US3668729A

US3668729A - Sliding apparatus of a movable bridge

Info

Publication number: US3668729A
Application number: US76068A
Authority: US
Inventors: Kunio Mori; Yoshio Shirage
Original assignee: Nippon Kokan Ltd
Current assignee: JFE Engineering Corp
Priority date: 1969-12-28
Filing date: 1970-09-28
Publication date: 1972-06-13
Anticipated expiration: 1989-06-13
Also published as: SE347037B; JPS5020376B1; DE2063621A1; NL141947B; NO130023B; NL7014696A; GB1301332A; FR2071809A5

Abstract

There is disclosed a bridge extendable away from, and retractable back towards, a quay, and including winch means, at least one flexible connection for extending the bridge and at least one flexible connection for retracting the bridge, said flexible connections coupling the winch means to the bridge, one of said flexible connections being wound and the other unwound by the winch means upon operation thereof to extend or retract the bridge, and weights suspended from said flexible connections between the winch means and the bridge. When a boat is secured to the outboard end of the extended bridge, movement of the weights allows the bridge to follow movement of the boat.

Description

United States Patent Mori et al.' [451 June '13, 1972 SLIDING APPARATUS OF A MOVABLE 598,012 93 BRIDGE 1,368,841 2/l92l Robb 474,l25 5/ l892 Haynes ..l4/54 [72] inventors: Kunlo Mori, Sohka; Yoshlo Shlrage, Fu-

jisawa, both of Japan Primary Examiner-Jacob L. Nackenoff An --S 81B [73] Assignee: Nippon Kokan Kabushiki Kaisha, Tokyo, omey embers lake Japan [57] ABSTRACT [22] Filed: W" 1970 There is disclosed a bridge extendable away from, and 76, retractable back towards, a quay, and including winch means, [2] 1 App] No 068. at least one flexible connection for extending the bridge and at least one flexible connection for retracting the bridge, said [30] Foreign Application Priority Data flexible connections coupling the winch means to the bridge, one of said flexible connections being wound and the other Dec. 28, 1969 Japan ..44/ 105076 unwound by the winch means upon operation thereof to tend or retract the bridge, and weights suspended from said "14M3 flexible connections between the winch means and the bridge. [51] Int. Cl ..E0ld 15/10 When a boat is secured to the outboard end of the extended [58] Field of Search "14/433, 54, 62; 104/124 bridge, movement of the weights allows the bridge to follow movement of the boat. 56 R t C'ted e erences 6 l sure UNITED STATES PATENTS arrangement and the bridge.

1 sunmc APPARATUS or A MOVABLE BRIDGE FIELD OF THE INVENTION The present invention relates to movable bridges for loading and unloading boats at a quay; for example ferry boats canying automobiles and passengers, In particular, it relates to bridges whichare extendable and retractable relative to a quay. 1

BACKGROUND OF THE INVENTION Such bridges can suffer from the disadvantage that movement of a boat secured to the outboard end of the extended bridge can damage the driving means for moving the bridge and can break the coupling between the bridge and the boat.

. SUMMARY OF THE INVENTION In particular, the present invention relates to an apparatus which assists in connecting and disconnecting the bridge easily from the boat when said boat is alongside the quay.

It is an object of the present invention to provide an extendable and retractable bridge which when it is extended and the outboard end thereof is secured, for example pivotally, to the boat, is still able to move with the movement of said boat. The present invention also provides apparatus having a simple structure which prevents accidental damage to driving means, for extending and retracting the bridge, resulting from movement of the boat, and uncoupling of the bridge from the boat.

According'to the invention there is provided a bridgear. ranged so as to be extendable away from, and retractable back towards, a quay and comprising a winch arrangement coupled to the bridge by at least one flexible connection for extending the bridge and at least one flexible connection for retracting the bridge, one of said flexible connections being wound and the other unwound by the winch arrangement upon operation thereof, whereby to extend or retract the bridge, and a weight suspended from each flexible connection between-the winch BRIEF DESCRIP'HON or' THE DRAWING An embodiment of the invention will now be described, by way of example, reference being made to the accompanying drawing, which shows a side elevation of a bridge according to the invention. 1

DESCRIPTION OF SPECIFIC EMBODIMENT In the drawing 1 is a bridge which is movable down an inclined surface at aquayside on rotatable wheels (not shown in the drawing) or the like, so that it can b'e extended away from and retract back towards the quay. Although not shown in the drawing, the outboard end of said bridge is preferably supported by some form of elevating apparatus so that that end can be adjusted vertically according to the height of the gangway of a boat when said boat comes alongside the quay.

Guides 2, 3 in the form of pits are arranged in the base over which the bridge 1 moves forward and backward, and stops in the form of shoulders 2a, 3a are provided near the upper ends of the guides 2, 3. Above the tops of the guides spaced apart pairs of guides wheels 4a, 4band 5a,.5b are supported on bearings 6 and 7.

Within said guides 2, 3 are pulley blocks 10, 11 from which are suspended weights 8, 9. Flexible connections consistuted by

wire ropes

12a, 12 b pass around the pulleys a, 11a of said pulley blocks 10, 11 and said

guide wheels

40, 4b, 5a, 5b

in a way to be described below. A return guide wheel 13 for supporting the wire rope 12a is supported on bearing 14. Wire ropes 12a and 12b are attached at one end to wire attachment points 16 and 15 on the lower side of bridge 1 and at their other ends to a winch l7.

Wire rope 12a is for extending the bridge. From the wire attachement point 16 nearer the front or outboard end of the bridge 1 it passes over the return guide wheel 13 and then fonns a loop between

pulleys

4a and 4b, the pulley block 10a being at the bottom of the loop. From there the rope 12a pases toone of the winding drums for the winch 17. The other wire rope 12b passes from attachment point 15 at the rear of the bridge 1 and forms a loop between pulleys 5a and 5b, the pulley block Ila being suspended from the bottom of the loop. It is then wound on to another winding drum of the winch l7.

When the winch 17 is actuated, one of the wire ropes 12a, 12b is wound and the other unwound from winch 17.

Assuming wire rope 12a is being wound, weight 8 becomes lifted until it comes into contact with stop 20 and thereafter the bridge 1 moves forward to project from the quay. The elevating means is used to place the outboard end of the bridge 1 on a boat alongside and that end is then secured to the boat. After the bridge 1 is thus supported by the boat, wire rope 12a is unwound so that both ropes are loosened and the weights 8, 9 are both at least partly lowered, thereby giving the arrangement flexibility and permitting free movement of the bridge 1.

Thus, if the boat pushes the bridge back theweight 9 descends and the weight 8 is elevated. If the boat slightly moves forward, then the weight 9 is lifted and the weight 8 descends. Thus, the bridge moves backwardly and forwardly following the movement of the boat.

When the bridge 1 is to be retracted, wire rope 12b is wound in by the winch l7 and the other wire rope 12a is unwound. Thus, the bridge 1 is retracted once weight 9 has contacted its stop.

In summary, in the described embodiment a wire rope for wound and unwound respectively by said winch and are attached to the bridge. A weight is suspended on both wire ropes via a pulley device placed between said winch and bridge, so that the bridge can be driven outwardly and inwardly relative to the quay by means of said winch. Also, when the bridge is extended outwardly and the end fixed to a boat alongside the quay, said bridge can move to follow the movement of the ferry, so that no accidental damage to the bridge or the driving means is caused by the ,movementof the boat and also the bridge is not detached from the .boat. Furthermore, when weights are suspended as aforementioned, the wire ropes are never loose, whether said bridge is in motion or not, which .would otherwise be an undesirable factor.

' forms a retracting flexible connection means for retracting the bridge, both of these flexible connection means being coupled with the winch means 17. The winch means 17 is operatively connected to both of the flexible connection means 12a and 12b to provide therein, respectively, lengths greater than the lengths required to extend from the bridge to the winch means, at least when the bridge is in its extended position, by

an amount suflicient to render the bridge in the latter position freely movable independently of the winch means. The weights 8 and 9 form a means operatively connected with both of the flexible connection means 12a and 12b to maintain the latter taut while the extended bridge is freely movable independently of the winch means, so that in this way undesirable looseness in the wire ropes is eliminated.

We claim:

1. In a bridge extendable into an extended position extending away from, and retractable back towards, a quay, winch means, at least one extending flexible connection means for extending the bridge into said extended position thereof and at least one retracting flexible connection means for retracting the bridge, said extending and retracting flexible connection means coupling the winch means to the bridge, one of said flexible connection means being wound, and the other unwound by the winch means upon operation thereof to extend or retract the bridge, and said winch means being operatively connected to said extending and retracting flexible connection means for providing therein lengths, respectively, greater than the lengths required to extend from the bridge to said winch means, at least when said bridge is in said extended position thereof, by an'amount sufiicient to render the bridge in the latter position freely movable independently of said winch means, and means operatively connected to said extending and retracting flexible connection means between the winch means and the bridge for maintaining both of said flexible connection means taut when the bridge is in its extended position so as to eliminate undesirable looseness in said extending and retracting flexible connection means while said bridge remains freely movable in its extended position independently of said winch means.

2. A bridge as claimed in claim 1 in which said means for maintaining said extending and retracting flexible connection means taut includes weights suspended from the extending and retracting flexible connection means on pulley blocks.

3. A bridge as claimed in claim 2 in which the bridge has an inboard end portion, said retracting flexible connection means for retracting the bridge extending from said winch means to said inboard end and including a downwardly extending loop,

spaced apart pulleys supporting said loop, and one of said weights being suspended from said loop.

4. A bridge as claimed in claim 3 comprising a return pulley, said extending flexible connection means for extending the bridge extending from said winch means round said return pulley to the bridge, a second downwardly extending loop situated between the winch means and the return pulley, and spaced apart pulleys supporting said second loop, and one of said weights being suspended from said second loop.

5. A bridge as claimed in claim 4, comprising stops coacting with said weights for limiting movement of the weight connected to said extending flexible connection means during movement of the bridge to its extended position and for limiting movement of the weight connected to said retracting flexible connection means during retraction of the bridge.

6. A bridge as claimed in claim 5 in which the stops coact with said weights for limiting movement thereof during extension and retraction of the bridge.

a a k a:

Claims

1. In a bridge extendable into an extended position extending away from, and retractable back towards, a quay, winch means, at least one extending flexible connection means for extending the bridge into said extended position thereof and at least one retracting flexible connection means for retracting the bridge, said extending and retracting flexible connection means coupling the winch means to the bridge, one of said flexible connection means being wound, and the other unwound by the winch means upon operation thereof to extend or retract the bridge, and said winch means being operatively connected to said extending and retracting flexible connection means for providing therein lengths, respectively, greater than the lengths required to extend from the bridge to said winch means, at least when said bridge is in said extended position thereof, by an amount sufficient to render the bridge in the latter position freely movable independently of said winch means, and means operatively connected to said extending and retracting flexible connection means between the winch means and the bridge for maintaining both of said flexible connection means taut when the bridge is in its extended position so as to eliminate undesirable looseness in said extending and retracting flexible connection means while said bridge remains freely movable in its extended position independently of said winch means.

3. A bridge as claimed in claim 2 in which the bridge has an inboard end portion, said retracting flexible connection means for retracting the bridge extending from said winch means to said inboard end and including a downwardly extending loop, spaced apart pulleys supporting said loop, and one of said weights being suspended from said loop.