US3753416A

US3753416A - Rat guard

Info

Publication number: US3753416A
Application number: US00183372A
Authority: US
Inventors: B Haglund; R Salvarezza
Original assignee: Coast Marine and Ind Supply Inc
Current assignee: Coast Marine and Ind Supply Inc
Priority date: 1971-09-24
Filing date: 1971-09-24
Publication date: 1973-08-21
Anticipated expiration: 1990-08-21

Abstract

A rat guard for ships'' hawsers and the like. A polygonal barrier plate has a bottom portion and has a top portion with two steeply converging edges meeting at a narrow vertex at the very top. A slot in the bottom portion extends up to a round hawser-engaging edge at about the center of gravity. A self-closing door is pivoted to the plate near the upper end of said slot. It is urged to a normally closed position by its weight and its relation to its pivot, and it then lies athwart the slot, with an edge mating with the round hawser-engaging edge to encircle the hawser. A stop or other holding means secured to the plate can hold the door about 180* away from its said normal position, where a portion lies across the slot''s upper end so that it will be engaged by a hawser that has entered the slot and thereby caused to swing around its pivot to enclose the hawser between itself and the plate.

Description

United States Patent Haglund et al.

[ 1 Aug. 21, 1973 Primary dm il:l8rM1liO1lB11Ch!f Assistant Examiner--Gregory W. OConnor Attorney-Owen, Wickersham & Erickson 1 1 ABSTRACT A rat guard for ships hawsers and the like. A polygonal barrier plate has a bottom portion and has a top portion with two steeply converging edges meeting at a narrow vertex at the very top. A slot in the bottom portion extends up to a round hawser-engaging edge at about the center of gravity. A self-closing door is pivoted to the plate near the upper end of said slot. It is urged to a normally closed position by its weight and its relation to its pivot, and it then lies athwart the slot, with an edge mating with the round hawser-engaging edge to encircle the hawser. A stop or other holding means secured to the plate can hold the door about 180 away from its said normal position, where a portion lies across the slots upper end so that it will be engaged by a hawser that has entered the slot and thereby caused to swing around its pivot to enclose the hawser between itself and the plate.

11 Claims, 7 Drawing Figures Patented Aug. 21, 1973 3,753,416

2 Sheets-Sheet l INVENTOR5 BERNARD F. HAGLUND BY ROBERT M. SALVAREZZA ATTORNEYS Patented Aug. 21, 1973 3,753,416

2 Shoots-Sheet 2 IN VENTORS BERNARD F. HAGLUND BY ROBERT M. SALVAREZZA ATTORNEYS RAT GUARD BACKGROUND OF THE INVENTION This invention relates to an improved rat guard, providing surer closure action, better centering action, easier release action, and improved protection from rats.

Rat guards are used around the hawsers of ships to prevent rats and other rodents on shore from boarding the ships by simply walking along the hawsers. Heretofore, rat guards have generally comprised large circular discs which have had to be installed on the ships hawsers by hand under inconvenient circumstances. Since they have been large discs, their curvature per foot of circumference has been relatively flat, so that large rats have often been able to place their forelegs on the upper edge, then to jump and get all four legs on the upper edge, and then jump down on the other side to the hawser and so board the ship[ In installing rat guards, reliance has typically been made on making the circular disc in two pieces which can be swung apart and which have to be bolted together. This bolting together is inconvenient and it makes it difficult to put on and take off the rat guard.

BRIEF SUMMARY OF THE INVENTION The rat guard of this invention may use a circular disc if that is desired, but preferably it uses a polygonal barrier plate with two steeply converging upper edges meeting at the narrow vertex at the very top. The vertex is so narrow that a rat cannot get all four of its legs on it, and therefore even if the rat is very large, it is extremely unlikely to be able to negotiate passage beyond the rat guard.

Whether round or polygonal, the rat guard of this invention is characterized by an assembly which makes for very easy installation and removal. The barrier plate has a slot extending up from the bottom about halfway to a round hawser-engaging edge. A self-closing door is pivoted to the plate near the upper end of the slot and to one side of it and is provided with a weight which tends to cause it to move into a position closing the door around the other side of the hawser, with a rounded edge portion being provided to encircle the hawser in combination with the hawser-engaging edge at the upper end of the slot at the plate. Prior to installation, the door is cocked by swinging it around its pivot until its edge engages a stop. At that point, the center of gravity of the door lies on the side of the vertical line through the pivot where the weight of the door urges the door against the stop, rather than causing the door to move into the closing position. The door is made so that in this cocked position an edge portion lies across the upper end of the slot where it is engaged by a hawser that has entered the slot. This happens when the rat guard is dropped down by ropes onto the hawser, and a pair of brackets is provided for enabling the attachment of ropes for just this purpose. These ropes and the door are, of course, placed on the ship side of the rat guard, so that the rat from shore has no access to the brackets or ropes. When the rat guard is then lowered into place against the hawser, the hawser engages the portion of the door lying across the slot and pushes on the door so as to swing the door away from the stop and move the center of gravity past the vertical line through the pivot, so that the door swings into its closed position around the hawser. A second stop may be provided to engage the door on closure a little ahead of the normal rest position so that the door is held more firmly, by its weight, around the hawser. When it is desired to remove the rat guard from the hawser, the rat guard is lifted by the ropes, and the hawser then swings the door far enough away from the second stop to enable extraction of the hawser from the slot. Then the door swings back to its normally closed position. It is recocked before reuse.

Other objects and advantages of the invention will appear from the following description of a preferred embodiment and from the drawings thereof.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a simplified view in perspective of a docked ship with two hawsers, each having a rat guard embodying the principles of the invention located on the hawser and held at a desired location by ropes attached to the rat guard and to a suitable member on the ship.

FIG. 2 is a view in front elevation of a rat guard embodying the principles of the invention with the holding ropes broken off in order to conserve space.

FIG. 3 is a view in perspective looking from the rear of the rat guard with the self-closing door in cocked position and with the hawser entering in the slot.

FIG. 4 is a view similar to FIG. 3 in which the hawser is moving the door away from its cocked position toward a position where the center of gravity of the door will cross the vertical line through the pivot.

FIG. 5 is a similar view with the door moved into its locked position and holding the rat guard around the hawser.

FIG. 6 is a similar view showing how the rat guard can be raised up from the hawser to cause the hawser to swing the door open enough to enable the hawser to be withdrawn from the slot.

FIG. 7 is a fragmentary enlarged view in section through the pivot.

DESCRIPTION OF A PREFERRED EMBODIMENT As shown in FIG. 1, a docked ship 10 is held to the wharf by hawsers, two hawsers or mooring lines 11 and 12 being shown here. If nothing more were done, rats, mice and other rodents could walk along the large hawsers and get aboard the ship, and they have often done this.

The present invention provides that each hawser 11, 12 be equipped with a rat guard 15, 15' which fits around the hawser 11, 12 and excludes rats by providing a barrier around which they cannot pass. Two guide ropes 16 and 17 and 16', 17' are used for holding the rat guard 15, 15' in the proper position and are also used in installing and withdrawing the

rat guard

15, 15

on and from the hawser 11, 12.

The rat guards 15 and 15' are identical, and FIG. 2, a view in front elevation, shows the rat guard 15 as it is seen by the rat, with the exception that the hawser 11 or 12 is not shown in place. The rat guard 15 may be any size desired, but is preferably made large enough, say a height of 18 to 20 inches above the hawser 11, to be beyond the stretch of a large rat and to prevent a rat from seeing over it or knowing enough what is beyond it to enable it to jump accurately over it.

The rat guard 15 of this invention may be made as a circular disc, but it preferably comprises a barrier plate of the polygonal shape shown in the drawings, because with a broad circle, a rat can put its front feet up on the top, lift the other two feet up, steady itself, and jump down. However, with the polygonal shape shown, the two upwardly converging

edges

21 and 22 of the plate 20 meet at a narrow vertex 23 and the

edges

21 and 22 are both too steep to enable the rat to hold on to either of them and get around the plate 20. The plates center of gravity keeps the vertex 23 at the top.

The vertex 23 is so narrow that the rat cannot get all four of its feet up there, in fact, it is doubtful whether it could get more than one, so that it cannot achieve a stable position atop the vertex 23, from which it might be able to progress further. Although a rat may still try to jump over the barrier plate 20, that usually results in missing the hawser 11 and falling into the water, and rats do not attempt such chances. The balance of the plate 20 is such that if a rat or other rodent should attempt to climb over or around it, the plate 20 rolls or tips toward him in response to his weight, dropping him into the water below. The plate 20 is more stable in gusty winds than a circular disc and is much less liable to be bent out of shape by the winds.

The plate 20 may be shaped, as shown, in a generally pentagonal shape with sloping

bottom sides

24 and 25 and a bottom edge 26 interrupted by a guide slot 27 which may be wider at the bottom than at its upper edge, which lies near or at the center of gravity of the plate 20 and where a circular upper portion 28 is provided to engage the hawser. The guide slot 27 enables crewmen easily to place the rat guard 15 on the hawser 11. The edges of the plate 20 and of its slot 27 may be folded over to protect crewmen from being cut.

Secured to the plate 20 is a self-closing door or ropeenclosing member 30, which is mounted on a pivot assembly 31. As shown in FIG. 7, the pivot assembly 31 may include a bolt 32 having a head 33 on the wharf face of the plate 20, a nut 34, a metal spacing washer 35 next to the plate 20, a metal washer 36 next to the nut 34, and a fiber washer 37 between the washer 35 and the door 30. The fiber washer 37 provides friction helping to prevent premature closing of the cocked door during installation. The door 30 may be shaped in any manner desired but preferably is provided with a round edge portion 38 adapted to engage the lower side of the hawser 11 and cooperate with the edge portion 21 to enclose the hawser 11 and prevent the passage of rodents there. The self-locking door 30 prevents the winds or tidal movement from dislocating the rat guard 15 and detaching it from the hawser l1. Preferably, the door 30 is also shaped to give a good closure across the bottom of the slot 27 and to provide near the portion 38 a sloping edge 39 and adjacent portions that project in the manner shown in FIG. 3 into the slot 27 when the door is set to a cocked position. Preferably, also, the door 30 has a weight 40 to enable concentration of the door's weight toward a single location, though the door 30 may be shaped to provide the needed location for the center of gravity, the weight 40 is preferably located distant from the pivot 31 near an edge 41.

The door 30 is set to a cocked position with the aid of the weight 40 and a stop 42 provided on the plate 20. In this instance the stop 42 may also serve as a bracket for the rope 17 with another bracket 43 being provided for the other rope 16 which does not act as a stop. The stop 42 could, of course, be a separate member from the rope-holding bracket, but this expedient is economical. The stop 42 holds the door 30 against rotating in one direction, and that direction is chosen to be the one in which the weight is then urging the door 30 against the stop. The door 30 is so shaped and weighted that when it is rotated on its pivot 31 away from the stop 42, as it can be by lowering it onto the hawser 11 so that the hawser 11 in effect presses up on the door 30, the door 30 swings around to a position (FIG. 4) where the center of gravity of the door 30 as a whole (including the weight 40) passes beyond the vertical axis through the pivot 31, and then the weight 40 makes the door 30 swing around to close around the hawser, as shown in FIG. 5. To insure good closure, this final position may be a position somewhat short of the position to which the door 30 would actually be urged by its weight 40, with a second stop member 44 holding it there and with the weight 40 urging the door 30 firmly against the second stop member 44. To give better contact of the door 30 with the stop 42, the edge 45 that engages the stop 42 is partially folded to provide a contact flange 46; similarly the edge 47 which engages the stop 44 is folded to provide a contact flange 48.

Comers

49 and 50 are preferably folded up somewhat to give better swinging action.

The device is easily installed by using a pair of

ropes

16 and 17 about fifteen to twenty-five feet long to lower the rat guard 15 along the hawser 11 while keeping it high enough so that, while the hawser l1 enters the slot 27 as shown in FIG. 3, the edge 39 does not touch the hawser 1 1. To give better action at this stage, the

brackets

42 and 43 are aligned on a line making an angle with the vertical axis of the plate 20, sloping down from the bracket 42 to the bracket 43. When the desired position is reached, the

ropes

16 and 17 are lowered or slackened so that the hawser 11 then engages the edge 39 and swings the door around the pivot 31, (FIG. 4), and then the weight 40 swings the door 30 into the closed position shown in FIG. 5. The

ropes

16 and 17 are left slack and tied to the ship.

When it is desired to remove the rat guard 15 from the hawser 11, the

ropes

16 and 17 are untied and pulled up, and the force of the door 30 against the hawset 11 swings the door 30 around until the hawser 11 can be withdrawn from the slot 27, and then the door 30 falls back into its normally closed position. The door 30 is later recocked by hand, usually aboard ship.

When a smaller rat guard is used on small cabin cruisers and yachts, a smaller aperture and slot are provided and additionally locking lugs for the door enable a padlock to be used for security from theft.

To those skilled in the art to which this invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.

We claim:

1. A rat guard for ships hawsers and the like, including in combination:

a large barrier plate having a bottom portion with a generally vertical slot affording entry to a said haw- 8:11 and extending up to a round hawser-engaging 8.

a self-closing closure door pivoted to said plate near the upper end of said slot and urged to a nonnal position by its weight and the relation of its center of gravity to its pivot, where it lies athwart said slot with an upper edge mating with said hawserengaging edge to encircle a said hawser, and

retaining means for said door secured to said plate for holding said door cocked away from its said normal position with a portion of said door lying across the upper end of said slot for engagement by a hawser that has entered said slot,

said door being actuated by engagement of said hawser when said door is in its cocked position, for causing said door to swing around its pivot to enclose said hawser snugly between itself and said plate.

2. The rat guard of claim 1 wherein said barrier plate has an upper portion above said hawser-engaging edge comprising two steeply slanted edges meeting at a narrow vertex at the top.

3. The rat guard of claim 1 having a pair of brackets for attachment of a rope to each said bracket, for placing said rat guard on said hawser and for removing it therefrom.

4. A rat guard for ships hawsers and the like, including in combination:

a large barrier plate having a generally smooth wharfside face and a shipside face, a bottom portion with a generally vertical tapered slot affording entry to a said hawser and extending up to a round hawserengaging edge,

a self-closing hawser closure door on the shipside face of said plate, pivoted to said plate near the upper end of said slot and having a weight thereon urging said door to a normal position where it lies athwart said slot with an upper edge mating with said hawser-engaging edge to encircle snugly a said hawser, and

stop means for said door secured to said plate and holding the door, when rotated against said slot, cocked away from its said normal position with a portion of said door lying across the upper end of said slot with a diagonally extending edge for engagement by a hawser that has entered said tapered slot,

said door being actuated by engagement with said hawser, when said door is in its cocked position, for causing said door to swing around its pivot to enclose said hawser between itself and said plate.

5. The rat guard of claim 4 having a pair of brackets on said shipside face above said door for attachment of a rope to each said bracket, for emplacing and removing said rat guard on a said hawser.

6. The rat guard of claim 5 wherein one said bracket functions also as said stop means.

7. The rat guard of claim 4 having second stop means for stopping said door short of the position to which it would normally be urged by said weight, when swung around a said hawser.

8. The rat guard of claim 4 wherein said barrier plate has a narrow vertex at its very tip and two steeply inclined edges leading down therefrom.

9. A rat guard for ships hawsers and the like, including in combination:

a polygonal barrier plate having a top portion with two steeply converging edges meeting at a narrow vertex at the very top and a bottom portion having a slot extending up from a bottom edge to a round hawser-engaging edge at the upper end of said slot,

a self-closing door pivoted to one side of said plate near the upper end of said slot and weighted toward a normal position by a weight secured thereto and by the relation of its center of gravity to its pivot, lying in said normal position athwart said slot with a rounded edge portion mating with said round hawser-engaging edge to encircle a said hawser snugly, and

a stop for said door secured to said plate on the same side as said door and engaging an edge of said door when said weight is swung over center in one direction to hold it away from its said normal position, a portion of said door then lying across the upper end of said slot for engagement by a hawser that has entered said slot,

the pressure of a hawser on said door when said door engages said stop causing said door to rotate around its pivot and place its said weight over center in the other direction and then to fall down and to enclose said hawser between itself and said plate. 1

10. The rat guard of claim 9 having two brackets secured to said plate on the same side as said door, having means for attachment of a rope to each said bracket, one said bracket also comprising said stop.

11. The rat guard of claim 10 having a second stop limiting the swing of said door away from the firstmentioned said stop.

t s a a a

Claims

1. A rat guard for ships'' hawsers and the like, including in combination: a large barrier plate having a bottom portion with a generally vertical slot affording entry to a said hawser and extending up to a round hawser-engaging edge, a self-closing closure door pivoted to said plate near the upper end of said slot and urged to a normal position by its weight and the relation of its center of gravity to its pivot, where it lies athwart said slot with an upper edge mating with said hawser-engaging edge to encircle a said hawser, and retaining means for said door secured to said plate for holding said door cocked away from its said normal position with a portion of said door lying across the upper end of said slot for engagement by a hawser that has entered said slot, said door being actuated by engagement of said hawser when said door is in its cocked position, for causing said door to swing around its pivot to enclose said hawser snugly between itself and said plate.

4. A rat guard for ships'' hawsers and the like, including in combination: a large barrier plate having a generally smooth wharfside face and a shipside face, a bottom portion with a generally vertical tapered slot affording entry to a said hawser and extending up to a round hawser-engaging edge, a self-closing hawser closure door on the shipside face of said plate, pivoted to said plate near the upper end of said slot and having a weight thereon urging said door to a normal position where it lies athwart said slot with an upper edge mating with said hawser-engaging edge to encircle snugly a said hawser, and stop means for said door secured to said plate and holding the door, when rotated against said slot, cocked away from its said normal position with a portion of said door lying across the upper end of said slot with a diagonally extending edge for engagement by a hawser that has entered said tapered slot, said door being actuated by engagement with said hawser, when said door is in its cocked position, for causing said door to swing around its pivot to enclose said hawser between itself and said plate.

9. A rat guard for ships'' hawsers and the like, including in combination: a polygonal barrier plate having a top portion with two steeply converging edges meeting at a narrow vertex at the very top and a bottom portion having a slot extending up from a bottom edge to a round hawser-engaging edge at the upper end of said slot, a self-closing door pivoted to one side of said plate near the upper end of said slot and weighted toward a normal position by a weight secured thereto and by the relation of its center of gravity to its pivot, lying in said normal position athwart said slot with a rounded edge portion mating with said round hawser-engaging edge to encircle a said hawser snugly, and a stop for said door secured to said plate on the same side as said door and engaging an edge of said door when said weight is swung over center in one direction to hold it away from its said normal position, a portion of said door then lying across the upper end of said slot for engagement by a hawser that has entered said slot, the pressure of a hawser on said door when said door engages said stop causing said door to rotate around its pivot and place its said weight over center in the other direction and then to fall down and to enclose said hawser between itself and said plate.

11. The rat guard of claim 10 having a second stop limiting the swing of said door away from the first-mentioned said stop.