Collar for telescopic cylinder for tipper vehicles and telescopic cylinder with such a collar

Abstract

A collar for a telescopic cylinder with a cap includes the terminal portion of the cap that presents the opening of the cap, such that the collar includes in the following order a first annular element with a contoured profile, which surrounds the terminal portion and is welded thereto, and a second annular element, which can move with respect to the terminal portion and to the first annular element. The collar further includes an O-ring, made of rubber, surrounding the terminal portion and a third annular element surrounding the terminal portion and welded thereto. The first annular element has, at its internal circumference, an annular guide with a curved internal circumferential surface, the internal circumferential surface having, at each point of its circumference, a vertical cross-section with a shape that is concave as it progresses toward the outside of the collar.

Claims

1. A collar for a telescopic cylinder with a cap, said cap comprising a terminal portion that presents an opening of said cap, said collar comprising, in the following order: a first annular element with a contoured profile, which surrounds said terminal portion and is welded thereto, a second annular element, which can move with respect to said terminal portion and to said first annular element, said second annular element having at least two pins which extend at right angles to an external surface thereof, said second annular element surrounding at least partially said first annular element and said terminal portion, said second annular element being in contact with said first annular element, and an O-ring, made of rubber, surrounding said terminal portion and interposed between said second annular element and a fixed third annular element, and interacting with both, said third annular element surrounding said terminal portion and welded thereto, wherein said first annular element has, at an internal circumference thereof, an annular guide with a curved internal circumferential surface, said curved internal circumferential surface having, at each point of its circumference, a vertical cross-section with a shape that is concave as it progresses toward an outside of said collar.

2. The collar according to claim 1, wherein said annular guide is made of plastic material.

3. The collar according to claim 1, wherein said first annular element is provided with a seat configured for accommodating said annular guide which is shaped complementarily thereto, said first annular element providing, with said annular guide, a substantially uniform surface.

4. The collar according to claim 1, wherein said first annular element is welded, at an upper end thereof, to a lower end of said terminal portion.

5. The collar according to claim 1, wherein said annular guide is shaped to have the curved internal circumference that substantially increases between: an upper end thereof, in which the curved internal circumference is substantially equal to the internal circumference of said cap, and a lower end thereof in which the curved internal circumference is greater than the internal circumference of said cap.

6. The collar according to claim 1, wherein said second annular element is shaped so as to have an internal circumferential surface subdivided into: a first section, which is shaped complementarily to said first annular element and is in contact with said annular element, and a second section, an internal circumference of which substantially increases between: a lower end, proximate to/at said first annular element, in which the internal circumference is substantially comparable with the external circumference of said cap, and an upper end, in which the internal circumference is greater than the internal circumference at its lower end.

7. A telescopic cylinder for tipper vehicles, comprising a collar according to claim 1.

8. The cylinder according to claim 7, wherein the cylinder is oil pressure-controlled.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further characteristics and advantages of the disclosure will become better apparent from the detailed description that follows of a preferred, but not exclusive, embodiment of the telescopic cylinder for tipper vehicles and of the cylinder with such a collar, according to the disclosure, which is illustrated for the purposes of non-limiting example in the accompanying drawings wherein:

(2) FIG. 1 is a partial cross-sectional view of a detail of a collar for an oil pressure-operated telescopic cylinder for tipper vehicles, according to the disclosure;

(3) FIG. 2 is a partial cross-sectional view of a telescopic cylinder, according to the disclosure, in a first configuration of use;

(4) FIG. 2a is an enlarged detail of the cross-section of FIG. 2;

(5) FIG. 3 is a partial cross-sectional view of a telescopic cylinder, according to the disclosure, in a second configuration of use; and

(6) FIG. 3a is an enlarged detail of the cross-section of FIG. 3.

DETAILED DESCRIPTION OF THE DRAWINGS

(7) With reference to the figures, a collar for a telescopic cylinder for tipper vehicles, according to the disclosure, is generally designated by the reference numeral 10.

(8) The collar 10 is associated with the cap 11 of a telescopic cylinder 12, which is oil pressure-operated.

(9) The collar 10 comprises the terminal portion 13 of the cap 11, which presents the opening 14 of the cap 11.

(10) The opening 14 allows the egress of the tubular portions 15 of the telescopic shaft 16 of the cylinder 12, during the extension thereof.

(11) Such collar 10 comprises, in order: a first annular element 17 with a contoured profile, which surrounds the terminal portion 13 and is welded thereto, a second annular element 18, which can move with respect to the terminal portion 13 and to the first annular element 17, and which has at least two pins 19 which extend at right angles to its external surface, such second annular element 18 surrounding at least partially the first annular element 17 and the terminal portion 13 of the cap 11 and being in contact with the first annular element 17, an O-ring 20, made of rubber, surrounding the terminal portion 13 of the cap 11 and interposed between the second annular element 18 and a fixed third annular element 21, and interacting with both, such third annular element 21 surrounding the terminal portion 13 of the cap 11 and welded thereto.

(12) One of the peculiarities of the disclosure is that the first annular element 17 has, at its internal circumference, an annular guide 22 with a curved internal circumferential surface 31, which has, at each point of its circumference, a vertical cross-section with a shape that is concave as it progresses toward the outside of the collar 10, as can clearly be seen in FIGS. 2a and 3a.

(13) In particular, the annular guide 22 is made of plastic material such as, for example, a copolymer of polyoxymethylene, known by the commercial name of “Hostaform”, made by the Celanese Corporation located in Irving, Tex., loaded with molybdenum sulfide (MoS.sub.2).

(14) It should be noted that, in the event of misalignment between the cap 11 and the shaft 16, such an annular guide 22 with a rounded profile prevents the formation of seizing/breakage as a consequence of collision between the two.

(15) Furthermore, such an annular guide 22 facilitates the return to axial alignment of the cap 11 with the shaft 16, when being closed, as schematically represented in the transition from the configuration of FIGS. 2 and 2a, to the configuration of FIGS. 3 and 3a.

(16) The first annular element 17 is provided with a seat 23 for the accommodation of the annular guide 22, which is shaped complementarily thereto and provides a substantially uniform surface therewith.

(17) In particular, the first annular element 17 is welded at its upper end 32 to the jacket of the cap 11 and, in particular, to the lower end 24 of its terminal portion 13.

(18) With particular reference to FIG. 1, the annular guide 22 is shaped/configured so as to have an internal circumference that substantially increases between: its upper end 25, in which the circumference is substantially equal to the internal circumference of the cap 11, its lower end 26, in which the circumference is greater than the internal circumference of the cap 11.

(19) It should be noted that such an annular guide, in the event of a particularly intense impact between the cap 11 and the shaft 16, can break, in so doing preserving the shaft 16.

(20) In the event of breakage it is sufficient to replace it in order to restore the cylinder 12 to operability, and it is not necessary to replace the collar or indeed the entire cylinder as occurs with the use of conventional cylinders.

(21) It should also be noted that such a damaged or broken annular guide can be an indicator of improper or incorrect use of the cylinder by the operator.

(22) The second annular element 18 is shaped so as to have an internal circumferential surface subdivided into: a first section 27, which is shaped complementarily to the first annular element 17 and is in contact with it, a second section 28, the internal circumference of which substantially increases between: its lower end 29, proximate to/at the first annular element 17, in which the circumference is substantially comparable with the external circumference of the cap 11, its upper end 30, in which the circumference is greater than the circumference at its lower end 29.

(23) Such configuration of the second annular element 18 allows, in the event of side loads, a certain play with respect to the cap 11 and therefore a movement discharging the stress absorbed by the O-ring 20, placed above the second annular element 18 by virtue of its compression.

(24) In practice it has been found that the disclosure fully achieves the intended aim and objects by providing a collar for a telescopic cylinder for tipper vehicles, and a telescopic cylinder with such a collar, that make it possible to minimize the consequences of collisions between cap and shaft in the event of misalignment between the two, thus preventing the generation of seizures or breakages on the shaft.

(25) With the disclosure a collar for a telescopic cylinder for tipper vehicles has been provided that facilitates the retraction of the cap when the shaft is being closed and the alignment thereof with the latter.

(26) With the disclosure a collar for a telescopic cylinder for tipper vehicles and a cylinder with such a collar have been provided which, in the event of impact between cap and shaft, owing to a side load, preserve the integrity of the shaft.

(27) The disclosure thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. Moreover, all the details may be substituted by other, technically equivalent elements.

(28) In practice the materials employed, provided they are compatible with the specific use, and the contingent dimensions and shapes, may be any according to requirements and to the state of the art.