IL22749A - Expansion fastening device - Google Patents

Description

PATENTS AND DESIGNS ORDINANCE SPECIFICATION E an Italian Via Costa Italy do hereby declare the nature of this invention and in what manner the same is to be to be particularly described and ascertained in and by the following This invention relates to an expansion pin of the type in which the pin is introduced sleeve body which by such introduction expands thus gripping within the body in which the sleeve had been formerly introduced without play in a corresponding Well known are different expansion pins with or without Besides the pin in which the sleeve deformation is caused by a in which the threaded pin is screwed and which consequently upon screwing approaches the free head or annular stop of the thereby deforming the sleeve between nut and the a number of pin types have already been proposed which by the only penetration in the sleeve are capable of deforming For this it is foreseen that the inner portion of the sleeve has at least from a certain point onward and substan tially up to its end a conical whilst starting from the same point onward such sleeve shows a number of slota along its generatrix permitting precisely said deformation In these expansion pin types it occurs that the major expansion point concentrates on the sleeve end which is opposite to the input end of the and it is this point of major expansion which ultimately causes the anchoring within the body in which the sleeve is because the other sleeve parts have minor deformations stressing the body in which the sleeve is introduced in a smaller extent than the maximum expansion It is an object of this invention to provide an expansion in which a zone of substantial expansion extends over a considerable length of the sleeve thus a greater grig within the in which the is A further object of this inventio to provide expansion in whic the pin may be without threads and may be besides of metal or the also of plastic for of the same material as the According to the present there provided an expansion fastening device in bination an expansion sleeve and a pi of cylindrical shape therein through a first of the bore both the bore and pin surfaces being said sleeve being provided with plurality of longitudinal slots hieh extend from an opposite end of the sleeve to an portion the bore of said being of circular section and constituted by at least axial that portion said first end being of diameter than the portion nearer second portions being separated by a transition conica said intermediate portion and said transition zone being apar by virtue of the fac that portion and the transition zone spaced distributio of pressure of the outer surface surrounding wall surface is obtained thereby resulting a the effective retaining the sleeve in the invention will now be described in d with reference to two preferred embodiments ih conjunction with the accompanying in which 1 an expansion pin according to a first embodiment in longitudinal section and with the sleeve fitted into a with the pin partially in the whilst 2 the same expansion pin with the pin fully inserted in the sleeve and with the shape taken by the sleeve when it expands by the introduction of the and the expansio is restricted by the hole in which it is 3 shows two expansion pins in mounted on two structures to be joined to each other built up of overlapped finally shows a modified in which the sleeve head is polgonally and in which the outer ribs of the sleeve have a screw now to the above 1 to it may be observed that the expansion pin comprises a pin I having cylindrical shape and provided with a comprising further a sleeve having a head 4 with shaped edge and having at the end opposite the head a set of successive peripheral saw serrations which are directed towards the head 4 and ar designed to ensure a proper the sleeve has an axial hole having alon a length or section 6 a certain diameter equal or slightly larger the diameter of the pin whilst along the trailing length or section 7 a hole of diameter is It will noted that the transition zone 8 between both diameters is nearer to the head 4 than the point where the slots 9 of the sleeve the originate Once the pin 3 is introduced without play in a hole previously made in the bodies in which the sleeve has to the pin is by striking if necessary its head by of a hammer or the It will be observed that along the entire section or in which the slots 9 of the sleeve the pin uniformly giving way to ah extended anchoring It has been found that such a feature ensures a more resistant anchoring than anchoring known heretofore by device of the same insufficientOCRQuality

Claims (3)

1. An expansion fastening device comprising in combination an expansion sleeve and a pi of cylindrical shape insertable therein through a f rst end of the bore thereof, both the bore and pin surfaces being smooth, said sleeve being provided with a plurality of longitudinal slots which extend from an opposite end of the sleeve to an intermediate portion thereof, the bore of said sleeve being of circular cross section and being constituted by at least two axial portions, that portion nearer said first end being of greater diameter than the portion nearer to second end, said portions being separated by a transition zone of conical shape, said intermediate portion and said transition zone being spaced apart.

2. A device according to Claim 1, wherein said intermediate portion is located outside the axial portion of greater diamete s

3. A device according to Claim 1 or 2, wherei the slotted end of said sleeve is provided with successive peripheral sawtooth like serrations which are directed towards the unslotted end of the sleeve. * An expansion fastening deviee substantially as herein* before described by way of example and with reference to the accompanying drawings*; O the Applicants ND PARSERS