Abstract: The present invention discloses a differential planet gear unit, in which a sun gear is engaged with first and second ring gears coaxially aligned through planet gears interposed therebetween, and the tooth number of the first ring gear is different from the tooth number of the second ring gear, in which the first and second ring gears engage with first and second portions of each planet gear, and the diameters of the addendum circles of the teeth of the first ring gear and the first tooth portion of each planet gear are different from those of the second ring gear and the second tooth portion of each planet gear, respectively, to reduce a difference between an approaching contact length and a receding contact length along a contact action line. The first ring gear and the second tooth portion of each planet gear may be formed with first and second chamfers, respectively, in both sides of the addendum of the teeth to reduce the difference between the approaching and receding contact lengths.

Abstract: A starter for an internal combustion engine is disclosed which comprises a motor, an output shaft operatively coupled to the armature shaft of the motor, and an axially slidable assembly splined to the output shaft and including an overrunning clutch and a hollow shaft having a pinion formed at the front end thereof. At least a portion of the pinion, the teeth of which have a top surface of substantial circumferential width, is, when the hollow shaft is at the extreme rear position, received into and supported by an annular ball bearing which is mounted to the front frame to rotatably and axially slidably support the hollow shaft.

Abstract: This invention involves a gear transmission mechanism and its device which incorporate double cycloidal equidistant conjugated gear mechanisms and devices, featuring in that a whole branch cyclic cycloidal equidistant curve at a side of the center of curvature of that cycloid is applied with the value of equidistance equal to or smaller than the radius of the rolling circle as the original tooth profile and thus conjugated mutually enveloping cycloidal equidistant curved gear mechanisms with one-tooth-difference, zero-tooth-difference or multi-tooth-difference can be made according to the requirement. Motor pumps and reducers made according to these mechanisms have the advantages of smaller sliding coefficient, smaller pressure angle, greater speed ratio range, lower noise, better strength, higher efficiency, more convenience in machining and lower cost. Therefore these mechanisms can be used to effectively replace the cycloidal lantern gearing with promising development of novel gear transmissions.

Abstract: A screw fluid machine comprising female and male rotors each including foward and backward flanks each having a reference profile, respectively, wherein on at least one of the forward and backward flanks of the female and male rotors a modified profile is obtained by appropriately angularly shifting the reference profile around a center of the associated rotor to provide proper backlash between the engaged rotors.

Abstract: In a gear arrangement consisting of two gears meshed with each other, at least one gear is constructed of a teeth portion having teeth along its circumference and a shaft portion adapted to be mounted to a support shaft, a gap space is retained between the teeth portion and the shaft portion, and an elastic body such as an O-ring, an annular spring, etc. is interposed in the gap space. And a tooth thickness of one gear of the above-mentioned two gears is made larger than that of the other gear. When the above-described two gears are meshed with each other, the teeth portion of the gear having the elastic body interposed therein moves in the radial direction with respect to the shaft portion, and thereby the teeth of the respective gears can be meshed without backlash.

Abstract: A modified gear operates in one direction only. The modified gear can be driven in either direction by a standard gear, but will drive another gear in only one direction. Every other tooth of the modified gear is partly cut away to form a step. The remaining sides are cut away to delay engagement with a driven gear. The sides of the teeth preferably have the shape of an involute curve, and each tooth is preferably cut along a line segment beginning at the midpoint of the top land of the tooth, and continuing along a path generally parallel to one side of the tooth. The step is located at a predetermined radial distance from the top land, this distance being a certain fraction of the total depth of the tooth. The modified gear can be used to drive, or be driven by, a conventional unmodified gear. It can also drive, or be driven by, another gear which has been modified in the manner described above.

Abstract: The gears according to the present invention have a unique tooth-profile in which the radius of curvature repeatedly increases and decreases from the pitch line in the direction of addendum and deddendum of a tooth without monotonously changing, and at the point where the relative of curvature is minimum, the center of the radius of curvature is positioned on the pitch line. Specifically, the curvature of the tooth-profile curve is a function which is not monotonously varied, is continuous and is capable of being differentiated, and a locus of the center of curvature forms a series of continuous curves which exist near the pitch circle. Forming the tooth-profile thus enables the relative of curvature to be brought from the value in the involute gear near that of a Wildhaver-Novikov type, with the contact interval being more than one.

Abstract: A new design for helical gearsets is disclosed in which the new gearsets meet all applicable ratings and standards of the American Gear Manufacturers Association (AGMA), and yet allows very substantial cost savings over prior similar gearsets having an equivalent AGMA rating. The gearsets of the instant invention generally are substantially thinner, and have fewer, but larger, gear teeth than the prior gearsets they replace. A helical gearset of the present invention includes a pinion and a gear, with the pinion and the gear each having a plurality of teeth. Each of these teeth has a helix angle ranging between about 18 degrees and 33 degrees. The pinion and the gear each have a face width and a whole depth, with the pinion having 13 or fewer teeth, and with the pinion and the gear having a face width-to-whole depth ratio of about 4.5 or less. The axial overlap of the gearset ranges between 1.001 and about 1.2.

Abstract: A tooth according to the invention is such that its flank (foot flank) (1B) situated inside the not entirely circular pitch curve (PA) follows an involute of a circle determined by a pressure angle (p), and has a face (2B) outside the pitch curve such that its current point (M) is determined by the intersection of the flank (1A) of the co-operating tooth with the tangent to the circles defining the flank (1A) passing through the instantaneous point of contact (N) of the pitch curves (P'A, P'B). The pitch curves may be circular arcs, logarithmic spiral arcs, elliptical arcs, or a succession of such arcs around an open or a closed curve in order to form gearing. Some lengths of the pitch curves may have no teeth.

Abstract: A tooth profile in a meshing mechanism is arranged in such a way that the tooth profile of a deflectable tooth row is formed by a circular-arc-shaped addendum and lines tangential to the circular arc, while the tooth profile of two second tooth rows meshing with the tooth row with that tooth profile, one of the second tooth rows being fixed and the other being moveable, are based on an envelope of the locus of movement of the circular-arc-shaped addendum, or a line approximated thereto by circular arcs and straight lines. In the meshing mechanism having this tooth profile, the deflectable tooth row and the two tooth rows mesh with each other over a wide region and a low level of angular backlash can be obtained thereby. For this reason, the contact pressure on the working surfaces of the teeth can be alleviated, and the lifetime of the teeth can be prolonged.

Abstract: The invention relates to a multi-groove and spline connection between a gear and cardan shaft of a rotary piston machine with an internal axis, wherein external toothing at the head of the cardan shaft engages internal toothing of the gear and an axial abutment co-operates with the end face of the head. The abutment is such that it is only contactable by the teeth of the head of the cardan shaft.

Abstract: A gear transmission with a variable pressure angle has the following meshing geometry: a contact ratio greater than one, height of the addendum of gear and pinion teeth being a function of its module "m" determined by the relationship m<h.sub.g <1.8, a height of a tooth root of the pinion being limited by the value of a profile angle .alpha..sub.z equal to .alpha..sub.z .gtoreq.8.degree., a height of a tooth root of the gear determined by the relationship m<H.sub.s <1.8 m and increased by the value of radial clearance and a height of an addendum of the greater teeth equal to the height of the tooth root of gear and pinion, decreased by the value of radial clearance. The teeth are made with racks of involute profile having cutting edges and their constant base circle determined from apparent number of teeth and a constant pressure angle.

Abstract: A strain wave gearing comprising a circular spline, flexspline disposed inside the circular spline, a wave generator for deforming the flexspline into, for example, an ellipsoid and a motor for rotating the wave generator to produce a relative rotation between the flexspline and the circular spline. The strain wave gearing is sometimes termed a harmonic drive transmission. In the strain wave gearing, the tooth face of each of the splines is formed in line with a mapping curve which is a similarity transformation having a reduced scale of 1/2 applied to a movement locus of the flexspline to the circular spline in accordance with the configuration of the wave generator, the transformation being effected on a reference point where the splines are transferred from the contact condition to a disengagement from each other. Thus, the teeth of the flexspline engage with those of the circular spline in the broad extent of the engagement region.

Abstract: Each of the teeth (5) of the sprocket has a Y-shaped top (10) in a view developed along the circumference of the sprocket (5). The principal branch (10a) of the Y extends along the direction (11) of rotation of the sprocket and is located in the central part of the top (10) of the tooth. The two divergent branches (10b, 10c) of the Y are located at the front of the branch (10a) in the direction of rotation of the sprocket. The part of the tooth in the vicinity of the top comprises inclined surfaces which facilitate the reception of a chain on the sprocket. The sprocket is in particular intended for a free-wheel for a cycle providing a plurality of speeds.

Abstract: A new design for helical gearsets is disclosed in which the new gearsets meet all applicable ratings and standards of the American Gear Manufacturers Association (AGMA), and yet allows very substantial cost savings over prior similar gearsets having an equivalent AGMA rating. The gearsets of the instant invention generally are substantially thinner, and have fewer, but larger, gear teeth than the prior gearsets they replace. A helical gearset of the present invention includes a pinion and a gear, with the pinion and the gear having a plurality of teeth. Each of these teeth has a helix angle ranging between about 18 degrees and 33 degrees. The pinion and the gear each have a face width and a whole depth, with the pinion having 13 or fewer teeth, and with the pinion and the gear having a face width-to-whole depth ratio of about 4.5 or less. The axial overlap of the gearset ranges between 1.001 and about 1.2.

Abstract: A micro-contoured surface is formed about a substantial portion of the edge of the end bearing face of each gear tooth of a gear having a plurality of circumferential gear teeth each with an end bearing face for carrying an axial thrust load against a flat housing bearing face or the like. The micro-contoured surface forms a wedge space between the bearing faces which when filled with a fluid establishes a hydro-dynamic film pressure distribution over the entire end bearing face of the gear tooth upon relative motion between the bearing faces.

Abstract: A reduction starter employing a planetary gear type reduction gear mechanism having an outer ring gear displaceable radially of a common axis of a central sun gear and an output shaft carrying planet gears for revolution about the common axis. The outer ring gear is formed by an internally toothed ring gear elastically deformable to assure uniform distribution of load torque to all planet gears. The tooth root bending stress of the ring gear is substantially equalized to the outer periphery bending stress thereof to improve the load performance of the planetary gear type reduction gear mechanism and thus reduce the size and weight of the starter. The outer ring gear has an outer rim of a radial thickness t and a plurality of radially inwardly extending teeth each having a height h. The rim thickness t is determined to'fall with a range of from +.ltoreq.0.8 h to +.gtoreq.0.4 h.

Abstract: A digital clock construction, a pinion gear therefor and methods of making the same are provided, the clock construction comprising a frame, first and second time indicating drums each being rotatably carried by the frame, and a pinion gear rotatably carried by the frame and having driving gear teeth disposed in meshing relation with an annular internal gear of the second drum whereby rotation of the pinion gear causes rotation of the second drum, the pinion gear having locking teeth extending from certain of the driving teeth thereof, the first drum having an annular internal locking surface that is adapted to slide against a pair of locking teeth to hold the pinion gear from rotation thereof while the first drum is being rotated through certain timed increments of movement thereof, the first drum having a pair of kicker teeth for meshing with the driving teeth of the pinion gear to rotate the pinion gear when the first drum is being rotated through a particular one of the timed increments of movement thereo

Abstract: Face-gear transmissions have been used hitherto only for secondary applications, with little running hours and low loads. They form a type of underdeveloped angle transmissions. When analyzing said underdevelopment, it was surprisingly found that well-known gear theory had not been applied correctly. Especially the teeth-tip-height can be increased considerably in the region where the face-gear teeth have increased pressure angles, resulting in considerably increased loading capacity and meshing quotient, all based on meshing cooperation with standard cylindrical gears with either straight (spur) or helical teeth. The angle between the transmission shafts may be 90.degree., less or over, the shafts may intersect or cross.

Abstract: A rack and pinion gear having helical teeth. A conical hob is employed for cutting recessed rack teeth in the work piece by continuously engaging the hob and work piece as the work piece moves longitudinally beneath (or with respect to) the rotating hob. To mate with the helical teeth in the rack, a helical gear having rounded or arcuate teeth is provided.

Abstract: A wave gear drive comprises a rigid gear, a flexible gear engaging at a plurality of bulged regions thereof with the rigid gear, and a wave generator for causing the flexible gear to perform wave motion. The number of gear teeth between adjacent bulged regions differs between the two gears and the relative motion between the two gears is caused by shifting of the engagement regions. The teeth of the two gears are formed to satisfy the conditions that the shapes of imaginary rolling contact plate which performs the same motion as the aforementioned relative motion are determined to correspond to the loci described on planes fixed on the respective teeth by the respective momentary centers of relative tooth motion and that the common normal of the respective teeth at the meshing point passes through the momentary contact point of the rolling contact plates.

Abstract: A spur gear system wherein each gear comprises two gear sections; gear te in the respective sections are staggered a one half tooth pitch distance. The effect is to achieve a relatively high contact ratio with relatively small diameter gears. Teeth on mating gears are of positive (convex) curvature and negative (concave) curvature to provide an enlarged contact area.

Abstract: A rotary pump device and an inner gear rotor therefore in which the inner gear rotor has a outer peripheral profile surface whose cross section perpendicular to its central axis is in the form of an inner envelope curve derived by moving a locus circle on an epitrochoidal curve. If the epitrochoidal curve is defined by a base circle of diameter A, a rolling circle of diameter B and an eccentricity of length e, and the locus circle has a diameter C, the inner rotor therefor having an eccentricity ratio f.sub.e =e/B, a locus circle ratio f.sub.c =C/B and a base circle ratio n=A/B, the ratios f.sub.e, f.sub.c and n are selected so as to make the inner envelope curve smooth without any edge portions by selecting the ratios to have values such that f.sub.c /K.sub.i .ltoreq.1.1, wherein K.sub.i =(n+1).times..vertline.1-2f.sub.e .vertline.. The inner gear rotor is rotatable in an outer gear rotor having circularly arched radially inwardly extending teeth.

Abstract: An improvement in a spur gear mechanism having a pair of engageable spur gears, a device for rotating the gears in one direction only, and a device for engaging and disengaging the gears. The improvement includes a chamfer on the top, circumferential surface of each tooth each of the gears. The chamfer starts at the working surface of the gear tooth and extends inwardly toward the juncture of the pitch line of the gear and the non-working surface of the gear tooth, whereby the opposing teeth of the engaging gears do not prevent the re-engagement of the gears when the gears are brought together for engagement.

Abstract: The invention discloses means to reduce the noise and vibration of gear sets by (a) minimizing the transmission error resulting from variations in the mesh stiffness at different phases of tooth engagement and (b) reducing the maximum rate at which load is transferred to the driven gear. A substantially constant mesh stiffness is achieved by shaping the teeth and the field of contact so the product of incremental tooth contact line length and tooth pair stiffness per unit length of tooth contact line integrated over the field of contact does not vary significantly as the tooth contact lines move across the field of contact. In addition, the maximum rate at which load is transferred to the driven gear is substantially reduced by shaping the teeth so the tooth contact lines intersect the entry and exit boundaries of the field of contact at an angle.

Abstract: A system of gearing that allows gears to be designed that are smaller than standard involute gears of corresponding torque capacity. This reduction in size is made possible by increasing the angle through which the teeth are engaged. The wider angle of engagement is achieved by adding to the path of contact two segments: (1) the path portion closest to the pinion is extended by adding on a slightly curved segment lying outside the circle that is the locus of interference points for involute gearing; and (2), the path portion closest to the gear is extended by adding a segment that is produced by the use of an exceptionally long pinion addendum. The reduced size of the gears made possible by the wider engagement angle obtained from addition of these two path segments not only reduces mass and pitch line velocity, but the wider engagement angle itself also affords an increased profile contact ratio that reduces transmission error. The wider angle of engagement thus reduces noise excitation in two ways.

Abstract: A gear tooth which has a combination of an involute and a non-involute profile, and specifically a constant relative curvature and a high contact ratio, i.e., a contact ratio which is at least 2.

Abstract: An endoscope has a handle portion and a separate shaft portion which can be joined to the handle portion. The shaft portion has a flexible shaft flexing movement of which is controlled by knobs on the handle portion, and this motion is transmitted across the handle/shaft interface by meshing gearwheels. Each tooth of each gearwheel has a crown shaped so as to have a central ridge between sloping sides which facilitate interengagement of the gearwheels when the latter are brought into crown-to-crown engagement in a non-rotating condition.

Abstract: The invention discloses means to reduce the noise and vibration that result from gear transmission error produced by variations in the mesh stiffness at different phases of tooth engagement. A substantially constant mesh stiffness is achieved by proportioning the teeth and the field of contact so that the product of incremental tooth length and tooth load per unit length at a given torque load integrated over the field of contact does not vary significantly as the tooth contact lines move across the field. To minimize deviations from the mean mesh stiffness, the teeth are made as flexible as possible and the total contact ratio as large as possible.

Abstract: A speed reducing transmission includes roller driving elements operating to transmit torque between opposed trochoidally formed surfaces. The device may have one or multiple reduction stages and may be either counterbalanced or counterweighted to achieve dynamic balance. The opposed surfaces are provided as conjugate epitrochoidal and hypotrochoidal gear elements, while the rollers are simple cylinders maintained suitably spaced by means of roller cages or retainers.

Abstract: A self-aligning gear train of enhanced load transmitting capacity comprises a pair of cylindrical gear wheels having intermeshing teeth with concavo-convex side surfaces. The opposed, peripheral surfaces of the intermeshing cylindrical gear wheels are square providing increased surface contact between meshing gear teeth from the base to the edges of the teeth with the convex tooth surface of one gear engaging a concave tooth surface of the other gear to provide self alignment of one cylindrical wheel with the other.

Abstract: The teeth of the sun pinion, planet wheels and hollow wheel have a profile correction changing continuously along the gear width and varying in opposite directions between the meshing gears. The sun pinion, hollow wheel and planet carrier are so mounted as to be fixed in the axial direction, whereas the planet wheels, allowed to slide individually in the axial direction on their stub shafts rigid with the planet carrier, are responsive to the axial force exerted by cup springs and mounted for swivel movement within predetermined limits on pendulum bearings. Furthermore, all the wheels, pinion and hollow wheel have crowned teeth.

Abstract: A sprocket construction for a zero caternary chain. In a zero caternary chain, a tensioning system is utilized to prevent caternary or slack in the chain and as a result of the high degree of tensioning, the bushings of the chain ride against the roots of the sprocket teeth. To prevent erosion of the sprocket teeth and bushings, the root diameter is modified to provide an enlarged operating pitch diameter for a predetermined increase in pitch length of the link. The pitch line clearance is enlarged so that it is equal to 2% to 25% of the working pitch diameter and produces a pressure angle of 20.degree. to 40.degree..

Abstract: In a transmission which comprises a reverse gear secured to a main shaft, a counter reverse gear secured to a counter shaft, and an axially movable reverse idler gear arranged between the reverse gear and the counter gear to mesh with them in order to establish and break the connection between the reverse gear and the counter gear, the reverse idler gear being provided, on its tooth surface corresponding to the counter reverse gear, with a tapered tooth trace having a tapered angle .beta. which is larger than a tapered angle .alpha. of a tapered tooth trace on the tooth surface of the counter reverse gear that meshes with the reverse idler gear.

Abstract: The invention relates to gears and gear trains, and more particularly to epicyclic gear trains of low cost and improved efficiency, and to gear teeth for use therewith. A novel driving means in the form of an eccentric crank/counterweight is provided, and the structural relationships between the several gears are such that the need for conventional bearings is completely obviated. The gear train is of modular construction, being split diametrically into matched halves. Thus, the gear ratio of the overall gear box may be quickly and easily varied by merely replacing one of the matched halves with another. The novel tooth construction for use with such epicyclic gearing employs a large pressure angle which allows circular arc profile involute teeth to be utilized.

Abstract: In a hydrostatic gear machine of the type having an internally toothed outer gear and an externally toothed inner gear wherein the gears have different numbers of teeth, the gears being meshed with the outer gear surrounding gear, particularly advantageous relationships between the numbers of teeth and the shapes of the tooth flanks are provided to permit economic manufacture of the machine for use as a motor or pump.

Abstract: An improved sprocket wheel for substantially planar feeding of a strip of film in a photographic camera by applying a thrust to end edges of two parallel and spaced apart rows of perforations provided along the film strip includes two corresponding trains of film feeding teeth, each tooth having a curved film thrusting surface confronting the plane along which film is fed in the camera and comprising a base portion having a gentler slope with respect to the film feeding plane than an involute tooth profile and an upper portion having a steeper slope with respect to the film feeding plane than an involute tooth profile, and further having a ridge defined between the outer side surface and the film thrusting surface of each tooth to substantially conform to a rounded corner of each film performation and thereby facilitate smooth feeding of the film.

Abstract: In an elastic coupling with two similar central gears assemblable on respective shaft ends and having rows of teeth, respectively, disposed adjacent one another, and a planet gear with a row of teeth having an angular pitch equal to that of the rows of teeth of the central gears, the central gears being turnable elastically resiliently so that the flanks of the teeth of the central gears form generally wedge-shaped virtual tooth gaps having a profile varying with reciprocal turning of the central gears, the teeth of the planet gear being also generally wedge-shaped and projecting into the generally wedge-shaped virtual tooth gaps, the tooth flanks of the teeth of the planet gear being in direct contacting engagement with the tooth flanks of the teeth of the central gears, and the teeth of the planet gear and the teeth of the central gears being spring-biased radially toward one another so that the teeth of the planet gear remain fully in engagement in the virtual tooth gaps.

Abstract: A gear clutch comprises an annular clutch casing with a plurality of internal teeth and a clutch hub having a plurality of external teeth meshed with the internal teeth. The clutch is coaxial with the clutch casing and the external teeth have a load bearing part and a root. The clutch hub has an annular axially extending groove extending into the root from one side of the external teeth and ending below the external teeth and an annular radially extending groove on an opposite side of the external teeth and defining with the axially extending groove a cylindrical annular break section of a size smaller than that of the load bearing part, whereby the break section breaks before the load bearing part breaks when the gear clutch is overloaded.

Abstract: A stepping motor causes a driving pinion to rotate by steps of 90.degree., he stopping position being such that a driven pinion is blocked with a very small backlash by the pressure of a tooth of the driven pinion against the top face of one of the teeth of the driving pinion. Both pinions have simple teeth with conventional profiles capable of being cut by means of a worm-hob. The pitch of the driving pinion is between one and two times that of the driven pinion, and the layouts of the teeth are such that the arc along which a tooth of the driving pinion engages the teeth of the driven pinion includes a portion tranversed freely and a portion along which the driving pinion rotates the driven pinion by one step of its toothing.

Abstract: A compressor or expansion machine for fluids comprises a rotor, a casing at least partially surrounding the rotor and a pinion which is rotatable about an axis which is not parallel to the rotor axis. The rotor is provided with helical threads having crests which are disposed on a surface of revolution about the rotor axis and the pinion has teeth which engage between two adjacent threads of the rotor to form a compression or expansion chamber in conjunction with the casing, the flanks of the pinion teeth comprising at least three skewed surfaces which intersect in at least two edges.

Abstract: A gear is disclosed with a heavy loading capacity which has teeth roots between adjacent gear teeth and contact area patterns on the face of each gear tooth. Each tooth root includes a concave fillet running substantially in a direction of the rolling element generator line of the gear. The top of each tooth is substantially equidistant and a mirror image of the tooth root fillet.

Abstract: The hinged mount for motor vehicle seats includes a wobble gear adjuster having an outer gear integrally formed on a hinged mount secured to the seat proper and an inner gear integrally formed on a hinged mount secured to the reclinable backrest. The toothing of the outer gear has an outline composed of an alternating succession of concave and convex circular sections having substantially the same diameter of curvature. The outline of the toothing of the inner gear is formed by concave curves forming the root flanks of respective teeth and being equidistant from a cycloid generated by the convex tips of the teeth of the outer gear. The cycloid root flanks are confluent with rounded crown flanks which transit into concave tips of the inner teeth having a shorter addendum than that of the outer teeth, and coinciding with the crown circle of the inner gear.

Abstract: A cylindrical gear wheel having helical teeth with different pitch diameters for the left hand and right hand sides of the teeth and convergent line of teeth in which one side of the teeth are characterized by positive values of addendum modification while the other side of the teeth has negative values of addendum modification. By positive addendum modification is meant an addition to the nominal pitch diameter to obtain the pitch diameter at one side of a tooth and by negative addendum modification is meant a substration from the nominal pitch diameter to obtain the pitch diameter of the other side of the tooth. In the range of normal values of tooth pitch (mn) from 2 to 6 mm or normal tooth module the angular difference of inclination between the left hand and right hand sides of the teeth is within the range of 30' to 3.degree. for pitch diameters up to 500 mn and the addendum modification values are in the range from 0.01 to 4 mn.

Abstract: A contra-angle housing made in two parts hinged together at one end encloses a drive shaft with drive gears at one end, and a geared hub for a dental tool or the like supported in apertures in or through the housing parts transverse to the drive shaft. A latch mechanism can be manually operated to release the two housing parts so that they can be opened to change tools, clutches or the like with integral gear hubs. When the housing parts are closed the gears on the hub automatically mesh with the drive shaft gears. Reinforced gears which can be made of molded plastic make possible low-cost interchangeable tools with integral gears.

Abstract: A single-stage high-ratio compound planetary gear system has gears configured for optimal tooth profile contact to minimize Hertzian stresses under relatively high contact loads characteristic of high-ratio gearing. Criteria is established for determining the optimal line of action required to attain a substantially constant relative radius of curvature between the teeth of a mating set and optimal tooth geometry for maximal contact between mating teeth.

Abstract: A gear tooth form is disclosed that maximizes the profile (transverse) contact ratio for coplanar axis gearing. As the tooth form allows teeth two or three times as fine as those of conventional involute gearing to be used without loss of torque capacity, the face (axial) contact ratio for helical or spiral bevel gearing is also maximized. The total contact ratio (profile plus face contact ratios) is therefore maximized, and the torque load is divided over the maximum number of teeth. This minimizes the transmission error, which in turn minimizes operating noise and vibration. The gearing employs a minimum pressure angle and a path of contact that includes a curved portion.

Abstract: In a face gear assembly comprising a face gear and a pinion engaged therewith, the crest or top land of each tooth of the face gear is so formed as to touch the root surface or bottom land between two adjoining teeth of the pinion which are in mesh with the tooth, whereby the mutual engaging relationship of the face gear and the pinion can be regularly maintained.

Abstract: A gear tooth, particularly for internal gears, such as a wobble gear transmission, has its angle of slew defined as a fraction of the radii of the pitch circles of a gear bearing the tooth and a gear adopted to engage with it. The critical factor in calculating the correct profile for a circular-arc gear tooth is (1-cos .theta.) where cos .theta.=r/R and r and R are the radii of the above pitch circles.

Abstract: Gear tooth profiles are disclosed that afford a higher torque capacity than that of previously disclosed fine-pitch gearing. To offset the weakness in bending of fine teeth, the transmitted force is divided among two to five times as many teeth as in conventional gearing, by using very low pressure angles, and the tooth interference that would occur between meshed involute teeth of equally small pressure angle is avoided by using profiles of shorter relative radius of curvature. The tooth flexibility needed to offset tooth separation at the ends of the line of action and to insure an equitable division of the load among the maximum number of teeth is obtained by deepening the dedenda. The resulting tooth form increases torque capacity by maximizing the transverse contact ratio and minimizes operating noise by increasing the axial contact ratio.