Floating dock having shock-absorbing coupling

A multi-element floating dock has shock-absorbing flexible tieing elements which are installed as a unit without any manual adjustment being required to create a pretensionin the shock-absorbing components. Elastomeric pads positioned in aligned cavities formed in the edges of the dock sections receive the ends of the flexible tieing elements. Stops located on the ends of the tieing elements engage the pads so that adjacent dock sections cannot be separated from one another without compressing the pads and thereby creating a compressibly yieldable restraint against the separation of the dock sections and preventing their being separated from one another past a predetermined limit. An elastomeric spacer located between adjacent dock sections provides a compressibly yieldable restraint against moving the dock sections toward one another and prevents them from coming closer to one another then a predetermined amount. Tension plates fit between the stops and the ends of the cavities to precompress the pads and the elastomeric joint is wider than the normal gap formed between the dock sections thereby requiring it to be precompressed when it is installed. A line-up sleeve located in the center of the cable is engaged by counterbores formed in the pads and by the ends of the cavities to prevent lateral and vertical movement between adjacent dock sections.

BACKGROUND AND SUMMARY OF THE INVENTION 
This invention relates to multi-element floating docks, and in particular 
to such docks in which the dock sections are joined together with flexible 
shock-absorbing couplings. 
It is a common practice to make docks for mooring boats and the like from a 
plurality of floating sections which are joined together end to end. These 
dock sections must be joined together in a manner which permits angular 
displacement between them in order to accommodate wave action and other 
movement of the dock. However, the dock sections must be prevented from 
moving laterally and vertically relative to one another in order to 
maintain alignment. In addition, while the amount of separation between 
the dock sections must vary somewhat if the dock sections are to 
accommodate wave action, the amount of this separation must be limited. 
In the past dock sections have been joined together by spanning both sides 
of adjacent dock sections with elongate wood planks or whalers. Threaded 
rods are inserted through aligned openings in the dock sections and the 
whalers and nuts are secured to their ends to clamp the whalers to the 
dock sections. This system has several shortcomings which limit its 
usefulness. First, since the threaded rods extend through the entire dock 
sections they are unwieldly and subject to breakage. In addition, while 
wood whalers are somewhat flexible, they do not permit the unlimited 
rotational movement between adjacent dock sections which is necessary to 
accommodate heavy wave action. Furthermore, the nuts on the ends of the 
threaded rods must be tightened sufficiently to achieve proper clamping 
action and not work free and yet must not be overtightened to the point 
where they compromise the strength of the components. Accordingly, the 
people who install the nuts must be skilled, and even then some 
overtightening and undertightening will occur. Because the coupling 
elements are partially concealed by the dock sections it is difficult to 
inspect them for damage. Even more of a problem is that the marine 
environment in which docks of this type are used will cause the nuts to 
become rusted onto the threaded rods making them difficult to remove. A 
final shortcoming of this prior art system is that in order to use it to 
attach finger piers to a main dock section, flanges must be attached to 
the finger pier which increases the cost and requires the use of different 
coupling elements. 
The subject invention overcomes the foregoing shortcomings and limitations 
of the prior art by using elongate, flexible, noncompressible tieing 
elements, such as cables, to couple adjacent dock sections together. The 
cables pass through openings in elastically compressible pads which are 
attached to the dock sections. The cables have stops located at each of 
their ends which engage the outer ends of the pads and prevent the cables 
from being pulled back out of the pads. Thus, the pads act as compressibly 
yieldable restraints against the separation of the dock sections and 
prevent their separation past a predetermined point. An elastically 
compressible spacer which fits between adjacent dock sections serves as a 
compressibly yieldable restraint against movement of the dock sections 
toward one another and prevents their being moved closer together than a 
predetermined amount. 
In a preferred embodiment of the invention the pads are placed in 
steel-lined cavities which are formed in the top surfaces of adjacent dock 
sections, which generally are made from reinforced concrete. This permits 
the steel liners to be welded to the reinforcing bar in the dock sections 
which spreads the load carried by the coupling elements over a wide 
portion of the dock sections. The pads are separated into top and bottom 
portions which have semispherical grooves in their mating surfaces which 
receive the cables. Thus, the bottom portion of a pad can be positioned in 
the cavity, the cable placed on top of it, and then the top portion of the 
pad installed over the top of the cable. 
Tension plates are inserted between the stops and the end walls of the 
cavities to precompress the pads and eliminate the free movement which 
would otherwise result from the clearance which is necessary to allow 
assembly of the components. In addition, the spacer which fits between the 
dock sections is wider than the nominal distance between the sections 
which causes this element to be precompressed also. 
A line-up sleeve, which is attached to each cable intermediate its ends, 
fits into counterbores located in the ends of the pads and in openings 
formed in the end walls of the cavity. Thus, the line-up sleeve prevents 
lateral and vertical movement of the joined dock sections relative to one 
another without limiting the rotational movement necessary to accommodate 
wave action. 
Accordingly, it is a principal object of the present invention to provide a 
multi-element floating dock having shock-absorbing flexible couplings 
which can be installed easily and quickly. 
It is a further object of the present invention to provide such a dock in 
which the coupling elements are readily accessible for inspection. 
It is a still further object of the present invention to provide such a 
dock in which the coupling elements are pretensioned automatically upon 
installation without the requirement of manual adjustment. 
It is a still further object of the present invention to provide such a 
dock in which the coupling elements can be replaced easily without the 
necessity of loosening threaded connectors. 
It is a yet a further object of the present invention to provide such a 
dock in which the same coupling components can be used for attaching main 
dock sections together and for attaching finger piers to the main dock 
sections. 
The foregoing and other objectives, features and advantages of the present 
invention will be more readily understood upon consideration of the 
following detailed description of the invention taken in conjunction with 
the accompanying drawings.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to FIGS. 1 and 2 of the drawings, docks, such as used for mooring 
boats, often are constructed from a plurality of floating dock sections 10 
which are tied together end to end. In addition, smaller dock sections 10a 
are attached to and extend out from the main dock sections to create 
finger piers to which the boats can be tied. The dock sections generally 
comprise inverted concrete shells having planar horizontal tops 12 and 
vertical side walls 14 which depend from the periphery of the tops. 
Styrofoam blocks 16 are placed under the shells to increase their 
buoyancy. 
Referring now also to FIGS. 3 and 4, the dock sections have cavities 18 
formed in their tops which carry the coupling elements which tie adjacent 
dock sections together. These cavities are located in each dock section 
next to the side wall which will abut the side wall of the adjacent dock 
section, and the cavities in adjacent dock sections are arranged in pairs 
which are aligned with one another. The cavities are lined with steel side 
walls 20, end walls 22, and bottom walls 24, with the outside end walls 
22a preferably replacing a portion of the concrete side wall 14. The 
cavity walls do not extend completely to the top surface of the dock 
section but are recessed from it by a distance equal to the thickness of 
the cavity walls. The cavity walls preferably are cast into the dock 
section when it is formed in order to create an integral unit. In 
addition, referring to FIG. 5, the cavity walls are welded to the 
reinforcing bar 26 which is embedded in the concrete of the dock section 
thereby spreading the loads which act on the cavity walls through a large 
portion of the dock section. 
The cavities are covered by access plates 28 which fit into the recess 
which is formed above the cavity walls. Referring now to FIG. 6, a slot 
30, having an arcuate lower extremity is located in the top portion of 
each outside end wall 22a. A tab 32 which depends from one edge of each 
access plate fills the upper portion of the slot 30 when the access plate 
is placed over the cavity. The bottom of the tab 32 also is arcuate so 
that a circular opening is formed between the end wall and the tab. 
Adjacent dock sections are connected to one another by elongate flexible 
tieing elements, such as cables 34, which fit into and are retained by the 
cavities 18. Each cable 34 has a sleeve 36 attached to each of its ends 
and stop plates 38 are attached to both sides of each sleeve. The stop 
plates 38 are rectangular and are dimensioned to fit snugly within the 
cavities 18. When it is placed in a cavity, the portion of the cable 34 
which extends between the inner stop 38b and the end wall 22a is enclosed 
with an elastomeric pad 40. The pad 40 substantially fills the cavity and 
is divided into top and bottom portions. Thus, the bottom portion can be 
placed into the cavity first, the cable can then be placed into the bottom 
portion of the pad, and the top portion can then be placed on top of the 
cable. As can be seen in FIG. 7, the pad portions have semi-cylindrical 
grooves 42 formed in them which form a cylindrical opening for the cable 
when the pad portions are brought together. At one end of the pads the 
grooves are enlarged to form a larger diameter counterbore 44, whose use 
will be described later. 
The length of the cable between the two inner stops 38b is greater than 
double the length of the pads by an amount which is equal to the desired 
distance between the adjacent pair of dock sections which are tied 
together by the cable. If the dock sections are forced further apart the 
inner stops engage the pads and cause them to become compressed. Thus, the 
pads act as yieldable restraints against further separation of the dock 
sections up to a point where the pads become totally compressed and no 
further separation is possible. In addition the length of the sleeve 36 is 
such that when the cable is installed in the pad there is a gap between 
the end wall 22 and the outer stop 38a. If a wedge (not shown) is driven 
between the adjacent dock sections the inner stops it will cause the pads 
40 to become compressed and the gaps between the end walls 22 and the 
outer stops 38a will be made larger. Tension plates, having a width equal 
to this larger gap, can be inserted into the gaps and the wedge removed to 
precompress the pads 40. This procedure eliminates any unrestrained 
movement of the dock sections away from one another which otherwise would 
occur due to the clearance which is necessary to install the cable into 
the pads in the first instance. 
After the pads have been precompressed by insertion of the tension plates 
46, an extruded elastomeric spacer 48 is inserted between the adjacent 
dock sections. The spacer acts as a yieldable restraint against movement 
of the dock sections toward one another and prevents them from becoming 
closer together than a predetermined distance. The spacer has a rounded 
cap 50 which smoothes the transition between the top surfaces of the dock 
sections. The width of the spacer is slightly greater than the normal 
space between the dock sections. Accordingly, the dock sections must be 
forced apart to insert the spacer and the spacer becomes precompressed 
when it is installed. As with the precompression of the pads, 
precompression of the spacer eliminates any unrestricted movement of the 
dock sections toward one another due to the clearance which would 
otherwise be necessary in order to insert the spacer between them. 
A line-up sleeve 52, similar to sleeves 36, is attached to the cable 34 
intermediate its ends. The line-up sleeve 52 has the same diameter as the 
opening formed between the tabs 32 and the end walls 22a, and the 
counterbore 44 formed in the end of the pads. Thus, the line-up sleeve is 
engaged snugly by the pads and the end wall to prevent lateral and 
vertical movement of a dock section relative to the dock section to which 
it is attached. However, the flexible nature of the cable permits angular 
movement of the dock sections relative to one another in order to 
accommodate wave action on the dock. 
When assembled the joint between the dock sections permits a predetermined 
amount of variation in either direction from the nominal amount of 
separation and yet does not permit movement past these predetermined 
limits. In addition, the dock sections are maintained in lateral and 
vertical alignment relative to one another at all times and yet angular 
movement is permitted to accommodate wave action. Furthermore, it is easy 
to inspect the joint elements to determine if they are damaged or have 
become worn beyond acceptable limits merely by lifting the access plates 
28 off of the cavities. 
Due to the fact that there are no elements which need to be tightened, the 
joint is easy to construct and the proper level of pretensioning is 
achieved automatically based on the size of the components. In addition, 
the lack of movable elements makes the joint easy to replace and rusting 
of the joint components will not impede their replacement. Finally, the 
joint components which attach main dock sections together can also be used 
to attach finger piers to the main dock sections. 
The terms and expressions which have been employed in the foregoing 
specification are used therein as terms of description and not of 
limitation, and there is no intention, in the use of such terms and 
expressions, of excluding equivalents of the features shown and described 
or portions thereof, it being recognized that the scope of the invention 
is defined and limited only by the claims which follow.