WATER SPORTS BOOT BINDING CAMLOCK SCREW
Background of the Invention Field of the Invention
This invention relates to a mounting apparatus. More specifically, it relates to a mounting apparatus for easily mounting a foot binding onto a board without the use of extraneous tools.
Description of the Related Art Board sports implements such as skis, wakeboards, snowboards, and the like, generally have foot bindings firmly attached to the implement for securing a rider's feet to the board. It is important that the bindings are firmly attached to the implement to provide the rider with positive control over the implement to maintain balance, perform various maneuvers, and as a safety precaution from the board becoming detached from the rider and injuring either the rider or other persons. This attachment usually requires a tool to install and tighten standard machine screws. Certain board sports, such as wakeboarding, for example, often see several riders sharing a common board in succession. Because of an individual's preference as to the location and orientation of the bindings to maximize comfort while riding the board, it is often necessary to remove and reattach the bindings between riders. Traditional binding mounting methods require a tool, such as a screwdriver, hexdriver, balldriver, etc., to remove and reattach the bindings in a desired position. Additionally, binding screws have a tendency to loosen when subjected to alternating stresses and vibration during use, and therefore must often be tightened between rides. This becomes especially difficult when trying to manipulate the screws with a tool while on a moving boat. A boat's erratic oscillations make it difficult to manipulate screws and can result in the tool being dropped, or even lost if dropped overboard.
Finally, repeated tightening of a screw into a threaded insert provided in a board, especially if excessive torque is applied, can result in the threaded insert being pulled out of, and damaging, the board. Therefore, there is a need for a binding attachment device that can be installed and tightened without the need for tools. Furthermore, it would be advantageous if there were a binding attachment device that was not loosened by vibration and the alternating stresses accompanying normal use. Finally, it would be a substantial improvement if there were a binding attachment that were more gentle with the threaded inserts provided in today's wakeboards.
Summary of the Invention
The preferred embodiments of the present camlock screw solve the above-mentioned problems by providing a camlock screw. More specifically, the preferred embodiments provide a device for attaching bindings to various sport riding implements without the use of extrinsic tools. The camlock device allows a user thereof to hand-tighten a binding to a riding implement without the use of any tools, and then use a cam mechanism to securely fasten the
binding to the riding implement. A camlever is attached to a screw such that when the lever is engaged, the screw is drawn upward, thus tightening the riding implement against the binding. Because the screw is not harshly torqued into the riding implement, there is no tendency to twist the threaded inserts out of the riding implement.
Brief Description of the Drawings Figure 1 illustrates one embodiment of a camlock screw in a non-engaged position. Figure 2 illustrates one embodiment of a camlever assembly.
Figure 3 illustrates one embodiment of a camlock screw mounted to a board in an engaged position. Figure 4 shows a cross-sectional diagram of the camlock screw of Figure 3 along section line 4-4.
Detailed Description of the Preferred Embodiment Figures 1 through 4 show a camlock screw 100 having features and advantages that solve the problems of the prior art. As used herein, the term "camlock" is used in its broad sense, and has its ordinary meaning, including, without limitation, a fastener wherein rotation of a cam translates into linear movement of an adjacent piece, thereby moving a first piece against a secondary piece. Referencing Figure 1, the camlock screw 100 comprises a camlever 10 preferably formed to have a handle section 18 and a camming section 12. The camming section 12 is configured to have a base radius R1 and a rise radius R2, where R2 > R1. The center of the camming section 12 has a through bore formed therein and is configured to receive a pin 20. The bore is slightly larger than the pin 20 such that the bore is rotatable about the pin 20. The camming section 12 rests on a cam washer 30, which is adjacent to a cup washer 40. In operation, the cam lever 10 is rotated either in a clockwise or counter clockwise direction about the center 28 of pin 20. As the camlever is pivoted, the washers 30, 40 provide a firm surface against which the camming surface 12 engages, thereby displacing the pin 28 vertically. The displacement distance is equal to R2 minus R1. In this manner, a pivotal movement of the camlever 18 translates into a linear, vertical displacement of the pin 20 as will be described in further detail below. Finally, a screw 50 is inserted through pin 20 and extends downward through the cam washer 30 and cup washer 40. Alternatively, it is contemplated herein that screw 50 could extend upwards from a sporting implement and be received into the camlock screw 100. This could be accomplished by first threading a screw into the threaded insert located in a mounting hole of a sporting implement. Alternatively, a sporting implement could be configured with a T-slot for receiving and securing the head of a screw. After which, the camlock screw 100 is attached to the screw extending from the board and the camlock screw 100 is used as described herein. Figure 2 illustrates one embodiment of a camlever 10 for use with the present camlock screw. In this top view figure, the camlever is in an engaged position, or parallel to a riding implement. Camlever 10 has a handle portion 18 and a camming portion 12. The camming portion 12 is bifurcated to expose the inserted pin 20. The pin 20 has a radial counter-bored through hole 22 formed therein to receive a screw (not shown). The hole 22 is preferably sized and shaped to securely hold a screw and prohibit rotational movement of the screw once inserted into the hole 22. This may be accomplished by providing a screw 50 in the form of a stud which has threads formed on both ends. The
stud is threaded into the hole 22 in the pin, and then the pin is compressed such that the threaded hole becomes slightly deformed. The slight deformation of the hole threads interfere with the screw threads and thus prevent the screw from rotating within the hole. Preventing rotational movement of the screw may further be accomplished by providing the hole 22 with a counter-bore 24, preferably with a hex shape to roughly half the hole's depth. The hole 22 below the counter-bore 24 has a circular cross section 26 and is sized to slidably receive a screw as will be discussed in more detail later. The bottom of the counter-bore 24 provides a shoulder that interferes with the screw head to prevent it from being pulled through the hole. An alternative embodiment utilizes a threaded hole into which the screw is threaded until the head sinks into the counter-bore. Additionally, the threaded hole may be slightly out of round before assembly which then requires a significant torque to thread the screw into the hole and provides enough thread friction to prevent the screw from backing out during use. Optimally, the screw is prevented from unintentionally backing out of the hole from the vibrations and alternating stresses concomitant with normal use through any acceptable configuration.
Figure 3 illustrates the camlock screw 100 attached to a board 70, and in the engaged position. The camlock screw 100 is used to mount a binding plate 60 onto a board 70. A pad 80 is disposed between the binding plate 60 and the board 80 to protect the board from damage from the binding and to provide some resilience in the mounting. As will be discussed in relation to figure 4, the screw 50 is threaded into the board 70. After which, the cam lever (not shown) is pivoted about centerline 28 in either direction, which causes the camming section 12 to rotate about the pin 20. Notably, the camming section 12 rotates relative to the pin 20, which remains stationary. As the cam lever 18 is pivoted and the camming section 12 slides on the cam washer 30, the distance between the pin center 28 and the cam washer 30 is thus increased from R1 to R2, thereby putting the screw 50 in tension and tightening the mechanism 100 against the board 70. The cam washer 30 is preferably made of a substantially self- lubricating material, such as nylon, polytetrafluoroethylene (PTFE) or Delrin®, such that the combination of the cam washer 30 and camming surface 12 has a low coefficient of friction and the cam washer 30 may act as a bearing to allow the camming surface 12 to rotate smoothly on the cam washer 30, even when under pressure. It is contemplated that the device will be used for water sports, among others, and consequently, other parts 10, 20, 50, and 40 are preferably made of a substantially non-corrosive metal such as aluminum or stainless steel.
In reference to Figure 4, a cross-sectional view taken along line 4-4 of Figure 3 is shown. The cam lever 10 has a through bore into which a pin 20 is received. The pin 20 has a radial through-hole 26 formed therein for receiving a screw 50. The camlock 100 is configured with a built-in, spring-loaded, ball detent mechanism. The cam lever 18 has a chamber 68 formed therein for receiving a spring 66 and a ball 64. The pin is further configured with dimples 62 formed on both sides thereof, the operation of which will be described in greater detail hereinafter.
In operation, the upper portion 52 of threaded screw 50 is preferably threaded up into the hole 26 during manufacture. The screw is threaded up a distance such that the upper end of the screw remains within the pin 20 and does not protrude therefrom. The screw is then fixedly positioned therein as described above, for example by crimping the pin until the hole threads deform and make removal of the screw 50 difficult. With the screw 50 secured in the
hole 26, the entire camlock mechanism 100 is rotated as the screw 50 is inserted into mounting holes formed within the board 70. The mounting holes each have a threaded insert 54 for receiving the threads of the screw 50. As the camlock is rotated clockwise, the screw 50 is threaded into the threaded insert 54. The camlock 100 is hand tightened until snug, after which, the cam lever 10 is rotated about the pin 28 until the cam handle 18 is substantially parallel to the board 70. As the cam lever 10 is rotated, the camming portion 12 slides on the cam washer 30 and vertically displaces the pin 20. As the pin is vertically displaced, the screw 50 and board 70 are drawn upward, while the washers 30, 40 and mounting plate 60 are pushed downward thus compressing the foam pad 80 and binding the mounting plate 60 and board 70 tightly together. The resultant force is dependent upon the shape of the camming section 12, and the elasticity of the foam pad 80. A specific force is not required to effectuate the binding, rather, it is sufficient that the resulting force draw the screw 50 in tension an amount to securely hold the binding plate 60 to the board 70. The camming section 12 is preferably shaped so that the lever 10 may be pivoted in either direction to effectuate the biding of the plate 60 to the board 70.
To help maintain the cam lever 10 in its desired position, a ball detent mechanism is integrated into the cam lever 10. The cam lever 10 has a chamber 68 which receives a steel spring 66 and a steel ball 64. A cooperating dimple 62 is formed in both sides of the pin 20. As the cam lever 10 is pivoted to its locked position as shown in
Figure 4, the spring 66 biases a portion of the ball 64 into the dimple 62. The detent mechanism provides a positive stop for the cam lever 10 as the contact of the ball and dimple interfere with additional, unwanted pivotal movement of the cam lever 10. Dimples 62 are provided on both sides of the pin 20 to allow the cam lever 10 to be pivoted either clockwise or counter-clockwise about the pin 20. Additionally, the hole 26 provides a recess for receiving a portion of the ball 64 when the cam lever 10 is in a vertical, or unlocked, position to prevent the cam lever 10 from being free to loosely flop around. The dimples 62 are configured with sidewalls such that intentional pivotal movement of the cam lever 10 forces the ball to retract into the chamber 68 and allows the cam lever 10 to pivot to its desired position.
One way to prevent a screw from loosening due to vibration is to tighten it. In other words, a screw may be prevented from loosening by applying a large mean stress to the screw such that the friction between the screw threads and the hole threads prevent loosening. A mean stress is traditionally applied by torquing the screw a predetermined amount to apply a tension force sufficient to slightly elongate the screw. The screw's elastic tendency to return to its original length maintains an increased contact force between the screw threads and the insert threads. In a similar way, the present camlock screw utilizes the cam mechanism to apply a tension force to the screw once it is hand-tightened into the threaded insert 54 in the board 70. By pre-tensioning the screw in this manner, the screw threads and the insert threads are engaged in frictional contact sufficient to overcome any tendency to loosen from vibration. Consequently, a simple tension force is transmitted to the threaded inserts 54 instead of a torque, which prevents the threaded insert from being twisted out of the board.
As will be obvious to those of skill in the art, a camlock screw 100 having features and advantages of the present camlock screw may also be used in conjunction with snow sports boards and skis as well as other boards
having bindings. Although the camlock screw has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present camlock screw extends beyond the specifically disclosed embodiments to other alternative embodiments or uses of the invention and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the present camlock screw disclosed and' described herein should not be limited by the particular disclosed embodiments described above, but should be solely determined by reference to the following claims.