Abstract: A safety device for a crane compares two signals, one of which represents the actual load in any configuration of the crane and the other of which represents the permitted or critical load in that configuration, and produces a third signal when the first signal exceeds the second signal. This third signal is used to actuate an alarm device or to prevent a dangerous maneuver from being continued by the crane.

Abstract: The piston of a fluid ram is provided with an end of stroke braking means comprisng a pusher adapted to contact the end wall of the ram cylinder as the piston approaches the end wall to restrict the flow of fluid from the outlet chamber of the ram to an outlet part. As the ram moves nearer the end the pusher opens a valve in the piston to connect the inlet chamber of the ram to the outlet part.

Abstract: This invention relates to a public works machine equipped with a bucket unloading device. According to the invention, this device comprises an endless member mounted for movement or translation along the jib and comprising blades, a chute disposed under the jib capable of being swept by said blades and a bucket whose section is identical to that of said chute, the shoot-bucket assembly then being completely swept by the blades. The material contained in the bucket is pushed via the shoot onto a conveyer belt which evacuates it to the rear of the machine.

Abstract: This invention relates to a bearing enabling a shaft to be pivotally mounted, constituted by a bearing body and by two half-bearings, the first half-bearing being fast with the bearing body, while the second half-bearing is mounted to slide in said body in a direction perpendicular to the plane defining the first half-bearing and a means for returning this second half-bearing into the configuration of effective holding of the shaft is interposed between said second half-bearing and the bearing body. The bearing surface of the second half-bearing is provided with a friction lining. One application of the present invention is the production of a cardan suspension in a grab bucket.

Abstract: This invention relates to a device for assembling a bucket on a frame comprising, in addition to said bucket, a zone of articulation of this bucket at a determined spot on the frame, disposed so that the resultant configuration enables the material to be loaded into the bucket and another zone of articulation of the bucket at another spot on the frame, disposed so that the other resultant configuration enables the material contained in the bucket to be unloaded. The changes in configuration are made by pins controlled by jacks and introduced selectively into orifices, the controls of the jacks being synchronized so as to permanently provoke the insertion of certain of the pins into the orifices of at least one of said two zones. One application of the present invention is the production of a loader bucket.

Abstract: This invention relates to a jib of a public works machine constituted by two elements, a piece for connecting said two elements, and removable means for locking the piece to the elements.The connecting piece is mounted on one element and comprises first holes disposed at the apex of a polygon; the other element comprises second holes separated from one another by distances equal to the length of the sides of the polygon; finally, when the jib is assembled, the connecting piece is fast with the first element via its axis of rotation and a removable pin introduced into a corresponding hole and in a special hole of said first element and fast with the second element via two removable pins introduced into corresponding holes.One application of this invention is the realization of a hydraulic shovel whose overall size is reduced for suitable road-transport.

Abstract: A braking system for the brake of a fluid motor including a jack for releasing the brake and two selectors for controlling the flow of working fluid to the jack. The first selector is responsive to the supply of fluid to the motor to place the jack in communication with a supply pipe and the second selector is responsive to pressure in a bleed pipe connected to the fluid supply to the motor to place the supply pipe in communication with a supply of working fluid under pressure.

Abstract: The present invention is directed to a supply circuit for a hydraulic jack employing two pumps in which a valve is positioned in a pipe which is branched to the delivery pipe of the first pump and is controlled by two jacks supplied by the fluid delivered by the second pump. A constrictor is positioned in the supply system for one of the jacks and another constrictor is placed in the discharge system for the two jacks with the invention being particularly applicable to achieving a stable control circuit for the load relief of the first pump.

Abstract: A fluid feed device comprising a constant cylinder capacity pump and at least one variable cylinder capacity pump driven from a single prime mover, the variable cylinder capacity pump being provided with a regulator for reducing its cylinder capacity as the feed pressure increases. The regulator is such as to reduce the power absorbed by the variable cylinder capacity pumps as the pressure increases by an amount equal to the increase in the power absorbed by the constant cylinder capacity pump such that the total power absorbed by the pumps remains constant and equal to the power of the prime mover.

Abstract: A public works appliance comprises a frame, a working attachment coupled to the frame and a control cab. The control cab contains a single control station and is mounted for rotation about an axis fixed relative to the frame. The cab may, therefore, be disposed in a first position in which the field of vision of a driver in the cab enables him to see and control the operation of the working tool, and in a second position in which the field of vision of the driver in the cab is unobstructed by the working attachment so that the appliance may be displaced, for example, along a road at a high speed.

Abstract: A hydraulic installation with means for storing energy produced by the prime mover during a rest period of the installation. Energy is stored by a fluid accumulator by suitable positioning of control valves during the reset period. Control of the valves is effected by a logic circuit responsive to pressure in the accumulator, pressure in the main feed conduit leading to the driven device, and the position of a feed conduit control valve.

Abstract: A dual function machine having a frame and a boom and means for adjusting the relative position of the frame and the boom, the frame having two mounting points each co-operable with a respective coupling on the boom to mount the boom on the frame in two different configurations. One of the configurations permits the machine to perform one function whilst the other configuration permits the machine to perform another function.

Abstract: In a method of subordinating the orientation of a grab on a Public Works machine to the angle of rotation of the turret three directions are chosen, the first two being determined by the desired orientation of the grab in the loading and unloading zones, respectively, and the third passing through the axis of rotation of the turret 2, the angle of rotation of the turret starting from the third direction is measured and compared with the angle between a straight line, passing through the point of intersection of the first two directions and the axis of rotation of the turret, makes and the third direction, the desired angle of the grab with respect to the boom in the loading or unloading zones is determined and the angle that the grab actually makes with the boom is measured and compared with the appropriate desired angle, the results of this comparison being used to control rotation of the grab to reduce the difference to zero.

Abstract: The invention relates to a supply apparatus for two receiving means having a pressure summation device.A relief valve with a double control system is provided on a pipe shunted to the delivery pipe of the pump and has two control connections, a rod connecting the discharge member of the pressure summation device to the first of the said connections and a control pipe connecting that portion of the discharge pipe located between the connection of the latter to the delivery pipe and the relief valve to the second of the said connections.The invention is applicable to the realization of a supply apparatus with a pressure transfer system.BACKGROUND OF INVENTIONThe present invention relates to an apparatus for supplying pressurized fluid to two receiving means with pressure transfer by means of a double control valve.Apparatuses for supplying two receiving means equipped with a pressure transfer system are already known. Such an apparatus is for example described in French Publication No. 2,218,007 of Sept.

Abstract: This invention relates to a public works machine comprising a frame, a working attachment, a counterweight and auxiliary jib moving above the counterweight and coupled to the working attachment.This auxiliary jib is provided with a guide member for a flexible connection means, said member being disposed above the counterweight, whilst such a connection means connects the counterweight to that part of the working attachment which is movable with respect to the part directly coupled to the frame by abutting on the guide member, constituting a link for handling said counterweight.One application of the present invention is the providing of a high power hydraulic shovel with a dismountable counterweight.

Abstract: An excavator comprising a plurality of buckets mounted on an endless chain on a jib, and a bottomless scoop at the working end of the jib through which the buckets pass in use. The scoop is power operated to break up the soil being excavated, and as each bucket passes through the scoop it co-operates with the scoop to form a complete digging bucket.

Abstract: In a pump or motor having a plurality of radial pistons adapted to perform a plurality of strokes per revolution, a stator, a rotor and a fluid-distributor slide valve fast with the stator and having a radially extending plane face opposite a radially extending plane face of said rotor, said slide valve is provided in a chamber which communicates with the interface between said faces and, by a pressure-maintaining device, with a substantially unpressurised enclosure such that the effect on said slide valve of the pressure of fluid in said chamber will substantially balance the effect of pressure of fluid acting on said interface between said faces.

Abstract: This invention relates to a telescopic jack constituted by a main cylinder, a first piston sliding in said main cylinder, a first piston rod fast with the first piston which passes in tight manner through a first bottom of the cylinder, a second piston which may be disposed in a bore of the first rod and is mounted to slide with respect to the first piston, and by a second piston rod which is fast with the second piston.The second piston rod passes through the second bottom of the cylinder whilst the piston is separable from the rod.One application of the invention is the production of an inexpensive telescopic jack.

Abstract: The invention refers to an axial-piston pump or motor, having a piston which defines, with a cylinder, a chamber. A first end of the piston bears against a plate by means of a hydrostatic shoe having a cavity in the bearing face, a duct connecting the chamber to that cavity and being furnished with a constriction.The piston has a recess which is arranged in the cylindrical portion of its second end remote from the first end, the constriction being constituted by the clearance lying between at least one collar portion of the piston which separates the recess from the chamber and the cylinder. A second recess is provided in the piston, the constriction being located between the first and second recesses.The invention is applicable to the execution of a pump having high operational characteristics, particularly as far as concerns pressure.

Abstract: The present invention relates to the construction of a slide connecting two bodies.A male member is fixed to the first body whilst a female member is fixed to the second body, whilst bolts for attaching the ring gear to the said first body are arranged to the right of the latter.The invention is more particularly applicable to the construction of "roller rings" on a public works vehicle having a pivoting turret.