LOCKING ELEMENT FOR ROLLER SKATE WHEELS

Abstract: A wheel locking element, characterised by comprising a pin (3) to be applied to the shoulders (12) of the support frame (1) for the wheels (2), said pin being provided at one end with a mushroom-shaped appendix (6) at least partly emerging from the frame shoulder, and further comprising an elastically compressible element (7, 17, 70) for engagement below the head of the projecting part of the mushroom-shaped appendix.

Description: Locking element for roller skate wheels This invention relates to a locking element for roller skate wheels. Known roller skates generally consist of a rigid plastic shoe which extends lowerly into a substantially inverted U- shaped frame for retaining a plurality of longitudinally aligned wheels. The wheels are generally secured to the frame shoulders by pins which after engaging the wheels are locked to the frame by nuts. This fixing system has however certain drawbacks, and in particular: - a non-predetermined fastening intensity which differs between one wheel and another in that it depends on the sensitivity of the user. The result is that in the case of excessive tightening there is a reduction in the axial clearance of the wheel bearings and hence a loss of rolling performance with consequent bearing heating, whereas in the case of insufficient tightening, vibration arises because of the gyroscopic effect of the wheels, - the need to provide said pins, screws and/or nuts with constructional expedients such as self-braking inserts, elastic washers, underhead undulated indentations and knurling to prevent self-loosening. These expedients make it even more difficult for the user to tighten with the correct intensity, - a loss of time required for tightening. An object of the invention is to eliminate these drawbacks by providing a locking element which enables a constant predetermined force to be exerted on the wheels retained by the skate frame. A further object of the invention is to provide a locking element which prevents any involuntary self-loosening of the pin. A further object of the invention is to provide a support element which enables the wheel to be easily mounted on and removed from the frame. These and further objects which will be apparent from the description are attained according to the invention by a locking element for roller skate wheels as described in claim 1. The present invention is further described hereinafter with reference to the accompanying drawings, in which: Figure 1 is a side view of a locking element being applied to a wheel support frame; Figure 2 is a cross-section therethrough; Figure 3 shows a modification thereof; Figure 4 shows a particular blade configuration for simultaneously engaging several wheels; Figure 5 shows it applied to the frame; Figure 6 is a side view of a modification of embodiment of Fig. 1; Figure 7 is a front view thereof; Figure 8 shows it on completion of insertion; Figure 9 is a front view thereof; Figure 10 shows it in the same view as Figure 3 with different shape of the head of the pin; Figure 11 shows the enlarged particular included in the circonference of Figure 10, before the locking phase; and Figure 12 shows it in the same view as Figure 10 after the locking phase. As can be seen from the figures, the locking element according to the invention is applied to a roller skate (not shown on the drawings) provided lowerly with a substantially inverted U-shaped frame 1 for retaining a plurality of longitudinally aligned wheels 2. Specifically, the locking element comprises a pin 3 provided with a head 4 and a shank 5 comprising at its end a substantially mushroom-shaped appendix 6. The locking element also comprises a bent metal bladed structure 7 substantially of U-shape, consisting of a flat blade 7' connected by a substantially cylindrical portion 8 to a blade 7" which has its central portion 9 slightly arched. The distance between the prongs of the blanded structure 7 is greater than the diameter of the stem 10 of the mushroom-shaped appendix 6 but less than the diameter of the appendix head 11. The locking element of the invention is used in the following manner: after interposing the wheel 2, the pin 3 is inserted through the frame 1 so that the appendix 6 projects from one shoulder 12 of the frame. The bladed structure 7 is then applied, with the concavity of the blade 7" facing the frame shoulder 12, so that the stem 10 of the mushroom-shaped appendix 6 becomes engaged between the prongs of the bladed structure. o avoid ugly projections, the outer lateral surface of the shoulder 12 is provided at the mushroom-shaped appendix of the pins with a recess 13 of suitable dimensions for housing the bladed structure. Further advancement of the bladed structure 7 in a direction perpendicular to the stem 10 of the appendix 6 causes the blade 7" to deform so that it reacts elastically to exert an axial displacement on the pin 3 and consequently an approach of the two shoulders of the U-support. Stability is ensured by the stem 10 passing beyond the dead centre represented by the vertex of the arched portion of the blade 7". If the wheel needs to be replaced it is necessary merely to engage the cylindrical portion 8 by a screwdriver tip or another implement, to disengage the bladed structure 7 from the pin. From the aforegoing it is apparent that the locking element according to the invention has numerous advantages, and in particular: - a constant defined traction load which is not influenced in any manner by the actions of the operator, - considerable coupling stability. In the embodiment shown in Figure 3, the shoulders 12 of the U-shaped support are shaped to form a seat 14 for housing the head of the pin 3 and a cavity 15 for hiding the bladed structure 7 from view. In the embodiment shown in Figures 4 and 5 a single blade 16 is provided comprising arched portions 17 at a distance apart corresponding substantially to the distance apart of the pins 3 arranged along the frame shoulders. At each arched portion there is provided a slotted hole 18 comprising two portions, one 19 of which is of circular section of diameter slightly greater than the diameter of the head 11 of the mushroom-shaped appendix 6, and the other 20 of which is of elongate form with a width greater than the diameter of the stem 10 of the mushroom-shaped appendix 6 but less than the appendix head 11. This embodiment has the further advantage of simultaneously engaging all the pins, it being possible to simultaneously insert all the heads 11 of the mushroom-shaped appendices 6 into the holes 19 in the blade and then axially slide the blade to engage the appendix heads 11 in the slots 20. In the embodiment shown in Figures 6-9, the bladed structure 70 is substantially of U-shape with its outer surface 70' comprising two helical inclined portions 22. In this embodiment the head 11 of the mushroom-shaped appendix 6 is of substantially rectangular cross-section. In this embodiment the bladed structure is used by inserting the head 11 of the mushroom-shaped appendix into the rectangular hole provided in the bladed structure and then rotating the pin so that the head rotates along the helical inclined surface portions until it abuts against stops 23 provided on the bladed structure. Again in this embodiment, rotating the pin elastically compresses the bladed structure, with consequent relative axial displacement the pin 3 with respect of the frame 1. In the embodiment shows in Figures 10-12, the surface of the seat 14, in which the head 4 of the pin 3 houses, presents the bottom slightly curved and provided with two semi-cylindrical horizontal recesses 24. The head 4 of the pin 3 presents in its turn two corresponding ribs 25. The locking element in this embodiment is used in the following manner: the blade 7 is inserted into the seat and subsequently the pin 3 is inserted which, after having engaged the wheel, engages its head 6 with the blade 7. During the insertion phase the pin is arranged so that the ribs 25 are arranged substantially vertically. Due to a rotation of 90° of the pin, the ribs 25 follow the outline of the curved surface thus causing the consequent approach of the two sprongs of the U-shaped support 1 until they firmly stop in the corresponding recesses 26.

Claims: C L A I M S 1. A wheel locking element, characterised by comprising a pin (3) to be applied to the shoulders (12) of the support frame (1) for the wheels (2), said pin being provided at one end with a mushroom-shaped appendix (6) at least partly emerging from the frame shoulder, and further comprising an elastically compressible element (7,17,70) for engagement below the head of the projecting part of the mushroom-shaped appendix. 2. An element as claimed in claim 1, characterised in that the elastically compressible elment consists of a substantially U-shaped arched bladed structure (7), for engaging between its prongs the projecting part of the mushroom-shaped appendix. 3. An element as claimed in claim 2, characterised in that the bladed structure (7) consists of two facing portions (7',7"), one of which is substantially flat. 4. An element as claimed in claim 1, characterised in that the elastically element consists of a bladed structure (70) , on the surface (70') of which there are provided two helical inclined surface portions (22) for engaging the projecting part of the mushroom-shaped appendix. 5. An element as claimed in claim 2, characterised in that the bladed structure (7) is housed in a corresponding seat (13) provided in the wheel support frame. 6. An element as claimed in claim 1, characterised in that the wheel support frame (1) extends into an appendix comprising a seat (15) for housing the bladed structure (7) . 7. An element as claimed in claim 1, characterised in that the elastically compressible element is provided on a blade (16) comprising a plurality of arched portions (17) at a distance apart corresponding to the distance apart of the wheel pins. 8. An element as claimed in claim 7, characterised in that each arched portion (17) comprises a slotted hole (18) formed in two portions, one (19) of which is of circular section of diameter slightly greater than the diameter of the head (11) of the mushroom-shaped appendix (6) , and the other (20) of which is of elongate form with a width greater than the diameter of the stem (10) of the mushroom-shaped appendix (6) but less than the appendix head (11) . 9. An element as claimed in claim 1 characterised in that the head (4) of the pin (3) is provided with two ribs (25) facing the external surface of the wheel frame (1) , said external surface being substantially arched and provided with two longitudinal recesses (24) for housing the ribs.

Inventors: GIUSTI DINO, GIUSTI, DINO
Applicants: GI DI MECCANICA S R L, GIUSTI DINO, GI.DI. MECCANICA S.R.L., GIUSTI, DINO
Application year: 1996
Main classification: A63C17
IPC codes: A63C17, F16B21