EP3527748B1

EP3527748B1 - Method and apparatus for making telescopic props

Info

Publication number: EP3527748B1
Application number: EP18425008.2A
Authority: EP
Inventors: Davide Gherardi
Original assignee: Gherardi Srl - Attrezzature Edili
Current assignee: Gherardi Srl - Attrezzature Edili
Priority date: 2018-02-15
Filing date: 2018-02-15
Publication date: 2024-05-22
Anticipated expiration: 2038-02-15
Also published as: EP3527748A1

Description

The present invention relates to a method and apparatus for making telescopic props.
In particular, the present invention finds application in the production systems for supports (props) adjustable in length, mostly used in the building sector.
Even more particularly, the present invention refers to a process for obtaining on the aforementioned telescopic props a scale for measuring and adjusting the length of the prop itself.
The telescopic props are generally constituted by a fixed portion having a substantially tubular shape with a circular cross-section.
The fixed portion has a first end typically provided with a floor support, or other similar support element, to be placed on a reference plane.
On the opposite side of the first end, a second open end extends, able to receive a respective movable portion within the fixed portion.
The movable portion also has a substantially tubular shape with a circular cross-section and is slidably inserted into the fixed portion to be moved axially with respect to the fixed portion itself.
In this way, by means of the sliding of the movable portion, the length of the entire prop is determined according to the various needs of use.
In this context, it should also be specified that the movable portion has an end opposite to the first end of the fixed portion, and configured to be supported on a respective surface to be supported, such as, for example, a ceiling, a wall of a formwork, or in general any structure to be supported by the prop.
In order to constrain the movable portion relative to the fixed portion in position, there are also provided reversible hooking systems, such as, for example, a pin that can be inserted in appropriate coincident holes formed on both portions.
In greater detail, the movable portion has a series of through holes, appropriately spaced apart and arranged linearly along the longitudinal extension of the movable portion.
The fixed portion in turn has an opening, generally a slot, formed at the respective second end, close to the movable portion.
In this way, once the height of the prop is adjusted by sliding the movable portion, it is locked by inserting the pin through the slot and the respective hole of the movable portion.
It should be noted that, for each height defined by the movable portion, a respective hole is always positioned at the slot.
In order to precisely adjust the position of the movable portion with respect to the fixed portion, a visual reference is preferably provided, such as a graduated scale and/or a numbering, suitable for providing a measurement of the length of the prop.
According to a first known art, the visual references are obtained by a marking drawn by means of suitable inks or other printing methods, and arranged at the holes to provide, for each hole, a respective length indication.
However, this solution is not reliable as the markings tend to be damaged and removed over time, thus making it impossible to read the length indications.
In this regard, it should be considered that the axial sliding of the movable portion in the fixed portion results in the rubbing of the respective tubular surfaces.
This rubbing action involves over time the partial removal of the ink layer impressed on the eternal surface of the fixed portion.
To overcome this drawback, visual references are also known that are impressed by punching on the outer surface of the tube as described in WO 2010/137984 A1 .
In this way, the visual references are engraved on the visible surface of the movable portion, preventing them from being removed over time.
An example of such a solution is described in the patent EP0765981B1 in which the mobile element undergoes a punching step before being shaped in a tubular form.
In particular, in this situation a flat element, in the form of a ribbon made of metallic material, is fed along a punching machine.
The flat element is intermittently advanced to allow the punching machine to make consecutive holes, and subsequently, or simultaneously, the numerical incisions.
Such incisions can be obtained both between the holes and laterally to the holes in order to provide greater visibility of the length of the prop.
Once the incisions have been made, the plane element is deformed and bent on itself. The opposite edges of the flat element are therefore brought together and mutually welded to define the tubular configuration.
This solution, although able to guarantee greater reliability, since the visual references are engraved on the tubular portion, is not free from important drawbacks.
Firstly, it should be noted that the punching step is carried out by intermittently advancing the plane element, precisely to allow the punch to perform the incision at the moment of stopping the advancement.
This intermittent advancement leads to an important slowdown in the entire production cycle of the props, resulting in disadvantages in terms of total production costs.
Moreover, the whole process, as well as the structure of the punching machine, are structurally complex, given the need to perfectly shape the tubular portion according to the through holes and the respective numerical references.
In other words, the deformation step of the flat element suitable for the tubular formation is controlled based on the positioning of the holes and the incisions, thus making the whole control system particularly complex and prone to errors in the welding steps.
In addition, this method is not very versatile and difficult to be adapted to the various, possible dimensions of the portions, and therefore also of the respective numerical incisions.
In this context, the technical task underlying the present invention is to propose a method according to claim 1 and apparatus according to claim 9 for making telescopic props able to overcome the drawbacks of the prior art mentioned above.
In particular, it is an object of the present invention to provide a method for making props able to simplify and significantly reduce the production times of each prop, in particular in the step of making the visual references.
The present invention also aims at providing an apparatus for making telescopic props, which is reliable, structurally simple and inexpensive. Finally, another object of the present invention is to propose a method and apparatus for making props, which is versatile and adaptable to the various, possible dimensions of the tubular portions, and to the type of visual reference.
The mentioned technical task and the specified aims are substantially achieved by a method and apparatus for making tubular props, including the technical specifications set out in one or more of the appended claims. According to the present invention, a method for making telescopic props s described, which comprises the steps of feeding a first tubular body preformed along a feed line; said tubular body having a series of through holes formed along the same longitudinal extension line of the tubular body; and simultaneously making a series of incisions at said through holes, each incision being representative of a measurement information of said prop.
According to the invention the incisions are made by means of a punching step carried out continuously by two counter-rotating rollers.
According to the present invention an apparatus for making telescopic props is also shown, comprising: a feed line for a first tubular body preformed having feeding means for moving the body with the respective longitudinal extension axis coinciding with said feed line; a forming station for forming a series of surface incisions on the outer surface of the tubular body, each incision being representative of a measurement information of said prop; and a pickup station of the preformed tubular body arranged downstream of said forming station.
According to the invention the forming station is provided with a punching member which carries out the continuous incisions during the advancement of the tubular body.
For this purpose, the member has two counter-rotating wheels arranged on the sides of the body.
Further characteristics and advantages of the present invention will become more apparent from the description of a exemplary, but not exclusive, and therefore non-limiting preferred embodiment of a method and apparatus for making telescopic props, as illustrated in the appended drawings, in which:

Figure 1 shows a perspective and schematic view of an apparatus for making props according to the present invention;
Figure 2 shows a perspective view of a constructive detail of the apparatus of Figure 1; and
Figure 3 shows a partially sectioned side view of a prop obtained by the method object of the present invention.

With reference to the attached figures, the reference number 1 globally indicates an apparatus for making telescopic props 2.
It should be specified that the term prop 2 means an element mostly used in the building sector, which is provided with two tubular bodies 3, 4 telescopically coupled to slide axially and define the height of the entire prop 2.
In this context, the present invention finds particular application for the realization of the internal tubular body 3 known to have a series of visual references 5 representative of the length of the prop 2.
In particular, with reference to Figure 3, the prop 2 is provided with a first tubular body 3, inside a second tubular body 4 and axially slidable with respect to the second body 4 to define the length of the prop 2. Both the tubular bodies 3, 4 have a substantially cylindrical shape with a circular cross-section.
Furthermore, both bodies can be provided at respective opposing ends of supports 6 (for example floor supports) adapted to rest on the respective surfaces to be supported.
The length of the prop 2 can therefore be variable according to the various needs of use and it is determined with the aid of the aforementioned visual references 5 impressed by incision on the outer surface of the first tubular body 3.
The first tubular body 3 also has a series of through holes 7 arranged along the longitudinal extension of the body 3 itself. Inside the holes 7 suitable reversible hooking systems (not shown) are inserted to keep the bodies 3, 4 constrained to each other once the length of the entire prop 2 has been adjusted. The reversible hooking systems act on through holes 7 formed in the first tubular body 3, and are not described and illustrated in detail as they are of known type and are not part of the present invention. The holes 7 are formed along two opposite longitudinal lines of the tubular body 3. Preferably, the visual references 5 are arranged between the holes 7, as advantageously illustrated in Figure 3.
However, the position and the dimensions of the visual references 5 can be any according to the various needs of use.
Again, the references 5 may consist of numbers and/or writings and/or a graduated scale.
Also in this case, the dimensions, the shape and the type of the references 5 can vary and be determined according to the various needs.
Purely by way of a non-limiting example, Figure 3 illustrates visual references 5 in the form of numbers arranged one above the other and each of them interposed between two respective holes 7.
As mentioned above, according to the present invention an apparatus 1 is provided for making telescopic props 2 of the type described above.
The apparatus 1 is in particular used for making the visual references 5 starting from the already preformed tubular bodies 3, 4, that is to say already in a tubular shape with a circular cross-section.
The apparatus 1 comprises a feed line "L" for a first tubular body preformed 3 provided with feeding means 8 adapted to move the body 3 in a longitudinal direction, that is, with the respective longitudinal axis of extension coinciding with the feed line "L".
Preferably, the feeding means 8 consist of a series of feed rollers 9 arranged along the line "L", and configured to engage the cylindrical outer surface of the tubular body 3 by rolling friction. Each roller 9 is suitably motorized and controlled by respective management systems not described in detail as of known type and adapted to feed the tubular body 3 at predetermined speeds.
The apparatus 1 further comprises a forming station 10, shown in detail in Figure 2, to realize a series of surface incisions on the outer surface of the tubular body 3.
Each incision, which constitutes a visual reference 5 on the tubular body 3, is representative of a measurement information of the prop 2.
A pickup station 11 of the preformed and finished tubular body 3 is further developed downstream of the forming station 10.
The pick-up station 11 preferably has a gripper 12 movable transversely to the line "L", to grip the tubular body 3 exiting the forming station 10, and to feed it to a further line for assembling it with the second tubular body 4 (not shown as not being part of the present invention).
With particular reference to Figure 2, according to the invention, the forming station 10 comprises a punching member 13 for making the incisions simultaneously with the continuous feed of the tubular body 3.
For this purpose, the punching member 13 consists of a pair of counter-rotating rollers 14, 15 facing each other and each of which having an annular surface 14a, 15a in contact with the surface of the tubular body 3. In this situation, the tubular body 3 is arranged between the annular surfaces 14a, 15a of the aforementioned counter-rotating rollers 14, 15. Advantageously, each annular surface 14a, 15a of the rollers 14, 15 has projections (not shown in detail) defining the incisions, which are carried out on the tubular body 3.
These protrusions are shaped according to the symbol to be impressed on the surface of the body 3.
In this manner, the rollers 14, 15 grasp and advance the body 3 along the line "L" and, at the same time, the pressure exerted by the projections formed on the annular surfaces 14a, 15a define the mentioned incisions.
The rollers 14, 15 are also suitably motorized and controlled by a management system, which operates on the rotation speed of the rollers. Moreover, in order to carry out a single superficial scratching of the tubular body 3, without thereby damaging the shape of the body 3 itself, movement means 16 for the pair of rollers 14, 15 are provided for moving the rollers 14, 15 themselves away and towards each other according to the cross-sectional dimensions of the tubular body 3.
In particular, the movement means 16 comprise a pair of slides 17 movable away and towards each other along a direction substantially perpendicular to the feed line "L".
The slides 17 are suitably motorized to move relative to each other and each of which is arranged to support a respective roller 14, 15.
In this way, according to the dimensions of the body 3, the tubular section and the degree of penetration of the projections designed to define the incisions, the movement means 16 place optimally the distance of the rollers 14, 15.
Furthermore, in order to make the whole apparatus 1 more versatile, the annular surfaces 14a, 15a can be removed and replaced according to the type of visual reference 5 to be impressed on the tubular body 3.
In addition, the present invention relates to a method for making telescopic props 2.
This method comprises the step of feeding the first preformed tubular body 3 along the feed line "L".
It should be noted that the tubular body 3, in addition to being already in the form of a tube, is already provided with the aforementioned through holes 7 made previously to the step of feeding the tubular body 3 along the feed line "L".
The tubular body 3 is passed through the forming station 10 in which a series of incisions are made at said through holes 7. As described above, each incision is a visual reference 5 which is representative of a measurement information of prop 2.
Following the step of making the incisions, a step is also carried out to telescopically connect the first tubular body 3 inside a second tubular body 4, which is also preformed, to define the telescopic prop 2.
The step of feeding the tubular body 3 is carried out by a series of feed rollers 9 to move the body 3 itself along the feed line "L" corresponding to its longitudinal extension axis.
The step of making a series of incisions is carried out by a punching step of the outer surface of the tube 3.
According to the invention this punching step is carried out continuously without stopping the feeding of the body 3 along the feed line "L".
In fact, the punching step is carried out by the aforementioned pair of counter-rotating rollers 14, 15, facing each other and spaced apart to allow the passage of the tubular body 3.
In this step, at least one roller 14, 15, preferably both the rollers are rotated on the outer surface of the body 3 to engrave on this external surface a series of visual references 5.
The punching step is also carried out by distancing the two rollers 14, 15 from each other according to the cross-sectional dimensions of the tubular body 3. In this way, the body 3 is only scratched superficially to make the incisions, without any deformation of the circular shape of the body 3.
The present invention solves the drawbacks of the prior art mentioned above and has important advantages.
In particular, the method and the relative apparatus 1 simplify and significantly reduce the production times of each prop 2, given the continuous processing in the step of making the visual references 5.
This advantage is provided precisely by the punching member 13 constituted by the counter-rotating rollers, which carry out the incisions during the continuous feeding of the body 3.
The production times of the entire prop 2 are then reduced, resulting in advantages in terms of production costs.
Moreover, the method and the apparatus 1 are particularly versatile as they can be adapted to the various dimensions and needs of the tubular portions 3.
Indeed, by means of the movement means 16, the distance of the rollers 14, 15 can be varied to adapt them to the dimensions of the body 3 and to define the degree of engraving of the references 5.
In addition, the annular surfaces 14a, and 15a of the rollers 14, 15 can be removed and replaced in order to obtain visual references 5 of different types.

Claims

Method for making telescopic props, comprising the steps of:
- feeding a first tubular body (3) preformed along a feed line (L); said tubular body (3) having a series of through holes (7) formed along the same longitudinal extension line of the tubular body (3); and

- making a series of incisions (5) at said through holes (7), each incision being representative of a measurement information of said prop (2);
characterized in that said step of making a series of incision (5) is made during the feeding step of the first tubular body (3) along the feeding line (L) and in that said step of making a series of incisions (5) is carried out by means of a punching step of the outer surface of the tube (3).
Method according to the previous claim, characterized in that it further comprises, following the step of making the incisions, a step of telescopically coupling said first tubular body (3) to a second preformed tubular body (4).
Method according to any of the previous claims, characterized in that prior to the step of feeding the tubular body (3) along the advancement line (L), a step is carried out to drill the preformed tubular body (3) to obtain said holes (7).
Method according to any of the previous claims, characterized in that said step of feeding the tubular body (3) is carried out by a series of feed rollers (9) to move the body (3) along the feed line (L) corresponding to its longitudinal extension axis.
Method according to claim 1, characterized in that said punching step is carried out continuously without stopping the feeding of the body (3) along the feed line (L).
Method according to claim 5, characterized in that said punching step is carried out by a pair of counter-rotating rollers (14, 15), facing each other and spaced apart to allow the passage of the tubular body (3).
Method according to the previous claim, characterized in that said punching step is carried out by rotating at least one roller (14, 15) on the outer surface of the body (3) to engrave on said external surface a series of visual references (5).
Method according to claim 6, characterized in that said punching step is carried out by distancing the two rollers (14, 15) from each other according to the cross-sectional dimensions of the tubular body (3).
Apparatus for making telescopic props, comprising:
- a feed line (L) for a first tubular body preformed (3) having feeding means (8) for moving the body with the respective longitudinal extension axis coinciding with said feed line (L);

- a forming station (10) for forming a series of surface incisions (5) on the outer surface of the tubular body (3), each incision being representative of a measurement information of said prop; and

- a pick-up station (11) of the preformed tubular body (3) arranged downstream of said forming station (10);
characterized in that said forming station (10) comprises a punching member (13) for making incisions simultaneously with the continuous feed of the tubular body (3).
Apparatus according to the preceding claim, characterized in that said feed line (L) comprises a series of feed rollers (9) arranged along the feed line and configured to engage the cylindrical outer surface of the tubular body (3) by rolling friction.
Apparatus according to claim 9, characterized in that said punching member (13) comprises a pair of counter-rotating rollers (14, 15), facing each other and each of which having an annular surface (14a, 15a) in contact with the surface of the tubular body (3), said tubular body (3) being arranged between the annular surfaces (14a, 15a) of said rollers (14, 15).
Apparatus according to the preceding claim, characterized in that each annular surface (14a, 15a) has projections defining the incisions (5) on the tubular body (3); said projections being shaped according to the symbol to be impressed on the surface of the body (3).
Apparatus according to claim 11, characterized in that said punching member (13) further comprises movement means (16) for said pair of rollers (14, 15) for moving the rollers (14, 15) themselves away and towards each other according to the cross-sectional dimensions of the tubular body (3).