Abstract:
A boat alignment device including a clamp for attachment, to a support and a block pivotally attached to the clamp. The block is provided with an aperture of elliptical cross section. A telescoping arm has an outer tubular member of elliptical cross section snugly, yet slidably positioned within the aperture in the block. The telescoping arm also has an inner tubular member of elliptical cross section nested within the outer member and capable of being withdrawn therefrom.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to ships and, more particularly, to boom-type mooring devices of extensible length. 
     BACKGROUND OF THE INVENTION 
     Cruisers, runabouts, and other motorized pleasure boats are typically removed from water after use to increase their longevity. Hoists employing hull-cradling slings have long been the preferred means of accomplishing this task. Unfortunately, centering a boat atop the submerged slings so that the boat is not elevated at an inconvenient list or incline has always been a problem. Most boaters have taken a trial and error approach to solving this problem. 
     Several attempts are often required to center a boat on hoist slings before it can be lifted from the water. Rough water and strong winds can slow the centering process. Much time and fuel is wasted in repeated attempts to correctly position a boat. If weather conditions are severe, great property loss could be the result of repeated delays in hoisting a boat. A need, therefore, exists for a device that quickly, easily and without guesswork centers a boat in a hoist for lifting from the water. 
     SUMMARY OF THE INVENTION 
     In light of the problems associated with the lifting of boats from a body of water for storage, it is a principal object of the invention to provide a device that eliminates guesswork in aligning a boat in a hoist. Use of the device minimizes the risk of damage to both boats and hoists. The device is easy to use and saves time and boat fuel. 
     It is another object of the invention to provide a device of the type described that that is impervious to corrosion and has a limited number of moving parts. Thus, the device is resistant to fouling by dirt or debris commonly found near bodies of water where boating takes place. 
     It is a further object of the invention to provide a boat alignment device that can be used with minimal instruction and with no special tools. The device can be adjusted to accommodate boats and hoists of varied dimensions. The device can be configured for compact, out of the way storage when not in use. 
     It is an object of the invention to provide improved elements and arrangements thereof in a boat alignment device for the purposes described that is lightweight in construction, inexpensive to manufacture, and dependable in use. 
     Briefly, the alignment device in accordance with this invention achieves the intended objects by featuring a retaining bracket having a block pivotally attached to a clamp. The block has a pair of surfaces that can be selectively engaged with a stop flange on the clamp. A telescoping arm has an outer tubular member of elliptical cross section that is snugly, yet slidably, positioned within an elliptical aperture in the block. An inner tubular member of elliptical cross section is snugly, yet slidably, positioned within the outer member. In use, the elliptical cross section provided to the outer tubular member permits such to be rotated into a tight, binding engagement with the block so that the portion of the outer tubular member projecting from the aperture can be fixed in length. Additionally, the elliptical cross section provided to the inner tubular member permits such to be rotated into a tight, binding engagement with the outer tubular member so that the length of the telescoping arm can be fixed. 
     The foregoing and other objects, features and advantages of the present invention will become readily apparent upon further review of the following detailed description of the preferred embodiment as illustrated in the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention may be more readily described with reference to the accompanying drawings, in which: 
     FIG. 1 is a perspective view of a boat alignment device in accordance with the present invention. 
     FIG. 2 is a cross-sectional view of the boat alignment device taken along line  2 — 2  of FIG.  3 . 
     FIG. 3 is a top view of the boat alignment device with portions broken away to reveal details thereof. 
     FIG. 4 is a side view of the boat alignment device with portions broken away to reveal details thereof. 
     Similar reference characters denote corresponding features consistently throughout the accompanying drawings. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the FIGS., a boat alignment device in accordance with the present invention is shown at  10 . Device  10  includes a telescoping arm  12  slidably attached to a retaining bracket  14 . Retaining bracket  14  has a pivot block  16  with an aperture  18  receiving arm  12  and a clamp  20  for firmly attaching device  10  to a support  22 . By varying the length and position of arm  12  relative to bracket  14 , device  10  can be quickly and easily used to align a boat in a hoist. 
     Telescoping arm  12  has an inner tubular member  24  nested within an outer tubular member  26  of substantially equal length. With a light pull by a user, tubular member  24  may be partially extracted from the inner end of tubular member  26  to increase the length of arm  12 . Complete disconnection of tubular members  24  and  26  is prevented by the engagement of a pair of tabs  28  extending radially outward from the inner end of tubular member  24  with a pair of fins  30  extending radially inward from the inner end of tubular member  26 . Preferably, tabs  28  and fins  30  are made by crimping tubular members  24  and  26 , formed of a non-corroding metallic alloy along with bracket  14 , in a conventional manner. 
     Tubular members  24  and  26  are provided with elliptical cross sections. (The term “elliptical,” as used herein, should be understood to encompass shapes other than true ellipses such as ovals, oblate circular forms, and other geometric shapes with a height greater than width.) Such cross-sectional configurations permit tubular member  24  to be rotated a few degrees into a tight, binding engagement with tubular member  26 . Thus, relative rotation of tubular members  24  and  26  permits the length of arm  12  to be fixed by a user. 
     Tubular member  26  is slidably positioned within aperture  18  in pivot block  16 . Aperture  18  is elliptical in cross section to allow tubular member  26  to be rotated into a tight, binding engagement with pivot block  16 . In this manner, a user can selectively vary the length of tubular member  26  projecting from either end of pivot block  16 . 
     Rubber end caps  32  and  34  are secured to the opposed ends of telescoping arm  12 . Because end caps  32  and  34  have larger diameters than aperture  18 , such serve as stops to prevent the detachment of arm  12  from block  16 . Of course, end caps  32  and  34  also serve as resilient bumpers for boats and other objects engaging arm  12 . 
     End caps  32  and  34  and the outer ends of tubular members  26  and  24  are penetrated by transverse apertures  36  and  38 . A lever  40  may be extended through either of the apertures  36  or  38  to assist in rotating tubular members  26  or  24 . It is anticipated that lever  40  will be especially beneficial should arm  12  become wet and difficult to grip during use. 
     A pivot pin  42  penetrating block  16  at right angles to aperture  18  connects block  16  to a retaining arm  44  of clamp  20 . Clamp  20  is preferably U-shaped and includes a crosspiece  46  connecting retaining arm  44  in opposing fashion to a retaining arm  48 . A flange  50 , coplanar with crosspiece  46 , projects outwardly from retaining arm  44 . Pivot pin  42  enters retaining arm  44  adjacent to the bottom of flange  50 . A pair of set screws  52  penetrates, and is threadably fastened to, retaining arm  48 . 
     Pivot block  16  is generally rectangular in form and is provided with top, bottom, front, back and opposed side surfaces  54 ,  56 ,  58 ,  60  and  62 . Preferably, all opposite surfaces are oriented parallel to one another and all adjacent surfaces are oriented at right angles to one another. A curved edge  64 , however, joins top surface  54  to back surface  60 . Edge  64  is provided with a radius of curvature that permits either top surface  54  or back surface  60  to be pivoted on pin  42  into flush engagement with flange  50 . So, bracket  14  provides arm  12  with a ninety degree range of pivotal motion. 
     Use of device  10  is straightforward. First, clamp  20  is positioned around support  22 , an upright of a boat hoist, and is attached to it by rotating set screws  52 . (Preferably, clamp  20  is positioned at a height above water level such that arm  12  will both engage a boat and permit easy manipulation by a user within the boat.) Next, with a boat centered in a hoist adjacent device  10  and arm  12  pivoted to horizontal, tubular member  26  is rotated in aperture  18  to lock such within block  16  with its inner end projecting as far as possible from front wall  58 . As shown in FIG. 2, lever  40  extended through aperture  36  will move from the horizontal, broken-line position to the solid line position to accomplish this task. Then, if arm  12  must be telescoped further to bring end cap  34  into engagement with the boat, tubular member  24  is withdrawn the needed distance from tubular member  26  and locked in place by rotating it within tubular member  26 . Finally, arm  12  is pivoted to a vertical orientation, to permit the boat to move unimpeded from the hoist. Device  10  is set to properly align this boat upon return to the hoist. 
     To align the boat in the hoist, arm  12  is pivoted downwardly to its horizontal position and into engagement with the boat. The boat is automatically located in a centered position within hoist. The previously submerged slings of the hoist may now elevate the boat. Arm  12  will automatically pivot to a near vertical position as the boat is elevated to prevent damage to the boat or device  10 . Should a boat of different dimensions be brought to the hoist, the procedure outlined in the previous paragraph must be followed before boat alignment will be automatically obtained. 
     Although one device  10  positioned near the midpoint of a boat may be sufficient to align a boat in a hoist, as a practical matter, several devices  10  may be necessary. Obviously, different arrangements of devices  10  are possible depending upon the configurations of the boat and hoist; but, it would be appreciated by any boater that at least three widely spaced devices  10  would be needed to provide optimum, i.e., hands-free, alignment capabilities. 
     While the invention has been described with a high degree of particularity, it will be appreciated by those skilled in the art that modifications may be made thereto. For example, the number nested tubular members could be increased to provide a telescoping arm of great extended length. Therefore, it is to be understood that the present invention is not limited to the sole embodiment described above, but encompasses any and all embodiments within the scope of the following claims.