Boots – shoes – and leggings – Boots and shoes – Occupational or athletic shoe
Reexamination Certificate
1999-12-23
2001-05-08
Kavanaugh, Ted (Department: 3728)
Boots, shoes, and leggings
Boots and shoes
Occupational or athletic shoe
C036S124000
Reexamination Certificate
active
06226899
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention concerns snowshoes, and more specifically the invention is directed to a snowshoe of hybrid construction, in which a pair of spaced rails form a central part of the frame, and molded plastic pieces form the nose and tail of the snowshoe.
Conventional snowshoes have been constructed in several different ways. One construction currently used is a bent frame construction, shown, for example, in U.S. Pat. No. 5,440,827, in which a metal frame (typically aluminum tubing) is formed with a number of bends, welded together at the tail end, to form the periphery of the snowshoe to which decking is attached. Another snowshoe construction essentially entirely of molded plastic, but with longitudinal reinforcing metal rails, is shown in U.S. Pat. No. 5,469,643.
Snowshoe frames constructed of formed and welded tubing are sturdy and reliable, but relatively expensive to produce. The all-molded plastic snowshoe of the latter patent referenced above, although a departure from most conventional snowshoe construction, does not represent a significant savings in construction costs, in part because of the need to assemble metal rails onto the bottom of the molded snowshoe deck, to provide sufficient rigidity; the all-molded snowshoe also lacks flexibility under the user's heel.
It is among the objects of this invention to form a snowshoe by hybrid construction, wherein a pair of spaced rails form the center of the snowshoe frame, with front and rear ends formed by relatively rigid molded plastic components secured to the rails, avoiding the need for an expensive metal frame and providing for versatility in producing snowshoes of different lengths.
SUMMARY OF THE INVENTION
A snowshoe constructed according to the invention has a nose of molded plastic material, which may be injection molded plastic, including a pair of rail-receiving aft portions positioned at outboard sides of the nose. A tail of similar molded plastic material has a pair of rail-receiving forward portions. Extending generally longitudinally between the nose and tail pieces are a pair of spaced apart rails which are secured to the nose and tail to give the snowshoe structural rigidity and to complete the snowshoe frame. The frame can be considered as formed by the rails and the periphery of the nose and tail pieces.
Located generally under the heel of the user is a flexible deck membrane extending between and secured to the two rails at left and right and preferably also secured to the front end of the tail piece and also to aft portions of the nose piece, or to the rails near the aft end of the nose piece. Near the forward end of the snowshoe is a boot harness, secured to a front claw assembly as in the above-referenced U.S. Pat. No. 5,440,827. Also as in that patent, the front claw/harness assembly is pivotable relative to the snowshoe frame, so that the tail can tip downwardly as the user takes a step forward. In the present invention the pivot connection may be made by means of pins securing the front claw structure to the aft portions of the nose piece, or to the rails, or both. In a preferred construction, a pin at each side secures the claw pivotally to the nose portions and to the metal rail, with the pin passing through the rail, thus also helping to secure the rails to the nose piece.
It is advantageous for the two rails to be straight, avoiding the need for bends as in prior construction, so that all bends are located in the molded plastic components. The rails may be formed of metal tubing, but many other cross sections are possible, such as square tubing, L-shaped structural members, etc. Also, the rails may be formed of material other than metal, such as injection molded plastic or composite materials, some of these materials being advantageous in that they can be directly bonded to the nose and tail pieces by heat bonding.
In a preferred embodiment the flexible membrane is stretched relatively tightly between the rails, wrapped around the rails at left and right, and riveted or heat sealed back to itself to complete the connection. Preferably a reinforcing layer is included, at the bottom of at least a portion of the stretched membrane, and a heel cleat with downwardly extending legs may be assembled so as to protrude through slits in the lower reinforcing layer. The reinforcing layer may advantageously be heat bonded to the main, upper layer, as by RF bonding or ultrasonic bonding. Such a flexible member for contact of the user's heel is an important feature to prevent discomfort, pain or injury to the user. Rigid material can be behind the heel, but a surface which gives is important under the heel.
The nose and tail pieces of the hybrid snowshoe, in one preferred embodiment, have downwardly protruding skegs, preferably at outboard locations, for engaging the terrain and preventing lateral slippage. These skegs, if included, are integral with the aft portions of the nose piece and the forward portions of the tail piece.
As is apparent from the construction described above, various different lengths of snowshoes can be produced simply by changing the length of rails included in the snowshoe frame. For different snowshoe lengths, the length of the stretched deck membrane is also modified, but if desired, a single deck component can be used for a number of different snowshoe lengths, by securing the rear end of the flexible deck through a slot in the tail piece and back against itself with different degrees of overlap. Thus, the invention encompasses not only the snowshoe itself, but also a method of constructing snowshoes of various lengths using the same components but with different rail lengths.
In one form of a snowshoe construction under the invention, a snowshoe is length-adjustable, through adjustment of the lengths of the rails. The rails, which can each comprise two-piece telescoped components, can be adjusted in length by depressing spring-biased lock buttons on the rails, enabling extension or retraction of the rails to different length positions in which the lock buttons will engage. Such length adjustment gives the snowshoes versatility for different conditions of snow density, different weights of users, or both; it also allows the snowshoe to be collapsed to a shorter length for storage and transport. The stretched flexible deck membrane can have a tail portion, secured through the slot in the tail piece, which has a large overlap that snaps against the bottom surface of the membrane at several different locations, accommodating the different snowshoe lengths. Two, three, four or more positions can be defined, thus providing for a similar number of snowshoe lengths.
In a variation of the snowshoe construction described above, the snowshoe can be formed with a molded plastic nose piece, but otherwise by a contoured frame which may be similar in most respects to that of U.S. Pat. No. 5,440,827 behind the harness assembly. This still obtains the benefit of fewer bends, in the case of a tubular metal frame, particularly at the forward end of a snowshoe where this part of the frame formation is most costly. In this regard, the disclosure of U.S. Pat. No. 5,440,827 is incorporated herein by reference relative to the frame, decking and heel cleat construction behind the harness assembly.
Although the rails, i.e., the intermediate frame members, are often described herein as of metal, or tubular metal in particular, they can, as noted above, be formed of molded plastic or composite materials, and this includes the construction just described wherein a frame including the central and tail portions is secured to a front nose piece of molded plastic material.
It is therefore a primary object of the invention to improve in the economy of production of a sturdy and rugged snowshoe, while also providing for versatility in production of similar snowshoes of different lengths, and in providing a single snowshoe which is easily adjustable in length. These and other objects, advantages and features will be apparent from the following description of preferred embodim
Emerson Daniel T.
Klebahn Perry A.
Atlas Snow-Shoe Company
Freiburger Thomas M.
Kavanaugh Ted
LandOfFree
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