US3872818A

US3872818A - Rat guard

Info

Publication number: US3872818A
Application number: US402398A
Authority: US
Inventors: Robert M Salvarezza
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-12-22
Filing date: 1973-10-01
Publication date: 1975-03-25
Anticipated expiration: 1992-03-25

Abstract

A rat guard for ships hawsers and the like. A polygonal barrier plate has a generally flat bottom portion and a top portion with two steeply converging edges meeting at a narrow vertex at the very top. The bottom portion is connected to these steeply converging edges by two upwardly diverging sides, one of which has a slot that extends up at an angle and then horizontally into the center to a round hawser-engaging edge at about the center of gravity. The center of gravity is so positioned that it will naturally hold the narrow vertex at the top and the flat bottom at the bottom. A door is provided to move into the slot end close around the hawser and hold the rat guard on the hawser. The door is opened and closed by a shift in the position of the barrier plate, which is made possible by a pair of guide ropes, one secured to or near the top vertex and the other near another vertex at the side and on the opposite side from the one having the slot.

Description

tlnited States Salvarezza Mar. 25, 1975 1 RAT GUARD [76] Inventor: Robert M. Salvarezza, I10 Braemar Dr., Hillsborough, Calif. 94010 [22] Filed: Oct. 1, 1973 [21] Appl. No.: 402,398

Related US. Application Data [63] Continuation-impart of Ser. No. 317,365, Dec. 22,

I972, abandoned.

Primary Examiner-Trygve M. Blix Attorney, Agent, or FirmOwen, Wickersham & Erickson [57] ABSTRACT A rat guard for ships hawsers and the like. A polygonal barrier plate has a generally flat bottom portion and a top portion with two steeply converging edges meeting at a narrow vertex at the very top. The bottom portion is connected to these steeply converging edges by two upwardly diverging sides. one of which has a slot that extends up at an angle and then horizontally into the center to a round hawser-engaging edge at about the center of gravity. The center of gravity is so positioned that it will naturally hold the narrow vertex at the top and the flat bottom at the bottom. A door is provided to move into the slot end close around the hawser and hold the rat guard on the hawser. The door is opened and closed by a shift in the position of the barrier plate, which is made possible by a pair of guide ropes, one secured to or near the top vertex and the other near another vertex at the side and on the opposite side from the one having the slot.

11 Claims, 9 Drawing Figures RAT GUARD CROSS REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of applica tion Ser. No. 317,365 filed Dec. 22, 1972, now abandoned.

BACKGROUND OF THE INVENTION This invention relates to an improved rat guard providing sure closure action, better centering, easier re lease, and improved protection from rats.

Rat guards are used around the hawsers of a ship to prevent rats and other rodents on shore from boarding the ship, as they otherwise could do by simply walking along the hawsers. Heretofore, rat guards have generally comprised large circular discs split into two hinged halves which have had to be installed on the ships hawsers by hand under inconvenient circumstances. Since they have been large discs, their curvature per circumference has been relatively flat, so that large rats have often been able to place their forelegs on the upper edge of the rat guard, then to jump with their lower legs and get all four legs on this upper edge, and then to jump down the other side onto the hawser and so board the ship.

Rat guards have heretofore been installed by making the circular disc in two pieces which can be swung apart and then which have to be bolted together. The bolting was inconvenient, and it was difficult to install or remove the rat guard.

SUMMARY OF THE INVENTION feet 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. It certainly cannot hold on to the steep sides below the vertex.

The rat guard of this invention, whether round or polygonal, is characterized by ease of installation and removal. Typically, the rat guard is pentagonal, having four straight sides and a fifth side providing somewhat above the bottom curved entry guiding into an angularly upwardly extending slot having a final substantially horizontal portion leading into the center. The center is located at or very near to the center of gravity, so that the rat guard naturally assumes its correct position on a hawser when it has been installed. A door is provided to lock the rat guard in place on the hawser, and this door is opened and closed by manipulation of a pair of spaced-apart ropes, one on or near the vertex and the other at some other convenient location near the edge, preferably near the edge opposite the slot. The manipulation is very simple: one of the two ropes is lifted to open the door and then is allowed to resume its former position, where the center of gravity takes control.

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

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 a hawser and held in a desired location by ropes attached to the rat guard and to a suitable part of the ship.

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

FIG. 3 is a view in rear elevation of the rat guard of FIG. 2 with the manipulated ropes broken off but shown with one rope raised to open the door to enable installation or removal of the rat guard with respect to hawser. In this view the hawser may be considered as just entering or just leaving the slot.

FIG. 4 is a view similar to FIG. .3. with the hawser in the slot and the door beginning to move toward its closed position.

FIG. 5 is a view in rear elevation of the rat guard with the door fully closed and with the rat guard in substantially its normal position.

FIG. 6 is an enlarged view in section of the bolt holding the door for pivoting action relative to the barrier plate.

FIG. 7 is an enlarged fragmentary view in section taken along the line 7-7 in FIG. 5.

FIG. 8 is a fragmentary view in rear elevation of the device with the door repivoted for use with a larger diameter rope. The door is shown in its fully closed position.

FIG. 9 is a view similar to FIG. 8, but with the door repositioned to a third pivot for use with a smaller diameter rope or cable.

DESCRIPTION OF A PREFERRED EMBODIMENT As shown in FIG. 1, a docked ship 10 is held to a wharf by hawsers, two hawsers or mooring lines 11 and 12 being shown in this view. 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 kind of thing.

In the present invention each hawser ll, 12 is equipped with a

rat guard

15, 15 which should surround their respective hawsers 11, 12 and excludes rats by providing a barrier around which they cannot pass. Two guide and manipulating

ropes

16 and 17 or 16' and 17 are used for installation and removal of the rat guard and helping it retain the proper position along the hawser 11 or 12.

The rat guards l5 and 15 are identical and in FIGS. 2 through 5 therefore, the rat guard 15 is shown, but the description equally applies to the rat guard 15'. The rat guard 15 may be of any size desired but is preferably made large enough, say a height of 18 to 20 inches or even bigger above the hawser 11,. so that it is beyond the stretch of a large rat and prevents a rat from seeing over it or knowing enough what is beyond it to enable it to jump accurately over it.

While the rat guard 15 of this invention might be made as a circular disc, it preferably comprises a barrier plate 20 of polygonal shape as shown in the drawings, because a rat can put its front feet upon the top of a broad circle, lift its two rear feet up, steady itself, and jump down onto the hawser and be past the rat guard. With the polygonal shape shown, however, this is not possible. Two upwardly converging

edges

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

edges

21 and 22 are both too steep to enable a rat to hold on to either of them and thereby keep him from getting around the plate 20. The plates center of gravity keeps the vertex 23 at the top, and the vertex 23 is so narrow that the rat cannot get all four of its feet up there at the same time. In fact it was doubtful whether it could get more than one up there. As a result, a rat cannot achieve a stable position on top of the vertex 23 from which it might be able to progress further. The rat might still try to jump over the barrier plate 20, but that usually results in its missing the hawser 11 and falling into the water, so that 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 on it, the plate 20 will roll or tip toward him in response to his weight, thereby usually dropping him into the water below. It should be noted that the plate 20 of polygonal shape is more stable in gusty winds than is a circular disc and is much less liable to bent out of shape by wind.

The plate 20 may be shaped as shown in a generally pentagonal form, with a straight sloping bottom side 24 and a bottom edge 25, where, to complete the pentagon, there would be another sloping side, instead there are

rounded edges

26 and 27 leading into a guide slot 28, which may be and preferably is somewhat wider at its entrance than near the center of the plate 20. The slot 28 leads upwardly and inwardly, with its edges converging, at an angle which extends just to one side of the center of the plate 20; however, a terminal portion 29 is substantially or nearly horizontal and leads in to that center, ending at a terminal edge 30 which is circular to engage the hawser 11 at a point lying near or at the center of gravity of the rat guard 15, and it is so positioned that the device is self-stablizing. The guide slot 28 enables crewmen easily to place the rat guard on the hawser l1, and the terminal portion 29 helps to prevent accidental departure of the hawser 11 from its engaged position.

Secured to the plate 20, by a pivot pin or bolt 31 is a door or closing member 32. The bolt may have its head 33 on the wharfside face of the plate 20, and washers 34 may be provided for spacing the door 32 from the plate 20 and from a nut 35, as shown in FIG. 6.

Openings

36, 37 and 38 (See FIGS. 3-5, 8 and 9) enable the bolt 33 to be moved for adjustment to larger or smaller hawsers. Thus, hawsers 11 having a circumference of inches or less (e.g., cables) may be employed with the bolt 31 extending through the opening 36 (FIG. 9). Hawsers 11 having a circumference of 6 inches, 7 inches, or 8 inches require the bolt 31 to extend through the opening 37 (FIGS. 3-5), and hawsers 11 having a circumference of 9 inches require the bolt 31 to extend through the opening 38 (FIG. 8).

The door 32 may be shaped with outwardly converging

flat edges

40 and 41, the edge 41 having an arcuate slot 42 at one end, which is of substantially the same diameter as the largest hawser 11 to be used with the rat guard, and which extends about three-fourths of the way around a circle. When the door 32 is closed, as in FIGS. 2 and 5, the slot 42 cooperates with the slot 28 to encircle the hawser l1, and thereby to hold the rat guard 15 in place. The slot 42 goes to a tongue-like portion 44.

FIG. 7 shows that where the edge 41 meets the slot 42, the sheet metal door 32 has an outwardly inclined portion 43; this is the portion that is the leading edge when the door 32 swings across the slot 28, and the outwardly inclined portion 43 prevents the door from crossing over from one face of the plate 20 to the other across the slot 28.

A drilled hole 45 with a washer-grommet (or a bracket 45, which may be L-shaped) is located near the vertex 23, and another bracket or hole 46 is located near a vertex 47 that joins the

edges

21 and 24. To these

brackets

45 and 46 the guide and manipulation ropes l6 and 17 are secured. As shown in FIGS. 2 and 5, when the two ropes l6 and 17 are slack (or when at least the rope 17 is slack) the rat guard 15 assumes the vertical position of FIGS. 2 and 5. In this position the door 32 is closed, as can be seen from FIG. 5. To open the door 32 for either installation or removal of the rat guard 15 on the hawser 11, all that needs to be done is to raise the rope 17 relative to the rope 16 so that the rope 17 is taut and the rope 16 is slack, in a position like that shown in FIG. 3 where the

holes

45 and 46 are at the same level, or where the

rounded edges

26 and 27 are approximately on the same level. Then the rat guard is inserted over the hawser 11 in the position shown in FIG. 4. Then, the hawser 11, when itengages the edge 41, swings the door to one side (to the left in FIG. 3) to enter the final portion of the slot 28 and the terminal portion 29 and to come to rest against the terminal edge 30. When the hawser 11 engages the tongue-like portion 44, the door 32 then pivots around the bolt 31 and swings around the hawser 11 and closes against it (FIGS. 2 and 5); simultaneously the rope 17 is slackened. The hawser 11 cannot then come out, unless the plate 20 is again rotated by the rope and the rat guard lifted. The removal of the rat guard 15 from the hawser 11 is just as simple and is achieved by the same operations in the reverse manner, for with the plate 20 in the position of FIG. 4, the upward movement of the plate 20 or the downward motion of the hawser 11 swings the door 32 out of the way. The simplicity and foolproof nature of the operation is quite important.

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 not intended to be in any sense limiting.

I claim:

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

a large barrier plate having a slot leading in upwardly at an angle with respect to vertical from an edge at a locus below the center of gravity of said plate to near the center and thence approximately horizontally into a round hawser-engaging edge at approximately said center of gravity, said plate by virtue of its shape and appending parts having a normal righted position which it automatically seeks,

a freely swingable closure door pivoted to said plate near said hawser-engaging edge and normally lying athwart said slot, said door having an arcuate edge portion near its pivot, said door at all times hanging freely,

a pair of guide and manipulation ropes secured to said plate for swinging said plate away from its normal righted position to a position where said freely swinging closure door hangs in a position where the hawser itself can swing the door open to enter the slot fully and engage said hawser-engaging edge, said door then swinging back to enclose said hawser with its said arcuate edge upon release of said guide and manipulation ropes as said plate rights itself to its normal righted position, where said hawser cannot cause said door to open and release said hawser until said ropes have once again been used to enable release.

2. The rat guard of claim 1 wherein said door has a leading corner that is inclined away from said plate so as to insure the door always lying exclusively on one face of said plate.

3. The rat guard of claim 1 wherein said door is pivoted to said plate by a pivot pin secured to said plate, said door having a plurality of pivot openings for adapting said rat guard to different diameters of hawsers.

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

a large barrier plate having a normal righted position which it automatically seeks with an upper end, a bottom, slot leading at an upward and inward inclination from an edge at a locus near said bottom and well below the center of gravity of said plate to a locus near and to one side of the center of gravity and then approximately horizontally into a round hawser-engaging edge at approximately said center of gravity,

a freely swingable closure door pivoted to said plate near the hawser-engaging edge and lying athwart said slot when said plate is in its normal righted position with its upper end at the top of said plate and is vertically above said center of gravity, said door having one edge lead to an arcuate edge near the pivot, said edge lying athwart said slot when the slot is approximately vertical and so that engagement with said hawser moves said door automati cally to gain entrance to said hawser-engaging edge, said door then closing to engage said hawser with its arcuate edge, and

a pair of guide and manipulation ropes mounted to said plate, a first said rope being mounted adjacent said upper end and a second said rope being spaced lower down near an edge opposite to the one having said slot, manipulation of said ropes being used to swing the plate away from its normal righted position and thereby to swing the freely swingable door to a position relative to said plate and said slot to enable installation and removal from said hawser of said rat guard.

5. The rat guard of claim 4 wherein said barrier plate is polygonal, having a bottom portion, inclined outwardly diverging side edges leading up from said bottom portion, and two steeply converging upper edges meeting each other at a narrow upper vertex at the very top, and meeting said side edges at lower vertices. 5 6. The rat guard of claim 5 wherein said second rope is mounted near one said lower vertex on the opposite side of said plate from said slot.

7. The rat guard of claim 5 wherein said slot has edges that converge toward said center and said plate has widely rounding edges leading into said slot.

8. The rat guard of claim 4 wherein said one edge meets said arcuate edge at a corner and the corner is inclined outwardly from said plate.

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

a large polygonal barrier plate having a bottom portion, inclined outwardly diverging side edges leading up from said bottom portion, and two steeply converging upper edges meeting each other at a narrow upper vertex at the very top, and meeting said side edges at lower vertices, one of said side edges having two rounded portions separated by a slot leading inwardly therefrom to a locus to one side ofthe center of gravity of said plate and terminating in a horizontal portion at said center with a round hawser-engaging edge,

a closure door pivoted to said plate near the upper end of said slot and swingable thereabout, said door having two downwardly converging edges, one of which meets an arcuate hawser-engaging edge at a corner which is bent outwardly from said plate, said one edge lying across said slot, when said slot is approximately vertical in a direction such that upward pressure by a hawser swings said door open, said door then closing when said hawser enters said horizontal portion, and

means for securing a pair of guide and manipulation ropes, one adjacent said upper vertex and the other adjacent a lower vertex on the side opposite said ment by a said hawser to aid in closing said door.

Claims

1. A rat guard for ships'' hawsers and the like, including in combination: a large barrier plate having a slot leading in upwardly at an angle with respect to vertical from an edge at a locus below the center of gravity of said plate to near the center and thence approximately horizontally into a round hawser-engaging edge at approximately said center of gravity, said plate by virtue of its shape and appending parts having a normal righted position which it automatically seeks, a freely swingable closure door pivoted to said plate near said hawser-engaging edge and normally lying athwart said slot, said door having an arcuate edge portion near its pivot, said door at all times hanging freely, a pair of guide and manipulation ropes secured to said plate for swinging said plate away from its normal righted position to a position where said freely swinging closure door hangs in a position where the hawser itself can swing the door open to enter the slot fully and engage said hawser-engaging edge, said door then swinging back to enclose said hawser with its said arcuate edge upon release of said guide and manipulation ropes as said plate rights itself to its normal righted position, where said hawser cannot cause said door to open and release said hawser until said ropes have once again been used to enable release.

4. A rat guard for ships'' hawsers and the like, including in combination: a large barrier plate having a normal righted position which it automatically seeks with an upper end, a bottom, slot leading at an upward and inward inclination from an edge at a locus near said bottom and well below the center of gravity of said plate to a locus near and to one side of the center of gravity and then apprOximately horizontally into a round hawser-engaging edge at approximately said center of gravity, a freely swingable closure door pivoted to said plate near the hawser-engaging edge and lying athwart said slot when said plate is in its normal righted position with its upper end at the top of said plate and is vertically above said center of gravity, said door having one edge lead to an arcuate edge near the pivot, said edge lying athwart said slot when the slot is approximately vertical and so that engagement with said hawser moves said door automatically to gain entrance to said hawser-engaging edge, said door then closing to engage said hawser with its arcuate edge, and a pair of guide and manipulation ropes mounted to said plate, a first said rope being mounted adjacent said upper end and a second said rope being spaced lower down near an edge opposite to the one having said slot, manipulation of said ropes being used to swing the plate away from its normal righted position and thereby to swing the freely swingable door to a position relative to said plate and said slot to enable installation and removal from said hawser of said rat guard.

5. The rat guard of claim 4 wherein said barrier plate is polygonal, having a bottom portion, inclined outwardly diverging side edges leading up from said bottom portion, and two steeply converging upper edges meeting each other at a narrow upper vertex at the very top, and meeting said side edges at lower vertices.

6. The rat guard of claim 5 wherein said second rope is mounted near one said lower vertex on the opposite side of said plate from said slot.

9. A rat guard for ships'' hawsers and the like including in combination: a large polygonal barrier plate having a bottom portion, inclined outwardly diverging side edges leading up from said bottom portion, and two steeply converging upper edges meeting each other at a narrow upper vertex at the very top, and meeting said side edges at lower vertices, one of said side edges having two rounded portions separated by a slot leading inwardly therefrom to a locus to one side of the center of gravity of said plate and terminating in a horizontal portion at said center with a round hawser-engaging edge, a closure door pivoted to said plate near the upper end of said slot and swingable thereabout, said door having two downwardly converging edges, one of which meets an arcuate hawser-engaging edge at a corner which is bent outwardly from said plate, said one edge lying across said slot, when said slot is approximately vertical in a direction such that upward pressure by a hawser swings said door open, said door then closing when said hawser enters said horizontal portion, and means for securing a pair of guide and manipulation ropes, one adjacent said upper vertex and the other adjacent a lower vertex on the side opposite said slot, so that by raising said lower vertex relative to the upper vertex, said slot is moved to a vertical position for installation around or removal from a hawser.

10. The rat guard of claim 9 wherein said door is pivoted to said plate by a pivot pin secured to said plate, said door having a series of pivot openings for adapting said rat guard to different diameters of hawsers.

11. The rat guard of claim 9 wherein said door has a tongue portion at the upper end of said slot, for enagement by a said hawser to aid in closing said door.