US3750610A

US3750610A - Motor-driven anchor davit

Info

Publication number: US3750610A
Application number: US00073059A
Authority: US
Inventors: C Davis
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-09-17
Filing date: 1970-09-17
Publication date: 1973-08-07
Anticipated expiration: 1990-08-07

Abstract

A motor-driven anchor davit mounted on a boat deck includes an anchor socket mounted on a drive shaft to pivot through a vertical plane between inboard and outboard positions. The anchor is guided into alignment with the socket at its entrance opening and slidably received thereinto by retracting a cable or line attached to the anchor. The socket is keyed to the shaft but has a limited degree of free swing on the shaft in the outboard position and inboard position and resilient means cushions between the shaft key and socket mount. When the anchor is positioned in the socket a motor drive including a gear train which is coupled between a motor shaft and the drive shaft is operative to pivot the socket vertically between said positions. A control circuit includes a power control switch to initiate motor drive movement in either direction from a point remote from the socket and trip members connected in the circuit are moved in response to the movement of the anchor socket to automatically stop the motor drive when the anchor socket approaches either of said positions.

Description

United States Patent [191 Davis [451 Aug. 7, 1973 MOTOR-DRIVEN ANCHOR DAVIT Charles F. Davis, 711 Bain Station Rd., Kenosha, Wis. 53140 [22] Filed: Sept. 17, 1970 [21] Appl. No.: 73,059

[76] Inventor:

Primary Examiner-Milton Buchler Assistant Examiner-Galen L. Barefoot Attorney-Reilly and Lewis [57] ABSTRACT A motor-driven anchor davit mounted on a boat deck includes an anchor socket mounted on a drive shaft to pivot through a vertical plane between inboard and outboard positions. The anchor is guided into alignment with the socket at its entrance opening and slidably received thereinto by retracting a cable or line attached to the anchor. The socket is keyed to the shaft but has a limited degree of free swing on the shaft in the outboard position and inboard position and resilient means cushions between the shaft key and socket mount. When the anchor is positioned in the socket a motor drive including a gear train which is coupled between a motor shaft and the drive shaft is operative to pivot the socket vertically between said positions. A control circuit includes a power control switch to initiate motor drive movement in either direction from a point remote from the socket and trip members connected in the circuit are moved in response to the movement of the anchor socket to automatically stop the motor drive when the anchor socket approaches either of said positions.

10 Claims, 9 Drawing Figures PATENIEUMIR 7 I975

sum

1 or 2 INVENTOR CHARLES E DAV/5 BY K4 M i ATTORNEYS ATTORNEYS PATENIEuAus

nan sum

2 or 2 .l fi' OUTBOARD O84 MOTOR-DRIVEN ANCHOR DAVIT This invention in general relates to anchor hoists for boats and more particularly to a novel and improved remotely controlled, motor-driven anchor davit for a boat anchor.

A variety of anchor davits have heretofore been devised to facilitate the launching and retrieving of a boat anchor from within the boat. In my previous patent application Ser. No. 767,595 entitled Weight for Boat Anchor," now U.S. Pat. No. 3,554,153, issued Jan. 12, I971, a pivotal anchor socket is mounted on the deck of the boat and arranged so that the shank of the anchor is first drawn into a chamber in an anchor socket by a rope or cable from a point on the boat inboard of the davit whereupon the anchor socket is pivoted vertically from an outboard position to an inboard position by manually retracting the cable attached to the end of the anchor shank, and a spring-biasing arrangement serves to move the socket from the inboard to the outboard position when the cable is released. While this approach is satisfactory for some applications, there are difficulties attendant to a manually operated davit, particularly from the standpoint of convenience, safety and speed of operation.

Accordingly, it is an object of this invention to provide a novel and improved motor-driven anchor davit.

Another object of this invention is to provide a motor-driven anchor davit which can be operated from a convenient location within the boat, such as, while at the driver's station and permits positive driving of the anchor through a vertical plane between inboard and outboard positions on the boat.

Yet a further object of this invention is to provide a novel-and improved remotely controlled, motor-driven anchor davit which may be used in combination with a variety of types of anchors.

In accordance with the present invention, in a preferred embodiment there is provided a vertically pivotal anchor socket for receiving an anchor to positively move it between an outboard, downwardly directed position away from the boat deck to an inboard horizontally directed position. The anchor socket is keyed for rotation through a vertical plane about a horizontally mounted drive shaft over a predetermined distance of travel but has a limited degree of free swing on the shaft at opposite end limits of movement to permit indepen-. dent movement of the socket with respect to the retrieved shaft so as to avoid undue strain on the gear train coupled to the drive shaft. An externally reversible motor drive preferably is coupled to a worm which drives a worm gear mounted on the drive shaft to rotate the shaft. A reversible power control switch preferably located at the driver's station and connected in a control circuit for the motor drive will selectively regulate the movement of the anchor socket toward either position, and radially spaced trip members movable with the socket actuate a trip switch connected in the control circuit when the socket approaches the outboard or inboard positions to automatically stop the motor drive after a predetermined amount of shaft rotation, after which the socket is free to move a limited distance independently of the shaft.

Other objects, advantages and capabilities of the present invention will become more apparent as the description proceeds taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a side elevation view of a motor-driven anchor davit mounted on the bow of a boat deck shown with an anchor retracted into the anchor socket;

FIG. 2 is a sectional view taken along the lines 2-2 of FIG. 1;

FIG. 3 is a horizontal sectional view taken along the lines 3-3 of FIG. 1;

FIG. 4 is an enlarged sectional view taken along lines 4-4 of FIG. 3;

FIG. 5 is a sectional view taken along lines 5-5 of FIG. 4;

FIG. 6 is a sectional view taken along lines 6-6 of FIG. 3;

FIG. 7 is a sectional view taken along lines 77 of FIG. 1;

FIG. 8 is a sectional view taken along lines 88 of FIG. I; and

FIG. 9 is a remote-controlled schematic control circuit diagram for the motor drive.

Referring now to the drawings, the anchor davit I0 is shown mounted on the bow of a boat deck 11 adjacent the outer edge and comprises a boat mount inclu sive of a flat base-plate 13 secured to the boat with vertical bolts 14, and a pair of upstanding outer

side support plates

15 and 16 are positioned in spaced parallel relation to one another along opposite sides of the base plate and project forwardly beyond the outer end of the base plate to overhang the edge of the boat. A drive shaft 17 has'its ends journaled in

bearings

18 and 19 in

side support plates

15 and 16, respectively, to be supported for rotational movement on a horizontal axis above and parallel to the base plate 13. A gear casing is provided above one side of the base plate which includes an intermediate upright support plate 21 between

plates

15 and 16 and a top wall 22 extending across the tops of plates 15 and 2-1 and end walls23 at the ends of the

side support plates

16 and 21. A bearing 20 in the intermediate wall 21 serves as an intermediate support for the drive shaft 17. Abutting portions of the plates forming the casing may be releasably fastened using bolts or like fasteners to permit access to interior parts within the casing.

An anchor socket 25 is mounted on the drive shaft 17 for vertical pivotal movement thereon between an outboard position in which it depends downwardly and outwardly away from the shaft and an inboard position extending inwardly and horizontally usually along the boat deck, as shown in dashed lines in FIG. I. An offset mounting for securing the socket to the drive shaft includes a transverse sleeve 26 secured at the inner end and along an inner side of the socket. The position of the sleeve in an offset position relative to the longitudinal axis of the socket permits the socket to be directed downwardly and away from the edge of the boat in a vertical direction with less overhang and affords better leverage in withdrawing the anchor to the inboard position. Sleeve 26 is keyed to the shaft for rotation therewith by an inner keyway 27 and the rotary motion of the motor shaft is imparted to the sleeve via a key 28 affixed to the drive shaft which cooperates with the keyway 27. The keyway 27 is enlarged so as to be substantially wider than the width of the key and the key is positioned on the shaft so that the sleeve has a limited degree of free travel or swing independently of the shaft when the socket is in its inboard and outboard positions.

Resilient cushion members

29 and 31 in the form of flexible, neoprene inserts arefitted in the keyway on each side of the key to provide a cushion effect between the sleeve and key.

The keyway 27 and key 28 are located so that the shaft will at least move the socket past a vertical center line and its weight will then carry it toward the inboard or outboard positions. Cushion 29 is shown in FIG. 4 as being compressed between the edge of the keyway and the key and in this position the socket may rest on the base plate 13. The socket is then free to swing upwardly on the shaft to the extent of the distance between cushion 31 and key 28. Usually when the anchor has been set in the water the line will be pulled to a flatter angle to the horizontal than the sharp incline of the outboard position of the anchor socket shown in FIG. 1. This limited degree of free swing may be as much' as 60 and permits the socket to follow a taut anchor line, the angle of inclination of which will depend on the position of the anchor relative to the boat and in the outboard position will thus serve to avoid undue tension on the drive shaft, key, sleeve and gear train mechanism and facilitate some free swing to align the anchor with the socket in retrieving the anchor.

As the shaft 17 is rotated upwardly from that shown in FIG. 4 toward the inboard position the key bears against the cushion member until the socket passes a center position and at this point the weight of the socket and anchor causes the sleeve to slip downwardly relative to the shaft and cushion'member 31 now becomes compressed between the side of the keyway and key. As the shaft 17 is further rotated the socket now follows the shaft ;with its weight moving it toward an at rest or inboard position which is generally horizontal and inwardly directed from the shaft. Once the socket reaches this position a trip switch hereafter described causes the motor to stop. Presumably there the cushion member will remain compressed between the key and keyway in the inboard position and the socket will have limited free swing independently of the shaft to the extent of the distance between cushion member 29 and the key. in the reverse sequence as soon as the direction of shaft rotation reverses key 28 is bearing against the cushion member and starts the socket rotating upwardly and this continues until the socket goes past the vertical center position at which time the socket swings relative to the shaft and cushion member 29 is again compressed between the key and keyway and the ;weight of the anchor and socket causes it to follow further movement of the shaft until the motor is stopped. it should also be observed that the shaft key may be advanced to a position between the cushion members prior to stopping the motor which permits some variation in the amount of free swing afforded the socket in either the outboard or inboard positions.

The anchor socket 25 takes the form of a generally tubular body with an inner chamber defined by a top wall 36, bottom wall 37 and parallel side walls 38 and terminates in an anchor-receiving opening 39 at one end and a line opening 40 at the other end adjacent the transverse sleeve 26. A conventional anchor is shown in the retracted position in the socket 25 and includes a shank 41 in the form ofa rod folded or doubled back upon itself to provide a forward bend 42 together with spaced upper and

lower rod sections

43 and 44. The rod section's extend rearwardly from the bend in a generally parallel relation and then diverge slightly to their rear terminal ends and have a support housing 45 disposed between their rear extremities. A fluke 46 is carried at the lower end of the shank and is pivotally mounted on a pivot member 47 supported in the housing 45 in the space between the rod sections. Fluke 46 has relatively flat forwardly convergent fluke sections 46a and 46b extending laterally on each side of the shank which are positioned to extend on a forward and downward incline to penetrate the soil. A line ring 48 is interlooped in the shank and will slide freely over the shank rod and normally be pulled against the inner surface of the forward bend 42 when the anchor is out. A cable or line 49 is shown as tied to the ring 48 and it extends upwardly through the socket, passes through line opening 40 and slidably moves along the upper exterior surface of sleeve 26 to a forward position in the boat to be grasped by the driver in the boat. In this way the sleeve also acts as a guide surface for the anchor line.

As best seen in FIG. 7, the top wall 36 of the socket generally bows outwardly and carries a pair of spaced, inwardly

convergent guides

51 and 52 disposed slightly inwardly of anchor-receiving opening 39. These guides serve to center the line 49 in the socket as it is moved therethrough and guide the ring 48 to a flat position parallel to the top and bottom walls as well as guide the upper portion of the shank as it is pulled therethrough. The bottom wall 37 also generally bows outwardly and terminates at its outer end in an outwardly curved lip 54 which serves to eliminate line fraying. The bottom wall 37 has an elongated slot 55 extending longitudinally thereof bounded by outwardly flared side edges 37a. Slot 55 terminates slightly inwardly of the lip 54 and upper end of the bottom wall. The retracting of the anchor into the socket is carried out by manually pulling on the line from a point in the boat and the anchor ring 48 is first drawn into the lower open end 39 followed by the shank. The shank of the socket is sufficiently wide at its upper end so that the lower section 44 will slide through the slot 55 in a guided sliding engagement with flared edges 37a and at the same time guides 51 and 52 will engage the sides of the upper section 43 of the shank and in this way the socket is properly aligned at the entrance of opening 39 so that further pulling on the line provides a guided movement of the shank in the socket. The anchor stops with the ring adjacent line opening 40, as best seen in FlG. 3. The portion of slot 55 in lip 54 serves to assist in holding the anchor in the socket during its initial rotation about the drive shaft from the outboard position.

The motor drive apparatus shown for moving the socket once the anchor is retracted as shown includes a conventional D.C. reversible gear motor represented schematically at 61 preferably located below the deck of the boat with its output shaft connected to a flexible cable 62. Cable 62 in turn is coupled by a coupling 63 to a vertical shaft 64 extending up through the deck. A worm 65 located within the gear casing above the deck is mounted on the vertical shaft 64. A worm gear 66 is mounted on the horizontal drive shaft at right angles to the worm and meshes with the worm to transfer rotary motion from the worm to the worm gear. The gear motor 61 is conventional and is comprised of a reversible electric DC. motor having its output shaft coupled to a gear box to change the output speed and torque characteristics. The combination of the gear box on the gear motor and worm and worm gear reduces the speed of the motor to provide for a relatively slow rotational movement of the socket.

An electric power supply for the gear motor is represented schematically as a storage battery 67 which may be disposed at a convenient location above or below the boat deck. The movement of the gear motor 61 is regulated by the activation of a conventional reversing switch 68 located remotely from the socket for handy access to the driver such as on the drivers instrument panel and a trip switch 69 positioned on the base plate in the gear casing. Generally, the reversing switch is connected in the power control circuit between the battery and the gear motor 61 in such a way as to reverse the connections between the battery terminals and the motor terminals and the trip switch 69 functions to open the inboard and outboard control portions of the power circuit when the anchor socket approaches either the inboard or outboard positions as described hereinafter.

Referring now to the schematic diagram, the reversing switch 68 may be represented as having two simultaneously movable contact arms 71 and 72 each connected to one of the battery terminals. Each contact arm is alternately engageable with one of a set of stationary contacts with one set being designated 03-1 and lB-l and the other set being engageable by arm 72 and designated 0B-2 and lB-2. Contacts 08-1 and 08-2 are connected in an outboard circuit to connect battery power for socket movement toward the outboard position. Contacts lB-l and lB-2 are connected in an inboard circuit to apply a reverse polarity from the battery to the motor terminals for socket movement toward the inboard position. The trip switch 69 is shown as having a toggle arm 73 which is spring-loaded to be at rest in a vertical position. This is an on position in that the control circuit is closed and the motor will rotate in one direction. A pair of radially spaced

trip members

75 and 76 are mounted on the outer face of the worm gear and are positioned relative to the position of the socket, sleeve 26, key 28 and key way 27 to move or trip the toggle arm 73 to one side when the socket approaches the outboard position as shown and to trip the toggle arm to the other side when the socket approaches the inboard position. As above described the trip members are preferably mounted so that the uppermost cushion member is under compression between the key and keyway although it is understood that they may be positioned to be driven to a position between the cushion members. In either of what are referred to as the inboard or outboard positions for the socket the trip switch 69 is moved by a trip member to remove the power from the motor terminals so each side position for the toggle arm is an off position. The trip switch 69 is represented schematically in H6. 8 as a pair of switches designated 69a and 69b. As shown in FIG. 9 the switch 69a is connected in the outboard circuit between the 08-1 and 08-2 contacts. The anchor 25 is represented in FIG. 9 as in an intermediate position and in this event both switches 69a and 69b are closed. However, as soon as the socket approaches the outboard position and arm 73 is moved to one side as shown in FIG. 6, then switch 690 opens to stop the motor. In turn switch 6% is connected in the circuit with contacts 18-! and 18-2 and remains closed at all times until trip member 75 moves to open it as the socket approaches the inboard position.

In the entire sequence of operation ofthe socket with the anchor manually retracted into the socket as above described, consider switch contact arms 71 and 72 are set in the outboard position shown and the motor is driving the socket toward the outboard position. Power is connected to the motor 61 through the reverse switch contacts 08-1 and 08-2 and switch 69a. When the socket 25 approaches the outboard position the trip member 76 opens the outboard 'circuit by opening switch 69a and the motor stops. The movement of the socket to the inboard position is effected by moving the arms 71 and 72 of the reversing switch to the inboard setting from that shown in FIG. 9. This completes the inboard circuit via switch 69b which remains closed until actuated by trip member 75. The gear motor will then continue to run toward the inboard position until switch 69b is opened by trip member 75. Once the socket lever leaves the outboard position, arm 73 returns to the upright position, switch 69a closes and the outboard circuit is effectively reset until the socket approaches the outboard position and switch 69a is opened. An intermediate position for arms 71 and 72 when not engaging any of contacts 08-1, 08-2, 18-1 and 18-2 is an off" position for switch 68.

While-the right angle worm and worm gear arrangement has been shown and described, it is understood that other forms of conventional gearing may also be employed. For example, a parallel-type gear box could be mounted on the deck with an extension of the output shaft of the gear boxforming the drive shaft. Another alternative is to use a right-angle gear motor mounted below the boat deck with a chain and sprocket coupled between the gear motor output shaft and the drive shaft shown.

Although the present invention has been described with a certain degree of particularity, it is understood that the present disclosure has been made by way of example and that changes in details of structure may be made without departing from the spirit thereof.

What is claimed is:

l. A motor-driven anchor davit adapted for mounting on the deck of aboat comprising a mounting base, a drive shaft on the base, a generally tubular anchor socket having an inner chamber opening at a free end to receive an anchor and having a line-receiving end provided with an opening to pass a line secured to said anchor, the line-receiving end being directly keyed for rotation with said shaft to advance in a vertical plane between an outboard position and an inboard position,

drive means directly coupled to the shaft to positively rotate the anchor socket between said inboard androutboard positions, and a control circuit including limiting means regulating movement of the drive means and responsive to rotational movement of the anchor socket into selected angular positions to automatically stop the drive means as the anchor socket approaches either of said inboard and outboard positions.

2. A motor-driven anchor davit as set forth in claim 1 wherein said socket is free to swing independently of said shaft in the inboard and outboard positions.

3. A motor-driven anchor davit as set forth in claim 1 wherein drive means includes an electric motor and a gear train mechanism with a vertical worm mounted in the deck and extending above the deck and a worm gear mounted on the end of said shaft and meshing with said worm.

4. A motor-driven anchor davit as set forth in claim 3 wherein said worm and worm gear are housed in a casing above the boat deck.

5. A motor-driven anchor davit as set forth in claim 3 including a pair of radially extending trip members mounted on the side of the worm gear at selected radially spaced positions. and a trip switch stationarily positioned to be engaged by said trip members as the worm gear is rotated.

6. A motor-driven anchor davit as set forth in claim 1 including a transverse sleeve secured to the socket, said sleeve having an enlarged keyway with opposed resilient side portions, said shaft having a key affixed thereto and positioned between said resilient side portions to provide for cushioned free swinging movement of the socket on the shaft through the limited degree of travel in the inboard and outboard positions.

7. A motor-driven anchor davit as set forth in claim 1 wherein said socket includes upper and lower guide means at said free end for the socket to align the anchor for sliding movement into the socket as the socket is pulled on from above.

8. A motor-driven anchor davit adapted for mounting on the deck of a boat comprising a mounting base, a drive shaft on the base, a generally tubular anchor socket with an inner chamber opening at its free end to receive an anchor and a line-receiving end provided with an opening to pass a line secured to said anchor, the line-receiving end being keyed for rotation with said shaft to advance vertically between an outboard position directed downwardly and outwardly away from the boat deck and an inboard position directed inwardly above the boat deck, said socket having a limited degree of free swing on said shaft in the inboard and outboard positions and resilient means to cushion the shaft at each extremity of its swing in said socket, drive means including a motor and a gear train mechanism coupled to the motor, said gear train mechanism being coupled to said shaft to rotate the anchor socket between said positions, and a control circuit for said motor including a reversing switch in the boat to regulate movement of the motor in either direction and a trip switch actuated in response to a selected angular position of the anchor socket to automatically stop the motor when the anchor socket approaches either of said positions.

9. A motor-driven anchor davit as set forth in claim 8 including a transverse sleeve on the socket adjacent said line-receiving opening and off-set from the longitudinal axis of the socket, for mounting said socket on said shaft, said anchor line extending through said linereceiving opening and being trained over an exterior surface of said sleeve as the anchor line extends to a forward position.

10. A motor-driven anchor davit comprising a mount secured to a boat deck adjacent an edge of the boat including a base plate (13), upstanding side plates (15 and 16) positioned on the base plate and projecting outwardly slightly beyond the base plate to overhang an edge of the boat, and a drive shaft (17) journaled in the side plates for rotational movement on a horizontal axis, a generally tubular anchor socket (25) with an inner chamber having an entrance opening (39) at its free end to receive the shank of a boat anchor and having an opening (40) at its supported end to pass a line (49) secured to the anchor, said socket having spaced inwardly diverging guide members (51,52) projecting from the top wall at the entrance opening and a longitudinal slot 55 in the bottom wall to align the shank in the socket as it is retracted thereinto, a transverse sleeve (26) encompassing the shaft and offset from the longitudinal axis of the socket at the supported end thereof to mount the socket on said shaft for vertical pivotal movement between an outboard position depending downwardly and outwardly from the shaft and an inboard position extending inwardly from the shaft along the deck of the boat, said sleeve having an enlarged key way (27) with a key (28) secured to the shaft positioned in the key way to key the socket to the shaft at a position to provide a limited degree of free swing of the socket on the shaft in the inboard and outboard positions, resilient members (29,31) in the key way on opposite sides of the key to cushion betweensaid sleeve and key, a reversible motor (61), a power supply (67) for the motor, a gear train mechanism including a meshing worm (65) and a worm gear (66) coupled between said motor and said shaft, a control circuit for regulating the power from said power supply to the motor including a reversible power switch (68) positioned at the boat instrument panel to stop and start the motor at selected angular positions, and a pair of radially spaced trip members and 76) on the worm gear and a trip switch (69) on the deck below the worm gear engageable by said trip members to automatically open said control circuit to stop the motor'when the socket approaches either the inboard or outboard positions.

Claims

1. A motor-driven anchor davit adapted for mounting on the deck of a boat comprising a mounting base, a drive shaft on the base, a generally tubular anchor socket having an inner chamber opening at a free end to receive an anchor and having a line-receiving end provided with an opening to pass a line secured to said anchor, the line-receiving end being directly keyed for rotation with said shaft to advance in a vertical plane between an outboard position and an inboard position, drive means directly coupled to the shaft to positively rotate the anchor socket between said inboard and outboard positions, and a control circuit including limiting means regulating movement of the drive means and responsive to rotational movement of the anchor socket into selected angular positions to automatically stop the drive means as the anchor socket approaches either of said inboard and outboard positions.

5. A motor-driven anchor davit as set forth in claim 3 including a pair of radially extending trip members mounted on the side of the worm gear at selected radially spaced positions and a trip switch stationarily positioned to be engaged by said trip members as the worm gear is rotated.

9. A motor-driven anchor davit as set forth in claim 8 including a transverse sleeve on the socket adjacent said line-receiving opening and off-set from the longitudinal axis of the socket, for mounting said socket on said shaft, said anchor line extending through said line-receiving opening and being trained over an exterior surface of said sleeve as the anchor line extends to a forward position.

10. A motor-driven anchor davit comprising a mount secured to a boat deck adjacent an edge of the boat including a base plate (13), upstanding side plates (15 and 16) positioned on the base plate and projecting outwardly slightly beyond the base plate to overhang an edge of the boat, and a drive shaft (17) journaled in the side plates for rotational movement on a horizontal axis, a generally tubular anchor socket (25) with an inner chamber having an entrance opening (39) at its free end to receive the shank of a boat anchor and having an opening (40) at its supported end to pass a line (49) secured to the anchor, said socket having spaced inwardly diverging guide members (51,52) projecting from the top wall at the entrance opening and a longitudinal slot 55 in the bottom wall to align the shank in the socket as it is retracted thereinto, a transverse sleeve (26) encompassing the shaft and offset from the longitudinal axis of the socket at the supported end thereof to mount the socket on said shaft for vertical pivotal movement between an outboard position depending downwardly and outwardly from the shaft and an inboard position extending inwardly from the shaft along the deck of the boat, said sleeve having an enlarged key way (27) with a key (28) secured to the shaft positioned in the key way to key the socket to the shaft at a position to provide a limited degree of free swing of the socket on the shaft in the inboard and outboard positions, resilient members (29,31) in the key way on opposite sides of the key to cushion between said sleeve and key, a reversible motor (61), a power supply (67) for the motor, a gear train mechanism including a meshing worm (65) and a worm gear (66) coupled between said motor and said shaft, a control circuit for regulating the power from said power supply to the motor including a reversible power switch (68) positioned at the boat instrument panel to stop and start the motor at selected angular positions, and a pair of radially spaced trip members (75 and 76) on the worm gear and a trip switch (69) on the deck below the worm gear engageable by said trip members to automatically open said control circuit to stop the motor when the socket approaches either the inboard or outboard positions.