To make possible the proposed objectives the inventor idealized the following preferred implementations:

b1. Sheets welding set up: a device was designed to provide alignment and parallelism between the butts of polymer sheets that will be joined by butt to butt welding process, where this device features inventive concept in the form of a ruler guide that is applied at the wedding of metal sheets of the table module (2), and the respective ruler is manufactured in such a way that the parallels between its sides is of great precision. In this way the operator only has to position the polymeric sheets on the tables and move their butts until the contact and interference with the parallel side of the ruler guide, to then proceed to the locking of the polymer sheets using fixation module of polymer sheets (m3), thus finishing the sheets welding set up.

b.2 Handling of the heating bar: a damper system was included in the form of a coil spring mounted at one end of the heating bar and base.

DESCRIPTION OF THE DRAWINGS

To complement this description of the descriptive report so as to obtain a better understanding of the characteristics of the present patent of invention, please attached find a set of drawings that reproduce a form of preferred embodiment for the XXXX, where: Figure .1 - representation in upper frontal perspective view of the welding equipment, showing improvements, with rule overlapped and not mounted on the support bases of polymer sheets; Figure .2 - an upper posterior perspective view of the welding equipment, showing improvements, with rule overlapped and not mounted on the support bases of polymer sheets;

Figure .3 - a side view of the welding equip- ment, evidencing with the rule overlapped and not mounted on the support bases of polymer sheets;

Figure .4 - a view of the second side of the welding equipment, showing improvements, with rule overlapped and not mounted on the support bases of polymer sheets;

Figure .5 - upper view of the welding equipment, showing improvements, with rule overlapped and not mounted on the support bases of polymer sheets;

Figure .6a - a plant view of the welding equip- ment, showing improvements, with the guiding rule in position immediately before to its mounting on the edges of the base module metal sheets;

Figure .6b - a side view of the welding equip- ment, showing improvements, with the guiding rule in position immediately before to its mounting on the edges of the base module metal sheets;

Figure .7a - a plant view of the welding equipment, showing improvements, with the guiding rule mounted on the edges base module metal sheets;

Figure .7b - side view of the welding equipment, showing improvements, with the guiding rule mounted on the edges base module metal sheets; Figure .8a - a plant view of the welding equipment, showing improvements, with the positioning of the polymer sheets on the metal sheets and their butts adjacent to the guiding rule side; Figure .8b - side view of the welding equipment, showing improvements, with the positioning of the polymer sheets on the metal sheets and their butts adjacent to the guiding rule side;

Figure .9a - a plant view of the welding equip- ment, showing improvements, with polymer sheets properly fixed by fixation module of polymer sheets;

Figure .9b - side view of the welding equipment, showing improvements, with polymer sheets properly fixed by fixation module of polymer sheets;

Figure .10a - a plant view of the welding equipment, showing improvements with polymer sheets fixed by fixation and withdrawal module of the guiding rule;

Figure .10b - side view of the welding equipment, showing improvements with polymer sheets fixed by fixation and with- drawal module of the guiding rule;

Figure .11a - side view of the welding equipment, showing the work positioning of the welding module of polymer sheets, at the beginning of its lifting;

Figure .11b - another side view of the welding equipment, showing the work positioning of the welding module of polymer sheets, at the beginning of its lifting;

Figure .12 - side view of the welding equipment, showing the longitudinal displacement of heating bar until the contact with the butt of the polymer sheet fixed to the metal sheet and beginning of the longi- tudinal displacement of approaching of the polymer sheet fixed to dynamic metal sheet;

Figure 13 - side view of the welding equipment, showing the contact and compression of the butts of polymeric sheets with the heating bar sides, starting the heating of the heating bar and consequent change of state of the butts of these sheets;

Figure .14 - side view of the welding equipment, showing the distancing longitudinal displacement of the polymer sheet fixed to the dynamic metal sheet in relation to the polymer sheets welding module;

Figure .15 - side view of the welding equipment, showing the beginning of the vertical retraction movement of the polymer sheets welding module to a level below that of the dynamic and static metal sheets and further horizontal movement of the same welding module, reaching a state of separation of the heated butts of the polymer sheets in relation to the heating bar;

Figure .16 - side view of the welding equipment, showing the distancing longitudinal displacement of the polymer sheet fixed to the dynamic metal sheet at the heated butt of the polymer sheet fixed to the static metal sheet;

Figure 17 - side view of the welding equipment, showing contact and compression of the butts of polymeric sheets consolidating the welding between the two sheets;

Figure .18 - side view of the welding equipment, showing the withdrawal of the fixation module of the polymer sheets; and

Figure .19 - side view of the welding equipment, showing the withdrawal of the polymer sheets properly welded.

DETAILED DESCRIPTION

The following detailed description should be read and interpreted with reference to the drawings presented, representing a form of preferred embodiment for the "improved polymer sheet butt welding equipment', with no intention limiting the scope of the invention, which is limited only to the explained in the claiming table.

a. Technological basis:

As evidenced in the figures 1 , 2, 3, 4, and 5 respectively, and complementing the state of the art for the conventional welding equipment (Eq) described in the chapter technique principles, a preferred embodiment is as following;

- Structural module (ml): is made on a metal structure;

- Table module (m2): formed of two steel sheets, a dynamic steel sheet (22) and a static steel bar (21) attached to crossbars (24) and (23) respectively, which are mounted on rails (25), where the cross bar (23) is fixed, and the cross bar (24) is dynamic and describes the lon- gitudinal displacement movement by means of a car type engine car (not shown), mounted inside the fairing (26), which in turn is triggered manually by means of a lever(27), see figures .1 and .3 respectively. .

- Module fixation of polymer sheets (m3): formed by a pair of linear bars (31), see detail on figure. 2, whose ends feature accommodation to receive fixation stay bolts (32), in the form of a threaded screw, which has a clamping nut mounted on its end (33), see detail figure. 2, where these are in turn mounted in an inclinable way at the ends of the crossbars (23) e (24) of the table module (m2). This way, once the polymer sheets are positioned, the operator just have to raise the stay bolts (32) so that its body is within the side openings of the linear bars (31), where the compression on the polymeric sheets will occur through the tapping of the fastening nuts.(33).

- Polymer sheets welding module (m4): essentially formed of a heating bar (41) in the form of a linear, preferably alumi- num bar, whose interior receives a resistance. This heating bar (41) is fixed to the structural module (ml) by means of a rod (42) mounted in the region of the gap between the steel sheets (21) and (22) of the table module (m2), being positioned in parallel to the butt of these sheets.

In addition, it is foreseen a mechanism for lifting and lowering the heating bar (41). This operation is performed of means of a lever (43) mounted on one end of the heating bar (41).

In addition to this lifting/lowering mechanism of the heating bar (41) it is also foreseen a longitudinal displacement

io mechanism in the form of a lever (47). Finally, it is foreseen a locking device (48) such as a butterfly twist lock to ensure the support of heating bar (41) at the operating height or even completely retracted during the setup of the sheets to be bonded;

- Operation control module (m5):

formed of electro electronic components that enable control (digital or not) of operational variables like temperature and heating time of heating bar (41).

b. Inventive concept:

b.1 Base module improvement (m2):

as shown in the figures. 1 to 5, it was idealized a ruler (Re) with "cross" shape cross-section, where the side rods act as fittings along the cavities (21') and (22') of the dynamic steel sheet (21) and a static steel bar (22), respectively. In turn, the upper vertical rod superior provide the alignments to the polymeric sheets butt (ch1) and (ch2), respectively. To assist in the handling of this ruler (Re), a lever (Re1) is mounted on its ends.

b.2 Welding module improvement (m4): a damper system in the form of a coil spring was included, (45) where one of its ends is mounted at one end of a rod (44) that is mounted on the bottom of the heating bar (41) and the other end of the spring (45') is mounted on the array (1 ) of the structural module (m 1 ).

c. Operation procedure:

The welding operation between the butts of two polymeric sheets (ch1) and (ch2) obeys the following sequential steps:

Step .1 : as shown in the figures 6a, 6b, the operator positions the ruler (Re) aligned with the cavities (21') and (22') of metal sheets (21') and (22') respectively;

Step. 2: as shown in the figures 7a, 7b, the operator activates (using a crack) (27) the displacement device of the crossbar (24) of the base module (m2), on rails (25), notably an approximation movement in relation to the central gap, so that the side tabs of the ruler (Re) fit perfectly in the cavities (21) and (22 ') of metal sheets (21) and (22) respectively;

Step .3: as shown in the figures 8a, 8b, the operator positions the polymer sheets (ch1) and (ch2) on the metal sheets (21) and (22) respectively, aligning their butts with the upper vertical stem of the ruler (Re),

Step .4: as shown in figures 9a, 9b, the o- perator mounts the fixing module (m4), positioning the pair of linear bars (31) on the polymeric sheets (ch1) and (ch2) to then move the stay bolts (32) into the lateral cavities of each of these linear bars (31), to then perform the locking of the system formed of linear bar (31) + polymer sheet (ch1)/(ch2) + metal sheets (21)/(22), performs the tapping of the fastening nuts (33);

Step. 5 as shown in the figures 10a and 10b, the operator activates (using a crack) (27) the displacement device of the crossbar (24) of the base module (m2), on rails (25), notably a retreat movement in relation to the central gap, in such a way that the sides of the rule (Re) are released from the cavities (21') and (22') of the metal sheets (21) e (22) respectively, allowing the removal of this rule (Re);

Step. 6: as shown in the figures 11a, 11b, the operator activates (using a crack) (46), the lifting device of the welding module (m4), notably a heating bar (41). This task is facilitated by the action of the spring (45) of the unprecedented bumper system, elevating this heating bar (41) above the height described by polymeric sheets (ch1) and (ch2);

Step. 7: as shown in the figure 12, the operator triggers the lever (47) and longitudinally displaces the whole welding module (m4), until one side face of the heating bar (41) is contact with the butt of the polymeric sheet (ch1);

Step. 8: as shown in the figure 13 as shown in the figures 7a, 7b, the operator activates (using a crack) (27) the displacement device of the crossbar (24) of the base module (m2), on rails (25), notably an approximation movement in relation to the central gap so that the butt of the polymer sheet (ch2) is in contact with a side face of the heating bar (41);

Step. 9: once the condition of the figure is obtained 13, the operator activates the operation control module (m5) adjusting the variables for butt to butt welding of polymeric sheets (ch1) and (ch2) respectively, whereby the heating bar (41) is heated and at the same time tensibned for a certain period of time in a way that the butts of the polymer sheets (ch1) and (ch2) are heated in melting temperature;

Step. 10: as shown in the figure 14, the operator activates, (using a lever) (27), the displacement device of the crossbar (24) of the base module (m2), on rails (25), notably a retreat movement in relation to the central gap, in such a way that the polymer sheet (ch2) with heated butt distances from the heating bar (41);

Step. 1 1 : as shown in the figure 15, the operator activates, (using a lever) (47) and longitudinally displaces the whole welding module (m4) in a way that the heating bar (41) gets distant from the polymer sheet (ch1 )

Step. 12: as shown in the figure 15, the operator activates, (using a lever) (46), and demotes the welding module assembly (m4), notably the heating bar (41).This task is facilitated by action of the spring (45) of the unprecedented bumper system, retreating this heating bar (41) below the height described by metal sheets (21) e (22);

Step. 13 as shown in the figure 16, the operator activates, (using a lever) (27), the displacement device of the crossbar (24) of the base module (m2), on rails (25), notably an approximation movement in relation to the central gap so that the heated butt of the polymer sheet (ch2) is in contact with the heated butt of the polymer sheet (ch1 );

Step. 14: as shown in the figure 17, the operator activates the operation module control (m5) adjusting the variables for butt to butt welding of the polymer sheets (ch1) e (ch2) respectively, in which is defined the time of contact and compression between the heated butt of the polymer sheet (ch2) and the heated butt of the polymer sheet (ch1) until their natural cooling, consolidating the weld between the sheets;

Step .15: as shown in figure 18, the operator dismounts the fixing module (m4) by loosening the fastening nuts (33) and then spread off through radial movement the stay bolts (32) from the interior of the side cavities of the linear bars (31) to then remove them;

Step .16: as shown in the figure 19, the operator removes the polymer sheet (Ch) resulting from the union made by weld- ing of polymer sheets (ch1) + (ch2).

The choice of the preferred way of execution of the invention object of claiming herein, described in the chapter of detailing of the invention is provided only as an example. Changes, modifications and varia- tions can be performed for obtaining any other forms of realization of the welding equipment of polymeric sheets by those skilled in the art, however the deviation of the objective revealed in the plea of the present patent, which is exclusively defined by the attached claims.

It appears from what was described and illu- strated that the "IMPROVEMENTS TO POLYMER SHEET BUTT WELDING EQUIPMENT" here claimed fits the standards governing the patent of invention according to the Industrial Property law, deserving for what has been exposed and as a consequence, the corresponding privilege.