Roller assembly for floating watercraft port

Abstract

One example provides a roller assembly for conveying a watercraft on a floating drive-on watercraft port. The roller assembly includes an axle, a center roller disposed on the axle, and a pair of shoulder rollers disposed on the axle, one shoulder roller disposed on each side of the center roller, the center roller and each shoulder roller free to spin independently from one another about the axle. Each shoulder roller includes an outer sidewall facing away from the center roller, and an inner sidewall facing the roller, a diameter of the shoulder roller at the outer sidewall being greater than a diameter of the shoulder roller at the inner sidewall such that an outer circumferential surface of the shoulder roller is downwardly angled from the outer sidewall toward the center roller.

What is claimed is: 
     
         1 . A roller assembly for conveying a watercraft on a floating drive-on watercraft port, comprising:
 an axle;   a center roller disposed on the axle; and   a pair of shoulder rollers disposed on the axle, one shoulder roller disposed on each side of the center roller, the center roller and each shoulder roller free to spin independently from one another about the axle, each shoulder roller having:   an outer sidewall facing away from the center roller; and   an inner sidewall facing the roller, a diameter of the shoulder roller at the outer sidewall being greater than a diameter of the shoulder roller at the outer sidewall such that an outer circumferential surface of the shoulder roller is downwardly angled from the outer sidewall toward the center roller.   
     
     
         2 . The roller assembly of  claim 1 , wherein each shoulder roller includes a cylindrical roller pocket on the inner sidewall which is coaxial with the axle, wherein opposing ends of the center roller are disposed within the cylindrical roller pockets of the pair of shoulder rollers. 
     
     
         3 . The roller assembly of  claim 1 , wherein the diameter at the inner sidewall is equal to a diameter of the center roller. 
     
     
         4 . The roller assembly of  claim 1 , each shoulder roller having:
 an outer portion including the outer sidewall; and   an inner portion including the inner sidewall,   wherein an outer circumferential surface of the outer portion is angled downwardly from the outer sidewall to a transition with the inner potion at a first angle of depression from a line parallel with a longitudinal axis of the axle, and the inner portion is angled downwardly from the transition with the outer portion to the inner sidewall at a second angle of depression form a line parallel with the longitudinal axis of the axle, where the second angle is greater than the first angle.   
     
     
         5 . The roller assembly of  claim 1 , each shoulder roller including:
 a rim including a center hub defining a bore to receive the axle; and   a tire disposed about a circumferential surface of the rim, the tire including a plurality of openings extending partially through the tire from the outer sidewall toward the inner sidewall.   
     
     
         6 . The roller assembly of  claim 5 , wherein a portion of the tire corresponding to the outer portion of each shoulder roller including a tread configured to shed water. 
     
     
         7 . The roller assembly of  claim 1 , the center roller comprising:
 a rim defining a bore to receive the axle; and   a tire disposed about a circumferential surface of the rim, the tire including a plurality of through-holes extending through the tire between opposing sidewalls.   
     
     
         8 . The roller assembly of  claim 1 , the center roller and each shoulder roller comprising molded copolymer materials. 
     
     
         9 . A floating watercraft port comprising:
 at least one floating dock section including:
 a first end; 
 an opposing second end; and 
 an upper surface including a hull depression formed therein extending symmetrically about a longitudinal axis of the dock section between the first and second ends, and 
   a wheel assembly disposed at the upper surface at the second end of the dock section for conveying a watercraft onto the dock section along the longitudinal axis, the wheel assembly comprising:
 an axle defining an axis of rotation orthogonal to the longitudinal axis; 
 a center roller disposed on the axle and centered on the longitudinal axis; and 
 a pair of shoulder rollers disposed on the axle, one shoulder roller disposed on each side of the center roller, the center roller and each shoulder roller free to spin independently from one another about the axle, each shoulder roller having: 
 an outer sidewall facing away from the center roller; and 
 an inner sidewall facing the roller, a diameter of the shoulder roller at the outer sidewall being greater than a diameter of the shoulder roller at the inner sidewall such that an outer circumferential surface of the shoulder roller is downwardly angled from the outer sidewall toward the center roller. 
   
     
     
         10 . The floating watercraft port of  claim 9 , including a recessed pocket extending into the upper surface, the wheel assembly disposed within the pocket 
     
     
         11 . The floating watercraft port of  claim 9 , wherein the diameter at the inner sidewall is equal to a diameter of the center roller. 
     
     
         12 . The floating watercraft port of  claim 9 , each shoulder roller comprising:
 an outer portion including the outer sidewall; and   an inner portion including the inner sidewall,   wherein an outer circumferential surface of the outer portion is angled downwardly from the outer sidewall to a transition with the inner potion at a first angle of depression from a line parallel with a longitudinal axis of the axle, and the inner portion is angled downwardly from the transition with the outer portion to the inner sidewall at a second angle of depression form a line parallel with the longitudinal axis of the axle, where the second angle is greater than the first angle.   
     
     
         13 . The floating watercraft port of  claim 9 , each shoulder roller comprising:
 a rim including a center hub defining a bore to receive the axle; and   a tire disposed about a circumferential surface of the rim, the tire including a plurality of openings extending partially through the tire from the outer sidewall toward the inner sidewall.   
     
     
         14 . The floating watercraft port of  claim 13 , a portion of the tire corresponding to the outer portion of each shoulder roller including a tread configured to shed water. 
     
     
         15 . The floating watercraft port of  claim 9 , the center roller comprising:
 a rim defining a bore to receive the axle; and   a tire disposed about a circumferential surface of the rim, the tire including a plurality of through-holes extending through the tire between opposing sidewalls.   
     
     
         16 . The roller assembly of  claim 9 , the center roller and each shoulder roller comprising molded copolymer materials. 
     
     
         17 . A wheel assembly for conveying a watercraft on a floating drive-on watercraft port, comprising:
 an axle;   a cylindrical center roller having a first diameter disposed on the axle; and   a pair of shoulder rollers disposed on the axle at opposing ends of the center roller, each shoulder roller comprising:
 an inner sidewall with a diameter equal to the first diameter disposed adjacent to the center roller; and 
 an outer sidewall opposite the center roller with a second diameter greater than the first diameter such that an outer circumferential surface of the shoulder roller angles downwardly from the outer sidewall to the inner sidewall. 
   
     
     
         18 . The wheel assembly of  claim 17 , each shoulder roller comprising:
 an inner portion including the inner sidewall; and   an outer portion including the outer sidewall;   wherein from a reference line parallel with a longitudinal axis of the axle, the outer circumferential surface of the outer portion has a first angle of depression from a line parallel with a longitudinal axis of the axle, and the outer circumferential surface of the inner portion has a second angle of depression, the second angle greater than the first angle.   
     
     
         19 . The wheel assembly of  claim 17 , where each shoulder roller comprises:
 a rim defining a bore through which the axle passes; and   a tire disposed about the rim, a circumferential surface of the tire forming the outer circumferential surface of the shoulder roller, wherein the tire includes:
 a plurality openings extending partially through the tire from the outer sidewall toward the inner sidewall, the openings arrayed about an inner circumference of the tire between the rim and the circumferential surface of the tire. 
   
     
     
         20 . The wheel assembly of  claim 17 , the center roller comprising:
 a rim defining a bore through which the axle passes; and   a tire disposed about the rim, a circumferential surface of the tire forming an outer circumferential surface of the center roller, wherein the tire includes:
 a plurality openings extending through the tire between opposing sidewall surfaces.