Roller Skate or the Like With Brake Attachment

My present invention relates to a wheeled skating device, such as a roller skate or a skate board, having at least one front wheel and a pair of rear wheels which are secured by respective mountings known as trucks to a thread plate or directly to the shoe of a user.

Such a device, and especially a roller skate with pairs of front and rear wheels journaled on respective transverse axles, is conventionally provided with a front bumper or stop of plastic material designed to facilitate push-off, figure skating and similar maneuvers. These stops, however, are generally not usable for braking at high speeds since, on the one hand, such action would result in rapid wear of the bumper and, on the other hand, the location of the stop at the forward end of the device may potentially give rise to accidents due to a flipping about the front-wheel axle.

In light of the high speeds attainable with today's efficiently constructed roller skates and skate boards, however, it is desirable to provide these devices with means for enabling a controlled deceleration or stopping whenever a need therefor should arise.

The object of my present invention, therefore, is to provide such a device with effective brake means for the purpose described.

In accordance with my present invention, a rocker member is fulcrumed on a truck member supporting the rear axle of a wheeled skating device, with a pivotal axis perpendicular to the rear wheels thereof, and has a tail end carrying a control roller rearwardly of that axle. During normal running, with all the wheels resting on a road surface, the control roller is held elevated above the ground and is biased by resilient means tending to maintain the rocker member in a predetermined limiting position relative to the associated truck member. One of these two members carries a pair of pressure elements, disposed close to the rear wheels and displaceable substantially parallel to their axle, while the other member is provided with camming means coacting with these pressure elements for driving them into frictional engagement with the rear wheels upon an elevation of the front wheel sufficient to lower the control roller onto the road surface and to swing the rocker member about its pivotal axis against a countervailing biasing force so as to exert a braking effect upon these wheels.

When the rear wheels consist of a polymeric material such as polyurethane, for example, I prefer to provide their inner faces confronting the pressure elements with a pair of wear-resistant liners in the form of metallic disks which advantageously may also constitute seats for ball, needle or other antifriction bearings supporting the rear wheels.

In an advantageous embodiment, the truck member forms a housing in which the pressure elements are slidably received, the camming means comprising a spring-loaded spreader which is carried by the rocker member and interposed between the pressure elements for separating them upon an upward swing of the roller-carrying tail end. The resilient restoring force may be supplied in that case by a coil spring surrounding a tip of the spreader guided in an upper or lower housing wall, the spring being inserted between that wall and a tapering section of the spreader which could be either frustoconical or wedge shaped with a vertex angle in a range of about 8.degree. to 22.degree., preferably around 15.degree..

Alternatively, the rocker member may be designed as a bracket straddling a preferably upwardly convergent extension of the truck member with a pair of wedge-shaped formations on forward extremities of two flexible lateral arms, these formations serving as the pressure elements. The countervailing biasing force may be provided in this instance by the resiliency of the bracket itself, especially by a rear part of that bracket interconnecting its lateral arms.

The above and other features of my invention will now be described in detail with reference to the accompanying drawing in which:

FIG. 1 is a perspective view of a roller skate showing a brake attachment according to my invention associated with its rear wheels;

FIG. 2 is a perspective view of the assembly of rear wheels and brake attachment;

FIG. 3 is a cross-sectional view of one of the rear wheels shown in FIGS. 1 and 2;

FIG. 4 is a cross-sectional view of a metal disk, secured to the wheel of FIG. 3, and of a ball bearing seated in that disk;

FIG. 5 is a longitudinal sectional view of a housing, forming part of the brake attachment of FIGS. 1 and 2, and of a pair of pressure elements in that housing coacting with a spreader;

FIG. 6 is a cross-sectional view taken on the line VI--VI of FIG. 5;

FIG. 7 is an axial sectional view of a control roller forming part of the brake attachment;

FIG. 8 is a side view of a modified brake attachment according to my invention with one of its pressure elements removed;

FIG. 9 is a rear view of an assembly similar to that of FIG. 2, including the modified brake attachment shown in section on line IX--IX of FIG. 8;

FIG. 10 is a sectional top view taken on the line X--X of FIG. 8;

FIG. 11 is a part-sectional view similar to that of FIG. 8 but showing a further modification;

FIG. 12 is a top view taken partly in section on the line XII--XII of FIG. 11;

FIG. 13 is a further view similar to FIG. 8, relating to another embodiment; and

FIG. 14 is a front view of the assembly of FIG. 13.

In FIG. 1, I have shown a roller skate comprising a tread plate 100 supporting the shoe of a user, a pair of rear wheels 2, 3 on an axle 1 and a pair of front wheels 102, 103 on an axle 101. Axles 1 and 101 are mounted on plate 100 with the aid of respective metallic trucks generally designated 5 and 105. The front of plate 1 also carries a conventional stop 4 which, like wheels 2, 3, 102 and 103, may consist of polyurethane or the like.

Each truck 5 and 105, as more particularly illustrated for truck 5 in FIG. 2, is secured to the plate 100 in well-known manner by a screw (not shown) traversing a socket 7 and by a boss 6 fitting into a complementary nipple on plate 100 to prevent swiveling about the screw axis. Each wheel is journaled on its axle by an outer and an inner bearing as particularly illustrated in FIGS. 1 and 2 for an outer rear-wheel bearing 70 and an inner rear-wheel bearing 71.

FIGS. 1, 2 and 3 also show metal disks 9 and 10 received in recesses 75 of the inner faces of rear wheels 2 and 3; these disks preferably consist of stainless sheet steel about 2 mm thick. A perforated central portion 74 of each disk is swaged to fit into a depression 76 for the purpose of accommodating the inner ball bearing 71 as illustrated in FIG. 4. Disks 9 and 10 may be held in their recesses 75 by adhesive bonding, for example. Another depression 77 (FIG. 3) of each wheel accommodates its outer bearing 70. The two recesses 76 and 77 are interconnected by a bore 79 to be traversed by axle 1.

A prismatic housing 13 rigid with truck 5, disposed rearwardly of axle 1, surrounds two pressure elements 11 and 12 for sliding movement parallel to the axle as illustrated in FIG. 5; the truck and the housing may be formed as a unitary casting. A spreader 15, also shown in FIG. 6, penetrates from below into housing 13 while resting on a bifurcate rocker member 30 (FIG. 2) which is fulcrumed on truck 5 for vertical swinging about a pivotal axis parallel to wheel axle 1 as more particularly illustrated in FIG. 8 with reference to a similar rocker member 30a. Rocker 30 has a bifurcate tail end with prongs 32, 33 between which a control roller 34, preferably of the same polymeric material as wheels 2 and 3, is journaled on a headed stud 31 held in position by a cotter pin 31' as illustrated in FIG. 10. Spreader 15 has a prismatic base 16 guided in a correspondingly shaped cutout 24 of a lower housing wall 23, a wedge-shaped intermediate section 8 with upwardly converging flanks 85 and 86 adjoining similarly beveled faces 25 and 26 of pressure elements 11 and 12, and a cylindrical tip 17 guided in a bore of an outward projection 78 of an upper housing wall 21. A coil spring 18, surrounding the tip 17 of spreader 15 within a recess 22 of projection 78, bears on the one hand upon the top of that recess and on the other hand upon a shoulder separating the tip 17 from the tapering intermediate section 8.

Spring 18 depresses the spreader 15 and with it the rocker 30 which, however, is maintained by suitable abutment means (described hereinafter with reference to FIG. 8) in a limiting position holding the roller 34 elevated above a plane tangent to the bottoms of all four wheels whereby the roller will not touch a road surface contacted by these wheels. It is only when the user lifts the front of the roller skate, causing it to swivel about rear axle 1, that roller 34 will engage the ground and with further swiveling will make the rocker 30 swing about its fulcrum (located below axle 1 as shown in FIG. 8) so as to raise the spreader 15 against the force of its loading spring 18, thereby moving the pressure elements 11 and 12 apart so that their outer faces will come into frictional contact with disks 9 and 10 of wheels 2 and 3. This is easily accomplished when the roller skate subjected to this braking operation is on the leading foot; the user can control the rate of deceleration by choosing the proper tilt angle. Even with rapid braking, the frictionally generated heat is readily dissipated by the metallic disks 9 and 10 without harm to the plastic material of the wheels.

As further shown in FIG. 5, each pressure element 11 and 12 is subdivided into two prismatic blocks 80, 82 and 81, 83, the inner blocks 80 and 81 being metallic while the outer blocks 82 and 83 are made of a plastic material which could be the same (e.g. polyurethane) as that used for the roller 34 and the wheels 2, 3 but could also be a cheaper, faster-wearing synthetic resin. The use of polymeric material for friction blocks 82 and 83 insures a softer contact and therefore a less abrupt braking action than would be the case with metallic blocks. The detachability of the outer blocks 82 and 83 from the inner blocks 80 and 81, to which they may be secured by screws 72 (only one shown), allows them to be readily replaced in the event of excessive wear.

Corresponding pressure elements in subsequent Figures, while not so illustrated, may be similarly subdivided into metallic inner and plastic outer portions detachable from each other.

FIG. 6 shows that parallel vertical sides 87 and 88 of spreader 15 are also positively guided between sidewalls 28, 29 of housing 13, thereby avoiding any possible canting of that spreader.

As illustrated in FIG. 7, roller 34 may be supported on its stud 31 by a pair of ball bearings 89, 90. As shown in FIG. 10, however, I may use a low-friction bushing 35 (of metal or Teflon, for example) in lieu of such bearings.

Reference will now be made to FIGS. 8-10 showing the modified rocker 30a with a bifurcate tail end having prongs 32a and 33a, each of these prongs being formed with several holes 36, 37 for the passage of mounting stud 31 whereby roller 34 may be positioned at different distances from wheels 2, 3 and at different elevations above ground for a faster or a slower braking action. Rocker 30a is flanked by lugs 41, 42 depending from a housing 13a which is integral with a truck 5a similar to truck 5 of the preceeding embodiment; these lugs are traversed by a headed stud 43, held in position by a cotter pin 40, on which the rocker 30a is fulcrumed directly below axle 1. A modified spreader 15a with a cylindrical base 16a guided in the lower wall 23a of housing 13a has a frustoconical intermediate portion 8a which converges upwardly and terminates in a tip 17a similar to the tip 17 of the aforedescribed spreader 15; a loading spring 18 again surrounds this tip and bears upon the upper housing wall 21a in which the latter is guided. Pressure elements 11a and 12a slidable in housing 13a have frustoconically concave faces contacting section 8a of spreader 15a whose operation is analogous to that described with reference to the wedge-shaped spreader 15 of FIGS. 5 and 6.

The front end of rocker 30a forms a ridge 39 with a part-cylindrical curvature merging into a flat land which rests against a shoulder 44 in the limiting position of FIG. 8 whereby the roller 34 is held elevated above ground. Thus, rocker 30a can swing only clockwise from that limiting position to raise the spreader 15a whose base 16a has a convex bottom end 27 adapted to roll on the upper surface of the rocker.

In FIGS. 11 and 12 I have shown a truck 5b rigid with a housing 13b which in this instance extends vertically below axle 1. Two pressure elements 11b and 12b slidable in this housing have downwardly converging beveled faces 111, 112 adjoining a spreader 15b with similarly converging sides; this spreader has a generally horizontal rearward extension or lever 48 swingable about a pivot pin 50 which traverses the housing 13b and also serves as a fulcrum for a rocker 30b whose bifurcate tail end is similar to that of rockers 30 and 30a shown in preceding Figures. Member 30b has a hollow front end 47 positively embracing the lever like extension 48 of spreader 15b whereby the rocker and the spreader are jointly swingable in a clockwise sense (as viewed in FIG. 11) about fulcrum 50 from the limiting position of that Figure defined by contact between extension 48 and the upper wall of housing 13b. The tail end of rocker 30b is here provided with three sets of holes 36, 37, 38 for a selective mounting of roller 34 in several positions.

A coil spring 49, inserted between the bottom wall of housing 13b and spreader 15b, tends to maintain the rocker in the limiting position referred to. When a counterclockwise tilting of the roller skate about axle 1 swings the rocker 30b clockwise with reference to truck 5b, pressure elements 11b and 12b are driven apart as in the preceding instances to exert a braking force upon the wheels 2 and 3.

It should be noted that only the spreader 15, 15a, 15b is shown spring-biased in the embodiments described up to now; the associated pressure elements will spontaneously move away from the rapidly rotating wheels toward a position close to each other. If necessary, however, these elements could be interconnected by a weak spring tending to keep them away from the confronting disks 9 and 10 of the inner wheel faces.

The embodiment of FIGS. 13 and 14 comprises a truck 5c with upwardly converging camming surfaces 60 and 61 confronting similarly converging beveled surfaces 55 and 59 of a pair of pressure elements 56 and 57 which constitute forward extremities of two lateral arms of a resilient metallic bracket 51 flanking the truck 5c. Bracket 51 has a rear wall 58 interconnecting these lateral arms which also have reinforced depending portions 53 and 54 supporting the mounting stud 31 of control roller 34. Bracket 51 is pivoted on truck 5c by a pin 52 disposed to the rear of wheel axle 1; the limiting position shown in FIG. 13 is established by contact between a shoulder 64 of truck 5c and lateral cheeks 65 of the bracket whose configuration is similar to that of ridge 39 shown in FIG. 8.

Pressure elements 56 and 57 are traversed by screws 62, 63 of opposite pitch holding in position a pair of replaceable friction layers 66 and 67 on the outer brake surfaces of these pressure elements.

In operation, the brack attachment of FIGS. 13 and 14 forces the wedge-shaped pressure elements 56 and 57 into the gap between truck 5c and wheels 2, 3, which advantageously are again lined with metal disks 9 and 10, when roller 34 is lowered into contact with the ground by a counterclockwise tilting of the roller skate about axle 1 as viewed in FIG. 13.

The angle included between camming surfaces 60, 61 of FIG. 14 ought to be somewhat larger than the vertex angle of wedge pieces 15, 15a, 15b of the preceding embodiments (ranging from slightly less than 10.degree. to a little over 20.degree.) in order to bias the bracket 51 into its illustrated limiting position by the resiliency of its arms carrying the pressure elements 56 and 57. If necessary, the bracket may be additionally spring-biased for this purpose, e.g. by a tensile spring interlinking its arms or by a hairpin spring anchored to the truck and the bracket.

The brake attachment of FIGS. 13 and 14 could be inverted by designing truck 5c with downwardly rather than upwardly converging camming surfaces, provided that the fulcrum 52 of bracket 51 is relocated to a position forwardly of axle 1. In that instance, however, the lateral bracket arms terminating in pressure elements 56, 57 would have to be located below the axle 1 where the available space is rather limited.

Bracket 51 may be conveniently bent from a single sheet-metal stamping, with the lower ends 53, 54 of its arms folded into several plies for properly supporting the roller stud 31.

As will be readily apparent, existing skating devices can be equipped with my brake attachment by merely substituting same for the conventional rear truck thereof, with or without the installation of contact disks 9, 10.