EQUIPMENT FOR THE CREATION OF A STABLE AND QUICK FIXING OF A PULLEY TO A RESPECTIVE SHAFT.

Description

DESCRIPTION in support of a utility model patent application entitled: “EQUIPMENT FOR THE CREATION OF THE STABLE AND QUICK FIXING OF A PULLEY TO A RESPECTIVE TREE”. Owner: VIC - Viterie Italia Centrale Srl, with registered office in Fabriano (An), Via Cesare Battisti 27 / A. DEPOSITED ON............. DESCRIPTION TEXT This patent application for a utility model has as its object equipment for the construction of the building and quick attachment of a pulley to a respective shaft. The invention in question, which is likely to find application in any sector of mechanics, has been expressly designed to solve a problem that is particularly evident in the washing machine sector. As is known, in fact, such an appliance makes use of of a cylindrical basket that rotates on a horizontal axis inside a suitable housing, accessible from the front or from above for loading laundry. Well, in such a context, it is also expected that the aforementioned basket has a tree on the back which, after having crossed the rear wall of the respective housing, it mates with a pulley which is connected to an engine via a traditional belt of transmission. In fact, the operation of the engine sets the pulley itself together with the basket attached to it. In the context of such a technology a need for of fundamental importance is precisely that of creating a perfect fit between the basket shaft and the hub of the pulley, so as to exclude any slightest mutual sliding between these two components. It is understood in fact that if such a coupling does not was sufficiently "rigid" and stable over time, yes would easily witness the emergence of unwanted "games" between the pulley hub and the basket shaft, such as to make dangerous and noisy vibrations may arise. To date, such a need has been met with a rather expensive and cumbersome solution, implemented starting from from a particular mutual configuration of the tree basket and pulley hub. More precisely, it is expected that the end of the shaft the basket must have two flat opposing faces, obtained following a specific milling process, as well as a threaded axial hole. For its part the pulley hub must have centrally a housing capable of accommodating exactly, by virtue of a male-male coupling female, the aforementioned shaped end of the shaft of the basket. The next operation, to be performed from outside the pulley, is the installation of a screw with a large head which, after passing through a suitable window made on the pulley, engages in the aforementioned axial hole of the shaft basket, preventing any possible accidental decoupling between the two aforementioned components. Once this helical coupling is completed, in fact, the head enlarged by the aforementioned screw is attested rigidly against the outer face of the pulley hub, ensuring its stable locking against the end of the basket tree. To have greater guarantees on the stability of such a coupling is finally foreseen, the application between the screw and the respective threaded housing hole, of a product chemical blocker. Well, despite its notable diffusion, this technology is certainly not free from drawbacks, the first of which certainly concerns the complicated and expensive processing to which the basket shaft must be subjected, in order to create the aforementioned flat faces on it opposite and the aforementioned threaded axial hole. A further drawback is certainly due to the timing long assembly times of the entire "system", linked to the need to first couple the basket shaft with the hub of the pulley, then to install the reciprocal tightening screw, with the appropriate preload, and finally apply the aforementioned chemical blocking product. Then consider that a coupling made according to these methods, and precisely by virtue of the aforementioned presence of the chemical blocker, often creates significant difficulties in case it is necessary to unscrew the aforementioned screw for the purposes of the dismantling of the pulley from the respective shaft. By virtue of such a critical evaluation of the technique front, specific purpose of the present invention is to to make equipment capable of making a more efficient, cheaper and faster coupling both as regards its assembly, as regards the its possible dismantling. Starting from the unavoidable need to realize in every case a prismatic coupling between the basket shaft and the impeller hub (functional for torque transmission) of rotation), the first idea underlying the present invention is to obtain, on the end of the same tree, a toothed crown (or other equivalent means) through the medium of a cold forming and rolling process that results certainly faster and cheaper than milling processes adopted so far in traditional techniques. Of course this also means that on the inside of the pulley hub is obtained by stamping a profile toothed, capable of engaging the crown gear properly provided on the end of the basket shaft. The further solution idea behind the invention in The subject is related to the methods adopted to stabilize, also in anti-slip function, the position of the pulley hub in relation to the basket shaft. A similar purpose is achieved thanks to a spring cup, which is actually simple and quick to assemble, so how to remove. In this regard, it is worth underlining that the installation of the cup spring, replacing the screw used up to now, It also allows you to avoid a further critical phase of the previous technique, consisting precisely in the execution of the axial threaded hole in correspondence of the end of the basket shaft. Such a cup spring is appreciated, always in in relation to the aforementioned traditional tightening screws, also for the fact of creating a larger contact surface in the comparisons of the outer face of the pulley hub. In addition to this, the aforementioned cup spring is profiled in order to always guarantee the same preload (when assembled) carried out) regardless of the specific environment installation, while it is evident that such a certainty does not can be guaranteed when using traditional tightening screw, unless you use a torque wrench. Furthermore, this preload, in addition to being constant, is It also reveals a rather high and constant level over time, such that “automatically” recover any problems relaxation to which printed pulleys can be subject in plastic materials. Finally, when using this cup spring, the following results are obtained: the variables of the related process are practically insignificant assembly, since the said spring is put in place for the through a screwing movement, which only involves a final position check, but not also a final position check of a couple. Among the additional advantages that the new equipment compared to the prior art, it is also necessary mention the smaller size it requires and its greater ability to permanently ensure the axial load of the pulley against the respective shaft. For greater clarity of explanation, the description of the found continues with reference to the drawing tables attached, which have only illustrative and not limiting value, in which: - figure 1 shows, with an exploded axonometric drawing, the components of the equipment in question; - figure 2A is a plan view of the cup spring; - figure 2B is the section of figure 2A with the plane AA; - figures 2C and 2D are two axonometric representations, with different views, of the aforementioned cup spring; - figures 2E and 2F are two different side views of the spring same; - figures 3A and 3B are two axonometric representations which show the installation methods of the aforementioned spring cup-shaped; - figures 4A and 4B show, with as many representations axonometric, two alternative construction versions of the spring cup shown in the previous figures; - figure 5 corresponds to figure 1, but refers to a second version of the aforementioned equipment; - Figure 6 is an enlarged side view of the end of the tree in figure 5; - Figures 7A and 7B correspond to Figures 3A and 3B, but these also refer to this second version of the same equipment. With reference to figures 1 to 4B, it is reiterated that the equipment in question is intended to create a coupling between the end (1) of the shaft (100) of a washing machine basket and the hub (2) of a respective pulley (200) which, in this specific case, adopts the typical structure of a multi-race cruise (regardless of whether in the same figures these breeds are "cut" near the hub). It is envisaged within the scope of the present invention in particular that the end (1) of the shaft (100) has a first cylindrical section with smooth walls (11) and a second section (12), more internal and of larger section, shaped like a crown toothed. Note again that from the front perimeter edge of the aforementioned first section (11) two protrude laterally short opposing radial fins (13). For its part the hub (2) of the pulley (200) adopts internally a toothed profile (21), capable of combining exactly with the aforementioned toothed crown (12) of the shaft (1), via a simple front coupling. With particular reference to figures 2A to 2F, the third component of the equipment in question consists of a cup spring (300), essentially consisting of a stud truncated conical metal (3), which has a hole at the top central, the presence of which is expected, in correspondence with the edge of this same hole, of two identical helical profiles diametrically opposed (31). These helical profiles (31) have the same direction of screwing and are separated by two spaces (32) which have a width substantially equal to or greater than of the width of the two aforementioned fins (13) protruding from the first section (11) of the end (1) of the shaft (100). Within each of these helical profiles (31) it is it is possible to identify a ramp of progressively higher heights increasing (33) which leads to a stretch of constant height (34), at the top of which a cradle (35) is obtained between two radial ribs (36, 37) that briefly surpass it in height, so that their upper ends protrude briefly above the cradle itself (35). The first (36) of these ribs is obtained at the point of connection between the ramp (33) and the constant height section (34), while the second (37) is obtained in correspondence of the free end of the latter. At this point all that remains is to clarify – with reference in figures 3A and 3B – the assembly methods of this spring cup (300), assuming that the aforementioned has already been implemented seating of the toothed crown (12) of the shaft (100) within the corresponding toothed profile (21) of the pulley (200), following which the aforementioned first section (11) of the extremity (1) of the shaft (100) emerges from the same annular profile toothed (21) of the hub (2) of the pulley (200). At this point it is necessary to insert the cup spring (300) on this first section (11) of the shaft (100), until it reaches struck against the outer face of the pulley hub (2) (200), as shown in Figure 3A. This same figure shows how the complete insertion of the cup spring (300) is possible thanks to the perfect alignment that is established between the fins (13) provided on the front edge of the first section (11) of the end (1) of the tree (100) and the free spaces (32) provided along the edge perimeter of the central hole of the cup spring itself (300). Note also that in this context the mouthpiece of each of the two ramps (33) of the helical profiles (31) of the spring (300) is placed at a height substantially equal to that of the rear face of the two aforementioned radial fins (11) belonging to the tree (100). Well, as anticipated, the spring in question (300) must be conducted in operational mode through a movement rotary, that is to say by virtue of a sort of screwing from perform against the front face of the pulley hub (2) (200) and around the aforementioned first smooth section (11) of the end (1) of the shaft (100). Compared to what is shown in the above figure 3A, the rotation that affects the spring (300) is a rotation counterclockwise, the effect of which is to allow the two fins (13) of the tree (100) to gradually climb along the ramps (33) of the two helical profiles (31), until they settle within the respective cradles (34), in the arrangement shown in the next figure 3B. At this stage the increasing height of the profiles (31) means that the latter, together with the entire conical boss (3) of the cup spring (300), are subject to a progressive crushing which determines the aforementioned necessary preload of the spring itself (300). Such a preload of the spring (300) entails of course a hub crushing pressure (2) of the pulley (200) against the appropriate stop shoulder (101) obtained on the tree (100). It should also be considered that each of the two fins (13) is in able to settle in the respective cradle (34) only if the rotation imposed on the entire spring (300) is sufficiently energetic enough to make him overcome the obstacle posed by the first radial rib (36). Under the interference that the rigid fin (13) generates against this last rib (36) made on the “yielding” body of the cup spring (300), the respective helical profile (31) is it bends elastically downwards, then snaps back up as soon as the interference of the aforementioned flap ceases rigid (13), now settled in the cradle (35). Needless to say, at this point, the same nerve (36) acts as an obstacle to a possible accidental rotation contrary to the cup spring (300), which would result in an unwanted loss of preload thereof. The same figure 3B also allows us to appreciate the function of the second radial rib (37) of each of the helical profiles (31) of the cup spring (300); these are evidently of an "end-of-travel" function exercised in the against any excessive rotation imposed on the spring (300), on the occasion of its installation, such that each fin (13) would be brought to “go beyond” the respective cradle (34). To facilitate the installation of the cup spring (300) it is it is possible to foresee the presence of appropriate means on it on which to grip with a suitable tool to impose them the aforementioned necessary rotation. With reference to the version shown in figure 4A, These means consist of a simple opposing pair of holes (38) drilled on the stud (3) in the most external position compared to the aforementioned profiles (31). Referring to the version shown in figure 4B, similar means consist of an opposing pair of radial ears (39), having a substantially oval shape “L”, which protrude outwards from the perimeter edge of the stud (3). The further figures from 5 to 6B refer, as said, to a second construction version of the components of the equipment according to the invention. Beyond the morphological differences that will be reported shortly, the fact remains that even in this case the task of locking the pulley (200) on the shaft (100) is entrusted to a cup spring (300) intended to be inserted and preloaded within the aforementioned first section (11) of the end (1) of the same shaft (100). Well, with particular reference to figure 5, the peculiarity of the above-mentioned first section (11) of the extremity (1) of the tree (100) lies this time in the fact that it brings externally two identical diametrically opposed helical profiles opposite (14) with similar sense of twisting, separated from two intermediate spaces (15). With particular reference to figure 6, note that on the back of the thinnest section (16) of each of these helical profiles (14) a saddle (17) is obtained. For its part, the cup spring (300) carries, in matching the edge of its central hole, two fins (38) arranged towards each other on the same plane, inside of the same central hole of the spring (300) and also equipped of a width compatible with that of the aforementioned spaces (15) which, within the end of the shaft (100), separate the two opposing helical profiles (14). Naturally, the installation of this second one version of the cup spring (300) must be performed after that the usual assembly between the pulley has been completed (200) and the tree (100). Immediately after, it is necessary to insert the aforementioned spring (300) into the first section (11) of the shaft (100), until it reaches the stop against the front face of the hub (2) of the pulley (200). This deep insertion can be performed taking care to align the aforementioned fins (38) of the spring same (300) with the aforementioned free spaces (15) provided on the sides of the aforementioned first section of the tree (11) in positions intermediate to the two helical profiles (14); a similar condition is shown in Figure 7A. With reference to the following figure 7B, the further operation is to rotate the cup spring (300), in such that its fins (38) are subjected to a gradually increasing pressure, therefore to a progressive preload, due to interference with the rear surface of the helical profiles (14) of the shaft (100). The rotation of this spring (300) must stop in the moment in which its aforementioned wings (38) settle stably within the aforementioned saddles (17) provided on the back of the thinnest section (16) of the respective helical profiles (14). Finally, it should be noted that even if, up to now, reference has been made to the fact that the end (1) of the shaft (100) has a section shaped like a toothed crown (12), nothing prevents it from give this same section a different section, provided that equally capable of transmitting torque; it being foreseen, consequently, that the hub (2) of the pulley (200) must have a suitable profile inside it achieve a perfect prismatic coupling with this same tree section (100).

Claims

1) Equipment for the creation of a stable and rapid fixing of a pulley to a respective shaft, characterised by the fact that it comprises: - a shaft (100) which has an end (1) formed by a first cylindrical section with smooth walls (11) and by a second rear section (12) having a section suitable for transmitting a twisting moment - a pulley (200) which has, inside the hub (2), a profile (21) suitable for coupling prismatically with the aforementioned second section (12) of the shaft (100), so that the aforementioned first cylindrical section (11) of the end (1) of said shaft (100) can protrude from the hub itself (2) - a cup spring (300) formed by a substantially conical boss (3) in the centre of which there is a hole which allows it to be inserted exactly along the aforementioned first cylindrical section (11) of the end (1) of the shaft (100),until it comes to rest against the hub (2) of the aforementioned pulley (200) - means (31, 13 / 38, 14) provided on the aforementioned cup spring (300) and on the aforementioned first cylindrical section (11) of the end (1) of the aforementioned shaft (100) capable of subjecting the spring itself (300), following its rotation, to a progressive crushing against the hub (2) of the pulley (200) and to create an interference with it which prevents it from accidentally slipping off from the same first cylindrical section of the end (1) of the shaft (100). 2) Equipment according to claim 1, characterised in that the aforementioned means which ensure cooperation between the cup spring (300) and the first cylindrical section (11) of the end (1) of the shaft (100) consist of: - a pair of opposing helical profiles (31), substantially conical, made with the same screwing direction on the edge of the central hole of the aforementioned cup spring (300), with the interposition of two free spaces (32);it being envisaged that each of such helical profiles (31) is formed by a ramp of progressively increasing height (33) which leads to a section of constant height (34), at the top of which a cradle (35) is obtained between a first (36) and a second (37) radial rib - a pair of radial fins (13) projecting in symmetrically opposite positions from the front edge of the aforementioned first section (11) of the end (1) of the shaft (100) and having a width equal to or less than that of the aforementioned spaces (32) which separate the helical profiles (31) of the cup spring (300);it being foreseen that each of these fins (13) is able, following the rotation of the aforementioned spring (300), to progressively rise along the ramp (33) of one of the aforementioned helical projections (31) of the latter, to then settle, after having overcome the resistance of the aforementioned first rib (36) Ing. CLAUDIO BALDI Srl - Viale Cavallotti 13 - Jesi (An) within the cradle (35).; 3) Equipment according to claim 1, characterised in that the aforementioned means which ensure cooperation between the cup spring (300) and the first cylindrical section (11) of the end (1) of the shaft (100) consist of: - a pair of radial fins (38) arranged on the same plane, one towards the other, which project in opposite positions from the edge of the central hole of the spring (300) - a pair of opposite helical projections with the same screwing direction (14) provided on the sides of the aforementioned first cylindrical section (11) of the end (1) of the shaft (100) and separated by two intermediate spaces (15) having a width equal to or greater than that of the aforementioned radial fins (38) of the cup spring (300);it being foreseen that said projections (14) are able, following the rotation of the spring itself (300), to create a progressive interference with the radial fins (38) behind them, which results in a progressive crushing of the entire spring (300), up to the point in which the fins themselves (38) are placed within respective cradles (17) obtained on the back of the thinnest section (16) of the aforementioned helical profiles (14).; 4) Equipment according to one or more of the preceding claims, characterised in that the aforementioned cup spring (300) has means for engaging tools suitable for setting it into rotation. Ing. CLAUDIO BALDI Srl - Viale Cavallotti 13 - Jesi (An) 5) Equipment according to claim 4, characterised in that the aforementioned tool engagement means are constituted by a pair of holes (38) made, in symmetrically opposite positions, on the boss (3) of the aforementioned cup spring (300). 6) Equipment according to claim 4, characterised in that the aforementioned tool engagement means are constituted by an opposing pair of radial ears, substantially shaped like an “L”, which protrude from the perimeter edge of the boss (3) of the aforementioned cup spring (300). 7) Equipment according to one or more of the preceding claims, characterised in that the aforementioned second section (12) of the end (1) of the shaft (100) consists of a toothed crown and that the aforementioned profile (21) provided on the inside of the hub (2) of the pulley (200) consists of a conforming and corresponding toothed profile (21). 8) Washing machine of the type equipped with a rotating basket from which a shaft (100) protrudes at the rear, characterised in that said shaft (100) uses, for the purposes of its coupling with the respective pulley (200), the equipment which is the subject of one or more of the previous claims.