Field of the Invention This invention relates generally to construction toy sets and particularly to a combination of construction toy set elements which may be used to fabricate a variety of gear drive apparatus in combination with other construction toy set elements.

Backqround of the Invention Construction toy playsets have been provided in different forms for many decades. Earliest construction toy sets provided a plurality of elongated metal elements together with suitable fastening devices to form various apparatus and play structures. Other early construction toy playsets utilize various elongated elements having end pegs together with coupling elements formed of wood or

similar material having plural peg receiving passages allowing the pegged elements to be assembled to form various structures and toy apparatus. Construction toy playsets provide substantial developmental activity for the child user and thus are very well received and appreciated by educators and parents.

The challenge for providing construction toy sets which enjoy commercial success is the dual roll of entertainment and amusement on one hand and child developmental skills on the other. In order for the child user to maximize the developmental activity, the user must remain interested in and challenged by the toy playset. The amusement and entertainment aspects of the toy playset provide the primary motivation for use which leads to the desired developmental skills.

Recognizing the enormous success of construction toy sets, practitioners in the art have, through the years, provided a virtually endless variety of such construction sets. Modern construction toy sets utilize large numbers of molded plastic parts which form cooperating interlock or snap-fit attachments to provide maximum flexibility and challenge for the user. As a result, construction toy sets are provided which facilitate assembling a great variety of items ranging from structural dwellings to toy vehicles or the like. In many instances, practitioners provide various specialty items within the plurality of generic construction elements to facilitate the assembly of challenging devices or apparatus.

One of the more fundamental and interesting specialty items within construction toy sets is the provision of motor drive or hand crank drive apparatus

for moving the structure fabricated using construction toy set elements. Within this general type of specialty item for construction toy sets, there arises a need to include gear drive or gear coupling apparatus. Since such gear drive or gear coupling apparatus is intended to be used with a variety of construction toy sets, one of the challenges presented to designers is the provision of flexibility to meet the user's creativity in arranging the construction toy set elements into various configurations. In addition, the appeal of the construction toy set is substantially improved when the fabricated structure allows the gear mechanisms to be viewable during operation.

US Patent 3,234,683 issued to Christiansen sets forth a TOY BUILDING ELEMENT INCLUDING A ROTATABLE BUSHING having plural interlocking building elements which accommodate a rotatable bushing and shaft combination. As a result, structures such as rotatable wheels may provided.

US Patent 5,069,647 issued to Zuviria sets forth a SOLID RECTANGULAR BUILDING BLOCK FOR TOY BUILDING SET having a plurality of block structures defining plural ribs and grooves allowing the blocks to interlock. Additional elements may be secured to the blocks such as wheel shafts or the like to enhance flexibility.

US Patent 5,310,376 issued to Mayuzumi, et al.

sets forth a TOY THAT CAN BE ASSEMBLED INDEPENDENTLY BY A CHILD having a planar base member defining a plurality of peg receiving holes therein together with

a plurality of coupling elements supporting plural outwardly extending pegs. Elongated flexible elements are interlockably received upon the coupling elements allowing various structures to be fabricated.

US Patent 3,604,130 issued to Forsstrom sets forth a CONSTRUCTION SERIES FOR MOLECULAR MODELS having a plurality of generally spherical interlocking elements which may be assembled to represent various atoms and molecules.

US Patent 4,109,398 issued to Hida sets forth an CONSTRUCTION TYPE EDUCATIONAL AND AMUSEMENT DEVICE having a basic element which defines a generally spherical hollow module or capsule having adjuncts which may be interconnected and operatively assembled into a large number of different configurations to form various apparatus.

US Patent 4,509,929 issued to Zawitz sets forth an ANNULAR SUPPORT DEVICE WITH PIVOTAL SEGMENTS having a plurality of torus segments interconnectable end to end to form an annular loop in which each segment is independently pivotal to form various shapes.

US Patent 4,631,040 issued to Shiraishi sets forth a CONSTRUCTION TOY SET having a variety of component parts including bases, housings and auxiliary members. Male and female connecting elements attached to the respective components allow for assembly in a variety of configurations.

US Patent 4,764,143 issued to Gat, et al. sets forth ASSEMBLY TOYS FOR JOINING CYLINDRICAL OBJECTS

having a plurality of devices for removably connecting a plurality of cylindrical objects. Each device includes apparatus for interconnecting to other devices at a variety of angles and for securing a cylindrical object.

US Patent 5,046,982 issued to Erickson sets forth CONSTRUCTION APPARATUS having a plurality of relatively flat components each having at least three sides. The apparatus further includes an elongated rod-like member extending along each side and in large corner portions between the members. A plurality of connectors are provided for interconnecting adjacent sides of members to form structures.

In many construction sets, apparatus is provided for specialized assembly such as toy vehicles or the like. For example, US Patent 4,802,876 issued to Bertrand sets forth an AXLE STRUCTURE AND AXLE JOINT FOR CONSTRUCTION TOY ASSEMBLY having a base plate, an abutment plate normal to one edge of the base plate, a cross-shaped columnar connector perpendicular to the base plate and a cross-shaped shaft perpendicular to the abutment shape. The shaft defines bulges at its free end and is attachable to the cross-shaped structure.

US Patent 5,071,384 issued to Poulsen sets forth a STEERING MECHANISM for use with toy building sets to assemble devices such as toy vehicles. The mechanism includes rack means and a pinion cooperating therewith.

US Patent 4,690,656 issued to Friedman, et al.

sets forth WHEEL AND WINCH ASSEMBLIES utilizing identical hubs and axles in a toy construction set. A special block having a axle projecting therefrom is provided and a hub mechanism is receivable upon the shaft to support a resilient tire.

US Patent 4,599,077 issued to Vuillard sets forth a MODULAR TOY while US Patents 4,202,132 and 4,136,482 both issued to Fischer set forth interacting structural elements generally related to construction toy sets.

While the foregoing described prior art devices have improved the art generally and have in some instances enjoyed commercial success, there remains nonetheless a continuing need in the art for evermore improved, interesting and challenging construction toy sets.

Summary of the Invention Accordingly, it is a general object of the present invention to provide an improved gear drive system for use in a construction toy set. It is a more particular object of the present invention to provide an improved gear drive system for use in a construction toy set which facilitates assembling a variety of gear drive combinations. It is a still more particular object of the present invention to provide an improved gear drive system for use in a construction toy set which facilitates assembling multiple gear drive combinations having gears which engage at different angles.

In accordance with the present invention, there is provided a gear system for use in a construction toy set, the gear system comprising: a plurality of gears, each capable of engagement with an additional one of the gears in either a quadrature or in-line relationship, each gear having a supporting rim and a plurality of gear teeth, each of the teeth having outer tapering edges and an outer straight edge portion; and means for supporting a plurality of the gears such that at least one of the gears engages another of the gears in a quadrature relationship while another of the gears engages one of the gears in an in-line relationship.

Brief Description of the Drawinqs The features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The invention, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings, in the several figures of which like reference numerals identify like elements and in which: Figure 1 sets forth a side elevation view of a gear system for construction toy set constructed in accordance with the present invention; Figure 2 sets forth a partial section view of the present invention gear system taken along section lines 2-2 in Figure 1;

Figure 3 sets forth a partial section view of an exemplary gear used in the present invention gear system taken along section lines 3-3 in Figure 2; Figure 4 sets forth a partial section view of a pair of engaged gear teeth depicting the engagement of the present invention gear system between orthogonal gears; and Figure 5 sets forth a partial section view showing engaging teeth of a pair of in-line gears used in the present invention gear system.

Description of the Preferred Embodiment Figure 1 sets forth a side elevation view of an exemplary gear system for construction toy set fabricated in accordance with the present invention and generally referenced by numeral 10. Gear system 10 is shown supported by an arrangement of construction toy set elements fabricated in accordance with the above-described related application. As is set forth in the above-described related application, a plurality of couplers are snap-fit attachable to various other elements such as straight beam elements and angle elements to fabricate relatively complex structures. As is also described in the above- referenced copending application, each coupler defines a plurality of passages therethrough which function to support elongated cylindrical shafts for further flexibility and for greater structural variety in the fabrication of devices using the construction toy set.

More specifically, with reference to Figure, gear system 10 includes a trio of gears 30, 40 and 50 engaged in a cooperating arrangement which illustrates the advantages of the present invention gear system.

It will be recognized that gears 30, 40 and 50 are identical and that the coupling mechanism provided by the present invention gears facilitates both a perpendicular engagement similar to conventional bevel gears as well as an in-line engagement similar to conventional straight gears. In accordance with an important aspect of the present invention, the capability of the gears within the present invention to engage both in quadrature and in-line relationships facilitates a variety of gear combinations without the need of providing dedicated bevel gear or in-line gear components.

Within gear system 10, a pair of couplers 14 and 17 are commonly joined to a beam element 16 in the snap-fit engagement described in the above-referenced application. In the manner also described in the above-referenced application, coupler 14 defines a passage 15 which receives shaft 25 in a rotatable attachment. Similarly, coupler 17 defines passage 18 which receives shaft 27 in a rotatable attachment.

Gears 40 and 50 are received upon shafts 25 and 27 respectively and rest against couplers 14 and 17 respectively. A pair of tight fitting annular sleeves 26 and 28 are fitted upon shafts 25 and 27 to further secure gears 40 and 50. Gear system 10 further includes an angle element 13 snap-fit attached to coupler 14 and supporting a further coupler 11 in a similar snap-fit attachment. Coupler 11 defines a passage 12 which receives a groove shaft 20. A gear

30 is received upon shaft 20 in a key engaging relationship better seen in Figure 2. Gear 30 is supported upon shaft 20 by a keyed hub 31 and is positioned in quadrature engagement with gear 40. A cylindrical sleeve 22 is snugly fitted upon shaft 20 to captivate gear 30 upon the shaft.

In operation, rotational forces are transmitted between gears 30 and 40 in a quadrature arrangement similar to that provided by conventional bevel gears.

Conversely, gears 40 and 50 are positioned in an in- line arrangement such that rotational force is communicated between gears 40 and 50 similar to a conventional in-line gear relationship. It will be recognized by those skilled in the art that the structural support combination of couplers 11, 14 and 17 together with angle element 13 and beam element 16 is representative of a variety of structural element combinations of the type found in the above-described construction toy set. Normally, in the anticipated use of the present invention gear system, it would be anticipated that gears such as gears 30, 40 and 50 would be supported within a complex structure fabricated using construction toy set elements. Of importance to the present invention is the capability of the bevel and straight gear engaging gear of the present invention as illustrated by gears 30, 40 and 50 to provide either straight line or quadrature engagement interchangably without resorting to bevel gear or straight gear elements.

Figure 2 sets forth a section view of gear system 10 taken along section lines 2-2 in Figure 1. Figure 2 shows gear 30 supported upon hub 31 which in turn

defines aperture 32 and gear element 33. Shaft 20 is correspondingly shaped and defines a groove 21 allowing shaft 20 to be inserted through aperture 32 such that groove 21 receives and engages key 33 of hub 31. It will be apparent to those skilled in the art that the present invention key may utilize either a keyed aperture such as that shown for key 30 or, alternatively, a conventional cylindrical bore such as that shown in dashed-line representation which facilitates use of a conventional nongrooved shaft.

With temporary reference to Figure 1, it will be understood that gears 40 and 50 are identical to gear 30 and thus provide identical teeth configuration as set forth below which facilitate the alternative engaging relationships of quadrature or in-line engagement. Thus, gears 30, 40 and 50 will be understood to be fabricatable using either a keyed aperture as shown for illustration in Figure 2 for gear 30 or, alternatively, a cylindrical aperture therethrough as shown in dashed-line in Figure 2.

Figure 3 sets forth an exemplary gear tooth constructed in accordance with the present invention and generally referenced by numeral 60. Gear tooth 60 is presented for illustration of the various pluralities of gear teeth formed on the present invention gears within the inventive gear system such as gears 30, 40 and 50 set forth above in Figure 1.

It will be understood by those skilled in the art that the plurality of gear teeth provided on the gears within the present invention system are substantially identical to gear tooth 60 and thus the description thereof will be understood to apply equally well to

the teeth found on each of the gears within the present invention system.

Thus, gear tooth 60 is shown supported upon a support web 36 which will be understood to extend inwardly to a supporting member such as a gear hub (see for example hub 31 of gear 30 in Figure 1). Web 36 terminates in an outer rim 61 which supports gear tooth 60 and which defines a pair of angled surfaces 68 and 69. Surface 67 extends outwardly from rim 61 and thus forms one side of tooth 60. As described above in connection with Figure 2, each of the surfaces of each tooth within the gears of the present invention system is angled to provide a tapered gear.

For example, and with temporary reference to Figure 2, it will be noted that tooth 34 defines angled surfaces 37 and 38 on each side thereof which provide the outwardly tapered structure of tooth 34. Returning to Figure 3, tooth 60 defines parallel sides 62 and 63 and angled edges 64 and 65. Edges 64 and 65 taper inwardly and terminate at a straight edge portion 66.

The provision of inwardly tapering edges 64 and 65 together with outer straight edge portion 66 result in a trapezoidal tooth profile which is an important aspect of the present invention. As is set forth below in Figures 4 and 5, the combination of angled edges 64 and 65 together with angled surfaces 68 and 69 of rim 60 facilitates the alternative engagement of the gears within the present invention system. It will also be apparent in the descriptions which follow that the substantial distance between straight edge 66 and rim 61 facilitates a large tolerance for positioning between a pair of engaged gears within the present invention system. This tolerance for

different gear spacing has been found to be extremely helpful in the operative environment of a construction toy set.

Figure 4 sets forth partial section views of gears 30 and 40 in a quadrature engagement while Figure 5 sets forth a partial section view of gears 30 and 40 in an in-line engagement. It will be apparent to those skilled in the art by comparing Figures 4 and 5 that the identical gear pair may, in accordance with the present invention, be engaged in either a quadrature or in-line relationship.

More specifically, Figure 4 sets forth partial section views of gears 30 and 40 in a quadrature arrangement showing a pair of gear teeth 34 and 42.

Gear 30 defines a supporting web 39 terminating in a rim 70. Rim 70 defines angled surfaces 71 and 72 and supports gear tooth 34. Gear tooth 34 defines parallel sides 73 and 74 and inwardly angled edges 75 and 76. A straight portion 77 is formed between the outer portions of edges 75 and 76. Similarly, gear 40 includes a supported web 43 terminating in rim 44 which defines angled surfaces 45 and 46. Gear 40 defines a gear tooth 42 having parallel sides 47 and 48 and angled edges 55 and 56. Edges 55 and 56 meet at an outer straight edge 49.

In accordance with the above-described invention, gears 30 and 40 are shown in Figure 4 to have teeth 34 and 42 engaged in a quadrature engagement. Thus, the provision of angled edges such as edges 75 and 76 of gear tooth 34 and edges 55 and 56 of gear tooth 42 are shown to provide for a quadrature engagement similar

to the action provided by conventional bevel gears.

It will be noted that a substantial distance is provided between angled edges such as edges 55 and 56 of the gear tooth and angled surfaces such as surfaces 45 and 46 of rim 44. This distance facilitates a substantial variation in the spatial relationship between quadrature engaging gears and thus provides a substantial tolerance in gear positioning.

Figure 5 sets forth gears 30 and 40 in a straight line or in-line engaging relationship illustrating gear tooth 34 of wheel 30 and gear tooth 42 of wheel 40 engaging in a straight line engagement. More specifically, Figure 5 sets forth gear 30 having a supporting web 39 terminating in a rim 70. Rim 70 defines angled surfaces 71 and 72 and supports gear tooth 34. Gear tooth 34 defines parallel sides 73 and 74 and inwardly angled edges 75 and 76. A straight portion 77 is formed between the outer portions of edges 75 and 76. Similarly, gear 40 includes a supported web 43 terminating in rim 44 which defines angled surfaces 45 and 46. Gear 40 defines a gear tooth 42 having parallel sides 47 and 48 and angled edges 55 and 56. Edges 55 and 56 meet at an outer straight edge 49.

In accordance with an important aspect of the present invention, gears 30 and 40 which are capable of quadrature engagement as shown in Figure 4 are also capable of in-line engagement as shown by Figure 5.

The tapered surfaces of each gear tooth such as angled surfaces 37 and 38 of gear tooth 34 seen in Figure 2, facilitate the in-line engagement of gears 30 and 40.

In this manner, a single common gear structure is

capable of either quadrature or in-line engagement and provides great flexibility and maintains a lower cost and a lower part count for a construction toy set.

Thus, what has been shown is a novel gear system for construction toy set having a novel gear structure which accommodates both a quadrature and in-line engagement without the need for separate bevel and straight gear components. The flexibility obtained by such a novel structure greatly enhances the gear train combinations which may be fabricated without resorting to additional bevel gear and straight gear components.

While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects. Therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.