Braking system for in-line skates

Abstract

Apparatus and method for simultaneously applying braking forces to two spaced apart rotating in-line roller skate wheel assemblies.

Description

BACKGROUND OF THE INVENTION

This invention relates generally to braking systems for in-line skates and more particularly to high heat transfer braking systems capable of simultaneously applying braking forces to multiple skate wheels.

In-line roller skates such as that disclosed in U.S. Pat. No. 5,028,058 to B. J. Olson have become increasingly popular for fitness, recreational, and competitive skating. The in-line roller skates enable skaters to achieve high skating speeds, particularly when skating outdoors on hilly terrain. A number of prior art braking devices have become available in an attempt to provide brakes which develop substantial braking forces that are required for safe operation under such conditions. Examples of various prior art brakes are illustrated in the following patents:

______________________________________U.S. Pat. No. Issue Date Inventor Class/Subclass______________________________________1,402,010 1/1922 Ormiston 280/11.21,956,433 4/1934 Young 188/773,224,785 12/1965 Stevenson 280/11.23,811,542 5/1974 Hamrick et al. 188/2593,828,895 8/1974 Boaz 188/77R4,033,433 7/1977 Kirk 188/254,275,895 6/1981 Edwards 280/11.24,943,072 7/1990 Henig 280/11.25,183,275 2/1993 Hoskin 280/11.25,226,673 7/1993 Cech 280/11.25,351,974 10/1994 Cech 280/11.25,375,859 12/1994 Peck et al. 280/11.25,388,844 2/1995 Pellegrini et al. 280/11.25,411,276 5/1995 Moldenhauer 280/11.25,511,805 4/1996 McGrath 280/11.2______________________________________

U.S. Pat. No. 5,411,276 applies braking forces to two adjacent wheels on an in-line skate using two different braking rollers with each braking roller contacting a different skate wheel. Each of the braking rollers has a brake pad applied to the surface of the braking roller which also contacts the skate wheel surface. The net result is that the heated surface of the braking roller contacts the skate wheel surface to overheat skate wheel during heavy brake usage and one of the skate wheels being braked can stop turning without the other skate wheel stopping to not only reduce the braking efficiency of the braking of the skate but also cause uneven wearing of the skate wheels.

U.S. Pat. No. 5,511,805 is not a braking device that is user applied, but rather, is used to retard the turning of the skate wheels while the user is learning to skate. Additional conventional braking devices are used to actually stop the skate.

The other prior art braking devices apply the braking forces to a single rotating member. First of all, this limits the amount of braking forces that can be applied to the skate. Secondly, the heat generated by the braking device is typically absorbed in the braking device itself which heats the skate wheel because of the contact between the skate wheel and the braking device. Because relatively large amounts of heat are generated and because the skate wheels are usually made of a resilient elastomer material, these prior art braking devices frequently damaged the skate wheel against which the braking forces were applied. Moreover, the limited heat dissipation achieved with these prior art systems contributed to increased wear of the braking device itself. As a result, the prior art has not been able to adequately brake in-line roller skates.

SUMMARY OF THE INVENTION

These and other problems and disadvantages associated with the prior art are overcome by the invention disclosed herein by providing a braking system for in-line roller skates which is capable of applying large magnitude braking forces to the skate wheel assemblies without excessive wear to the brake pad and/or the skate wheel assemblies, which distributes the braking forces equally between at least a pair of the skate wheel assemblies to effectively reduce the per wheel stopping forces required to stop the in-line roller skate, and which isolates the heat generated by braking from the skate wheel assemblies so as to prevent excessive wear and/or damage thereto. The invention also reduces the vibrations transmitted to the wearer through the skates, permits greater control over the application of the braking forces by the user, and automatically varies the contact force between the roller skate wheel assembly and the brake proportional to the magnitude of the braking forces being generated to provide improved safety of operation.

The invention is directed to a braking system for applying braking forces to a pair of adjacent rotating skate wheel assemblies on in-line roller skates, and can be applied to both pneumatic and elastomeric type skate wheel assemblies. The invention also is directed to a braking method which lends itself to the braking of in-line roller skates and to the cooling of the member used to apply the braking forces to the skate wheel assemblies.

The braking system of the invention simultaneously engages a pair of spaced apart skate wheel assemblies on an in-line roller skate and includes an engaging assembly for engaging the rotating skate wheel assemblies, mounting means for mounting the engaging assembly adjacent the rotating skate wheel assemblies, braking means for applying braking forces to the engaging assembly, and actuation means for causing the engaging assembly to engage the periphery of the rotating skate wheel assemblies while the braking means applies braking forces to the engaging assembly to brake the rotation of the skate wheel assemblies. Limit means is provided for preventing the engaging assembly from passing between the skate wheel assemblies.

The engaging assembly defines a peripheral engaging surface therearound having a diameter greater than the minimum distance between the peripheries of the rotating skate wheel assemblies. The engaging surface is adapted to frictionally engage the peripheries of the rotating skate wheel assemblies so that the engaging assembly is rotated by the skate wheel assemblies while engaged. The engaging assembly may include a thermally conductive cylindrical brake drum with an annular transfer section around the brake drum connected to the brake drum through a thermal resistance section for thermally isolating the transfer section from the heat generated in the brake drum by the frictional interface between the brake drum and the braking means.

The mounting means mounts the engaging assembly adjacent the peripheries of the skate wheel assemblies so that the engaging assembly is free to move a limited distance toward and away from both of the rotating skate wheel assemblies for engagement therewith while rotating about its central axis, while having its central axis maintained generally parallel to the rotational axes of the skate wheel assemblies, and while keeping the engaging assembly laterally aligned with the skate wheel assemblies. The mounting means comprises a leaf mounting assembly carried between the skate side frames and rotatably mounting the engaging assembly thereon. The leaf mounting assembly may include at least one and preferably two elongate leaf members flexible in a first direction and substantially inflexible in a second direction normal to the first direction where the leaf members are mounted so that the second direction is oriented substantially parallel to the axes of rotation of the skate wheel assemblies, and where the engaging assembly is rotatably mounted on the leaf members so that the leaf members can flex to allow the engaging assembly to move toward and away from the peripheries of the skate wheel assemblies but the engaging assembly is maintained laterally of the rotating members. A thrust bearing washer may be positioned between the sides of the transfer section around the brake drum and the adjacent sides of the braking means to reduce friction.

The actuation means selectively forces the engaging assembly toward the pair of skate wheel assemblies so that the contact forces between the engaging assembly and the skate wheel assemblies are substantially equalized. The actuating means may be operated by the pivotal cuff on the skate shoe.

The braking means for the engaging assembly may include arcuate brake pad means for frictionally engaging the cylindrical brake pad engaging surface on the engaging assembly. The brake pad means is mounted on the mounting means. The actuation means and the mounting means may be constructed and arranged to selectively cause the brake pad means to frictionally engage the engaging assembly while simultaneously forcing the engaging assembly against the peripheries of the skate wheel assemblies to brake same.

The limit means is mounted between the side frames on the skate to physically limit the movement of the engaging assembly so as to keep the engaging assembly from passing between the adjacent skate wheel assemblies being braked. The limit means may include a limit roller rotatably mounted between the skate side frames so that the engaging assembly can continue to rotate when the limit means is engaged to continue to apply braking forces to the skate wheel assemblies. When used with pneumatic tired skate wheel assemblies, the limit roller may be located so as to cause the engaging assembly to continue to provide braking forces to the undeflated skate wheel assembly in the event one of the tires becomes deflated.

The braking method of the invention comprises the steps of rotatably positioning an engaging member between the skate wheel assemblies so that the engaging member is in peripheral contact with both skate wheel assemblies; restraining the engaging member so that the engaging member is maintained in lateral alignment with the rotating skate wheel assemblies while being free to move toward and away from the rotating members; moving the engaging member toward the skate wheel assemblies so that the engaging member exerts approximately equal forces on the skate wheel assemblies; and, applying braking forces to the engaging member to resist the rotation thereof so that approximately equally divided braking forces are applied to the skate wheel assemblies. The braking method may further comprise the step of cooling the engaging member to prevent heat buildup in the engaging member during braking so as to deleteriously affect the skate wheel assemblies.

These and other features and advantages of the invention will become more clearly understood upon consideration of the following detailed description and accompanying drawings wherein like characters of reference designate corresponding parts throughout the several views and in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a right side perspective of an in-line roller skate embodying the invention;

FIG. 2 is an enlarged longitudinally extending vertical cross-sectional view taken just inside the right skate side frame;

FIG. 3 is a vertical cross-sectional view taken generally along line 3--3 in FIG. 2;

FIG. 4 is an enlarged exploded perspective view of the engaging assembly and braking means of the invention;

FIG. 5 is an enlarged end view of the engaging assembly of the invention; and,

FIG. 6 is a cross-sectional view taken along line 6--6 in FIG. 5.

These figures and the following detailed description disclose specific embodiments of the invention, however, it is to be understood that the inventive concept is not limited thereto since it may be embodied in other forms.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

As best seen in FIGS. 1-3, the invention disclosed is directed to a braking system 10 for in-line roller skates IRS which equalizes the braking forces exerted against a pair of spaced apart skate wheel assemblies SWA on the skate and which provides for cooling that part of the braking system contacting the skate wheel assemblies to prevent overheating the skate wheel assemblies. The braking system 10 is described as being applied to an in-line roller skate IRS with pneumatic tires SWT designed for off-road use but may be applied to any in-line roller skate as more fully set forth in my copending application Ser. No. 08/620,675 incorporated herein by reference.

As best seen in the FIGS. 1-3, the braking system 10 is applied to an off-road type in-line roller skate IRS. The skate IRS has a pair of side frames SSF mounted on the bottom of the skate shoe SSH. A plurality of skate wheel assemblies SWA are rotatably mounted between the side frames SSF at axially spaced apart positions along a common path PA.sub.SW (FIG. 1) lying in a vertical plane PL.sub.CM (FIG. 3) in which the skate longitudinal axis AX.sub.RS (FIG. 1) also lies. The skate wheel assemblies SWA rotate about axes AX.sub.SW normal to the plane PL.sub.CM and spaced apart an axle distance AD.sub.SW (FIG. 2).

As best seen in FIG. 2, each of the skate wheel assemblies SWA includes a rim assembly SWR rotatably mounted on an axle AXL extending between the side frames SSF on appropriate bearings SWB as is known in the art. A pneumatic tire SWT is mounted on the rim assembly SWR and provided with a ground engaging tread GET on which the skate rolls. Appropriate fill valves SWV are provided on the rim assembly SWR to inflate the tires SWT. The skate wheel assemblies SWA are significantly larger than the skate wheel assemblies typically used with on-road type in-line roller skates, being typically in the order of six inches in diameter. It is to be understood, however, that the braking system 10 can be applied to either on-road or off-road type in-line roller skates without departing from the scope of the invention. Likewise, it is to be understood that the tires SWT may be solid foam type tires rather than pneumatic without departing from the scope of the invention.

As best seen in FIGS. 2 and 3, the braking system 10 includes an engaging assembly 11 frictionally engaging the tire treads GET of the skate wheel assemblies SWA; mounting means 12 mounting the engaging assembly 11 adjacent the tire treads of the skate wheel assemblies SWA so that the engaging assembly 11 is free to move a limited distance toward and away from both of the skate wheel assemblies SWA; and actuation means 14 for selectively forcing the engaging assembly 11 toward the pair of rotating skate wheel assemblies SWA so that the contact forces between the engaging assembly 11 and the skate wheel assemblies SWA are substantially equalized. The braking system 10 also includes braking means 15 for applying a braking force to the engaging assembly 11 so that the engaging assembly retards the rotation of the skate wheel assemblies SWA when the actuation means 14 forces the engaging assembly 11 against the skate wheel assemblies SWA. The braking system 10 also includes limit means 16 which physically prevents the engaging assembly 11 from passing between the skate wheel assemblies SWA even if one of the tires SWT becomes deflated while at the same time insuring that the engaging assembly 11 still will apply braking forces to the remaining inflated tire SWT. Further, the braking system 10 may also include temperature control means 18 for preventing overheating of the engaging assembly 11 or the skate wheel assemblies SWA due to the heat generated by the braking process.

As seen in FIGS. 4-6, the engaging assembly 11 includes a cylindrical tubular brake drum 20 around which is formed an enlarged diameter transfer section 21. The enlarged diameter transfer section 21 may be integral with the drum 20 as illustrated herein or a separate member attached to the drum 20 as disclosed in my copending application Ser. No. 08/620,675. The brake drum 20 is designed to have the braking forces applied thereto by the braking means 15 and is movably mounted by the mounting means 12 adjacent the pair of skate wheel assemblies SWA. The transfer section 21 projects out around the outside of the brake drum 20 at a position intermediate its length.

The brake drum 20 has an annular side wall 22 defining a central axially extending passage 24 therethrough about the longitudinally extending axis AX.sub.BD of the drum. Opposite ends of the brake drum 20 are oriented normal to the brake drum axis AX.sub.BD to define opposed end side engaging surfaces 25 thereon. The brake drum 20 has a prescribed length L.sub.BD (FIG. 6) which is slightly less than the transverse distance TD (FIG. 3) between the skate side frames SSF as will become more apparent so that the brake drum 20 will freely pass between the side frames SSF while being oriented so that its central axis AX.sub.BD is generally horizontal and normal to the skate longitudinal axis AX.sub.RS and the plane PL.sub.CM. The brake drum 20 is preferably heat conductive so that it will transfer heat therethrough to the inside peripheral surface 26 of the side wall 22. The outside peripheral surface on the drum side wall 22 serves as a base from which the transfer section 21 is mounted.

The transfer section 21 has a length LG.sub.TS (FIG. 6) less that of the brake drum side wall 22 and is located midway the length of the side wall so that a pair of cylindrical brake pad engaging surfaces 28 are defined on opposite ends of the outside peripheral surface of the drum side wall 22 outboard of the transfer section 21. These surfaces 28 are concentric of the drum central axis AX.sub.BD and centered on a plane normal to the drum central axis AX.sub.BD. These surfaces 28 are frictionally engaged by the braking means 15 to apply braking forces to the engaging assembly 11 and retard its rotation as will become more apparent. As will also become more apparent, a significant amount of the heat generated at the braking means 15/brake pad engaging surfaces 28 interface is transferred through the side wall 22 to the inside surface 26 of the side wall 22. While any convenient material may be used for the brake drum 20, steel as well as metal matrix/refractory ceramic composites have been used satisfactorily to provide the necessary strength to support the forces to which the side wall 22 is exposed, conduct the heat from the surfaces 28 through the side wall 22 to the inside surface 26, and not excessively wear when the frictional braking forces are applied to the surfaces 28.

The transfer section 21 is an annular cylindrical portion 30 joined to the brake drum side wall 22 through a reduced width spacer portion 31 so that the section 21 will be maintained concentrically of the brake drum central axis AX.sub.BD with the section 21 centered on a plane normal to the drum central axis A.sub.BD. The transfer section 21 has an outside diameter DA.sub.TR (FIG. 5) which is greater than the clearance space SP.sub.SW (FIG. 2) between the adjacent skate wheel assemblies SWA so that the engaging assembly will not pass down between the skate wheel assemblies SWA when the tires SWT are inflated but rather will engage the tire treads GET of the two skate wheel assemblies.

The spacer portion 31 of the transfer section 21 connects the section 21 to the brake drum 20 and has a width WD.sub.SP (FIG. 6) much less than the length LG.sub.TS of the transfer section 21. As best seen in FIG. 5, the spacer portion 31 also has openings 36 therethrough to further reduce the net cross-sectional area through which heat can be conducted from the drum 20 to the transfer section 21. It will thus be seen that the spacer portion 31 acts as a resistance to the transfer of heat generated by the braking action to the transfer section 21 so as to minimize the heat transferred to the skate wheel tires SWT. The spacer section 31 is centered under the transfer section 21 so that a pair of annular recesses 34 are defined on opposite ends of the section 21.

The mounting means 12 includes a leaf mounting assembly 41 best seen in FIGS. 2-4 mounted between the skate side frames SSF in the space between the two skate wheel assemblies SWA which are to be engaged by the engaging assembly 11. The engaging assembly 11 is mounted by the leaf mounting assembly 41 between the skate side frames SSF above path PA.sub.SW along which the skate wheel assemblies SWA are centered.

The leaf mounting assembly 41 and braking means 15 best seen in FIG. 4 are combined so as to both position the engaging assembly 11 and also apply braking forces thereto. The leaf mounting assembly 41 includes a pair of elongate flat resilient leaf members 50 which can be resiliently flexed easily in one plane but not in the other.

Each of the leaf members 50 has a transverse width slightly less than the distance the end of the brake drum 20 projects out past the transfer section 21 so that, when the leaf member 50 is oriented parallel to the skate side frames SSF and adjacent one of them, the leaf member 50 will just clear the end edge of the transfer section 21. Each leaf member 50 has a connector end 51 and a projecting pad support end 52.

The connector end 51 of each leaf member is provided with a connector loop 54. The connector loop 54 is pivotally mounted on a pivot pin 55 extending between the opposed skate side frames SSF below the path PA.sub.SW along which the skate wheel assembly axes lie and generally centered longitudinally between the skate wheel assemblies SWA being braked. The leaf members 50 angle upwardly at an angle AN.sub.LM of about 30-40.degree. from the vertical illustrated in FIG. 2. This locates the leaf members 50 adjacent the skate side frames SSF so as to provide clearance for the skate wheel tires SWT and the transfer section 21 on the engaging assembly 11. The leaf members 50 are oriented so that their longitudinal centerlines AX.sub.LC seen in FIG. 4 can move in a vertical plane as the leaf members flex but lateral movement of the leaf members is substantially precluded so that movement of the centerlines AX.sub.LC away from the vertical plane PL.sub.CM is substantially prevented. As will become more apparent, this helps keep the engaging assembly 11 in lateral registration with the skate wheel tire treads GET and centered between the side frames SSF on the roller skate IRS.

The flexible leaf member 50 has an arcuate brake pad holder section 60 (FIG. 4) extending from the projecting end 52 toward the connector end 51 with the section 60 designed to encircle a portion of the cylindrical brake pad engaging surface 28 on the end portion of the brake drum 20 as seen in FIG. 2. A similarly shaped flexible brake pad 61 (FIG. 4) is affixed to the inside of the brake pad holder section 60 to frictionally engage the surface 28 on the brake drum. The projecting end 52 of the leaf member 50 is provided with a second connector loop 62 (FIG. 4) for connection to the actuation means 14 as will be explained.

The leaf mounting assembly 41 also includes part of the lateral alignment arrangement 65 that keeps the engaging assembly 11 laterally centered between the side frames SSF. The inwardly facing side edges 66 (FIG. 4) of both the brake pad holder sections 60 and the brake pads 61 form a bearing surface that engages a thrust washer 68 (FIG. 4) fitted into the recess 34 on the transfer section 21 facing the edges 66. This serves to both maintain the brake drum 20 in position laterally of the skate wheel assemblies SWA and keep the brake drum from falling out from between the side frames SSF. The thrust washer 68 has a planar annular flange 69 (FIG. 4) forming the plane of the washer which bears against the side of the transfer section 21 in the recess 34 and an annular lip 70 integral with the outside edge of the flange 69 oriented normal to the plane of the flange 69 to help retain the washer 68 in the recess 34 and prevent the brake pad holder section 60 from engaging the transfer roller 21 and damaging it. The lip 70 also helps maintain the shape of the brake pad holder section 60 as it flexes when the braking forces are applied to the brake drum 20 as will become more apparent.

The lateral alignment arrangement 65, then, includes the edges 66 on the brake pads 61 and holder sections 60 that engage the thrust washer 68. The lateral alignment arrangement 65 also includes the inside engaging surfaces IES (FIG. 3) on the side frames SSF that engage the outside surfaces of the leaf members 50. This keeps the outside peripheral surface 32 on the transfer section 21 laterally aligned with the peripheral tire tread GET on the adjacent pair of skate wheel assemblies SWA as seen in FIG. 3.

When an actuation force is applied that forces the projecting ends 52 of the leaf members 50 downwardly, the brake pads 61 are tightened against the peripheral brake pad engaging surfaces 28 on opposite ends of the brake drum 20 to apply braking forces to the brake drum 20 and resist rotation of the brake drum 20. At the same time, the engaging assembly 11 is forced downwardly toward the skate wheel assemblies SWA so that the peripheral surface 32 on the transfer section 21 frictionally engages the peripheral tire treads GET on the two skate wheel assemblies SWA sufficiently for the skate wheel assemblies SWA to rotationally drive the engaging assembly 11. Thus, the braking forces resisting rotation of the engaging assembly 11 are transferred to the skate wheel assemblies SWA to effectively brake the skate wheel assemblies. Because of the flexibility of the leaf members 50, the engaging assembly 11 can shift forwardly or rearwardly in the direction of the skate centerline AX.sub.RS until the braking forces are equally divided between the pair of skate wheel assemblies SWA. Thus, this arrangement is not only automatically compensating for skate wheel tire and transfer roller wear as well as wheel assembly out-of-roundness, it also insures equal division of the braking forces between the skate wheel assemblies being braked. By dividing the braking forces between two skate wheel assemblies, larger braking forces can be applied without sliding the skate wheel assemblies on the ground and also excessively loading either of the skate wheel assemblies so as to extend the life of the skate wheel tires. This also reduces the wear to the transfer section 21 by reducing the frictional force level to be applied at a single point on the transfer section periphery.

The actuation means 14 is illustrated as being driven by the pivotal cuff PSC on the skate IRS in FIG. 1, however, it is to be understood that various arrangements may be utilized to provide the actuation forces necessary to operate the braking means 15. Examples of alternate actuation means are hand held actuation devices; ground engaging pads or rollers attached to the skate itself; and cables connecting the cuff PSC to the leaf members 50.

The actuation means 14 illustrated in FIGS. 1 and 2 includes a motion multiplying pivot assembly 75 mounted on an extension 76 projecting out behind the side frames SSF at the upper rear ends thereof and connected to the connector loops 62 on the projecting ends 52 on the leaf members 50 through a dual rod linkage 78 best seen in FIG. 2. The motion multiplying pivot assembly 75 is connected to the lower rear portion of the pivotal cuff PSC by an adjustable rod linkage 79 as seen in FIGS. 1 and 2. When the cuff PSC is pivoted in a counterclockwise direction as seen in FIG. 1, the braking forces will be applied to the skate wheel assemblies SWA.

The motion multiplying pivot assembly 75 includes a pair of drive links 81 pivotally mounted at one of their ends on pivot pin 82 extending through the upper projecting end of the extension 76 and pivotally mounting one end of the dual rod linkage 78 at the opposite ends thereof. One end of the adjustable rod linkage 79 is pivotally connected to the links 81 intermediate their ends so that the amount of movement imparted to the links 81 by the linkage 79 will be multiplied to the linkage 78.

The dual rod linkage 78 includes a pair of drive rods 95, one connecting the projecting end of one of the drive links 81 to one of the connector loops 62 on the end of the leaf members 50 while the other connects the projecting end of the other drive link 81 to the other connector loop 62 on the end of the other leaf member 50. The diameters of the rods 95 are such that they will just fit between the outside of the leaf members 50 and the side frames SSF when connected to the connector loops 62 on the ends of the leaf members 50 as seem in FIG. 3. This maintains the connections between drive rods 95, the drive links 81 and the leaf members 50.

The limit means 16 includes a limit roller 96 rotatably mounted on the pivot pin 55 between the connectors 54 of the leaf members 50 as best seen in FIGS. 2 and 3. The limit roller 96 is sized to clear the tires SWT on the skate wheel assemblies SWA but to prevent the engaging assembly 11 from passing down between the tires SWT in the event one of the tires SWT becomes deflated or the tires SWT are sufficiently deformed by the downward forces on the drum 20. The roller 96 is also sized to cause the engaging assembly to still apply braking forces to the tire SWT remaining inflated for safety.

The temperature control means 18 serves to dissipate the heat generated at the frictional interface between the brake pads 61 and the brake drum 20 and to thermally isolate the brake drum 20 from the skate wheel assemblies SWA. The thermal isolation of the brake drum 20 from the skate wheel assemblies SWA is provided by the heat flow restriction capability of the spacer portion 31 of transfer section 21 as explained above. A certain portion of the heat generated by braking is transferred to the air flowing through the skate wheel area of the skate by the exposed surfaces of the leaf members 50 while additional heat dissipation is provided by air flow openings 98 through the side frames SSF in alignment with the opening through the brake drum 20 as best seen in FIGS. 1-3 to allow air to flow through the passage 24 of the brake drum 20.

Claims

1. An in-line roller skate used on a skating surface, said roller skate comprising:

a pair of side frames;

at least two skate wheels assemblies rotatably mounted between the side frames about parallel skate wheel rotational axes spaced apart a prescribed wheel spacing distance so that the skate wheel assemblies are generally aligned along a common straight path and so that the peripheral surfaces on adjacent skate wheel assemblies define a minimum clearance distance therebetween;

an engaging assembly defining a central axis therethrough and a generally cylindrical peripheral skate wheel engaging surface therearound having a diameter greater than the minimum distance between the peripheries of the skate wheel assemblies, said skate wheel engaging surface adapted to frictionally engage the peripheries of the two adjacent skate wheel assemblies so that said engaging assembly is frictionally engaging the skate wheel assemblies;

means for selectively moving said engaging assembly toward the peripheries of the two adjacent skate wheel assemblies so that said engaging assembly frictionally engages the peripheries of the two adjacent skate wheel assemblies and is rotated thereby while the contact forces between said engaging assembly and the two adjacent skate wheel assemblies are substantially equalized; and

means for applying a braking force to said engaging assembly so that said engaging assembly retards the rotation of the two adjacent skate wheel assemblies while said engaging assembly is frictionally engaging the peripheries of the two adjacent skate wheel assemblies, said means further including secondary means for limiting the movement of said engaging assembly toward the two adjacent skate wheel assemblies to prevent said engaging assembly from passing between the two skate wheel assemblies,

wherein said secondary means comprises limit means for contacting said engaging assembly to limit the movement thereof toward the two adjacent skate wheel assemblies, and

wherein said limit means includes a limit roller rotatably mounted between the skate side frames adapted to engage said engaging assembly to limit the movement thereof toward the two adjacent skate wheel assemblies while allowing said engaging assembly to roll on said limit roller and while maintaining frictional driving contact between the two adjacent skate wheel assemblies so that said engaging assembly continues to apply braking forces to the two skate wheel assemblies while engaging said limit roller.

2. The in-line roller skate of claim 1, wherein said limit roller is rotatably mounted between the skate side frames about a fixed axis of rotation equidistantly spaced between and substantially parallel to the adjacent parallel skate wheel rotational axes where said fixed axis of rotation is located so that the rotational axis of said engaging assembly remains generally above the line joining the adjacent skate wheel rotational axes when said engaging assembly contacts said limit roller.

3. An in-line roller skate used on a skating surface, said roller skate comprising:

a pair of side frames;

at least two skate wheels assemblies rotatably mounted between the side frames about parallel skate wheel rotational axes spaced apart a prescribed wheel spacing distance so that the skate wheel assemblies are generally aligned along a common straight path and so that the peripheral surfaces on adjacent skate wheel assemblies define a minimum clearance distance therebetween;

an engaging assembly defining a central axis therethrough and a generally cylindrical peripheral skate wheel engaging surface therearound having a diameter greater than the minimum distance between the peripheries of the skate wheel assemblies, said skate wheel engaging surface adapted to frictionally engage the peripheries of the two adjacent skate wheel assemblies so that said engaging assembly is frictionally engaging the skate wheel assemblies;

means for selectively moving said engaging assembly toward the peripheries of the two adjacent skate wheel assemblies so that said engaging assembly frictionally engages the peripheries of the two adjacent skate wheel assemblies and is rotated thereby while the contact forces between said engaging assembly and the two adjacent skate wheel assemblies are substantially equalized; and

means for applying a braking force to said engaging assembly so that said engaging assembly retards the rotation of the two adjacent skate wheel assemblies while said engaging assembly is frictionally engaging the peripheries of the two adjacent skate wheel assemblies, said means further including secondary means for limiting the movement of said engaging assembly toward the two adjacent skate wheel assemblies to prevent said engaging assembly from passing between the two skate wheel assemblies,

wherein said means for moving said engaging assembly and applying braking forces thereto further includes:

pivot shaft mounted between the side frames and between the adjacent skate wheel assemblies so that the centerline of said pivot shaft is substantially parallel to the skate wheel rotational axes, and

a pair of flexible elongate leaf member assemblies pivotally mounted on said pivot shaft at spaced apart positions and projecting upwardly therefrom on opposite sides of said skate wheel engaging surface and around a portion of said engaging assembly to rotatably mount said engaging assembly therebetween; and,

wherein said secondary means includes a limit roller rotatably mounted on said pivot shaft between said leaf member assemblies.

4. The in-line roller skate of claim 3, wherein said engaging assembly further comprises:

a thermally conductive cylindrical brake drum defining a pair of spaced apart cylindrical brake pad engaging surfaces thereon in registration with those portions of said leaf spring assemblies extending around a portion of said engaging assembly, and,

an annular transfer roller section around said brake drum and defining said peripheral skate wheel engaging surface thereon for frictionally engaging the skate wheel assemblies, said transfer roller section constructed and arranged to restrict the flow of heat from said brake drum to said peripheral skate wheel engaging surface on said transfer roller section; and,

wherein said means for moving said engaging assembly and applying braking forces thereto further includes:

flexible brake pads mounted on said leaf member assemblies at positions to engage said spaced apart cylindrical brake pads engaging surfaces on said brake drum and apply braking forces to said brake drum as said engaging assembly is moved into driving engagement with the skate wheel assemblies.

5. The in-line roller skate of claim 4 further including cooling means for cooling said brake drum, said cooling means comprising:

at least one air passage defined in said brake drum and extending therethrough; and

an opening defined through each of the side frames of the roller skate in registration with said air passage defined through said brake drum so that air is free to flow through said brake drum to cool same.

6. The in-line roller skate of claim 4 wherein said engaging assembly is made out of a heat conductive material and further comprises a cylindrical transfer section projecting out from and integral with said brake drum, said transfer section defining said skate wheel engaging surface therearound, and said transfer section including heat flow restricting means for limiting the heat transfer rate from said brake drum to said skate wheel engaging surface so that the skate wheel assemblies are not overheated.

7. The in-line roller skate of claim 6 wherein said engaging assembly is made out of steel.

8. The in-line roller skate of claim 6 wherein said engaging assembly is made out of a metal/matrix/heat conductive ceramic composite.

9. A method of braking a pair of spaced apart rotating skate wheel assemblies on in-line roller skates which are rotatable about generally parallel, spaced apart axes and equipped with resilient tires, said method comprising the steps of

(a) rotatably positioning an engaging assembly between the rotating wheel assemblies so that the engaging assembly is in peripheral contact with the resilient tires on both rotating skate wheel assemblies;

(b) restraining the engaging assembly so that the engaging assembly is maintained in lateral alignment with the rotating skate wheel assemblies while being free to move toward and away from the resilient tires on the rotating skate wheel assemblies;

(c) moving the engaging assembly toward the resilient tires on the rotating skate wheel assemblies so that the engaging assembly exerts equal forces on the rotating skate wheel assemblies;

(d) applying braking forces to the engaging assembly to resist the rotation thereof so that an equally divided braking force is applied to the rotating skate wheel assemblies;

(e) physically limiting the movement of the engaging assembly toward the resilient tires on the rotating skate wheel assemblies so as to prevent the engaging assembly from passing between the resilient tires; and

(f) restricting the flow of heat generated by the braking forces applied the engaging assembly to that portion of the engaging assembly in contact with the resilient tires of the skate wheel assemblies to prevent overheating the resilient tires.