Device for facilitating manual gripping of pipes and connectors

Information

  • Patent Grant
  • 6516496
  • Patent Number
    6,516,496
  • Date Filed
    Monday, March 26, 2001
    23 years ago
  • Date Issued
    Tuesday, February 11, 2003
    21 years ago
Abstract
A device for facilitating manual gripping of pipes and connectors includes first and second elements hingedly interconnected and biased open by a spring element. Each element includes a channel with projections deployed to define gripping features for gripping a roughly cylindrical object of given outer diameter. The first and second elements provide grasp surfaces which, in the closed position, lie within a cylindrical volume of diameter four times the given outer diameter and generally circumscribe the object.
Description




FIELD AND BACKGROUND OF THE INVENTION




The present invention relates to tubing systems in which flexible pipes are interconnected by forced insertion of connectors and, in particular, it concerns a device for facilitating manual gripping of pipes and connectors.




It is known to employ systems of flexible plastic pipes with various connectors for drip irrigation. Drip irrigation is of particular importance in hot climates with low rainfall, where water is a valuable commodity. Drip irrigation is widely used in commercial agriculture in many areas of the USA, South America, southern Europe, the Middle East, South Africa, China, India and Australia. The use of drip irrigation systems for public gardens, domestic applications and in hot-houses is also rapidly growing.




For pipes of large diameter or which are used for high pressure, large multi-piece connectors are used. These connectors are relatively expensive and require a series of operations to deploy them. In most cases, attachment of pipes of diameter up to about 25 mm is achieved more cheaply and simply by forcing the end of a pipe onto a simple, one-piece, molded-plastic connector which has a number of barbed ridges which prevent the pipe from slipping off. This attachment operation is typically performed manually by gripping the pipe in one hand, the connector in the other, and pushing them together. The tightness of the fit and the difficulty in gripping the smooth pipe and the small connectors render this operation strenuous and uncomfortable to perform. The operation is repeated very many times during assembly of a typical irrigation system, resulting in excess strain on the workers and frequently leading to formation of blisters or other minor injuries.




In the field of devices and accessories for connection to irrigation systems, there exist many clamping structures configured for permanent clamped connection to an irrigation pipe. None of these, however, is capable of instantly gripping a pipe or connector to facilitate the attachment procedure and then immediately releasing the pipe or connector.




In other fields of technology, it is known to use pipe-gripping pliers, typically with a scissors-type action which have jaws formed for gripping a pipe lying transverse to the length of the scissors arms. The position of the handles of such pliers is far from the pipe itself. As a result, such devices are suited for supporting a pipe during processing such as for welding a section of metal pipe, but are not suitable for applying significant forces along the length of a pipe such as is required during the aforementioned attachment operation for flexible pipes.




There is therefore a need for a device for facilitating manual gripping of pipes and connectors which would be instantly deployable and removable, and which would make easier the operation of attaching pipes and connectors for irrigation systems, and which would increase both the speed and quality of work performed.




SUMMARY OF THE INVENTION




The present invention is a device for facilitating manual gripping of pipes and connectors.




According to the teachings of the present invention there is provided, a device for facilitating manual gripping of pipes and connectors comprising: (a) a first element; (b) a second element hingedly attached to the first element at a hinge structure, the hinge structure being configured such that the first element is rotatable relative to the second element about a hinge axis from a closed position through a range of angles no more than 180° to a fully open position; and (c) a spring element deployed to bias the first element relative to the second element towards the open position, wherein each of the first element and the second element includes a channel extending substantially parallel to the axis, a plurality of projections being deployed projecting into each channel so as to define gripping features, the channels and the gripping features being formed such that, when the first element and the second element assume the closed position, the gripping features are located so as to grip a substantially cylindrical object of outer diameter D located parallel to the axis between the first element and the second element, and wherein the first element and the second element are configured to provide, respectively, first and second grasp surfaces which, at least in the closed position, lie within a cylindrical volume of diameter 4D circumscribing the channels, the first and second grasp surfaces being shaped such that they can be pressed together by a single hand of a user to close the device around a substantially cylindrical object such that the gripping features grip the object and the grasp surfaces substantially circumscribe the object.




According to a further feature of the present invention, the second element is substantially a mirror image of the first element.




According to a further feature of the present invention, the projections are implemented as projecting ridges extending around at least part of the channels in a direction substantially perpendicular to the axis, the projecting ridges being spaced apart along the axis.




According to a further feature of the present invention, the channels extend across an entire dimension of the first and the second elements from a first edge to a second edge along a length L, a portion of the channels which lies within at least about 10 percent of length L from the first edge being formed such that, when the first element and the second element assume the closed position, the channels accommodate a cylindrical element of diameter at least 15 percent greater than D.




According to a further feature of the present invention, the first and the second elements each further include a lateral recess configured such that, when the first element and the second element assume the closed position, the lateral recesses form a lateral opening of diameter at least 15 percent greater than D interconnecting with the channels.




According to a further feature of the present invention, the first and the second elements each further include a lateral recess configured such that, when the first element and the second element assume the closed position, the lateral recesses form a lateral opening of diameter approximately equal to D interconnecting with the channels.




According to a further feature of the present invention, there is also provided a detachable hole puncher element formed with at least one blade configured for forming a hole through a plastic wall of a pipe, the hole puncher element and the first and second elements being formed with complementary engagement features configured such that the hole puncher element releasably engages the first and second elements so as to retain the first and second elements in the closed position to provide a handle to facilitate operation of the hole puncher element.




According to a further feature of the present invention, the hole puncher element is configured to engage the first and second elements from either of two directions.




According to a further feature of the present invention, the first and the second elements are each formed primarily from a molded plastic material.




According to a further feature of the present invention, each of the first and the second elements is formed with a plurality of drainage holes connecting between the channel and an external surface of the element.




According to a further feature of the present invention, the hinge structure is configured such that the first element is rotatable relative to the second element about the hinge axis from the closed position through a range of angles no more than 90° to the fully open position.











BRIEF DESCRIPTION OF THE DRAWINGS




The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein:





FIG. 1

is an isometric view of a preferred implementation of a device, constructed and operative according to the teachings of the present invention, for facilitating manual gripping of pipes and connectors, the device having a pair of elements shown here in an open position;





FIG. 2

is an isometric view of the device of

FIG. 1

with the pair of elements in a closed position;





FIG. 3

is a plan view of the device of

FIG. 1

in a closed position;





FIG. 4

is an end view of the device of

FIG. 1

in a closed position;





FIG. 5

is an isometric view of one of the elements from the device of

FIG. 1

;





FIG. 6

is a cross-sectional view illustrating the use of the device of

FIG. 1

for gripping a pipe;





FIG. 7

is a cross-sectional view illustrating the use of the device of

FIG. 1

for gripping a straight (180°) connector in a first position;





FIG. 8

is a cross-sectional view illustrating the use of the device of

FIG. 1

for gripping a straight (180°) connector in a second position;





FIG. 9

is a cross-sectional view illustrating the use of the device of

FIG. 1

for gripping a T-type connector;





FIG. 10

is a cross-sectional view illustrating the use of the device of

FIG. 1

for gripping an L-type (90°) connector;





FIG. 11

is a cross-sectional view illustrating the use of the device of

FIG. 1

for gripping a one-sided branch connector;





FIG. 12

is an exploded isometric view of a preferred implementation of a hole punch element, constructed and operative according to the teachings of the present invention, for use together with the device of

FIG. 1

;





FIG. 13

is a side view of the hole punch element of

FIG. 12

after assembly;





FIG. 14

is an isometric view of the hole punch element of

FIG. 12

mounted on the device of

FIG. 1

ready for use;





FIG. 15

is an isometric view of a pair of devices similar to

FIG. 1

interconnected by the hole punch element of

FIG. 12

;





FIG. 16

is an isometric view of an alternative preferred implementation of a hole punch element, constructed and operative according to the teachings of the present invention, for use together with the device of

FIG. 1

; and





FIG. 17

is an isometric view of a simplified version of the device of

FIG. 1

, for use alone or together with the device of FIG.


1


.











DESCRIPTION OF THE PREFERRED EMBODIMENTS




The present invention is a device for facilitating manual gripping of pipes and connectors, primarily for the purpose of attaching them.




The principles and operation of devices according to the present invention may be better understood with reference to the drawings and the accompanying description.




Referring now to the drawings,

FIGS. 1-5

illustrate the structural features of a preferred implementation of a device, generally designated


10


, constructed and operative according to the teachings of the present invention, for facilitating manual gripping of pipes and connectors. The particular significance of a number of these preferred features will then be illustrated in the context of a number of applications with reference to

FIGS. 6-11

. Then, with reference to

FIGS. 12-16

, the structure and operation of various hole punch elements, configured for use together with one or more device


10


, will be described. Finally, a simplified implementation of the device of

FIG. 1

will be described with reference to FIG.


17


.




Turning first to

FIGS. 1-5

, generally speaking, device


10


includes a pair of elements


12


and


14


which are hingedly attached to each other at a hinge structure


16


. Hinge structure


16


is configured to allow relative rotation of elements


12


and


14


about an axis


18


from a closed position (

FIG. 2

) through a range of angles of no more than 180°, and preferably no more than 90°, to a fully open position (FIG.


1


). A spring element


20


is deployed to bias elements


12


and


14


towards the open position.




Each element


12


and


14


includes a channel


22


extending substantially parallel to axis


18


. A number of projections


24


project into each channel


22


so as to define gripping features


26


. Channels


22


and gripping features


26


are formed such that, when elements


12


and


14


are in the closed position, gripping features


26


are located so as to grip a substantially cylindrical object of outer diameter D located parallel to the axis between the first element and the second element. Elements


12


and


14


are also configured to provide, respectively, first and second grasp surfaces


28


and


30


which, at least in the closed position, lie within a cylindrical volume of diameter 4D circumscribing channels


22


(FIG.


4


). First and second grasp surfaces


28


and


30


are shaped such that they can be pressed together by a single hand of a user to close the device around a substantially cylindrical object such that gripping features


26


grip the object and grasp surfaces


28


and


30


substantially circumscribe the object.




At this stage, it will be readily understood that the device of the present invention provides an instantly deployable and removable tool to enhance manual gripping of a pipe or connector in a manner facilitating application of axial forces such as required for attachment of pipes and connectors. Specifically, the device is held between the thumb and fingers of one hand in its biased-open state of

FIG. 1

, positioned around a pipe or connector and closed by pressure applied between the thumb and fingers. Once closed, the device firmly grips the surface of the pipe or connector while providing contoured grasp surfaces for the user's hand which facilitate comfortable and effective application of axial forces. The location of the grasp surfaces, substantially circumscribing the pipe or connector, avoid generation of a twisting moment from the axial force applied. On relaxation of the user's hand, the device opens itself under the action of spring element


20


, thereby releasing the pipe or connector. Thus, the operations of gripping and releasing the pipe or connector are performed in an intuitive manual fashion without any impediment, while the discomfort normally associated with application of the forces required for attachment is greatly reduced or eliminated. These and other advantages of the present invention will be better understood from the additional detailed description which follows.




Gripping features


26


are described as being “located so as to grip a substantially cylindrical object of outer diameter D” when elements


12


and


14


assume their closed position. It should be noted in this context that device


10


is useful for gripping pipes, connectors and other elements with a significant range of diameters from D up to 10 or 15% larger than D. For each diameter, clamping occurs at a corresponding stage of closure of the device. The dimension D defined by the device in its fully closed state is the minimum value of object diameter for which effective clamping can be achieved.




Turning now to the features of a preferred implementation of the present invention in more detail, elements


12


and


14


are shown here implemented substantially as a mirror image of each other. This renders the device symmetrical in use such that it can be held in either hand and inverted. Thus, in a preferred implementation in which a user is to be provided with a pair of devices


10


, one for each hand, the user need not differentiate between a “left-handed” device and a “right-handed” device. The elements are described as “substantially a mirror image” so long as the variations between them do not render them clearly asymmetric with respect to right- or left-handedness. In the preferred implementation illustrated here, the only significant features which are not a mirror image are the interlocking projections forming part of hinge structure


16


. Here, the projections are clearly complementary rather than symmetrical.




Parenthetically, it should be noted that an alternative asymmetric implementation (not shown) provides alternative advantages for certain applications. Specifically, in an implementation in which grasp surfaces


28


and


30


are shaped to be specific to a right-handed grip or a left-hand grip, these surfaces may be formed to provide near-optimal ergonomic grip contours to further spread forces applied to the hand during use.




As best seen in

FIGS. 1 and 5

, projections


24


are here implemented as projecting ridges


24


extending around at least part of channels


22


in a direction substantially perpendicular to axis


18


. This configuration is particularly effective for securing a pipe or connector against axial slippage. Projecting ridges


24


are preferably spaced apart along axis


18


, thereby gripping a pipe at multiple locations to avoid localized stress.




Preferably, channels


22


extend across an entire dimension of each element


12


and


14


from a first edge


32


to an opposite edge


34


along a length L. A portion


22




a


of channels


22


which extends along a length l corresponding to at least about 10 percent of length L from first edge


32


is preferably formed such that, in the closed state, channels


22


accommodate a cylindrical element of diameter at least 25 percent greater than D. This is typically achieved by omitting projections


24


from this end portion


22




a


. The oversized end portion


22




a


provides clearance around a connector to allow insertion of an end of a pipe which is forced onto the connector to form a joint.




It is a particularly preferred feature of most implementations of device


10


that is can accommodate an L-shape or T-shape connector, most preferably configured to facilitate attachment of a pipe to two ports of such a connector without requiring a change of grip on the device holding the connector. To this end, first and second elements


12


and


14


preferably each further include a lateral recess


36


configured such that, in the closed position, lateral recesses


36


together form a lateral opening interconnecting with channels


22


. Here too, to facilitate attachment of a pipe to the transversely-projecting connector port, the lateral opening preferably has a diameter at least 15 percent greater than D. To facilitate connection to two ports of the connector without shifting the grip on the device, lateral recesses


36


are preferably located within, or adjacent to, the region of oversized end portion


22




a.






In order to increase the tolerance of device


10


to accommodate a wide range of sizes of connectors, at least one rubber pad


37


is preferably deployed in channel


22


of each element


12


and


14


adjacent to lateral recess


36


. These pads are effective to grip small connectors with external diameters even smaller than the nominal minimum operative diameter D of device


10


, while at the same time being sufficiently flexible to accommodate large connectors. Pads


37


are conveniently implemented with a barbed pin which engages within corresponding openings


39


in each element


12


and


14


.




In a similar vein, it should be noted that some or all of gripping features


26


may optionally be implemented using rubber or similar material to enhance the tolerance of the device to grip different sized pipes and to increase friction. In many cases, however, the simpler molded plastic structure shown herein with the addition of only pads


37


provides excellent results in a highly cost effective manner.




According to a further preferred feature, first and second elements


12


and


14


each further include a second lateral recess


38


configured such that, when device


10


is closed, second lateral recesses


38


together form a second lateral opening of diameter approximately equal to D interconnecting with channels


22


. This second lateral opening is particularly suited for gripping a straight connector in a laterally projecting position which renders it comfortable to force into engagement with a pipe end, as will be described with reference to

FIG. 8

below.




It will be noted that the device of the present invention is not limited to any particular choice of materials. Nevertheless, it is thought particularly advantageous that first and second elements


12


and


14


are each formed primarily, and typically exclusively, from a molded plastic material. This offers the required durability and corrosion resistance while being lightweight and comfortable to handle. Preferably, each of elements


12


and


14


is formed with a plurality of drainage holes connecting between channel


22


and an external surface of the element, thereby facilitating rinsing out of any mud or dirt which may collect within the device. These drainage holes also help to further enhance the grip of a user's hand on grasp surfaces


28


and


30


.




Turning now briefly to

FIGS. 6-11

, these illustrate schematically a number of principal modes of use of device


10


. Firstly,

FIG. 6

shows device


10


used to grip a portion of pipe. In certain applications, one device


10


is used in this manner to grip a pipe while a second is used as described below to grip a connector for the purposes of attaching them to form a connection. It will be noted that the device can readily accommodate and grip pipes with a range of diameters slightly greater than the nominal diameter D, typically by up to about 10 or 15 percent. The larger diameter is accommodated by incomplete closing of the two elements against each other. In fact, in order to ensure reliable and highly effective gripping of the tube, the device is preferably designed so as to clamp a pipe of the intended nominal diameter D just before the two elements fully close against each other.





FIG. 7

illustrates a first manner of gripping a straight connector between ends


34


of elements


12


and


14


.





FIG. 8

illustrates the use of the second lateral opening, formed by lateral recesses


38


, to grip a straight connector.





FIGS. 9 and 10

show, respectively, the use of device


10


to grip a T-shaped and an L-shaped connector with the lateral connection port projecting through the lateral opening formed by recesses


36


. In this position, pipe ends can readily be attached to two ports of the connector without the user releasing his grip on the connector.





FIG. 11

shows the use of device


10


for gripping a one-sided connector used for inserting through a small hole formed in a larger diameter pipe to add a new branch pipe.




Turning now to

FIGS. 12-15

, it is a further preferred feature of the present invention that device


10


may be used together with at least one additional element to form a hole-punching tool, such as is frequently needed in installation of irrigation systems for installing additional drip emitters or secondary pipes. Thus,

FIG. 12

shows a first preferred implementation of a hole puncher element


40


. Hole puncher element


40


is formed with at least one, and preferably two, round blades


42


configured for forming a hole through a plastic wall of a pipe, as is known in the art.




In order to facilitate use of hole puncher element


40


, hole puncher element


40


and elements


12


and


14


are preferably formed with complementary engagement features configured such that hole puncher element


40


releasably engages elements


12


and


14


so as to retain them in the closed position. In this engaged position, elements


12


and


14


provide a handle (

FIG. 14

) to facilitate operation of the hole puncher element.




In the specific non-limiting example shown in

FIGS. 12 and 13

, hole puncher element


40


is formed with pairs of transversely projecting tabs


44


which frictionally engage corresponding slots


46


(

FIGS. 1 and 5

) in elements


12


and


14


. Clearly, many other forms of complementary engaging features could be used.




Preferably, hole puncher element


40


is configured to engage device


10


from either of two directions. In the case of a hole puncher with two blades


42


for punching different diameter holes, this renders the hole punching element reversible to alternately present each of the blades. Additionally, this feature preferably allows simultaneous engagement of two devices


10


with hole puncher element


40


as shown in

FIG. 15

to provide a compact storage configuration for a complete set of hole puncher plus two gripper devices. This storage configuration is particularly convenient for handling and transportation.




Referring briefly to

FIG. 16

, it will be noted that hole puncher element need not be a linear configuration. Thus,

FIG. 16

shows an alternative implementation in which a two-blade hole puncher element


48


is implemented in an L-shape form to be received by device


10


in a manner similar to the L-shape connector of FIG.


10


.




Finally, referring to

FIG. 17

, it should be noted that a simplified version of device


10


, without either of the lateral openings, may be used to good effect for a subset of the intended uses of device


10


. Thus, by way of example,

FIG. 17

shows a simplified device


50


, generally similar to device


10


, but without the lateral openings formed by recesses


36


and


38


of the preferred implementation. Device


50


may be used alone to grip pipes, and is thought to be particularly useful as the pipe-gripping part of a set including also device


10


described above.




It will be appreciated that the above descriptions are intended only to serve as examples, and that many other embodiments are possible within the spirit and the scope of the present invention.



Claims
  • 1. A device for facilitating manual gripping of pipes and connectors comprising:(a) a first element; (b) a second element hingedly attached to said first element at a hinge structure, said hinge structure being configured such that said first element is rotatable relative to said second element about a hinge axis from a closed position through a range of angles no more than 180° to a fully open position; and (c) a spring element deployed to bias said first element relative to said second element towards said open position, wherein each of said first element and said second element includes a channel extending substantially parallel to said axis, a plurality of projections being deployed projecting into each channel so as to define gripping features, said channels and said gripping features being formed such that, when said first element and said second element assume said closed position, said gripping features are located so as to grip a substantially cylindrical object of outer diameter D located parallel to said axis between said first element and said second element,and wherein said first and said second elements each further include a lateral recess configured such that, when said first element and said second element assume said closed position, said lateral recesses form a lateral opening of diameter at least 15 percent greater than D interconnecting with said channels,and wherein said first element and said second element are configured to provide, respectively, first and second grasp surfaces which, at least in said closed position, lie within a cylindrical volume of diameter 4D circumscribing said channels, said first and second grasp surfaces being shaped such that they can be pressed together by a single hand of a user to close the device around a substantially cylindrical object such that said gripping features grip the object and said grasp surfaces substantially circumscribe the object.
  • 2. The device of claim 1, wherein said second element is substantially a mirror image of said first element.
  • 3. The device of claim 1, wherein said projections are implemented as projecting ridges extending around at least part of said channels in a direction substantially perpendicular to said axis, said projecting ridges being spaced apart along said axis.
  • 4. The device of claim 1, wherein said channels extend across an entire dimension of said first and said second elements from a first edge to a second edge along a length L, a portion of said channels which lies within at least about 10 percent of length L from said first edge being formed such that, when said first element and said second element assume said closed position, said channels accommodate a cylindrical element of diameter at least 15 percent greater than D.
  • 5. The device of claim 1, wherein said first and said second elements each further include an additional lateral recess configured such that, when said first element and said second element assume said closed position, said additional lateral recesses form a lateral opening of diameter approximately equal to D interconnecting with said channels.
  • 6. The device of claim 1, further comprising a detachable hole puncher element formed with at least one blade configured for forming a hole through a plastic wall of a pipe, said hole puncher element and said first and second elements being formed with complementary engagement features configured such that said hole puncher element releasably engages said first and second elements so as to retain said first and second elements in said closed position to provide a handle to facilitate operation of said hole puncher element.
  • 7. The device of claim 6, wherein said hole puncher element is configured to engage said first and second elements from either of two directions.
  • 8. The device of claim 1, wherein said first and said second elements are each formed primarily from a molded plastic material.
  • 9. The device of claim 1, wherein each of said first and said second elements is formed with a plurality of drainage holes connecting between said channel and an external surface of said element.
  • 10. The device of claim 1, wherein said hinge structure is configured such that said first element is rotatable relative to said second element about said hinge axis from said closed position through a range of angles no more than 90° to said fully open position.
  • 11. A device for facilitating manual gripping of pipes and connectors comprising:(a) a first element; (b) a second element hingedly attached to said first element at a hinge structure, said hinge structure being configured such that said first element is rotatable relative to said second element about a hinge axis from a closed position through a range of angles no more than 180° to a fully open position; and (c) a spring element deployed to bias said first element relative to said second element towards said open position, wherein each of said first element and said second element includes a channel extending substantially parallel to said axis, a plurality of projections being deployed projecting into each channel so as to define gripping features, said channels and said gripping features being formed such that, when said first element and said second element assume said closed position, said gripping features are located so as to grip a substantially cylindrical object of outer diameter D located parallel to said axis between said first element and said second element,and wherein said first and said second elements each further include a lateral recess configured such that, when said first element and said second element assume said closed position, said lateral recesses form a lateral opening of diameter approximately equal to D interconnecting with said channels,and wherein said first element and said second element are configured to provide, respectively, first and second grasp surfaces which, at least in said closed position, lie within a cylindrical volume of diameter 4D circumscribing said channels, said first and second grasp surfaces being shaped such that they can be pressed together by a single hand of a user to close the device around a substantially cylindrical object such that said gripping features grip the object and said grasp surfaces substantially circumscribe the object.
  • 12. The device of claim 11, wherein said second element is substantially a mirror image of said first element.
  • 13. The device of claim 11, wherein said projections are implemented as projecting ridges extending around at least part of said channels in a direction substantially perpendicular to said axis, said projecting ridges being spaced apart along said axis.
  • 14. The device of claim 11, wherein said channels extend across an entire dimension of said first and said second elements from a first edge to a second edge along a length L, a portion of said channels which lies within at least about 10 percent of length L from said first edge being formed such that, when said first element and said second element assume said closed position, said channels accommodate a cylindrical element of diameter at least 15 percent greater than D.
  • 15. The device of claim 11, wherein said first and said second elements each further include an additional lateral recess configured such that, when said first element and said second element assume said closed position, said additional lateral recesses form a lateral opening of diameter at least 15 percent greater than D interconnecting with said channels.
  • 16. The device of claim 11, further comprising a detachable hole puncher element formed with at least one blade configured for forming a hole through a plastic wall of a pipe, said hole puncher element and said first and second elements being formed with complementary engagement features configured such that said hole puncher element releasably engages said first and second elements so as to retain said first and second elements in said closed position to provide a handle to facilitate operation of said hole puncher element.
  • 17. The device of claim 16, wherein said hole puncher element is configured to engage said first and second elements from either of two directions.
  • 18. The device of claim 11, wherein said first and said second elements are each formed primarily from a molded plastic material.
  • 19. The device of claim 11, wherein each of said first and said second elements is formed with a plurality of drainage holes connecting between said channel and an external surface of said element.
  • 20. The device of claim 11, wherein said hinge structure is configured such that said first element is rotatable relative to said second element about said hinge axis from said closed position through a range of angles no more than 90° to said fully open position.
US Referenced Citations (11)
Number Name Date Kind
1730820 Holden Oct 1929 A
2819111 Cozzens Jan 1958 A
3547355 Salazar Dec 1970 A
3730209 Binard et al. May 1973 A
4470177 Ganung et al. Sep 1984 A
4647073 Kosaka Mar 1987 A
5694972 King Dec 1997 A
6183400 Pope Feb 2001 B1
6247204 Hamby et al. Jun 2001 B1
6317950 Irwin Nov 2001 B1
6360402 Crabtree Mar 2002 B1