US3195472A

US3195472A - Slot car racer

Info

Publication number: US3195472A
Application number: US372905A
Authority: US
Inventors: Fred J Rannalli
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-06-05
Filing date: 1964-06-05
Publication date: 1965-07-20
Anticipated expiration: 1982-07-20

Description

y 1965 F. J. RANNALLI 3,195,472

SLOT CAR RACER Filed u 1964 2 Sheets-Sheet 1 INVENTOR. 1 :0 JfAw/vmu FOWZEIF K/I/OBBE GAMBIPEAL July 20, 1965 F. J, RANNALL] 3,195,472

SLOT GAR RACER Filed June 5, 1964 2 Sheets-Sheet 2 INVENTOR. 17950 JZA/V/VALL/ BY ran/4E2, mvoeas 64M51ELL United States Patent 3,195,472 SLOT CAR RACER Fred J. Rannalli, Santa Ana, Calif, assignor to James B. Gambrell Filed June '5, 1964, Ser. No. 372,905 (Ilaims. Cl. 104-60) This invention relates to self-propelled miniature scaled toys, and more particularly to improvements in the slot guide suspension systems of toy automobiles moved along a slotted track by an electrical motor.

Slot car race-rs, scaled to or size of their real counterparts, have become quite popular. The electric motors used are normally energized by conductor strips or bars disposed on each side of the center slot and the motors speed is controlled by a portable variable resistor which controls the amount of current that flows through the motor winding.

The motors currently used on such racers are capable of such high speeds that attention has been given increasingly to banking the tracks and improving the overall roadability of the racers. Conventional speeds are now so high that the racers are made as light as possible and their centers of gravity designed to be close to the roadbed.

Many prior art toy racers of the kind adapted to be used on slotted roadbeds employ a slot guide connected to the fixed frame of the toy with a pair of contacts or brushes connected on each side of the slot guide to make contact with the conductor bars affixed to the track on each side of the slot. Later prior art racers in an effort to improve roadability have used a slot guide assembly which turns the front wheels as the slot guide is carried around a curve of the roadbed. While these prior art devices may have much to commend them, none will permit a racer to course a typical oval track at a high rate of speed unless special care is given to suspension, weight distribution and the like.

The present invention constitutes a breakthrough in slot guide suspension systems. By following the inventive concept disclosed herein, nearly any racer can attain speeds which were heretofore believed unobtainable without sophisticated design of all parts of the slot car. Moreover, the substantial improvement in the readability of slot car racers obtained by the present invention may be easily incorporated into many existing racers.

The present invention utilizes a slot guide arm pivotally mounted towards the rear of the frame of a slot car so that the front of the car and the arm can move in vertical directions relatively independently of each other. The forward end of the arm is also weighted so that the slot guide carried thereon remains in the slot as the racer moves over the track. The composite result of the pivot arrangement and weighting is such that the slot guide tends to be driven into the slot as the speed is increased and the cars ability to take curves without derailing is improved substantially.

Tests of racers utilizing the principle of this invention have shown that its transfers the major ingredient of competition between slot car racers from that of specially designing racers to that of merely controlling the racer by the variable resistor control. Thus, this invention puts most slot-oar racing competitors on an even footing without their having to develop the special design know-how for building racers.

Whereas a great deal of effort in the past has gone towards working out ways in which the front wheels can be turned as the slot guide follows the slot on a curve in order to improve a racers ability to negotiate curves at higher rates of speed, the present invention distributes the weight on the front and rear wheels of the slot car racer so that the front wheel-s act more as a touch-down or contact points and do not contribute to the turning characteristics of the racer. In fact, because they are not directly connected to the slot guide arm at all, they slide crossways on the track as the slot guide arm carries the heavier rear part of the racer around a curve.

Broadly speaking, the present invention is improved slot guide suspension means comprising a slot guide arm having a slot guide depending from one end, means connecting the other end of the arm to the frame of the car so that the arm is movable in a vertical plane and with the slot guide disposed toward the front of the car and means urging the slot guide and arm towards the track so that the slot guide rides interior of the slot as the car moves over the roadbed.

More specifically, this improved suspension means combines .a slot guide arm having a slot guide depending from one end; means pivotally connecting the other end of the arm to the frame of the car for vertical movement with the slot guide disposed toward the front of the car and normally depending below the plane of the roadbed; and weight means associated with the forward end of the arm to urge it downwardly towards the track so that the slot guide tends to be driven into the slot of the roadbed as the car move-s thereover.

Another feature of this invention pertains to a variable length slot guide suspension arm formed by a pair of tubular member, one telescoped within the other, so that the relative length of the slot guide suspension system can be changed to work with different size frames and racer bodies.

In a more limited sense, the present slot guide suspension means comprises a tubular slot guide arm pivotally connected to the frame of a racer forward of its rear axle for movement in a vertical plane transverse to the axles of the racer; an arm extension telescoped interior of the slot guide arm to permit adjustments in the overall length of the arm; a lead weight of preselected magnitude afiixed to the forward end of the arm extension; a plastic slot guide supported in the weight for rotation about a vertical axis; and a pair of contact brushes electrically connected to the motor affixed to each side of the slot guide to contact the conductors bars on the roadbed.

In addition to the improvement in slot guides suspension means per se, the present invention also envisages a complete frame and slot guide suspension system for sel propelled slot car racers wherein the frame assembly can be adjusted to change the front-to-rear axle separation to accommodate different size bodies just as the slot guide arm can be varied in length.

These and other objects, advantages and features of the present invention may be more fully understood when the following detailed description is read with reference to the drawings in which:

FIG. 1 is an exploded perspective of the frame and guide suspension means of a slot car racer constructed in accordance with the present invention;

FIG. 2 is a side view of a slot car racer illustrating the relationship between the frame, slot guide suspension means, and front and rear wheels;

FIG. 3 is a front view of the frame and slot guide suspension means of the present invention;

FIG. 4 is a bottom view of the slot car racer constructed in accordance with the present invention;

FIG. 5 is a plan view of the weight and slot guide taken along line 55 of FIG. 2;

FIG. 6 is a front view taken along broken line 66 of FIG. 4 to illustrate the restoring couple of the slot guide suspension arm as a car negotiates a curve;

FIG. 7 is an alternative embodiment of the slot-car frame illustrated in FIGS. 1-5 wherein the rear wheels are not part of the motor assembly; and

FIG. 8 is a partial perspective of an alternative embodiment of the slot guide suspension means designed to put the point of attachment of theslot guide suspension further outboard of the frame member.

In the first exemplary embodiment of the invention as illustrated in FIGS. 1-6, the slot car racerw can be seen to include a frame ;a' slotguide'suspension system l l, a motor and rear wheelassembly "12, a front axle 13,;front. Wl166lS 16, and a plurality of body attachment tabs ,18.

The frame assembly 10 comprises an H-shaped rear section 21, which is formed by a pair oftubular members 22 held in a spaced-apartpara'llel relation by atransverse pin 23 affixed at each of its end to the tubular members" 22. Apertures 24 are provided on the rear end of the" H-shaped frame section 21 to holdjthe motor and rear wheel assembly 12 thereon, e.g. by screws 26. p A front frame section 31 generally in the shape of a U is also provided, formed of'two tubular members 32 spaced apart in parallel relation and held thereby a front axle bearing or hollow tube 33 through which the front axle 13 is disposed. The endsof axle 13 are threaded to mount the front wheels 16 and lock nuts 17 hold them on, The

outside diameter of tubular members 32 are" smaller than the inside diameter of tubular members 22 of rear section 21, and are adapted to telescope interior of the members 22' so that the front-to-rear axle distance on the frame can be varied to mount diiferent size bodies on the frame. A plurality of outwardly disposed tabs 18, which can be i to the ,roadbed. In the FIG; 6 view, the wheels are shown in an exaggerated condition as; they would be if the racer ere going around'a' left curve. I s i With the general organization of parts illustrated in FIGS. ,15, a racer havingthe; dimensions and weights shown in FIG. 7 has been. found to work quite well. The pertinent data is as follows: {54 scale model; Model.DC7,05

, motor manufactured by the Pittman, Corporation of Sci:

bent at their ends in upstanding relation 41 are provided to secure a body 24! tothe frame. 42 hold the body 20. v The slot guide assembly suspension means 11 includes Self-threading screws a T-shaped slot guide arm 51,.the cross segmentof the T: I being pivotally supported on the pin 23 for rotation in a vertical plane between and roughly parallel to the

tubular members

32 and 22. A slot guide extension 56 is telescoped interior of the tubular leg 53 of the T-shaped arm 51 and, a lead weight 58 is atfixed to the forward end (to the right of FIG. 1) of the slot guide extension arm 56. A metallic circular liner or bushing 61 is force-fitted into the Weight 58 and is adapted to receive the shaft 65 on the slot guide 66 so that it can pivot along a vertical axis as the racer is moved over the track.

The slot guide 66 is formed of nylon, Teflon, or some. comparable plastic. sleeve or bushing 61 in the weight 58. Slot guide 66 has apertures67 which receive screws 68"to hold a pair of Normally itjis press-fitted into the i 'ler'sville, Pennsylvania; front-torear'axledistance of approximately 3% inches; slot guide.suspension'assembly 11. pivotally supported (on a pin 23.) approximately -one' inchforwardrof theirear axle; weight center of the-2% to S-ounce motor located approximately inch forward of the rear. axle; .arm weight of approximately /2 ounce.

, Thesedistribute the weight between the. rear and .front wheel in a ratio of approximately 4: 1.,

In the event the axle-to-axle distance is increased substantially, it is desirable. to increase the weight slightly.

For example, with; an axle-t-o'-axle spacing of approximately'4Vz inches,'the slot' guidefassembly appears to work 7 better withafik-ounce. weight on arm extension 51.

While it isfnot certain. just why the: present invention realizes such asubstantial improvement in slot car racer perforance and, even though the reason for the superlor performance is really immaterial,v the following tentative explanation is offered: r

Theweight attac'hed'to the front; of the'slot guide assembly holds the slot guide in the slot and prevents interruptions ofthe electrical path with its attendant spurting, which performance degrades the stability of a racer.

The :weight also constitutes a lifting force for the weight of the racer just forward of the center of gravity of the motor. As the racer moves along the r-oadbed, the weighted slot guide'tends to be driven into the track 1 which, in an opposite sense, offsets part of the weight of braided contacts or brushes 69 so that they can engage the conductor bars 71 disposed on each side of the slot 72 of the roadbed (see FIG. 2). The brushes 69 are'con- .nected to the terminals of the motor by leads 55.

The relationship of the slot guide to the roadbedcan be seen best in FIG. 3. p The conductor bars .71 are disposed on each side of the slot 72 and the lower end 73;

of the slot guide assembly 66 fits interior of the slot 72.

and acts to guide the racer as it moves along the roadbed. It will be noted that the slot guide suspensionassembly little forward'of the motor 81. Of course, the motor and Wheel assembly 12 need not be a separate assembly; instead the wheels could be connected to the-frame as illusstrated in FIG. 7. In this latter case, the motor will be a separate unit adapted to'fit on the frame 10 in order to rotate the rear wheels 14.

the motor byproviding a lift to the front end of the frame (at its point'of' attachment). As a result, as the car enters a curve the front part of the raw: carries less of the weight of the frame and the motor. Thus, the front 11 is pivoted on the frame aboutaxis 23 at. apoint wheels slideacross the track with less resistanceiin re-.

sponse to the turning'force set in motion by the slot guide moving along the" curving track. The front wheels really *act as stabilizing points, not as wheels in theconventional F -t-F 'phflS .the'forceat the pivot points F attributable to the weight ,W These relations can be obtained by taking the sum of themoments about the various points high as the dotted outline indicates, the slot guide continues to ride in the slot 72 and carry the rear'wheels and rear part of the frame assembly with it. Thus, instability of the front" wheels, 16 of the raceriwilli. have Over and above the static lift, the dynamic forces opposing the movement of'the motor away from the track are concentrated at theirear axle and just forward of the. motor (atv the pivot'point forthe'arm). Not only does the weighted suspension arm tend to return the motor and frame to the roadbed or hold it there, but the transverse twist on the arm establishes couple A which counteracts the centrifugal force of the motors weight as a curve is being negotiated. I V V r FIG. ti-"illustrates another embodiment of'the slot guide suspension arm. In this case, an A-type slot guide sus pensioniassembly 91 is provided. A pair of arms 94 are. .pivotally connected to a pin'92 outboard'of the sidesof the frame 93to provide .additional stability; The slot;

' guide suspension arm 91 functions essentially like" the T-suspension assembly 11; however, the restoringjcouple,

illustrated in FIG. 6 as A, is greater because its operates at points farther outboard of the frame.

The frame and slot guide suspension system is easy enough to assemble for a variety of body sizes. After determining the proper axle-to-ax-le distance to accommodate the body, it is attached to the outwardly projecting tabs 18, the tubular members 22 are crimped on the tubular members 32 and tubular member 52 is crimped on the extension 56 of the suspension arm so that the weight and slot guide are forward of the front axle 33. The ends of the outwardly projecting tabs 18 are bent upwardly and the body is connected thereto by screws 42.

While the present invention has been explained with respect to different illustrative embodiments, it should be apparent to those skilled in the art that other changes and arrangements are contemplated which come within the ambit of the present teaching. For this reason the invention should be limited only to the extent of the appended claims.

What is claimed is:

:1. In a slot car race-r of the type designed to be guided along a track by a longitudinal slot formed in the roadbed thereof and having an electric motor energized by a source of power associated with the roadbed, the improvement in the slot guide suspension means comprising,

a slot guide arm having a slot guide depending from one end,

means connecting the other end of said arm to the frame of the car so that the movement of said arm is substantially restricted to a vertical plane and said slot guide is disposed toward the front of the car, and means urging said slot guide and arm downwardly toward the track whereby the slot guide rides interior of the slot in the roadbed as the car moves thereover.

2. In a slot car racer of the type designed to be guided along a track by a longitudinal slot formed in the roadbed thereof and having an electric motor energized by a source of power associated with the roadbed, the slot guide suspension means comprising,

a slot guide arm having a slot guide depending from one end,

means pivotally connecting the other end of said arm to the frame of the car for movement substantially restricted to a vertical plane, said slot guide disposed forward of the front axle of the car and normally depending below the plane of the roadbed, and weight means urging said arm downwardly toward the track whereby said slot guide tends to be driven into the slot in the roadbed as the car moves thereover.

3. A frame and slot guide suspension system for a selfpropelled slot car racer of the type designed to be guided by a longitudinal groove in the track roadbed comprising, in combination,

a frame assembly having front and rear axles and Wheels rotatably mounted thereon,

means cooperating with said rear wheels to drive the slot car, a slot guide mounted on a support member, means pivotally connecting said support member on said frame for movement which is substantially restricted to a vertical plane, and

means urging said guide downwardly so that it ride-s interior of the longitudinal slot formed in the roadbed as the car moves thereover.

4. A frame and slot guide suspension system for a selfpropelled slot car racer in accordance with claim 3 wherein said frame assembly and support member are adjustable to change the overall length of the frame and slot guide suspension system for different size racer bodies, and

said means urging the guide interior of the slot can be changed to provide a normal force at said slot guide of a desired magnitude.

5. A frame and slot guide suspension system for selfpropelled slot car racers of the type designed to be guided by a longitudinal groove in the roadbed of the track comprising, in combination,

a frame having tubular side members spaced apart in parallel relation,

axle support means affixe-d to the forward end of said frame; a front axle rotatably supported in said axle support means;

a transversely oriented pin connected between the side members toward their other ends;

an arm pivotally connected to said pin at one end so that its rotation is substantially restricted to a vertical plane,

the forward end of said arm terminating forward of said axle support;

weight means attached to the forward end of said arm;

a slot guide pivotally supported in said weight means for movement in a plane roughly parallel to said roadbed;

means including the rearward part of said frame to support a rear axle, wheel and motor assembly; and

means operable to change the longitudinal distance between front and rear axles of the racer to accommodate different size racer bodies.

6. A frame and slot guide suspension system for selfpropelled slot car racers in accordance with claim 5 wherein the Weight of the propelling means and the magnitude of the weight means and their locations on the frame are selected to distribute the weight on the rear and front wheels of the racer in a ratio of approximately 4: 1.

7. A frame and slot guide suspension system for a selfpropelled slot car racer of the type designed to be guided by a longitudinal groove in a track comprising, in combination,

:a forward frame section having a pair of parallel tubular side member-s connected at their forward ends by a transversely oriented tubular bearing to support the front axle and wheels of the racer;

a rear, H-shaped frame section having a pair of parallel tubular side members;

the forward ends of said rear tubular side members spaced apart to telescope over said forward side members;

a transverse pin connected between intermediate parts of said rear tubular members to maintain said side members in spaced-apart relation;

means including the other set of ends of said rear tubular members to support the rear axle and wheels and the propelling means for said racer;

body support tabs aflixed to each of said tubular members and extending outwardly therefrom;

A T-shaped tubular slot guide arm having the tubular cross of the T-supported on said pin to permit rotation in a longitudinally disposed vertical plane;

a tubular slot guide arm extension telescoped interior of the leg of the tubular slot guide arm and extending forward beyond the front axle of said slot car;

:a slot guide mounted at the forward end of said extension to ride in the groove in said tracks; and,

means urging said slot guide interior of said groove as the racer moves over the roadbed.

8. A frame and slot guide suspension system in ac cordance with claim 7 wherein said means urging said slot guide interior of said slot in the roadbed as a preselected weight aflixed to said forward end of said extension arm adjacent said slot guide; and

said slot guide is pivotally mounted in said weight for rotation in a roughly horizontal plane.

9. In a self-propelled slot car racer of the type designed to be guided along a track by a longitudinal slot formed in the roadbed thereof and having an electrical motor energized by a source of .power connected to conductor 7 v bars'on each side of the. slot, the improvement in slot guide suspension means comprising ,1 r a a tubular slot guide 'arm pivotally connected at one end to the frame of a racer forward of the rear axle for movement only in .a generallyfvertical plane trans- I a plastic slot guide supported'tby said Weightfor r0tation about a vertical axis; and I a pair of contact brushes electrically connected to the motor aflixed to each side of said, slot guide to contact the conductor bars onthe roadbed.

. 10. A frame and slot guide suspension system for a selfpropelled slot car racer of the type designed to begui-ded by a longitudinal groove in the track roadbedzcomprising, in combination, a a

aslot.guide;and,'

,a frame-assembly having front and rear'vaxles and Wheels'rotatably mounted thereon; r 1 means associated with some of saidv wheels operable to drive the slot car along the track; a v I 1 I a support'member. having its movement restricted genv. erally to a vertical plane both pivotallylconnecting thesslot guide to the frame assembly and urging the slot guide to ride interior of the longitudinal groove formed in the track.

7 lieferen'cesfiited hy the Examiner 1 UNITED STATES PATENTS 1,704,012 I 3/29 'Marx 104-173 1,981,655 '11/34' Lucke 104-445 3,163,123 12/64 Ziroli -1. 104-60 ARTHURIL. LA POINT, Primary Examiner I '20 MILTON BUCHLER, Examiner.

Claims

1. IN A SLOT CAR RACER OF THE TYPE DESIGNED TO BE GUIDED ALONG A TRACK BY A LONGITUDINAL SLOT FORMED IN THE ROADBED THEREOF AND HAVING AN ELECTRIC MOTOR ENERGIZED BY A SOURCE OF POWER ASSOCIATED WITH THE ROADBED, THE IMPROVEMENT IN THE SLOT GUIDE SUSPENSION MEANS COMPRISING, A SLOT GUIDE ARM HAVING A SLOT GUIDE DEPENDING FROM ONE END, MEANS CONNECTING THE OTHER END OF SAID ARM TO THE FRAME OF THE CAR SO THAT THE MOVEMENT OF SAID ARM IS SUBSTANTIALLY RESTRICTED TO A VERTICAL PLANE AND SAID SLOT GUIDE IS DISPOSED TOARD THE FRONT OF THE CAR, AND MEANS URGING SAID SLOT GUIDE AND ARM DOWNWARDLY TOWARD THE TRACK WHEREBY THE SLOT GUIDE RIDES INTERIOR OF THE SLOT IN THE ROADBED AS THE CAR MOVES THEREOVER.