VELOCIPEDE WITH DRIVEN WHEEL AND SKATE WHEEL
Background of the Invention
This invention relates to velocipedes and mor particularly to a velocipede of the general type includin a frame, a seat mounted on an upper portion of the frame, a drive wheel mounted in a rear fork bracket portion of th frame, a sprocket and chain drive system for the driv wheel, and a steering gear assembly of the skateboard typ mounted on the forward lower end of the frame. Skateboards of this general type are shown fo example in U.S. Patents No. 4,417,743 and 4,523,770. Thi type of velocipede combines certain features of traditional bicycle with certain features of a skateboar and, specifically, enables a rider positioned on the sea to perform intricate maneuvers by the use of appropriat leaning or weight shifting actions which, because of th skateboard assembly at the forward end of the frame, resul in intricate and dramatic movements of the velocipede. Whereas velocipedes of this general type have proven to b challenging, amusing, and pleasant to ride, the prior ar designs for this type of velocipede have embodied certai disadvantages. Specifically, the prior art designs hav sometimes generated imprecise movements of the vehicle; th prior art designs have proven to be difficult to adjust t provide specific performance characteristics; and the prio
art designs have embodied structural failure modes that have shortened the useful life of the velocipede.
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Summary of the Invention This invention is directed to the provision of an improved velocipede of the described type in which the movement of the velocipede in response to rider input is precise and positive; the characteristics of the desired movement may be readily adjusted; and the durability of the velocipede is improved with respect to the prior art designs. "
According to an important feature of the invention, the skateboard or steering gear assembly secured to the lower forward portion of the frame includes a mounting plate adapted to be secured to the forward lower frame portion; an axle including a pivot arm portion, mounting the axle for pivotal movement on the mounting plate, and a suspension arm portion; and a suspension assembly including a bolt passing downwardly through the mounting plate and through an aperture in the axle suspension arm portion, upper and lower silent block members positioned on the bolt above and below the axle suspension arm portion, and a nut secured to the lower free end of the bolt suspension assembly and operative to clamp the suspension assembly to the lower face of the mounting plate with the upper and lower silent block members clamped to the upper and lower faces of the axle suspension arm portion". This specific construction of the steering gear
assembly allows the suspension assembly to be readily adjusted simply by loosening or tightening the nut to thereby selectively adjust the performance characteristic of the velocipede. According to a further feature of the invention, the upper silent block member is formed of a relatively soft material and the lower silent block member is formed of a relatively hard material. This specific arrangement and construction of the suspension assembly provides more predictable straightline performance for the velocipede and more positive cornering for the velocipede. In the disclosed embodiment of the invention the upper silent block member is formed of a soft rubber material and the lower silent block member is formed of a polyurethane material.
According to a further feature of the invention, the mounting plate includes a socket opening in the upper face of the mounting plate and a bore opening at its upper end in the bottom of the socket and opening at its lower end in the lower face of the mounting plate, and the head of the bolt is positioned in the socket with the shaft of the bolt passing downwardly through the bore for coaction with the silent block members and the nut. This specific mounting arrangement for the bolt provides a simple and durable construction and yet allows the performance characteristic of the velocipede to be readily adjusted by a simple loosening or tightening of the nut coacting with the lower end of the bolt.
According to a further feature of the invention, the mounting plate includes a generally planar main body portion defining a generally flat upper face for securement to the lower forward portion of the frame member and a rearward heel portion extending downwardly from the lower face of the main body portion; the socket opens in the upper face of the main body portion above the heel portion; and the bore extends downwardly through the heel portion and opens at the lower face of the heel portion. This specific arrangement further enhances the strength of the steering gear assembly and further facilitates the ready adjustment of the performance characteristics of the steering gear assembly.
According to a further feature of the invention, the main body portion of the mounting plate is generally rectangular and further includes a pair of stiffening ribs extending downwardly from the lower face of the main body portion and extending along the respective opposite side edge portions of the lower face outboard of the heel portion of the mounting plate. The rectangular configuration of the main body portion of the mounting plate substantially eliminates a common failure mode in prior art steering gear assemblies and the stiffening ribs further add to the strength and durability of the invention construction.
Brief Description of the Drawing
FIGURE 1 is a side elevational view of a velocipede according to the invention;
FIGURE 2 is a view of a steering gear assembly for use with the invention velocipede; FIGURE 3 is a perspective view of a mounting plate employed in the steering gear assembly of Figure 2 with the mounting plate turned bottom side up for purposes of illustration;
FIGURE 4 is a top view of the mounting plate of Figure 3;
FIGURE 5 is a cross-sectional view taken on line 5-5 of Figure 4;
FIGURE 6 is a perspective view of the axle structure employed in the steering gear assembly of Figure 2;
FIGURE 7 is a cross-sectional view taken on lines 7-7 of Figure 6;
FIGURE 8 is a bottom view of the axle structure of Figures 6 and 7; FIGURE 9 is an exploded perspective view of a suspension assembly employed in the steering gear assembly of Figure 2; and
FIGURE 10 is a cross-sectional view taken on line 10-10 of Figure 1.
Detailed Description of the Preferred Embodiment
The invention velocipede, broadly considered, includes a frame 10, a seat 12, a drive wheel 14, a
sprocket and pedal assembly 16, and a steering gear assembly 18.
Frame 10 is of steel construction and includes a main body tubular member 20 and a rear fork bracket structure 22.
Main body tubular member 20 includes a vertical upper post portion 20a and a downwardly and forwardly extending lower portion 20b joined to upper post portion 20a by a curvilinear knee portion 20c. A flange plate 24 of generally rectangular configuration is welded to the lower forward end of lower tube portion 20b.
Bracket structure 22 includes a pair of spaced U-shaped bracket members 26 each secured by welding at its one end 26a to frame post portion 20a and at its other end 26b to frame lower portion 20b. Members 26 are positioned on opposite sides of frame member 20 and are laterally spaced in known manner to accommodate drive wheel 14. A downwardly extending wheel mounting bracket plate 28 is welded to each bracket member 26 and each bracket plate 28 includes a downwardly and forwardly opening adjustment slot 28a.
Seat assembly 12 includes a saddle 30 of known construction, a saddle post 32 telescopically received in known manner in the upper end of frame post portion 20a, and a handle 34 projecting forwardly from saddle 30 for grasping by the hands of the rider. An adjustment collar 36 "on the upper end of frame post portion 20a provides vertical adjustment of seat assembly 12 in known manner.
Rear wheel 14 includes a pneumatic tire 38, a wheel 40, and an axle 42.
Tire 38 is of known form and includes a valve stem 44. Wheel 40 is preferably a plastic molded article formed for example of urethane and includes a rim portion 40a mounting the tire 38 and a plurality of integral spoke portions 40b terminating in a central hub portion (not seen) concentrically surrounding axle 42. Axle 42 is mounted in known manner in adjustment slots 28a of brackets 28.
Pedal assembly 16 includes a pedal sprocket 44, a wheel sprocket 46, pedal assemblies 48, and a chain 50. Pedal sprocket 44 is of known construction and is rotatably mounted on frame 20 in known manner by a sprocket tube (not seen) welded to the upper face of lower frame portion 20b. Wheel sprocket 46 is drivingly connected in known manner to wheel 40 via the intermediary of a coaster brake.
Each pedal assembly 48 includes a pedal crank 52 carrying a pedal' 54 at its free or outer end. Chain 50 is trained around pedal sprocket 44 and wheel sprocket 46 so that rear wheel 38 is driven in response pedaling action of a rider seated on seat 30 with the coaster brake interconnecting wheel sprocket 46 and wheel 40 allowing coasting movement of the rear wheel without movement of the pedals, in known manner.
Steering gear assembly 18 includes a mounting plate 60, an axle structure 62, a suspension assembly 64, and wheels 66.
Mounting plate 60 is preferably formed as a steel casting and includes a main body portion 60a of generally rectangular configuration corresponding generally in size and shape to flange plate 24 of the frame structure; a rearward heel portion 60b extending downwardly from the lower face 60c of main body portion 60a and defining a lower face 60d that is upwardly and forwardly angled relative to lower surface 60c; a forward toe portion 60e extending downwardly from the lower face 60c of main body portion 60a and defining a lower face 60f that is angled rearwardly and upwardly relative to lower face 60c; a central reinforcing rib portion 60g interconnecting heel portion 60b and toe portion 60e; a pair of longitudinal stiffening rib portions 60h extending downwardly from lower face 60c and extending along the respective opposite side edge portions of lower face 60c outboard of heel and toe portions 60b and 60e; and a mounting hole 60i at each corner of the mounting plate. Heal portion 60b, rib 60g and toe portion 60e together extend in unitary fashion from rear to front of the mounting plate as a single central stiffening and reinforcing structure for the mounting plate.
A rectangular bolt socket 60j is provided in the mounting plate in generally overlying relation to heel portion 60b, and an axle pivot socket 60k is provided in
toe portion 60e. Socket 60j opens in the upper face 601 of the mounting plate and defines a bottom wall 60m generally parallel to heel lower face 60d. A bore 60n, having a central axis generally normal to the plane of heel portion lower face 60d, opens at its upper end in the bottom wall 60m of bolt socket 60j and opens at its lower end in the lower face 60d of heel portion 60b.
Axle pivot socket 60k opens at its lower end in toe portion lower face 60f, is centered on an axis generally normal to toe portion lower face 60f, and is sized to receive a cup shaped elastomeric grommet 70. The upper face 601 of main body portion 60a presents a flat, rectangular mounting surface for mounting coaction with mounting flange plate 24. Mounting flange 60 is secured to the underface of flange plate 24 by the use of a plurality of bolts 72 passing through apertures 24a in mounting flange 24 and through the corresponding apertures 60i in mounting plate 60 for coaction with nuts 74 to clamp the mounting plate 60 to the mounting flange 24 with a rectangular, elastomeric cushioning block 76 interposed therebetween in sandwich fashion to provide shock absorption as between the mounting plate 60 and the flange plate 24.
Axle structure 62 is preferably formed as a cast steel member and includes a main body portion 62a of generally circular cross-sectional configuration; a pair of spindle portions 62b extending from the opposite ends of main body portion 62a coaxial with main body portion
62a; a pivot arm portion 62c extending centrally and radially from main body portion 60a and terminating in a fulcrum tip 62d; a triangular reinforcing flange structure 62e providing reinforcement as between main body portion 62a and pivot arm portion 62c; and a suspension arm portion 62f extending centrally and radially from main body portion 62a.
Suspension arm portion 62f is of generally circular configuration and defines an upper socket 62g defined by a rim portion 62h; a lower socket portion 62i defined by a rim portion 62j ; and a central bore 62k extending centrally through suspension arm portion 62f and opening at its upper end in the bottom wall 621 of upper socket 62g and opening at its lower end in the top wall 62m of lower socket 62i. Triangular gusset portions 62n interconnect main body portion 62a and suspension arm portion 62f to provide strengthening and stiffening reinforcement as between these two portions of the axle structure. Suspension assembly 64 includes a hex head bolt
80, an'upper silent block 82, a lower silent block 84, and a nut 86.
Bolt 80 includes a hex head 80a sized to fit loosely but non-rotatably in mounting plate socket 60 and a threaded shank portion 80b sized to pass loosely through mounting plate bore 60n and axle structure bore 62k.
Upper silent block 82 includes a circular, annular member 88 and a metal cap 90 press fit over the
upper end of annular member 88. Member 88 is formed of an elastomeric material and is preferably formed of a relatively soft rubber material having a durometer rating of approximately 50 shores. Lower silent block 84 includes a circular, annular member 92 and a metal cap 94 press fit on the lower end of annular member 92. Annular member 92 is formed of a relatively hard, non-elastomeric material .cp3 such for example as a polyurethane having a durometer rating in the range of approximately 65-75 shores.
Wheels 66 are of the caster or dirigible type and may be formed for example of rubber or polyurethane. As seen, the diameter of wheels 66 comprises a very small fraction of the diameter of drive wheel 14. In the assembled relation of the steering gear assembly, grommet 70 is press fit into socket 60k in mounting plate 60; fulcrum 62d of axle structure 62 is pivotally received in grommet 70; bolt 80 is mounted on mounting plate 60 with the hex head 80a of the bolt positioned non-rotatably in bolt socket 60j and the shank portion 80b of the bolt extending downwardly through bore 60n and projecting below the lower face 60d of mounting plate heel portion 60d along an axis generally normal to the plane of heel portion lower face 60d; upper silent block 88 is positioned around bolt shank 80b with cap 90 seated against heel portion lower face 60d and the lower end- of silent block 88 seated in socket 62g in axle structure 62; lower silent block 92 is positioned on the
lower end of bolt shaft portion 80b with the upper end of silent block 92 seated in socket 62i of the axle structure; nut 86 is threaded onto the lower end of bolt shank portion 80b in seating engagement with cap 94 so as 5 to clamp upper silent block 88 between axle structure suspension arm portion 62f and the lower face 60d of mounting plate heel portion 60b and clamp the lower silent block 92 between the lower face of suspension arm portion 62f of the axle structure and the nut 86; and wheels 66 are
10 suitably journaled on spindle portion 62b and held in position by nuts 100.
The velocipede of the invention, and particularly the steering .gear assembly of the invention velocipede, will be seen to provide many important • advantages as
15 compared to prior art structures. For example, the described suspension assembly, with a bolt positioned non-rotatable in a socket in the mounting plate and extending downwardly through the silent blocks for coaction with a lower nut, allows the performance characteristics
20 of the steering gear assembly to be readily and simply adjusted simply by tightening or loosening the nut. It will be understood in this regard that tightening the suspension assembly provides more precise straightline performance and loosening the suspension assembly enables
25 easier and sharper cornering or turning performance. The relatively soft upper silent block construction in
-;** combination with the relatively hard lower silent block construction also provides better handling and more
positive cornering as compared to prior art constructions utilizing soft upper and lower silent blocks. And the mounting plate of the invention steering gear assembly, with its rectangular construction conforming to the rectangular construction of the flange plate on the frame and with the stiffening ribs running along the sides of the lower face of the plate outboard of the heel and toe portions, provides a very strong and durable construction as compared to prior art constructions. Whereas a preferred embodiment of the invention has been illustrated and described in detail it will be apparent that various changes may be made in the disclosed embodiment without departing from the scope or spirit of the invention.