Field of the Invention
The present invention relates to an improvement in a push-in locking joint for small diameter tubes whose development aims at reducing the size of the locking joint, and consequently its manufacturing time, factors which are reflected in its final cost, while increasing grasping strength of the locking joint, which is particularly beneficial in use with polyurethane tubes or other similar tubes.
Background of the Invention
Known tube joints for small diameter tubes of the push-in type are generally characterized by an external tubular body which has manufactured in its interior, an adaptation to receive a glove with flexible stems equipped with a row of teeth, that, after the insertion of the tube, the glove is retracted so as to press the stems and, consequently the teeth against the external tube surface.
These joints have been considered to be too long, primarily as a function of the length of the glove. The glove is generally characterized by a tubular body equipped, in one of the extremities of a ring relief, to act as a stop when retracted, during the act of locking a tube. The body includes a straight section that, for a certain distance includes a plurality of longitudinal cuts, distributed in an equidistant way, ending at the other extremity of the glove at an external ring relief and a row of teeth placed near its internal edge.
This construction, besides increasing the length of the locking joint, requires substantial consumption of very expensive material, and the use of specialized equipment and manpower, so as to manufacture these parts perfectly. However, the straight section, without cuts, of the glove body was not necessary and the prior locking joints did not lock, with due efficiency, the pipes made of polyurethane or similar material.
Summary of the Invention
By the present invention, an improvement is introduced in a push-in locking joint for small diameter tubes constituted by the manufacture of a glove with a reduced length, with longitudinal cuts going up to a back edge of a traction relief ring and having two ring teeth rows on an internal edge of an opposite extremity of the glove, a construction that is suitable for the locking of polyurethane or pipes made of similar material.
This construction allows for a reduction in the length of the internal groove of the joint body and, consequently, a smaller length of the joint itself, which means less time and less use of equipment and specialized manpower for its manufacture, being thus characterized as a reducing factor in cost and an increase in security, by avoiding the formation of defects in the tube which might cause leaks.
Brief Description of the Drawings
So as to better understand the objective of this invention, reference shall be made to the attached drawings where:
FIG. 1 shows, in an upper posterior blown up view, and a longitudinal cut of its components, with a focus on longitudinal cuts applied to the glove, going up to the traction relief ring of the glove and including two ring rows of teeth,
FIG. 2 shows, in a longitudinal cross section, the separate parts aligned for assembly,
FIG. 3 depicts, in a longitudinal cross section the parts assembled and receiving the insertion of the tube, and
FIG. 4 shows, in a longitudinal cross section, the tube locking, after its insertion to the bottom of the tubular body, and the subsequent traction of the ring relief, so that its teeth bite the surface of the tube, progressively locking the tube with more axial pressure required to remove the tube.
Detailed Description of the Preferred Embodiments
The present invention includes an external tubular body 1 with an axial cylindrical passage 2 leading into a short radially widened section 3 of a diameter to accommodate a tube 4 and, moving towards an end of body 1, a further radially widened section 5 to receive a hermetically sealing O-ring 6, which is supported by a wall 7 between section 5 and section 3. The section 5 leads to a short, conically tapering surface 8 terminating in a straight axial section 9. Section 9 terminates at an inverted conically tapering surface 10 to facilitate the insertion of glove 11 into body 1.
Glove 11 is made of a tubular body with a plurality of longitudinal cuts 12 extending to a frontal ring relief 13 used for the gripping and subsequent locking of the tube 4. An axial passage 14 terminates at a conically tapered aperture 15 for receipt of a tube. The cuts 12 form flexible stems 16 having external bevelled edge ring 17 at an opposite extremity of the glove 11 from the ring relief 13. Two rows of teeth 18 are formed internally of the glove 11 at the end of the glove 11 at which bevelled edge ring 17 is located.
The axial passageway 14 of the glove 11 includes a straight axially extending section 20 located at one end of the glove's tubular body adjacent to the ring relief 13. A conical surface 21 tapers inwardly at one end 22 from the straight axially extending section 20 in a direction towards the other end of said tubular body. Another straight axially extending section 23 extends from the other end 24 of the conical surface 21. The two rows of teeth 18 are located at the other end of the tubular body. The straight axially extending section 20 has an internal diameter greater than an internal diameter of the other straight axially extending section 23.
In FIG. 3, glove 11 is shown inserted into body 1. The tube 4 is then inserted into the interior of the glove 11 within the tubular body 1 up to the end of the short widened section 3 of the tubular body 1 as shown in FIG. 3. Upon withdrawal of the tube 4 in the direction indicated by an arrow in FIG. 4, the bevelled edge ring 17 is forced against the conically tapered surface 8. The flexible stems are thereby pressed to converge towards tube 4 and the teeth 18 bite against the outer surface of the tube 4 to lock the tube 4 in place.