US2168128A - Portable derrick - Google Patents

Description

Aug. 1, 1939. B. KERVARREC PORTABLE DERRICK Filed Jan. 15, 1937 2 Sheets-Sheet l Aug. l, 1939.

B. KERVARREC PORTABLE DERRICK Filed Jan. 15. 1937 2 Sheets-Sheet 2 o w W W v 1 9 Q w w. w 4. 4 v b v 3 0 0 I m I 6 Z 5 B 5 2 2%.. UIMWWHH 4. m 0 2 V2 l I.l.ll|L

Patented Aug. 1, 1939 UNITED STATES PATENT OFF|E Application January 15, 1937, Serial No. 120,791

7 In France January 15, 1936 2 Claims.

This invention has for its object improvements in portable derricks for the hoisting and manipulation of loads.

Said invention comprises more particularly in 5 combination with a hoist frame comprising sheers located on a movable platform and a cable which is used at the same time as a translating member and as a balancing member for such sheers.

The cable is secured at two fixed points one of which is located on the level of the translating path, and the other is located at a point corresponding to the top of the sheers, with a view to allow said sheers to be translated by winding or paying out said cable on members such as winches. The winches may be located either on the sheers themselves or on the corresponding translating platform, the parts or sections of said cable being preferably parallel with each other thus allowing the sheers to be displayed with substantially constant inclination.

In the accompanying drawings which diagrammatically show by way of example as a preferred embodiment of said invention a constructional form of sheers which are designed for being located on a ship for picking up hydroplanes:

Fig. 1 is a perspective diagrammatic view of the sheers according to the invention located on the deck of a boat,

Fig. 2 is a diagrammatic view of a compressed air pulley block mounted on said sheers,

Fig. 3 is a detailed view of a part of the sheers designed for mooring hydroplanes,

Fig. 4 is a diagrammatic View of a servo expanding device.

35 The sheers according to the invention comprise two legs or spars 2, connected at their higher ends and carry a shaft 3 of the hoisting pulley 4. Said legs are hinged at their lower ends on a common shaft 5, fixed to a carriage 6 which may be displaced upon supporting and .guiding rails 1 which are conveniently secured on the deck 8 of a ship.

Mounted on the shaft 5 are drums 9 which receive a double cable In, H for translating and driving the carriage, and which are secured at fixed points |2, |3 located for instance at the rear end of said deck 8. Said elements II), II, pass upon guiding pulleys l4, l5, located on the upper ends of legs I, 2, and they are secured to the upper end of a tower H5. The fixation of said cables upon said tower l6 may be either rigid or the ends of said cables may, for instance, pass over the guiding pulleys l1 located on the upper end of said tower for being secured at a convenient fixed point at the foot of said tower. In this latter event said cable may for instance pass upon a winch which would allow the cables In, H to be slackened when necessary.

A controlling device not shown in the drawings 60 is provided on shaft 5 for controlling the rotation of same as well as of drums 9 for translating carriage 6 and legs I, 2,

The rear part of carriage 6 is provided with additional or auxiliary sheers more particularly designed for securing in a convenient position the hydroplanes which are to be picked up by the above described device particularly when the apparatus is being used for rescuing hydroplanes at sea.

For that purpose the additional sheers l8 are provided with a hoisting cable passing on a pulley |9 fixed to the main sheers l, 2. The auxiliary sheers are provided with a hooking device 28 (Fig. 3) which may be connected either directly or by means of a convenient extension piece with a funnel-like piece 2| which is designed for constituting a guide for the nose 22 of a hydroplane, said nose being diagrammatically shown in dotted lines in Fig. 3. The mooring cable 36 of the hydroplane passes in the hollow stem 31 of the piston of auxiliary sheers Hi and is connected with a brooch 38 which is provided with a spring 39 for dampening shocks, shakings or pushes which a hydroplane may have to bear during its hoisting or picking-up.

The operation of the sheers is controlled by means of compressed air operating a cylinder which is secured on legs I, 2 by means of braces 24 and comprising, as shown in the diagrammatic view of Fig. 2, a compressed air cylinder 25 having a piston provided with a stem 26 and a hoisting pulley 21. The piston which controls the displacement of said pulley 21 is actuated by compressed air fed to cylinder 25'through a pipe 28 provided with a spring operated valve 29 which comprises a controlling piston 30 with servomotor 3| provided with a hand lever 32 for the control thereof. The lever 32 .is connected with a piston valve located in the casing 3| which permits compressed air coming from pipe 28, 44 and through conduit 60 to be sent to the piston 30 through pipe 6|.

Located on the pipe 28 is a servo-expanding device provided with tubulures 4|,42 for receiving air under pressure from the conduit 28 and having another tube-like opening 43 connected with the valve chest 28 by means of a pipe 44.

The chest 4!] of servo-expanding device contains a cylindrical slide valve 45 open at both its ends in communication with tubulures 4|, 42, and having in its central part an opening 46. The middle'portion of the cylinder 48 is provided with an annular chamber 4'! connected with the tubulure 43.

The valve 45 is provided With a hand operating rod 48 and connected by a rod 49 with a piston .50 slidably mounted in a cylinder 5| pro vided at meet its ends with an orifice-52 connected by means of a pipe with a tank 53 which contains compressed air at a conveniently determined pressure. The other end of cylinder is connected through an orifice 54 with the pipe 44.

The operation is as follows:

Let us suppose that an operation to be effected is the picking up of a hydroplane at sea. Such hydroplane is first of all seized and moored through its nose 22 in the funnel-like piece 2| provided with a rotula connection and which is connected either directly or through a convenient extension device not shown, with the piston rod 31 of the auxiliary sheers. Said hydroplane being thus conveniently moored, hook 62 of the hoisting pulley block of sheers is connected with a convenient member provided for that purpose on the hydroplane and not shown in the drawings. Tank 53 has a supply of compressed air at a suitable determined pressure which may vary according to the weight of the load to be hoisted. Once the hydroplane is conveniently moored and gripped, the operator brings the orifice 52 in communication with tank 53.

Displacing the piston 50 in the direction of the arrow F (Fig. 4) brings the slide valve 45 in its middle position shown in Fig. 4 and the tubulures 4|, 42, connected with an air accumulator not shown in the drawings, bring a large supply of compressed air through tubulure 43 and pipe 44 into cylinder 25 of the pulley block the piston of which displaces itself together with pulley 2'! for effecting the raising of hydroplane.

When the pressure in the cylinder of pulley block and in pipe 44 attains a value equal to that of the fluid stored in tank 53, piston 50 is moved in a direction opposite to arrow F, and brings slide valve 45 in a position obturating its central orifice 46, thus cutting off the arrival of compressed air in the pulley block, and avoiding any danger of injury which could be caused by an over-pressure inside said cylinder 25.

With the arrangement described it is thus possible to obtain for the operation of the compressed air pulley block any desired pressure of motive fluid, whatever may be the pressure in the accumulator. The movements of the slide valve 45 are independent of the pressure and the position thereof depends only on the difference between the pressure existing in the tank 53, and the pressure which exists in the pipe 44.

It is possible to provide two or even a larger number of regulating pistons such as 50, braking and dampening devices being also provided with any desired arrangement.

Once the hydroplane or any other load is raised to the level of deck 8 of the ship, the controlling device not shown of drums 9 or of shaft 5 is acted upon for causing the displacement in the direction of the arrow of the unit constituted by carriage 6 and sheers I, 2, which carry the hydroplane not shown in the drawings. Said hydroplane may thus be brought upon the ships deck where it will be conveniently gripped and secured in position.

The arms or cables ID, ll, being parallel, the legs I, 2 of the sheers will keep the same inclination during their whole translation. The cable could comprise three or even a larger number such as I0, I I, a tension equalizing device of any kind being provided and located at any convenient place.

The arrangement of the apparatus operated by compressed air makes it possible to very rapidly perform the raising of loads to be manipulated which constitutes an important advantage and especially in the case of picking up of hydroplanes while said arrangement constitutes at the same time a resilient supple and efficient dampening which avoids any shock or injury.

The sheers may of course be used for hoisting and manipulating any load, and they may also be used on the ground where they constitute a practical economical hoisting device.

The sheers according to this invention offer the following advantages:

1. The several parts of said sheers are submitted only to tensile or crushing stresses said parts being at no time submitted to flexion or torsion stresses. Said sheers offer a very small surface to the wind and may easily be completely lowered in case of need.

2. The reaction on the supports are only tractive or crushing stresses which are relatively small, which allows a reduction of the foundation which supports the sheer,

3. The sheers being in a position to be translated without any rotation, it is possible to reduce the width of the carrying ship, since the transverse stability may be reduced.

4. Owing to the nature of the movements received by the several parts, the sheers have the very important advantage that they are practically independent of some dimensions of loads to be hoisted in view of the general dimensions.

5. The hoisting by means of the compressed air operated pulley block gives a great suppleness in combination with considerable power.

6. The described hoisting device in combination with the guiding device by means of the additional sheers I 8 prevents the drawback due to the inertia effects and to the shock or allows same to be reduced.

The carriage 6 may have any desired construction the guiding of same being effected in any convenient manner and the control of drums 9 may be effected by hand or by means of any motor either pneumatic or other desired arrangement.

The invention applies for hoisting and manipulation of loads of any kind and for any application.

What I claim is:

1. Movable apparatus for the lifting and manipulation of loads comprising in combination a derrick mounted on a movable platform, at least one multiple transmission cable serving simultaneously as a member for translatory movement and a member for equilibrating the reactions of the top of the derrick, said cable being connected at its ends to two fixed points one of which is arranged substantially at the level of the platform and the other of which is placed substantially at the height of the head of the derrick so as to permit the translation of the derrick by the simple winding or unwinding of said cable, said ends of the cable being substantially parallel to thus permit the displacement of the derrick with a substantially constant inclination.

2. Apparatus as claimed in claim 1 wherein the lifting cable of the derrick is operated by a pneumatic tackle comprising, a compressed air cylinder rigidly secured to legs of the derrick, and. piping at the head of the cylinder for the delivery of compressed air controlled by a valve provided with an adjustable compressed air operated regulator.

BERNARD KERVARREC.

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