GB2098914A - Mechanical device used in the construction of various tools - Google Patents

Abstract

The device which in particular is usable in the construction of an extractor for pulleys and similar elements, is composed of two primary bars (3, 12) each with a projection to hold the object to be extracted, and two secondary bars (1, 2, 13, 14) placed transversely to the primary ones. Of the secondary bars, the upper barisa guide for the primary bars (3, 12) to remain co-axial while the lower bars (2, 14) by means of their inclined planes and together with the complementary inclined planes (16) which are present on the primary bars (3, 12), contribute to the two primary bars (3, 12) moving closer together or respectively further away from each other. <IMAGE>

Description

SPECIFICATION Mechanical device capable of deviating a force of 900, causing a lateral, co-axillary and parallel movement, utilizable in the construction of various tools.

The invention relates to a mechanical device, the functional principle of which can be applied in all the situations in which the above-mentioned qualifications are required, as in the construction of extractors, universal spanners, clamps and other tools.

The present description refers to the application of the above-mentioned device as applied to the construction of an extractor.

The function of an extractor is that of separating a pulley or gear from the shaft to which it is fitted.

The extractor referred to in this invention, consists of two horizontal bars, placed one above the other, parallel in the central portion co-axillary and with the extremities devaricated in such a way as to form two angles of equal width. These two horizontal bars can be dispiaced, according to the use required, in such a way that the angles obtained both remain either divergent or convergent in relation to the vertical axis.

The divaricated extremities of these bars are inserted into specially adapted angular guides, in which they can move freely. By application of a force from a vertical direction on the two horizontal bars, a corresponding shifting of the vertical bars (legs) will be provoked in a horizontal direction. This movement can cause the two legs either to move further away or closer together simultaneously, in respect of the vertical axis, depending on whether the angles formed by the two horizontal bars are convergent or divergent in relation to the axis.

The lateral and parallel movement of both legs, which is also co-axillary and perpendicular in respect of the axis, is co-ordinated by the angles formed by the two horizontal bars. These bars, under the action of a vertical force, which tends to vary the distance one from the other by shifting the angles contemporarily and along the horizontal line, compel the two legs to move in unison.

An analogous, but contrary effect, in respect of the horizontal bars is obtained when a force from a horizontal direction is applied to the legs.

The same functional principle is valid in an extractor when, instead of having only two vertical legs at 1800 in respect of the vertical axis, there should be three placed at 1200 one from the other.

An extractor, in regard to its most desirable requisites, should be: (1) Auto-central (2) Constantly parallel, with exclusive regard to the legs during their variation in width (3) Reversible (4) Auto-adjustable under progressive pressure, and (5) Easy to handle.

The extractor described in the present invention, is in possession of all the above mentioned requisites: (1) Auto-central: The legs, while they are able to be moved at will from the large central screw, will always remain equidistant from it. This is due to the fact that the angles formed by the two horizontal bars, by maintaining a constant width, do not permit a single leg movement without the simultaneous movement of all the others in the same direction.

(2) Parallel: During the variation in width, the legs do not move at an angle but, held in place by the horizontal bars, the function of which is that of guide, are kept constantly parallel, adhering perfectly to the object being extracted.

(3) Reversible: It is sufficient to slide the legs out of the horizontal bars, and rotate then by 1800. The horizontal bars are also rotated by 1 800 and the legs are re-inserted. All of this without the aid of tools.

(4) Auto-adjustable under progressive pressure: During the operation of extraction, the large central screw tends to vary the distance between the horizontal bars which, by means of the angled guides, exert a pressure on the legs from a horizontal direction. This pressure provokes a movement of the legs towards the inside, in the case of an external grip and towards the outside, in the case of an internal grip. This effect of the legs approaching (adjusting to) the object to be extracted, improves the grip and becomes progressive with the lengthening of the screw.

(5) Easy to operate: The regulation, the taking apart and the reversal are all performed without having recourse to any type of tool.

The above-mentioned characteristics are also present when the extractor is furnished with more than two legs.

In the various types of extractors that one finds on the market, these requisites are not all available in the same device; in fact, where some of the requisites are present, others are absent.

The originality of this invention is due to the fact that all the desirable functional requisites are present in the same tool, thereby offering a complete solution to the existing technical problem.

Figures 1, 2, 3 and 4 show the device, in its various positions, in which the principle is applied to the construction of an extractor.

Figures 5 and 6 demonstrate a form of preferred embodiment, not limitative, of an extractor with two legs which are positioned to effect an external grip.

Figure 5 shows the extractor at its maximum aperture, and Figure 6 at its minimum.

Horizontal bars 1 and 2 are co-axillary in respect of the central screw 6 and their extremities, divaricated, slide into guides 5 present in the legs 3, form two angles 4, equal and divergent in respect of the central screw 6.

The central screw 6 passes freely through the top horizontal bar 1, while it is screwed into the lower horizontal bar 2, which has its extremities suitably inclined upwards.

Figures 7 and 8 demonstrate the same extractor, reversed, to effect an internal grip function.

Figure 7 shows the extractor at its maximum aperture and Figure 8 at its minimum.

The configuration of Figures 7 and 8 is obtained after having laterally taken it apart and rotating by 1 800 the legs 3 in Figure 5; the inferior horizontal bar 2 is also rotated by 1 800 in respect of the horizontal axis, and the whole is re-assembled.

In Figures 7 and 8 the inferior horizontal bar 2 shows the extremities inclined downwards and the angles 4 are convergent in respect of the central screw 6.

The prototype as per Patent Specification No.8118643 of the 24/4/81, has the defect, when the upper parts of the legs are under pressure, of inclining slightly towards the center.

This defect, although it does not seem to compromise the grip, is due to the fact that while the lower part of the legs leans against the pulley to be extracted, the upper part is almost free. The upward thrust of the angled bar, provoked by the tightening of the screw, causes the angled guides on the upper part of the legs to push the latter towards the centre, leaving them slightly blocked when the pressure on the central screw is released.

In order to avoid this inconvenience, yet remaining within the same functional principle, alternative solutions are possible, amongst them those as represented in Fig. 9 and Fig. 13. In both solutions, the main bar is now the upper one and not the lower one any longer. This upper bar is straight, thicker and threaded. The lower bar, thinner and angled, assures auto-centralisation and acts in such a way as to maintain the parallelism of the legs, thereby avoiding their devarication during the extraction.

The models in Figs. 9, 10, 11 8 12 have a knurled nut 7, that is turned manually until it touches against the upper part of the angled guide-bar 2. The function of nut 7 is that of adjustment of the grip and the maintenance of the adjustment.

The adjustment of the grip is obtained by pressure on the lower bar 8 exerted by nut 7. This latter initially turns together with the central screw 9, while the central screw advances downwards. In this way the adjustment of the grip, by means of projections 10, is obtained as follows: towards the inside for external grips, Figs. 9, 10, and towards the outside for internal grips, Figs. 11, 12, without exerting any excessive pressure on the angled bar 8.

The maintenance of the adjustment is obtained after nut 7 having stopped against the lower bar 8, allows the central screw 9 to continue turning freely on its own, without turning nut 7 any longer.

In order to allow this blockage of nut 7 it is advantageous that the contacting surfaces of the angled bar 8 and nut 7 should have radial grooves.

Fig. 13 represents a model in which the parts of the legs 11, between the two horizontal bars 13, 14, are enlarged. The function of these enlargements 11 is that of acting on the inferior bar 14 in such a manner as to maintain the initial adjustment and the parallelism of the legs 12 when, under pressure, these latter tend to divaricate.

These two latest models offer additional advantages above the original described, in that both can be utilised as well on eccentric pulley, by using them, in exceptional cases, without the lower bar 8, 14 and they are more rapidly reversible because of not ever having to unscrew the upper bar 1 3.

Claims (7)

1. Mechanical device capable of deviating a force of 900, causing a lateral movement, particularly useful in the construction of an extractor for pulleys and the like, characterised in that it is composed of two primary bars (3,12) which have projections (10) at opposite ends, and these, together with the central screw (6, 9), have the function of extracting the object, as well as two secondary bars (1, 2, 13, 14) placed transversely to the primary ones, of which the upper one (1, 13), acts as a co-axillary guide to the primary bars (3, 12), while the transverse lower bar (2, 8, 14), by means of its inclined plains (1 5) and together with the complementary inclined planes (16) which exist on the primary bars (3, 12), contribute to the primary bars (3, 12) moving closer together or, respectively, further away from each other.

2. Mechanical device as claimed in claim 1, characterised in that the primary bars (3) are capable of being moved in opposite directions.

3. Mechanical device as claimed in claims 1 and 2, characterised in that the lower bar (2) of the said secondary bars, presents a central portion from which two equally inclined and symmetrical side portions (15) extend.

4. Mechanical device as claimed in claims 1 to 3, characterised by said inclined portions (15) going through complementary apertures existing in said two primary bars (3).

5. Mechanical device as claimed in claims 1 to 4, characterised in that the said primary bars (3, 1 2) and the lower bars (2, 8, 14) of the said secondary bars can be turned by 1800, in such a way that their respective projections (10) are orientated internally or respectively away from each other.

6. Mechanical device as claimed in claim 1, characterised in that between the two secondary bars, upper and lower, a portion of the said primary bar (12) is enlarged (11), that this enlargement (11) presents the lower base (16) inclined and complementary to the inclination (15) of the inferior bar of the said secondary bars (13, 14), while the upper base of the said enlargement is orthogonal at the longitudinal axis of the primary bars and complementary to the corresponding surfaces of the upper bar (13).

7. Mechanical device a claimed in claim 6, characterised in that on the screw (9) and between the said secondary bars (8, 1 3) there is a threaded nut(7) which is adaptable in respect of the secondary bar (8).