US3196824A

US3196824A - Boat mooring apparatus

Info

Publication number: US3196824A
Application number: US302307A
Authority: US
Inventors: Donald D Howard
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-08-15
Filing date: 1963-08-15
Publication date: 1965-07-27
Anticipated expiration: 1982-07-27

Description

July 27, 1965 HOWARD 3,196,824

BOAT MOORING APPARATUS Filed Aug. 15, 1963 3 Sheets-Sheet 1 3 lxvvnvroxe DONALD D. HOWARD Dana/1 bf 244$? ATTOAIVE? July 27, 1965 D. 0.. HOWARD 3,196,824

BOAT MOORING- APPARATUS Filed Aug. 15, 1963 3 Sheets-Sheet 2 .:Er I

59 PM H,

Arrows [v 1 7, 1965 D. D. HOWARD 3,196,824

BOAT MOORIHG APPARATUS Filed Aug 15, 1963 5 Sheets-Sheet 3 Arrow/Ev;

United States Patent 3,196,824 BQAT MGURING APPARATUS Donald 1). Howard, 3% 19th St, Spirit Lake, llowa Filed Aug. 15, 1963, Ser. No. 302,307 16 Claims. (Cl. lid-23o) This invention relates to a boat mooring apparatus and in particular to a quick release anchor means.

Mooring devices presently available do not have the capability of being completely disengaged by the operator from the boat, or being engaged to the boat by the operator from the dock. Most of these mooring devices require the operator to perform one or more acts both in the boat and on the dock for mooring the boat to the dock and releasing it therefrom. A further limitation to most mooring devices presently available is that they are not readily adjustable to accommodate boats of different widths and lengths.

Therefore, it is an object of this invention to provide a mooring apparatus having an anchor arm which upon contact with a socket assembly within the boat will automatically place the socket in looking engagement with the anchor arm;

It is a further object of this invention to provide a mooring apparatus having one or more quick release socket assemblies mounted within the boat which may be simultaneously disengaged from their respective anchor arms by operation of a single latch release control;

It is a further object of this invention to provide a mooring apparatus having anchor arms that will automatically spring backwardly to a vertical position upon release from a boat;

It is a further object of this invention to provide a mooring apparatus having an anchor assembly which may be readily moved along the dock to accommodate boats of different lengths and widths;

It is a further object of this invention to provide a mooring device having an anchor assembly with a spring tensioned anchor arm wherein the spring tension may be varied readily as desired;

It is a further object of this invention to provide a mooring apparatus having a spring tension anchor arm which is limited in its return pivotal movement by a safety stop means;

It is a further object of this invention to provide a mooring apparatus which may be employed as a boat hoist means if desired; and

A further object of this invention is to provide a boat mooring apparatus which is simple in design, economical to manufacture and refined in appearance.

This invention consists in the construction, arrangements, and combination, of the various parts of the device, whereby the objects contemplated are attained as hereinafter more fully set forth, specifically pointed out in the claims, and illustrated in the accompanying drawings, in which:

FIG. 1 is a perspective view of the boat secured to a clock by a pair of mooring apparatuses and additionally showing the anchor arms of the mooring apparatuses by dash lines when they are disengaged from the boat;

FIG. 2 is a fragmentary perspective view of onemooring apparatus including the socket assembly mounted in the fore end of a boat;

FIG. 3 is a perspective view of only the anchor assembly of the mooring apparatus and showing in particular the carriage assembly positioned such that the anchor arm extends parallel to the track rails; when the carriage assembly is mounted in this position on the track rails, it is capable of being selectively positioned to accommodate boats of varying widths;

FIG. 4 is a cross-sectional view along line 4--4 in FIG. 2 of the carriage assembly;

FIG. 5 is a cross-sectional view taken along line 55 in FIG. 4 of the carriage assembly and showing in particular the anchor arm in its boat engaging position and then in its disengaged position as represented by the dash lines;

FIG. 6 is a perspective view of the spring tensioner employed in the carriage assembly;

FIG. 7 is a perspective view of the carriage plate and the housing base plate;

FIG. 8 is a perspective exploded view of the socket assembly with the bottom cover plate separated from the housing to show the means for connecting it thereto;

FIG. 9 is a cross-sectional plan view along line 9-9 of FIG. 8 showing the top of the socket assembly when the ball on the end of the anchor arm is held in a locked position within the socket assembly;

FIG. 10 is an elevation cross-sectional view taken along line 1(l1tl in FIG. 9 showing the inside construction of the socket assembly and the relationship of its parts when the anchor arm is locked therein;

FIG. 11 is a cross-sectional view of the socket assembly similar to FIG. 10, however showing the latch means pulled out of engagement with the shoulders of the jaws for releasing the ball member on the end of the anchor arm from the socket assembly; and

FIG. 12 is a top plan view of a boat having two socket assemblies mounted at the stern end and one at the fore end wherein each of the socket assemblies are operated by a single latch release control means connected by cable line extending to the respective socket assemblies.

In FIGS. 1 and 2 of the drawings a boat mooring apparatus is referred to generally by the reference numeral 10. It is shown to comprise an anchor assembly 12 which is fastened to a clock 13 and a socket assembly 14 mounted flush in the fore end of a boat 15. A similar anchor assembly l2 and socket assembly 14' are employed for securing the stern end of the boat 15 to the dock 13.

The anchor assembly 12 is shown in FIG. 2 as comprising a pair of parallel spaced

rails

16 and 18 supported by U-shaped support brackets 2t) and 22 at opposite ends thereof. A sleeve bearing 24 is provided on the upper ends of the upstanding legs of the support brackets 29 and 22 for slidably receiving the

rails

16 and 18. A vertical opening 26 is formed in each of the bearing sleeves 24 for selective alignment with one of the openings 28 in the

rails

16 and 13. A pin or the like may then be inserted through the

openings

26 and 28 to hold the

rails

16 and 18 and the

support brackets

20 and 22 against relative movement.

A carriage assembly 30 is mounted on the rails and includes a base plate 32 secured to sleeve bearing elements 34 and 36 which slidably embrace the

rails

16 and 18. Stop pins 38 are provided adjacent each of the corners of the base plate 32 as shown in FIGS. 3 and 7.

A housing 40 is positioned atop of the base plate 32 and includes a semi circular cover shield 42 having mating semi circular end walls 44 and 46 (FIG. 4) resting on a base plate 48. The base plate 48 is rotatably secured to the carriage base plate 32 by a bolt and nut assembly 49 (FIGS. 4 and 5). The cover shield 4-2 is provided with slots 5% and 52 adjacent end walls 4-4 and 46. The slots extend approximately half of the peripheral Width of the cover shield 42. A center peripheral slot 54 extends from the opposite side edge of the housing through about degrees of the semi circle. Pin holes 55 are provided along a circular line in the end plates 44 and 46 (FIG. 5). A shaft 56 extends centrally through the

end walls

44 and 46 and has

circular lock plates

58 and 60 respectively (FIG. 4) mounted thereon at the outer opposite ends.

An anchor arm 62 (FIG. 2) is connected at one end to the boat 15 and at the other end to the shaft 56. It has a ball member 64 secured to an arm portion 66 which in turn terminates in a second arm portion 68. A third arm portion 78 extends outwardly in the same direction as arm portion 66 from portion 68 and terminates in a transverse sleeve portion 72 (FIG. 4). The sleeve portion 72 is rotatably mounted on the shaft 56 and in C0111- bination with the third arm portion '7 provides a T-shaped end for the anchor arm 62. Additional rigidity is provided for the third arm portion 70 and its connection to the sleeve portion 72 by the angular braces 74 extending therebetween on opposite sides of the portion 70. A coil spring 76 is mounted on the shaft 56 and has two spaced

apart end coils

78 and 80 interconnected by a central section 82 having a concave shape for matingly engaging the arm portion '7 0. Each

end coil

78 and 86 has a

wire end

84 and 86 respectively extending perpendicular to the longitudinal axis of the coil spring 76.

A spring tensioner 88 (FIG. 6) has a pair of spaced

arms

90 and 92 with

circular disk bearings

94 and 96 provided on their outer ends for mounting on the ends of the shaft 56 inside the housing 40 adjacent the

end walls

44 and 46. The

arms

90 and 92 extend through the

slots

58 and 52 and converge outwardly of the housing 41 on the opposite side thereof from the anchor arm 62. A foot plate 98 is attached to the outer ends of the

arms

96 and 92. The

disk bearings

94 and 96 have pins 190 and 102 respectively facing each other along the line parallel to the longitudinal axis of the shaft 56 for bearing contact with the

spring ends

84 and 86 respectively as shown in FIG. 4.

An anchor arm stop 1114 is provided in the housing 40 and secured to the base plate 48. It has a cradle element 106 for matingly receiving portion 70 of arm 62 when it springs back to a generally vertical position as shown by the dash lines in FIGS. 1 and 5. With the arm portion 70 extending at a 60 degree angle with the horizontal, the center arm portion 68 is held substantially vertical with the outer arm portion 66 extending forwardly as well as upwardly. It is thus seen that as the spring tensioner 88 as viewed in FIG. is rotated clockwise it will increase the spring pressure through portion 82 against the anchor arm portion 70. Pins, not shown, may be inserted in the desired openings 55 in the

end walls

44 and 46 to hold the

spring tensioner arms

96 and 92 in the appropriate position for the desired spring tension.

The socket assembly 14 illustrated in detail in FIGS. 8 through 11 is mounted in the appropriate position on the boat 15 for detachably receiving the ball 64 on the end of the anchor arm 62. The socket assembly comprises a housing 108 having side walls 110, a top plate 111 and a base plate 112. Pins 114 extend from the bottom edges of the walls 110 through holes in the base plate 112. Key elements 116 (FIG. are inserted through the pins 114 in supporting contact with the base plate 112. The top plate 111 has a central concave seat portion 118 (FIG. 11) with

diametrical slots

120 and 121 extending through it. The bottom of the seat portion 118 has a bridge element 122 separating the lower ends of the slots 129 and 121.

Jaws

124 and 126 having semi

circular arms

130 and 132 mounted in the

slots

120 and 121 and pivoted by pins 134 to the top plate 111. Semi circular concave

inner surface members

136 and 138 are secured to the upper ends of the

arms

130 and 132 for mating engagement with the ball member 64 (FIG. 10). Pins 14-11 are provided on the outer lower edges of the

arms

130 and 132 and face pins 142 on the adjacent housing side wall (FIG. 11). A spring 144 has its ends embracing the

pins

140 and 142 to urge the

jaws

124 and 126 to an open position as shown in FIG. 11. At the lowermost end edge of the

arms

130 and 132, shoulders 146 are formed.

A latch 148 is provided below the shoulders 146 for locking engagement therewith. A sleeve 150 extends through the base plate 112 and is secured thereto with a movable rod 152 positioned therein. A circular latch element 154 is provided on the upper end of the rod member 152 for engagement with the shoulders 146 on the

arms

136 and 132. A spring 156 encircles the rod member 152 and normally urges the latch element upwardly into engagement with the shoulders 146 and/ or the stop element 122 bridging the side portions of the seat 118. A cable or line 168 is connected at one end to the lower end of the rod member 152 and extends through the lower end of the sleeve 150. The other end of the line 160 is connected in any convenient manner to a latch release control 162 as shown in FIG. 12. In FIG. 12

additional cables

164 and 166 are shown leading to socket assemblies 14' and 14" respectively located at the stem end of the boat 15. Thus by single operation of the latch release control 162 any anchor arms connected to the boat would be simultaneously released therefrom.

When the boat 15 is to be moored, the anchor arm 62 is pivoted to a position wherein its ball element 64 bears against the inner edges of the lower ends of the arms and 132 whereby these arms are pivoted to a closed position about the ball 64 and the latch element 154 simultaneously moves into engagement with the shoulders 146 to hold the

jaws

124 and 126 in their locked position. When it is desired to move away from the dock, all that is required to disconnect the anchor arm from the socket assembly 14 is to pull the cable 166 by operation of the latch release control 162, thereby allowing the springs 144 to pivot the

jaws

124 and 126 to an open position as shown in FIG. 11. The spring 76 mounted on the shaft 56 in the carriage assembly 30 will automatically pivot the arm 62 to an upright position as shown by the dash lines in FIGS. 1 and 5.

Should it be desired to increase the uplift force of the anchor arm 62 on the boat 15, it is only necessary to press the spring tensioner foot paddle 98 downwardly to the appropriate position thereby increasing the tension in the spring 76. It is to be further understood that the housing 40 which is rotatably connected to the carriage base plate 32 by the bolt assembly 49 is capable of rotating relative to the carriage base plate to accommodate t-he fore and aft motion or angular motion surface-wise of the moored boat 15 under the action of waves striking the boat. Stop pins 38 will limit the degree of rotation of the housing 40 on the carriage base plate 32. It is further emphasized that as shown in FIGS. 1 and 2 the carriage assembly 30 may be moved along the track rails 16 and 18 to accommodate boats having different lengths. If it is desired to extend the anchor arm 62 farther from the dock 13, the carriage assembly 30 may be mounted on the track rails 16 and 18 in the manner shown in FIG. 3 and the anchor assembly positioned on the dock to extend across rather than along the dock side, whereby as the carriage 30 is moved along the

rails

16 and 18 the anchor arm 62 will extend inwardly and outwardly from the dock 13.

From a consideration of the foregoing disclosure, it will be obvious that all of the initially recited objects of the present invention have been achieved in this specification.

Some changes may be made in the construction and arrangement of my boat mooring apparatus without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims, any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

I claim:

1. A boat mooring apparatus, comprising, in combination,

a pair of anchor assemblies adapted to be secured along the edge of a dock in spaced relationship to each other, a carriage assembly rotatably connected to each anchor assembly and adapted to be selectively moved along said dock, a rigid anchor arm pivoted at one end to said carriage assembly, a spring means in engagement with said arm for biasing said arm towards an upwardly extending position, and said arm being adapted to be pivoted against the action of said spring to a substantially outwardly and downwardly extending position;

a pair of socket assemblies adapted to be mounted on a boat in spaced relationship to each other, said carriage assemblies adapted to be moved along said dock to be adjacent one of said socket assemblies, and each of said socket assemblies having jaw means to detachably receive the other end of said adjacent anchor arm against the action of said spring means, a latch means for locking said jaw means in engage ment with said other end of said anchor arm whereby upon actuation of said latch means to an open position out of engagement with said jaw means, said spring means will return said anchor arm to its up wardly extending position; and

stop means for limiting rotation of said carriage assem bly relative to said dock whereby a boat connected to said arms will be limited in movement towards said dock.

2. The structure of claim 1 wherein said apparatus includes means operatively secured to each of said latch means for moving both of them simultaneously to an open position.

3. The structure of claim 1 wherein said apparatus includes means, adapted to be located in a boat and operatively secured to each of said latch means for moving both of them simultaneously to an open position.

4. A boat mooring apparatus, comprising,

a pair of parallel spaced rails adapted to be secured to a dock;

a base plate extendinng between said rails and slidably secured thereto;

means for operatively engaging said base plate and said rails for limiting movement therebetween;

a housing mounted on said base plate;

an anchor arm having a T shaped portion at one end pivotally connected to said housing, said arm adapted to pivot about an axis through the cross of said T-portion, the other end of said arm adapted to extend outwardly from said rails and pivot from a generally horizontal position to a generally vertical position; and

connecting means carried on the other end of said arm adapted to releasably engage a mating connecting means on a boat.

'5. The structure of claim 4 wherein said housing is retatably connected to said base plate.

6. The structure of claim 4 wherein said housing is adapted to rotate on said base plate and stop means is provided to limit said rotation.

7. The structure of claim 4 and spring means being in engagement with said arm to urge it towards said vertical position.

8. The structure of claim 4 and spring means being in engagement with said arm to urge it towards said vertical position, stop means for limiting movement of said arm beyond said predetermined vertical position.

'9. The structure of claim 4 and spring means being in engagement with said arm to urge it towards said vertical position, stop means for limiting movement of said arm beyond said predetermined vertical posit-ion and means in engagement with said spring for selectively adjusting the tension therein, said means having a portion extending outwardly of said housing and adapted to be manually adjusted by a persons foot.

10. The structure or claim 7 wherein said spring is in the form of a coil spring having end portions in axial alignment with the cross portion of said arm and a center portion in engagement with the arm adjacent said cross portion, and adjustable means adapted to engage the outer end portions of said spring to vary the spring tension.

11. A boat mooring apparatus, comprising,

a pair of parallel space-d rails adapted to be secured to adock;

a base plate extending between said rails and slidably secured thereto;

a housing mounted on said base plate and having end walls;

a shaft extending between said end walls;

an anchor arm having a transverse sleeve portion at one end embracing said shaft;

a coil spring having end portions on opposite ends of said sleeve portion and embracing said shaft, said spring having a center portion for engagement with said arm for urging it towards an upwardly extending position;

stop means for engagement with each of said spring end portions; and

12. A boat mooring apparatus, comprising,

a pair of parallel spaced rails adapted to be secured to a dock;

at base plate extending between said rails and slidably secured thereto;

a housing mounted on said base plate and having end Walls;

a shaft extending between said end walls;

a coil spring having end portions on opposite sides of said sleeve portion and embracing said shaft, said spring having a center portion for engagement with said arm for urging it towards an upwardly extending position;

a pair of elongated members pivotally connected to said shaft adjacent said end portions of said spring, said members extending outwardly of said housing and having portions for engagement with said spring end portions whereby pivotal movement of said members will vary the tension in said spring; and

connecting means carried on the other end of said arm adapted to releasably engage a mating connecting means on a boat,

13. A quick release connecting means for boats, comprising,

a male connecting member having a ball element on one end;

a female socket assembly for receiving said ball element including a frame member, a pair of concave jaw members pivotally connected to said frame intermediate their ends, spring means in engagement with the lower end of each of said jaw members for urging the lower ends towards each other and the other end of said jaw members away from each other to an open position, a latch means adapted to be positioned between the lower ends of said jaw mem bers to hold the other ends of said jaw members in a closed position, spring means for normally biasing said latch means into engagement with said lower ends of said jaw members, and means for releasing said latch means from engagement with said lower ends of said jaw members against the action of said latch spring whereby said other ends or" said jaw members will separate to an open position, and said ball element adapted to be received between said jaw members and bear against the inside surface of said lower ends causing them to separate against the action of said spring means and to permit said latch means to move therebetween and thereby hold said jaws in a closed locked position about said ball element;

said lower ends of said jaw members each having a pair of shoulders forming a notch, one of said shoulders being vertically disposed and the other shoulder being horizontally disposed when said jaw is in said closed position, and

said latch means including a rod secured to said frame and being vertically disposed below said jaw members for vertical slidable movement only, a horizontally disposed planar element on the upper end of said rod, said spring means for biasing said latch means including a coil spring on said rod in operative bearing engagement against said planar element to urge it into the notch and into engagement with said pair of shoulders on the adjacent jaw members, the peripheral edge of said planar element bearing against said vertically disposed shoulder and said horizontally disposed shoulder bearing against the top surface of said planar element when said jaw members are in their closed position, said :horizontally disposed shoulder preventing downward movement of said jaw members and said vertically disposed shoulder preventing upward movement of said jaw members.

14. A boat mooring apparatus, comprising, in combination,

a pair of anchor assemblies adapted to be secured along the edge of a dock in spaced relationship to each other,

each assembly comprising,

a base member adapted to be rotatably secured to the dock for rotation in a horizontal plane,

a rigid elongated anchor arm pivoted at one end to said base member for movement in a vertical plane,

spring means connected to said arm adjacent said one end to bias said arm to a raised upwardly extending position, said arm adapted to be moved against the action of said spring to a lowered position extending outwardly and downwardly of said dock;

a pair of socket assemblies adapted to be mounted on a boat at opposite ends thereof for releasable locking engagement with the outer free ends of said anchor arms,

and stop means for limiting rotation of said base member relative to said dock whereby a boat connected to said arms will be limited in movement towards said dock.

15. The structure of claim 14 wherein a ball element is provided on the outer free end of each of said anchor arms and each of said socket assemblies include a frame, a pair of concave jaw members pivotally connected to said frame intermediate their ends, spring means in engagement with the lower end of each of said jaw members for urging the lower ends towards each other and the other end of said jaw members away from each other to an open position, a latch means adapted to be positioned between the lower ends of said jaw members to hold the other ends of said jaw members in a closed position, spring means for normally biasing said latch means into engagement with said lower ends of said jaw members, and means for releasing said latch means from engagement with said lower ends of said jaw members against the action of said latch spring whereby said other ends of said jaw members will separate to an open position, and said ball element adapted to be received between said jaw members and bear against the inside surface of said lower ends causing them to separate against the action of said spring means and to permit said latch means to move therebetween and thereby hold said jaws in a closed locked position about said ball element.

16. The structure of claim 14 wherein a ball element is provided on the outer free end of each of said anchor arms and each of said socket assemblies include a frame, a pair of concave jaw members pivotally connected to said frame intermediate their ends, spring means in engagement with the lower end of each of said jaw members for urging the lower ends towards each other and the other end of said jaw member-s away from each other to an open position, a latch means adapted to be positioned between the lower ends of said jaw members to hold the other ends of said jaw members in a closed posi tion, spring means for normally biasing said latch means into engagement with said lower ends of said jaw members, and means for releasing said latch means from enga'gement with said lower ends of said jaw members against the action of said latch spring whereby said other ends of said jaw members will separate to an open position, and said ball element adapted to be received between said jaw members and bear against the inside surface of said lower ends causing them to separate against the action of said spring means and to permit said latch means to move therebetween and thereby hold said jaws in a closed locked position about said ball element, said lower ends of said jaw members each having a pair of shoulders forming a notch, one of said shoulders being vertically disposed and the other shoulder being horizontally disposed when said jaw is in said closed position, and said latch means including a rod secured to said frame and being vertically disposed below said jaw members for vertical slidable movement only, a horizontally disposed planar element on the upper end of said rod, said spring means for biasing said latch means including a coil spring on said rod in operative bearing engagement against said planar element to urge it into the notch and into engagement with said pair of shoulder-s on the adjacent jaw members, the peripheral edge of said planar element bearing against said vertically disposed shoulder and said horizontally disposed shoulder bearing against the top surface of said planar element when said jaw members are in their closed position, said horizontally disposed shoulder preventing downward movement of said jaw members and said vertically disposed shoulder preventing upward movement of said jaw members.

References Cited by the Examiner" UNITED STATES PATENTS 1,452,679 4/23 Fisher 294- X 2,920,597 1/60 Dick 1l4230 2,970,796 2/61 Ross.

3,012,811 12/61 Sandrock 294-83 3,019,759 2/62 Woods 114-230 3,120,831 2/64 Fulton l14230 FERGUS S. MIDDLETON, Primary Examiner.

Claims

1. A BOAT MOORING APPARTUS, COMPRISING, IN COMBINATION, A PAIR OF ANCHOR ASSEMBLIES ADAPTED TO BE SECURED ALONG THE EDGE OF A DOCK IN SPACED RELATIONSHIP TO EACH OTHER, A CARRIAGE ASSEMBLY ROTATABLY CONNECTED TO EACH ANCHOR ASSEMBLY AND ADAPTED TO BE SELECTIVELY MOVED ALONG SAID DOCK, A RIGID ANCHOR ARM PIVOTED AT ONE END TO SAID CARRIAGE ASSEMBLY, A SPRING MEANS IN ENGAGEMENT WITH SAID ARM FOR BIASING SAID ARM TOWARD AN UPWARDLY EXTENDING POSITION, AND SAID ARM BEING ADAPTED TO BE PIVOTED AGAINST THE ACTION OF SAID SPRING TO A SUBSTANTIALLY OUTWARDLY AND DOWNWARDLY EXTENDING POSITION; A PAIR OF SOCKET ASSEMBLIES ADAPTED TO BE MOUNTED ON A BOAT IN SPACED RELATIONSHIP TO EACH OTHER, SAID CARRIAGE ASSEMBLLIES ADAPTED TO BE MOVED ALONG SAID DOCK TO BE ADJACENT ONE OF SAID SOCKET ASSEMBLIES, AND EACH OF SAID SOCKET ASSEMBLIES HAVING JAW MEANS TO DETACHABLY RECEIVE THE OTHER END OF SAID ADJACENT AN CHOR ARM AGAINST THE ACTION OF SAID SPRING MEANS, A LATCH MEANS FOR LOCKING SAID JAW MEANS IN ENGAGEMENT WITH SAID OTHER END OF SAID ANCHOR ARM WHEREBY UPON ACTUATION OF SAID LATCH MEANS TO AN OPEN POSITION OUT OF ENGAGEMENT WITH SAID JAW MEANS, SAID SPRING MEANS WILL RETURN SAID ANCHOR ARM TO ITS UPWARDLY EXTENDING POSITION; AND STOP MEANS FOR LIMITING ROTATION OF SAID CARRIAGE ASSEMBLY RELATIVE TO SAID DOCK WHEREBY A BOAT CONNECTED TO SAID ARMS WILL BE LIMITED IN MOVEMENT TOWARDS SAID DOCK.