US3811720A

US3811720A - Releasable hook

Info

Publication number: US3811720A
Application number: US00305089A
Authority: US
Inventors: I Epstein
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-11-09
Filing date: 1972-11-09
Publication date: 1974-05-21
Anticipated expiration: 1991-05-21

Abstract

In the mooring of ships and boats to a dock, it is necessary to have a line running from the ship or boat to the dock. The line can be more or less tight and must be fixed so as to allow relatively sudden movements of the ship or boat with respect to the dock. Then, when it is necessary to allow the ship or boat to sail away from the dock, it is necessary to disengage the line from the fastening means on the dock. This invention relates to a fastening means whereby a line can be positioned to the fastening means for securing the ship or boat adjacent to the dock. Then, the person on the dock can, by means of a motor and electric control, if desirable, at a remote position from the fastening means, actuate the fastening means to allow the line to slip away from the fastening means and also to allow the ship or boat to sail away from the dock. This fastening means is identified as a releasable hook.

Description

United States Patent [191 Epstein [111 3,811,720 [4 May 21, 1974 RELEASABLE HOOK Inventor: Irving Epstein, 4216 Shore Club [57] ABSTRACT 7 in the mooring of ships and boats to a dock, it is nec- Dr., Mercer Island, Wash. 98040 essary to have a line running from the ship or boat to the dock. The line can be more or less tight and must [22] Wed: 1972 be fixed so as to allow relatively sudden movements of [21] Appl. No: 305,089 the ship or boat with respect to the dock. Then, when it is necessary to allow the ship or boat to sail away from the clock, it is necessary to disengage the line g 294/83 from the fastening means on the dock. This invention relates to a fastening means whereby a line can be po- [58] new of Search" 294,82 83 83 83 sitioned to the fastening meansfor securing the ship or 294/84 104 boat adjacent to the dock. Then, the person on the dock can, by means of a motor and electric control, if [56] References C'ted desirable, at a remote position from the fastening UNITED STATES PATENTS means, actuate the fastening means to allow the line to l ,l0l,l l3 6/l9l4 Attfield .L 294/84 slip away from the fastening means and also to allow 3,054,635 9/ 1962 Voss...., 294/83 R the ship or boat to sail away from the dock. This fas- 3,6l0,674 l0/l97l Jan'ssenmsm 294/83 R tening means is identified as a releasable hook. 1,377,159 5/1921 Spechtmeier 294/84 2,896,995 7/1959 Stephens. 294/83 R 21 Chums, 14 Drawlng Flgures Primary Examiner-Richard E. Aegerter Assistant Examiner-Johnny D. Cherry /0 53 a 5 7 80 I6 6 4 /2 l 4: -70

|.'g a j 76-. /4 'l v 1- 44 zoo l RELEASABLE HOOK When a ship or a barge is in a harbor, it may be anchored in open water, or it may be secured to a pier or other stationary structure. In either event, the vessels own gear is used. When securing to a pier, for example, the ships lines are brought out from the ship andsecured to various kinds of fittings on the stationary structure. The ships line may have a loop or large eye, spliced into the end of the line which is brought from the ship and secured to the fitting on the stationary structure. Sometimes, both ends of the mooring line are retained aboard the ship and the bight of the line is brought out from the ship and secured to a fitting on the stationary structure. The fitting on the stationary structure may be a bollard, or it may be a cleat, or it may be a pair of mooring bitts, or the fitting on the stationary structure may be a releasable hook. This invention discloses a releasable hook for retaining a mooring line. The hook may be opened or closed by hydraulic pressure under remote control. In the event of the failure of a power source to energize the hydraulic pressure in the hook, the hook may be released manually.

When it is desired to release the mooring line from this hydraulically releasable hook, the job can be done as rapidly as with any other form of mechanical releasable hook. The hook rotates to release the mooring line. Before rotating, however, the hook mechanism permits the hook to move toward the vessel, thus reducing the tension in the mooring line. The hook can be released under tension, but not accidentally. Actual unmooring of the line occurs only when the hook reaches full release position. Line tension from the weight of the unloaded slack mooring line, or tension caused by the ship pulling away from the dock, trips the hook completely. The hook then returns to a loading position. The hook slides back hydraulically, under control, and locks itself into position when a mooring line is placed in it. The hook can be stopped and returned to its starting position at any point during the open or close cycle. This positive control in any position makes this hydraulic release hook easier to use, more dependable, and speeds up the loading of mooring lines to a degree not possible with previous releasing hooks.

The shock and impact of tight lines being released is reduced markedly by the decreased load on the line as the hook moves forward before it trips. A fail-safe interlock mechanism provides for manual release in case of power failure.

It is an object of this invention to provide a release hook that may be controllably retained in any position from open to close. It is a further object to provide a hook that is rugged in design and has few moving parts. It is a further object of the invention to provide a hook that will automatically reduce tension in the mooring line prior to release of the line. It is a further object to provide a' hook that can be partially or fully cycled without a power source. 7

FIG. 1 is a perspective view, partly cut away to show the essential operating mechanism of the hook;

FIG. 2 is a side elevation;

FIG. 3 is a top plan view with the cover partly'cut away;

FIG. 4 is a sectional elevation illustrating the hook in a fully closed position; I

FIG. 5 is a sectional elevation showing the hook partly extended;

FIG. 6 is a sectional elevation showing the hook in the act of releasing;

FIG. 7 is a sectional elevation showing the hook in a full release position;

FIG. 8 is a schematic diagram of the remote control system;

FIG. 9 is a wiring diagram of the electrical control system;

FIG. 10 is a plan view of the remote control box; FIG. 11 is'an elevation of the remote control box; FIG. 12 is an elevation taken at line 12-12 of FIG.

FIG; 13 is an elevation view of an attachment means for the hook assembly, partially broken away to show-- the attaching bolt; and

FIG. 14 is a plan view taken at line l4-14 of FIG. 13.

It will be seen that the hook construction is symmetrical about its longitudinal center line; that is, portions of the mechanism on either side of the center line are mirror images of each other.

Referring now to FIGS. I-4 and 12 the hydraulic release hook assembly 10 comprises a generally U- shaped hook 12 having a main body portion 14, a first leg 16 and a second leg 18. The end 20 of the first leg 16 and the end 22 of second leg 18 are substantially rounded. Within the arc formed by the U-shaped hook l2, and adjoining end 22, is a flat contact surface 24. The plane of contact surface 24 is approximately horizontal when the hood assembly 10 is in a closed position as indicated in FIG. 1. The first leg 16 has mirror image flat sides 28, which tend to converge toward end 20. Second leg 18 has mirror image flat sides which tend to converge toward end 22. Between the outer arcuate edges of sides 28, there is a surface 32.

The frame 34 comprises two parallel, spaced apart, mirror image sides 36. The sides 36 are joined at the bottom by horizontal base 38, having a flat upper surface 40. Extending across the upper portion of the space between sides 36 there is a guide 42. The guide 42 is stationary with respect to the sides 36 and is firmly affixed thereto. The guide 42 has a flat lower surface 44.

Each of the sides 36 has a sloping right end' 46 and a curved right lowerend portion 48. The curved end 48 is below the sloping end 46. Centrally located within the are formed by curved end 48 is-a transverse pivot hole 50. symmetrically disposed around the pivot hole 50, on the facing surface of each of the sides 36, is a boss 52. The purpose of the pivot holes 50 is to provide accomodation for a means whereby the hook assembly 10 may pivot vertically as illustrated in FIG. 7.

There is a top cover plate 53, made of relatively light sheet metal, extending across the top of the hook assembly 10 as illustrated in FIGS. 1, 3, and 13. There is a rear cover plate 55, also made of relatively light sheet metal, extending across the sloping rear 46 of the hook assembly 10. The

cover plates

53 and 55 are secured in place by suitable screws 57.

Slidable between the sides 36 is a pair of spaced apart drag links 54. The drag links 54 are joined at one end by the pin 26, and at the other end by a pin 56. Hook 12 rotates on pin 26 between drag links 54. The drag links 54 are also joined approximately midway of their length, by a restraining rod 59 extending across the space between the drag links 54. Rotatably mounted on pin 56, between drag links 54, is cross head 58, having a center block 60 and transversely extending arms 62. In each of the sides 36 there is a rectangular slot 63. The arms 62 extend through slots 63 as can be seen in FIGS. 2 and 3. In the upper surface of center block 60 is a notch 64 defined by two conjoining, downwardly extending

ramps

66 and 68, as can best be seen in FIGS. -7.

There is a pin 70 mounted so as to extend across the space between opposite sides 36. There is a latch 72 rotatably mounted on pin 70. Latch 72 has a counterweight 74 at one end and a ramp 76 at the other end. The bottom surface 78 of latch 72 is flat. The included angle between

ramps

66 and 68 of the center block 60 is approximately the same as the included angle between ramp 76 and bottom surface 78 of latch 72. It can be seen in FIGS. 1, 4, and 5, that when the hook assembly is in a closed position, the latch 72 will fall into notch 64 in center block 60 to prevent opening motion of the hook 10. The purpose of counterweight 74 is to reduce the force required to rotate latch 72 in a counterclockwise direction.

There is a bridge plate 80 extending across the top of sides 36. Mounted in the center of the bridge plate 80 is a solenoid 82 having a plunger 84. When the solenoid 82 is electrically energized, the plunger 84 is in the retracted position shown in FIGS. 6-8. At the lower end of plunger 84 is a horizontally extending finger 86. The finger 86 extends through eye 88 in latch 72. When the plunger 84 is retracted as shown in FIGS. 5, 6, and 7, the finger 86 lifts latch 72 out of engagement with crosshead 58.

At the other end of the plunger 84 from finger 86, is a ring handle 90. The handle 90 is useful in the event of electrical power failure. The plunger 84 can be retracted manually, thereby rotating latch 72 out of engagement with crosshead 58.

At one end of each of sides 36 are extensions 94. Extending outwardly from base 38 are wings 96. Firmly attached to each extension 94 and wing 96 is a cylinder support 98 having an ear 100. A cylinder 102 is rotatably mounted on pin 104 which extends through ear 100. Slidable within cylinder 102 is a piston (not shown except schematically in FIG. 8). Attached to the piston is a piston rod 106. The piston rod 106 is attached to arm 62 of crosshead 58. At either end of the cylinder 102 are

ports

108 and 109 for passage of hydraulic fluid in and out of the cylinder 102. Position of the piston within the cylinder 102 is controlled by controlling the flow of hydraulic fluid under pressure to and from the cylinder 102 through the

ports

108 and 109. When the piston is caused to move by hydraulic pressure, piston rod 106 will move crosshead 58, causing drag link 54 to move in the same direction as the piston rod 106. Hook 12 follows the motion of drag link 54.

Operation of the hook assembly 10 is illustrated in FIGS. 4 7. In FIG. 4, the hook assembly 10 is shown' in a fully closed position as it would be when a mooring line 92 is secured and is taking a strain. Second leg 18 is beneath guide 42 with surface 24 of second leg 18 in contact with surface 44 of guide 42. Second leg 18 is also in contact with restraining rod 59. Piston rod 106 (FIGS. 1-3) would be fully extended. Latch 72 is resting in notch 64 of crosshead 58. Solenoid 82 is not electrically energized. In order to release a mooring line 92, the latch 72 is lifted by energizing solenoid 82. The

crosshead 58 can then be moved by the piston rod 106 allowing drag link 54, and thus hook 12, to slide to the left as shown in FIG. 5. As movement to the left progresses, end 22 of hook 12 will reach a point where it can rotate in a counterclockwise direction free of guide 42, as illustrated by arrow A of FIG. 6. It will be noted, in FIGS. 4 and S, that when surface 24 is in contact with surface 44, second leg 18 is in contact with the surface 40. When counterclockwise rotation begins, as shown in FIG. 6, no portion of the outer arcuate surface of hook 12 is in contact either with the surface 40 of base 38, or with the ground or dock surface indicated by reference line B on which the hook assembly 10 normally rests. At some point during the counterclockwise rotation of hook 12, a point on surface 32 of first leg 16 will touch the ground B. Under the influence of inertia, as well, possibly, as the continued influence of the mooring line 92, the hook 12 will continue to rotate in a counterclockwise direction. The curvature of surface 32 on first leg 16 is such that, as counterclockwise rotation continues after surface 32 contacts the ground B, pin 26 is forced upward. Upward movement of pin 26 causes the hook assembly 10 to rotate around pivot hole 50, and the hook assembly 10 is lifted off the ground B. The weight of the hook assembly 10, acting downward through pin 26 as indicated by arrow C, then exerts a moment around point D where surface 32 contacts ground B. Point D refers to any point where hook 12 contacts the ground B. A dynamic couple is thus formed, with the other member of the couple being the moment exerted by the weight of the hook l2 acting vertically through its center of gravity. The moment of hook assembly 10 eventually overcomes the moment of hook 12, so that the hook 12 is caused to change its direction of rotation from counterclockwise to clockwise as indicated by arrow E in FIG. 7. The hook assembly 10 will then, of its own momentum, return to a position where the hook 12 may be retractedto a closed position.

Hydraulic pressure to operate the hook assembly 10 is supplied by a conventional commercial power pack (not shown, except schematically in FIG. 8). The commercially procurable power pack may comprise an electric motor, a motor starter, an oil pump driven by the motor, an oil tank and an electrically operated fourway solenoid valve to control the direction of the flow of hydraulic fluid to the cylinders 102.

The hydraulic circuit is indicated schematically in FIG. 8. There is a motor driven pump 110 supplying pressure to tank 112. Hydraulic fluid from tank 112 is supplied to solenoid valve 114. Under electrical impulse (to be described below) the solenoid valve may act to direct the flow of fluid through tube 116 in the direction indicated by the arrow on the tube 116. At the same time, solenoid valve 114 will be in a position to receive hydraulic fluid coming from tube 118 in the direction indicated by the arrow on tube 118. It can thus be seen that a piston 101 within cylinder 102, slidable between

ports

108 and 109, can be moved by a controlled flow of hydraulic fluid.

The electric circuit to control linear movement of the hook 12 is illustrated schematically in FIG. 9. The circuitry illustrated in FIG. 9 would be contained within a control box, a preferred embodiment of which is illustrated in FIGS. 10 and 11. FIGS. 10 and 11 show a control box 126 having an electrical lead 128 issuing therefrom. Mounted in the cover 130 of control box 126,

. are closed when the button in the switch is depressed,

and are open at all other times.

Referring back now tolFlG. 9, there are incoming electrical lines L1 and L2 from a source of electrical power (not shown). The voltage is preferably 110 volts of alternating current, although other voltages may be used, and direct current may be used depending on the requirements of the power pack selected. There is a key-operated switch 132 which, when closed, completes a circuit to the pump motor 110, causing the motor to start, whereupon the pressure of hydraulic fluid'is built up within tank 112 and valve 114. Closing of switch 132 also provides a source of electricity to the terminals of push-

button switches

134, 136 and 138. When push-button switch 134 is closed (depressed), a circuit is completed to solenoid valve 114 so as to direct hydraulic fluid into cylinders 102 through ports 109, thereby tending to move the hook 12 in an opening direction. Push-button switch 136 controls electricity to the solenoid 82. When switch 136 is closed, solenoid 82 is energized, raising plunger 84 and latch 72. Pushbutton switch 138 can complete a circuit to solenoid valve 1 14, so as to direct hydraulic fluid into cylinders 102 through ports 108, thereby tending to move the hook in a closing direction. Push-

button switches

134 and 138 are interlocked so that if both are depressed simultaneously, neither will be able to complete a circuit.

When the hook assembly is in the position shown in FIG. 12, that is when latch 72 is engaged with crosshead 58 so as to prevent opening motion of the hook, it may be necessary to move the hook in a closed direction before the latch 72 can be raised by solenoid 82.

draulicvalve 114 hasmeans to control the four-way valve position manually so that the flow of fluid may be directed in the direction of the arrows in FIGS, or may be directed in the reverse direction selectively. In FIG. 8 there is shown a hand pump 120 connected to tubing 116 and to tank 112. To release the hook without electrical power, the four-way valve is manually moved to a position which will direct the flow of fluid as indicated by the arrowsin FIG. 8. Flow in that direction would tend to move the hook 12 in a closing direction. Then, the handle 90 of solinoid 82 is pulled upwards manually. At the same time, a couple of strokes of the hand pump 120 will provide sufficient pressure to move the hook, 12 in a closing direction so as to enable latch 72 to be rotated clear of crosshead 58. The four-way v 12 will cause the pistons 101 to move in the cylinders 102 in such a direction as to cause hydraulic fluid to move in a direction opposite to that indicated by the arrows in FIG. 8. In effect, under these conditions, when the hook 12 is moving in a releasing direction without a hydraulic pump operating, the pistons 10] act as a pump under the influence of the mooring line 92 acting on hook 12. i

The releasable hydraulic hook assembly 10 may be secured to a stationary structure in the manner illustrated in FIGS. 13 and 14. There is a fastening plate fastened by bolts or lag screws (not shown) through holes 142 to a horizontal surface of a stationary structure (not shown). Extending upwardly from the plate 140 is a fastening post 144 supported by reinforcing ribs 146. Fastening post 144 has the shape of a hollow semicylinder. Extending outwardly from the top of fastening post 144 is cap 148. Cap 148 has the shape of a circular disc. Extending through the center of cap 148 is a passageway 150. In fastening plate 140 there is a threaded passageway 152, aligned axially with passageway 150 and cap 148. A threaded bolt 154, having a head 156, is located through passageway 150 and threaded in passageway 152. Bolt 154 supports a mounting member 158. Mounting member 158 comprises a barrel 160 and an outwardly and downwardly depending arm 162. Am 162 has a rounded end 164, having therein a passageway 166. The hook assembly 10 is rotatably secured to mounting arm 162by means of a pin 168 passing through passageway 166 and mounting arm 162 and through passageways 50 in hook assembly 10.. Pin 168 is rotatable with respect to both the hook assembly 10 and the mounting arm 162. It is understood thatthe hook assembly 10 may be secured to a stationary structure in any manner which will'permit it to pivot vertically and horizontally. The arrangement illustrated in FIGS. 13 and '14 is merely one of many ways in which this can be done.

I claim: 1. A releasable hook, said releasable hook comprising:

a. a frame; i v

b. a generally U-shaped hook having a first leg and a second leg;

c. a movable carriage;

d. a-first means connecting said U-shaped hook and said movable carriage to mount said U-shaped hook on said movable carriage;

e. said U-shaped hook being capable of rotating with respect to said movable carriage;

f. a second means connecting said movable carriage and said frame;

g. said second means being capable of moving said movable carriage with respect to said frame.

2. A releasable hook according to claim 1, said releasable hook comprising:

a. said second means comprising a fluid actuated cylinder and plunger. r

3. A releasable'hook according to claim 1, said releasable hook comprising:

a. said movable carriage having a third means; v

b. said third means being a catch means;

c.' a fourth means;

d.'said fourth means being a catch means;

e. a fifth means connecting said frame and said fourth means; and,

f. said fourth means being capable of rotating so as to be in engagement with said third means to prevent movement of said movable carriage and so as to be out of engagement with said catch means to allow movement of said movable carriage with respect to said frame.

4. A releasable hook according to claim 3, said releasable hook comprising:

a. a sixth means connecting with said fourth means and for rotating said fourth means; and,

b. said sixth means being capable of rotating.

5. A releasable hook according to claim 4, said releasable hook comprising:

a. said sixth means comprising an electrical solenoid.

6. A releasable hook according to claim 1, said releasable hook comprising:

a. said second means comprising a hydraulic actuated cylinder and plunger; and,

b. a motor and a pump and a valve connecting with said second means for moving said plunger and cylinder with respect to each other.

7. A releasable hook according to claim 1, said releasable hook comprising:

a. said frame comprising a base and two spaced apart sides;

b. said movable carriage comprising two spaced apart drag links and a crosshead;

c. said drag links being on the outside of said U- shaped hook;

d. said first means connecting said drag links and said U-shaped hook;

e. a means connecting said drag links and said crosshead;

f. said second means connecting said frame and said crosshead; and,

g. said drag links capable of moving between said two spaced apart sides.

8. A releasable hook according to claim 7, said releasable hook comprising:

a. said crosshead of said movable carriage having a third means;

b. said third means being a catch means;

c. a fourth means;

d. said fourth means being a catch means;

e. a fifth means connecting said frame and said fourth means; and,

f. said fourth means being capable of rotating so as to be in engagement with said third means to prevent movement of said movable carriage and so'as to be out of engagement with said third means to allow movement of said movable carriage with respect to said frame.

9. A releasable hook according to claim 8, said releasable hook comprising:

b. said sixth means being capable of rotating.

10. A releasable hook according to claim 9, said releasable hook comprising:

a. said sixth means comprising an electrical solenoid.

11. A releasable hook according to claim 10, said releasable hook comprising:

a. said second means comprising a hydraulic actuated cylinder and plunger; and,

12. A releasable hook according to claim 11, said releasable hook comprising:

a. an electrical circuit for connecting said motor and said valve to a source of power and for controlling selectively the movement of said fourth means and said hook.

113. A releasable hook according to claim 11, said releasable hook comprising:

a. a portable electric control console; and,

b. said console containing circuitry for connecting said pump and said valve to a source of power and for energizing said sixth means and for controlling selectively the movement of said hook.

14. A releasable hook according to claim 7, said releasable hook comprising:

a. a guide connecting said two spaced apart sides of said frame;

b. said first leg capable of moving between said two spaced sides;

0. said U-shaped hook being of such a configuration that said first leg causes said U-shaped hook to rotate around said first means to have the second leg above said first leg; and,

d. said first leg being capable of moving in a groove defined by said two spaced apart sides and said guide.

15. A releasable hook according to claim 14, said releasable hook comprising:

a. said crosshead of said movable carriage having a third means;

b. said third means being a catch means;

0. a fourth means;

d. said fourth means being a catch means;

e. a fifth means connecting said frame and said fourth means; and,

f. said fourth means being capable of rotating so as to be in engagement with said third means to prevent movement of said movable carriage and so as to be out of engagement with said third means to allow movement of said movable carriage with respect to said frame.

16. A releasable hook according to claim 15, said releasable hookcomprising:

b. said sixth means being capable of rotating.

1.7. A releasable hook according to claim 16, said releasable hook comprising:

a. said sixth means comprising an electrical solenoid.

1s. A releasable hook according to claim 17, said releasable hook comprising:

a. said second means comprising a hydraulic actuated cylinder and plunger; and, b. a motor and a pump and a valve connecting with and for positioning said fourth means. 20. A releasable hook according to claim 18, said releasable hook comprising:

b. an eighth means connecting with said frame to allow said frame to rotate in a second plane; and,

c. said first and said second planes being substantially at ninety degrees to each other.

Claims

1. A releasable hook, said releasable hook comprising: a. a frame; b. a generally U-shaped hook having a first leg and a second leg; c. a movable carriage; d. a first means connecting said U-shaped hook and said movable carriage to mount said U-shaped hook on said movable carriage; e. said U-shaped hook being capable of rotating with respect to said movable carriage; f. a second means connecting said movable carriage and said frame; g. said second means being capable of moving said movable carriage with respect to said frame.

2. A releasable hook according to claim 1, said releasable hook comprising: a. said second means comprising a fluid actuated cylinder and plunger.

3. A releasable hook according to claim 1, said releasable hook comprising: a. said movable carriage having a third means; b. said third means being a catch means; c. a fourth means; d. said fourth means being a catch means; e. a fifth means connecting said frame and said fourth means; and, f. said fourth means being capable of rotating so as to be in engagement with said third means to prevent movement of said movable carriage and so as to be out of engagement with said catch means to allow movement of said movable carriage with respect to said frame.

4. A releasable hook according to claim 3, said releasable hook comprising: a. a sixth means connecting with said fourth means and for rotating said fourth means; and, b. said sixth means being capable of rotating.

5. A releasable hook according to claim 4, said releasable hook comprising: a. said sixth means comprising an electrical solenoid.

6. A releasable hook according to claim 1, said releasable hook comprising: a. said second means comprising a hydraulic actuated cylinder and plunger; and, b. a motor and a pump and a valve connecting with said second means for moving said plunger and cylinder with respect to each other.

7. A releasable hook according to claim 1, said releasable hook comprising: a. said frame comprising a base and two spaced apart sides; b. said movable carriage comprising two spaced apart drag links and a crosshead; c. said drag links being on the outside of said U-shaped hook; d. said first means connecting said drag links and said U-shaped hook; e. a means connecting said drag links and said crosshead; f. said second means connecting said frame and said crosshead; and, g. said drag links capable of moving between said two spaced apart sides.

8. A releasable hook according to claim 7, said releasable hook comprising: a. said crosshead of said movable carriage having a third means; b. said third means being a catch means; c. a fourth means; d. said fourth means being a catch means; e. a fifth means connecting said frame and said fourth means; and, f. said fourth means being capable of rotating so as to be in engagement with said third means to prevent movement of said movable carriage and so as to be out of engagement with said third means to allow movement oF said movable carriage with respect to said frame.

9. A releasable hook according to claim 8, said releasable hook comprising: a. a sixth means connecting with said fourth means and for rotating said fourth means; and, b. said sixth means being capable of rotating.

10. A releasable hook according to claim 9, said releasable hook comprising: a. said sixth means comprising an electrical solenoid.

11. A releasable hook according to claim 10, said releasable hook comprising: a. said second means comprising a hydraulic actuated cylinder and plunger; and, b. a motor and a pump and a valve connecting with said second means for moving said plunger and cylinder with respect to each other.

12. A releasable hook according to claim 11, said releasable hook comprising: a. an electrical circuit for connecting said motor and said valve to a source of power and for controlling selectively the movement of said fourth means and said hook.

13. A releasable hook according to claim 11, said releasable hook comprising: a. a portable electric control console; and, b. said console containing circuitry for connecting said pump and said valve to a source of power and for energizing said sixth means and for controlling selectively the movement of said hook.

14. A releasable hook according to claim 7, said releasable hook comprising: a. a guide connecting said two spaced apart sides of said frame; b. said first leg capable of moving between said two spaced sides; c. said U-shaped hook being of such a configuration that said first leg causes said U-shaped hook to rotate around said first means to have the second leg above said first leg; and, d. said first leg being capable of moving in a groove defined by said two spaced apart sides and said guide.

15. A releasable hook according to claim 14, said releasable hook comprising: a. said crosshead of said movable carriage having a third means; b. said third means being a catch means; c. a fourth means; d. said fourth means being a catch means; e. a fifth means connecting said frame and said fourth means; and, f. said fourth means being capable of rotating so as to be in engagement with said third means to prevent movement of said movable carriage and so as to be out of engagement with said third means to allow movement of said movable carriage with respect to said frame.

16. A releasable hook according to claim 15, said releasable hook comprising: a. a sixth means connecting with said fourth means and for rotating said fourth means; and, b. said sixth means being capable of rotating.

17. A releasable hook according to claim 16, said releasable hook comprising: a. said sixth means comprising an electrical solenoid.

18. A releasable hook according to claim 17, said releasable hook comprising: a. said second means comprising a hydraulic actuated cylinder and plunger; and, b. a motor and a pump and a valve connecting with said second means for moving said plunger and cylinder with respect to each other.

19. A releasable hook according to claim 18, said releasable hook comprising: a. a manual means connecting with said fourth means and for positioning said fourth means.

20. A releasable hook according to claim 18, said releasable hook comprising: a. a manual means connecting with said second means for moving said plunger and said cylinder with respect to each other.

21. A releasable hook according to claim 1, said releasable hook comprising: a. a seventh means connecting with said frame to allow said frame to rotate in a first plane; b. an eighth means connecting with said frame to allow said frame to rotate in a second plane; and, c. said first and said second planes being substantially at ninety degrees to each other.