OPERATING LEVER WITH SAFETY DEVICE FOR CONTROL VALVES OF MANUALLY-OPERATED SLIDING-SPOOL TYPE USED IN HYDRAULICALLY-OPERATED LIFTING GEARS AND CONVEYING PLANTS

Abstract: The piston (10) housed within the control valve (2) is worked by a lever whose shaft (26) moves as one with a pivot (16) coupled in rotation with a bush (15) which carries a yoke (14) provided with a pair of slots (13) engaging a pivot (29) located in the shank (11) of said piston; the opposite extremity of said pivot (16) bears a radial arm (19) furnished with a lateral tooth (20) which establishes a 'safe' position by engaging slot (6) located in a given fixed portion (5) of the fixture (3) which, attached to control valve body (2) by way of the appropriate plate (1), affords the necessary support for the transverse pivot (28); the said 'safe' engagement coming about by dint of return action in a torsion spring (21) ensheathing the pivot (16) mating with said bush (16); a lateral movement of lever (26) causing rotation thereof about its own pivot (16), solicitation of the spring (21), and disengagement of the tooth (20) from the slot (6), followed by angular displacement of the lever itself around transverse pivot (28), provides the purchase necessary to operation of the control valve.

Description: Operating lever w#ith safety device for control valves of P 9 Y .,, . v manually-operated sliding-spool type use#d in hydraulically operated lifting gear and conveying plant The invention relates to an operating lever, incorporating a safety device, for control valves of manually-operated sliding-spool type used in hydraulically-operated lifting gear and conveyor systems -that is, a stick on which to lay hold and by means of-which manipulate the control valve which operates machinery, or parts thereof, employed in the lifting of loads or the moving about of materials by intern al industrial conveyor plant: the inclusion of the safety device in the lever assembly being intended more especially to guard against untimely function of machinery arising out of unwarranted operation by unskilled personnel, Current technology makes no provision for such a safety device incorporated into the operating lever mechanism, only a shield for protection of the lever itself against damage by accidental impact, The aforesaid technology, such as it is, is susceptible to further improvement with regard to the fact that a simple shield affords insufficient protection in itself against the possibility of the lever's being manipulated by a child, or other inexpert individual, occasioning unwanted operation of machinery or parts thereof and consequent risk of serious danger to persons and property, From the above outline one may discern the necessity for a solution to the technical problem posed by a lever incapable of operation by a child or other inexpert individual -that is, a lever correspond ing to recently prescribed accident prevention standards, The invention described herein resolves. the said technical problem by adoption of a lever whose traditional, longit udinally-directed movement is impeded: the new direction when manipulating lies transversely to the former, and involves a lateral, angular displacement of the lever itself by rotation around a pivot, against the influence of a torsion spring, followed by longitudinal displacement thereof around a further pivot disposed trasversely with respect-to the first pivot, The advantage provided by the invention is that of having created a sinple and effective safety device which will prevent the lever's being moved in the accepted direction of operation, in the event of its being laid hold on by a child or other inexpert individual, One embodiment of the invention will now be described, by way of example, with the aid of the three accompaying sheets of drawings, in which: : Fig 1 is a lateral view of the device in its locked posit ion, -corresponding to the control valve piston's return position; Fig 2 is a cross-section plotted according to Il-Il in fig 1, showing the control valve piston's articulated contol mechanism; Fig 3 is a cross-section plotted according to Ill-Ill in fig t, showing the device's articulated disengagement mechanism; Fig 4 is the same view of the device as in fig 1, showing the control valve piston in working position; ; Fig 5 shows a view of fig 4 from above, demonstrating the position of the locking mechanism with piston on working stroke With reference to the drawings, 1 denotes a plate connect ing fixture 3 to the valve body 2, fixture 3 furnished with a bracket 4 extending into a further portion 5 provided with a slot denoted by 6; 7 denotes centres located in plate 1 for fixing thereof to pump body 2 by means of insert ing and tightening bolts 8; 9 denotes an aperture in plate I through which the piston 10 of control valve 2 is destinled to pass; 11 denotes the shank of piston 10, furnished with a through hole by means of which to accomodate a pivot provided with two prismatic extremities 12 forming sliding pairs with relative slots 13 located in a yoke 14 protrud ing forth from bush IS, the latter accommodating a pivot 516 coupled in rotation therewith and retained axially there in by means of a tangientally located pin 17 engaging an undercut in said pivot 16; 19 denotes a radial arm extend ing forth from pivot 16, at the extremity of which arm a tooth 20 is affixed, this being disposed laterally thereon and designed to seek out and mate with slot 6 in portion 5 thus establinshing the locked, or safe position; 21 denotes a torsion spring ensheathing pivot 16, the extremities of which 22 & 23 engage with that face of radial arm 19 other than the face bearing tooth 20, and with the rearward edge of yoke appendage 14, respectively; 24 denotes a cramp affixed to the uppermost extremity of pivot 16 furnished with a bolt 25 for holding fast the extremity of operating lever shaft 26, the latter being provided with handgrip, or knob 27; 28 denotes the transverse pivot prov iding articulation between fixture 3 and bracket 4; (in fig 2) 29 denotes a pivot accommodated within valve piston shank 11 by passing through hole 30, retained therein by dint of aforesaid prismatic extremities 12; 31 & 32 denote respective section of a hole passirig through fixture.3 and yoke 14 for accommodation of pivot 28, the latter constituing the coupl ing necessary thereto, and retained thus by retaining rings, or circlips 331 The invention functions in the following manner: from the locked position (fig 1) the operator caused the device to pass into one of the working positions (fig 2) by manipulat ing lever shaft 26 so as to produce its rotation around pivot 16 thereby soliciting torsion spring 21, thus occagon- ing lateral disengagement of tooth 20 from slot 6 in bracket portion 5; this accomplished, the operator then works on lever 26, causing its rotation around transverse pivot 28 in the normal fashion thus making pidPn 10 to stroke in one direction or the other in order to procure the flow of hydraulic fluid through the body of chamber 2. Angular displacement of lever 26 in the traditional direction produces a corresponding angular movement in arm 19 and yoke 14, which in turn causes a related movement between shank 11, pivot extremities 12 and slots 13, and ultimately pivot 29 When carrying the invention into effect, materials, as well as dimensions and design particulars -the shape of lever shaft 26 for instance, and the fact that this could be comected direct to pivot 16 thereby dispensing with cramp element 24- may all differ from those given in the specification, whilst retaining an equivalent technical character, and by no meanstraying from within the bounds of protection afforded to the basic concept as described above, and claimed below,

Claims: CLAIM An operating lever with safety device for control valves ofnanual ly-operated sliding spool type lied in hydraulically operated lifting-gear and conveying-plant comprising a shaft (26) connected to a yoke (14), the latter rotating around transverse pivot (28) mounted to bracket (4) extending from plate (1) attached to the control valve body (2) wherein a piston (10) is caused to stroke, the shank (11) of the latter being furnished with a pivot (29) whose extremities (12) engage two slots (13) in said yoke, characterised by the fact that lever shaft (26) and pivot (16) are integrated, the latter rotating within and accommodated by bush (15), this in turn integral with yoke (14); ; the extremity of said pivot other than that lodged within said bush bearing an affixed radial arm (fug) furnished with lateral tooth (20) designed for insertion into slot (6) located in a portion (5) of said bracket forming an integral part of fixture (3), thus establishing a safe position, said fixture constituting means by which transverse pivot (28) is mounted to fixture plate (1) hence to the body (2) of aforesaid control valve; and that a torsion spring (21) ensheathing the pivot (16) of the lever shaft (26) has extremities anchored against said arm (19) on the one hand, and against an appendage issuing from said yoke (14) on the other, respectively,

Inventors: SALAMI, GIUSEPPE
Applicants: SALAMI S.P.A.
Application year: 1981
Main classification: G05G5
IPC codes: F16H61, G05G5