Safety system
OwnerYavor PACHOVinventor
Life of this patent
Estimating the term…
Abstract
This safety system (S) is adapted to be used with a mechanism having one or several turning members (34), and comprises a toothed wheel (6), connected in rotation with at least one turning member (34) to be braked, and a worm (8), driven in rotation by a motor (5) during rotation of the turning member (34), this worm (8) being in permanent engagement with the toothed wheel (6). The worm (8) is contained within in a bore formed in a housing, this bore being delineated by a continuous wall of the housing extending all along the worm (8) outside the area facing the toothed wheel (6) and having a diameter such that said wall is in the immediate vicinity of the peripheral edges of the threads of the worm (8).
Claims16
1- Safety system (S), intended to be fitted to a mechanism, with one of more rotating members (34), comprising a toothed wheel (6), connected rotationally with respect to at least one rotating member (34) to be braked, and a worm (8), driven rotationally by a motor (5) upon the rotation of the rotating member (34), this worm (8) being permanently in mesh with the toothed wheel (6);
- characterized in that the worm (8) is contained within in a bore formed in a housing, this bore being delineated by a continuous wall of the housing extending around the worm (8) outside the area where the toothed wheel (6) is in mesh with the worm (8) and having a diameter such that said wall is at the immediate vicinity of the peripheral outer edges of the threads of the worm (8).
2- Safety system (S) according to claim 1, characterized in that the worm (8) comprises at least one cylindrical portion (8a) coaxial with its threaded portion and the said bore has a diameter such that said wall delineating said bore is at the immediate vicinity of this or these cylindrical portions (8a).
3- Safety system (S) according to claim 1, characterized in that the peripheral outer edges of the threads of the worm are flat viewed in a plane parallel to the axis of the worm.
4- Safety system (S) according to claim 1, characterized in that it comprises specific energy absorption/dissipation means (10, L, 12;
- 13 to 16;
- 19 to 21), in addition to the energy dissipation means constituted by the friction of the worm against the wall delineating the bore.
5- Safety system (S) according to claim 4, characterized in that the said specific energy absorption/dissipation, means comprise a sliding mounting of the worm in the said bore and energy absorption/dissipation means (10, L, 12;
- 85) associated with this worm (8) and actuated by it upon its sliding.
6- Safety system (S) according to claim 5, characterized in that the said associated energy absorption/dissipation means comprise at least one resilient means (10, 85), such as an elastomer spring, interposed between at least one end of the worm (8) and the walls of the housing (1) delimiting the bore.
7- Safety system (S) according to claim 6, characterized in that the said associated energy absorption/dissipation means comprise at least one safety washer (83) which is made in a material that is permanently deformed when it undergoes forces beyond a predetermined threshold, and which, when deformed, prevents the safety system to return to its normal position and thus making impossible the normal use of the safety system.
8- Safety system (S) according to claim 5, characterized in that the said associated energy absorption/dissipation means comprise:
- a liquid (L) contained in the space delimited by at least one piston (8a), against which one end of worm (8) comes to bear, and the walls of the said part (1) delimiting the bore, and
- one or more ducts (12) and/or interstices for this liquid ′(L) to escape upon the sliding of the worm (8), this or these ducts (12) and/or interstices having restricted flow sections, suitable for allowing the said liquid (L) to escape only over a non-instantaneous time interval.
9- Safety system (S) according to claim 8, characterized in that the said one or more ducts (12) and/or interstices comprise means (15) for adjusting the flow of liquid (L).
10- Safety system (S) according to claim 8, characterized in that the said one or more ducts (12) and/or interstices comprise means (16) for preventing the return of this liquid (L), which make it possible to obtain a different damping for each sliding direction of the worm (8).
11- Safety system (S) according to claim 9, characterized in that the means (15, 61, 62) for adjusting the flow rate of the liquid (L) comprise a ring (60) secured to the worm (8), a tubular member (61), engaged adjustably through this ring (60) and a rod (62) engaged adjustably in the tubular member 61, the tubular member (61) and the rod (62) having radial holes (67, 68, 73, 74) communicating with each other, the rod (62) having grooves (76) extending in the circumferential direction and of variable depth, and being adapted to be disposed in a predetermined angular position relative to the tubular member 61.
12- Safety system (S) according to claim 5, characterized in that it includes sensors or detectors of the sliding of the worm (8), which actuate command or control means which act on the means for driving the said one or more rotating members (34).
13- Safety system (S) according to claim 4, characterized in that the said specific energy absorption/dissipation means comprise friction connecting means (19 to 21) between the toothed wheel (6) and its hub or between the toothed wheel (6) and the shaft receiving this wheel (6), freeing the pivoting of this wheel (6) with respect to this hub beyond a certain torque threshold, with friction.
14- Safety system (S) according to claim 4, characterized in that the said specific energy absorption/dissipation means comprise a flexible and/or floating mounting of the safety system (S) with respect to the frame which contains it.
15- Safety system (S) according to claim 1, characterized in that it comprises an electronic controller (40) for controlling the maximum speed of the motor (5) for actuating the worm (8).
16- Safety system (S) according to claim 15, characterized in that the supply to the motor (5) and the control of the speed thereof are performed separately from those of the motor (30) of the mechanism, by means of an electronic controller (50) and a controller (51) having an independent link to the control station (42) of the mechanism, this control station (42) delivering redundant information to the said controller (51).