US2821863A - Composite gear cone - Google Patents

Description

Feb. 4, 1958 H. N. BLlss Alfz'l-Al. 2,821,863'

COMPOSITE GEAR CCNE Filed Dec. 9, 1952 mm2 iii Z3 44 42 l /ZO 40 n 46.232

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United States Patent O COMPOSITE GEAR coNE Harvey N. Bliss, Windsor, and Otto Wild, Jr., West Hartford, Conn., assignors to Veeder-Root Incorporated, Hartford, Conn., a corporation of Connecticut Application December 9, 1952, Serial No. 324,922

2 Claims. (Cl. 74-348) This invention relates in general to gears, land pertains more particularly to an improved gear cone which will find especial utility'in computing devices such as that shown and described in U. S. Patent No. 2,111,996, issued March 22, 1938 to Edward A. Slye.

In the above alluded to Slye patent, and which has heretofore been the general practice in making gears of this type, the gear cone is die cast as an integral unit about a drive shaft which projects from either end of the cone. Unfortunately, the entire cone size is determined by the size of the iirst or smallest gear step, and the first gear step size is in turn directly influenced by the shaft diameter, for there must be suliicient base or root metal circumjacent the shaft in order that torque may be transmitted from the shaft to the gear teeth on this first and smallest step. diameter must be sufficiently larger than the shaft to carry the encountered loads.

Not only can the cost of the cone gear be appreciably reduced through a saving of material when it is made smaller, but even more importantly the inertia of the cone is greatly lessened which permits the construction of more sensitive computing mechanisms. Since these mechanisms are subjected to abrupt starts and stops, and in most instances the amount of available actuating power is limited, such as in the liquid dispensing apparatus described in the previously referred to patent wherein the computer is driven from a meter whose power is derived .solely from the moving liquid; from a design standpoint it is extremely desirable to minimize the mass of the gear cone. for modern trends have demanded more compact computers and the gear cone is usually the largest single element employed so that by reducing its size it is possible to reduce in turn the overall dimensions of the entire computer.

Making the gear teeth smaller or making the root diameter less (i. e., reducing the body of the gear step between the shaft and the teeth in the latter situation) have not solved the problem, because the gear step cannot then carry the maximum load to which it will be subjected in use. Up to this time, in order to provide sufficient strength, it has not been practical to reduce the number of teeth in the first step below about eight in the variators currently being manufactured, one of which is pictured in the aforesaid Slye patent. Also, it has not been. feasible to reduce the shaft diameter, because this creates a limiting weakness of the shaft for the loads involved.

Accordingly, the primary object of the invention is to provide a gear cone which will possess at least the strength of gear cones in present use, but which will be much smaller, thus minimizing the inertia, reducing the cost and permitting the design of more compact computers. More specifically, when the teachings of the present invention are followed, the number of teeth in the first step may be reduced to as lowas five in number without changing the pitch, i. e., without reducing the number of teeth per inch of diameter. Also, it is an In other words, the root Also, from a style angle, it is desirable, i'

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aim of the invention to make the gear cone smaller without reducing the shaft size.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth and the scope of the application of which will be indicated in the appended claims.

In the drawing:

Figure 1 is an elevational view of a portion of a variator showing preferred use of the gear cone forming the subject matter ofthe invention;

Fig. 2 is an elevational view, partly in section, illustrating the constructional details of the gear cone;

Fig. 3 is a plan view of the gear cone;

Fig. 4 is an enlarged plan view of only the smallest two gear steps; and

Fig. 5 is a perspective view of the smallest gear step, together with its oppositely extending shaft portions.

To illustrate the invention, reference should first be had to Fig. l of the drawing, which depicts certain details of a variator 10, more fully shown in the previously mentioned Slye patent. The variator 10 includes a gear cone 12, which will be described later in detail, the gear cone having a lower shaft end 14 provided with a coupling 15 adapted to be driven by a meter (not shown) measuring the amount of liquid dispensed and an upper shaft end 16 drivably connected to a gallonage totalizer (also not shown) for registering progressively throughout each dispensing operation the number of gallons passing through the meter. While in actual use three sets of gearing are employed in association with a single gear cone in order to obtain the cost of the iiuid dispensed, that is, to indicate variations in steps of ten cents, of a single cent, and of tenths of a cent, respectively, for the sake of simplicity only a single set is herein briefly described. lncluded in this set is a take-olf gear 18 engageable with any of the gear steps by reason of its being mounted on a bell crank 20 slidably vertically on a rotatable shaft 22. Although not visible in the drawing, there is a pinion gear meshed with the take-off gear 18 which is keyed to the shaft 22 in order to transmit rotative motion to said shaft. Carried near the upper end of the shaft 22 is a second pinion 24 having engagement with a spur gear 26 loosely encircling the shaft end 16 which has mechanical connection with differential gearing (not shown) utilized in combining properly the several rotative movements of the three sets previously alluded to. The differential gearing in turn may be employed to drive a money totalizer (also not shown). With the fore going in mind, it is thought that sufficient information has been presented for a full understanding of an eX- emplified computer where our invention will find full utility. However, if further information is desired, then resort should be made to the earlier identified Slye patent.

Directing attention now to Fig. 2, the composite gear cone 12 includes a first gear cone section 30 comprising a series of progressively larger gear steps beginning with a relatively small gear step 32a and terminating in a relatively large gear step 32h, there being six intermediate steps 32h, 32C, 32d, 32e, 32], and 32g. In the specific arrangement shown, the number of teeth progress in multiples of five from ten to forty-five, that is, the gear step 32a has ten teeth whereas the gear step 32h has forty-five teeth. Presently, it will be shown that there is a still smaller step having only live teeth thereon.

Continuing with the discussion of the gear cone section 30, this section of the complete gear cone 12 is preferably of a zinc alloy or practically all aluminum, metals, used quite extensively in the making of conventional gear cones for computers and which metals permit the ready die casting of the gear cone section 30 into the pictured configuration. During the casting process, a steel shaft insert 34 having a serrated upper end36 is held centrally in the mold so that a sleeve 38 is formed tightly thereabout to provide the downwardly projecting shaft end 14, previously referred to in the description of Fig. 1. At the same time, an upwardly facing recess 40 equipped with a plurality of inwardly directed splines for a purpose presently to be explained is formed at the upper end.

A second gear cone section 42, preferably of steel, includes in addition to the stud or shaft end 16 a gear step 44, provided with tive teeth and acting as the smallest gear step of the entire cone 12, and a stud portion 46 having a series of splines 48 disposed about its periphery. Although not easily seen from the drawing, the splines 4S are tapered from their upper ends subjacent the step 44 inwardly toward their far ends, and therefore can be wedged or press fitted into the complementally splined recess 4&1. In Fig. 4, an enlarged plan view of the steps 32a and 44, the taper existing on the splines 48 is shown to be present by means of the dotted arcuate lines 50 and 52, the outer lines 50 representing the region immediately beneath the step 44 and the lines 52 indicating the lower ends of these splines.

Although-the second section 42 may be fabricated in a number of ways, one suggested way is to extrude the blanks from which the individual sections 42 can be machined. When extruded, the blank is of indeterminate length and the extrusion die is configured so as to produce continuous teeth which extend the full length of the blank which have an outer diameter, it will be seen, equal to that of the teeth in the gear step 44. After cutting the blank strip into desired shorter lengths, the cylindrical end 16 may be formed thereon by a lathe operation and likewise the shaft portion 46 may be machined down until the appropriate size of splines 48 is reached. Thus, in the method just described, the splines 48 are merely axial continuations of the teeth 44 with the tips thereof removed.

Since the gear step 44 is equipped in the exemplied embodiment with five teeth, it will be seen that this step actually functions as the smallest or first step in the series of steps extending up to and including fortyfive teeth, that is, all of the steps labeled 32 with their distinguishing lettered subscripts. Also, it will be recognized that the ends of the teeth 44 adjacent the splines 48 firmly abut (Fig. 2) the upper end of the rst described section 30, lmore specifically the `gear step 32a thereof because the shaft portion 46 is made sufficiently short so to assure some clearance intermediate its lower end and the serrated upper end 36 of the insert 34. 1n this manner, the gear cone 12 resembles in outward appearance any conventional gear cone and functions in an identical fashion, although it is of much smaller size, the fact that the smallest gear step is composed of only live teeth instead of the usual eight being indicative ot' the contrast. Accordingly, it will be appreciated that the composite gear cone forming the subject matter of this invention possesses all of the attributes of the conventional prior art cones with the additional advantage of being smaller, the reasons for which have already been given.

We claim:

1. In a speed change mechanism, a gear cone comprising a series of gear steps of increasing diameter and number of teeth and having an axial recess therein, a shaft secured in said recess and extending outwardly from the small end of the cone, and a ring of gear teeth integrally formed on the shaft adjacent the small end of the cone having an outer diameter smaller than the root diameter of the smallest gear step and having a root diameter approximately equal to the diameter of the axial recess.

2. 'In a speed change mechanism, a cast gear cone comprising a series of gear steps of increasing diameter and number of teeth supported on an internally splined axial sleeve, a shaft formed with longitudinal splines received in the splined axial sleeve and extending outwardly from the small end of the cone, said splines of the shaft being enlarged radially adjacent said small end of the cone to form a ring of integral teeth providing an additional gear at the small end of the cone of smaller outer diameter than the root diameter of the smallest gear step of the cone. and having a root diameter approximately equal to the inner diameter of the sleeve.

References Cited in the tile of this patent UNITED STATES PATENTS 1,196,883 Parker Sept. 5, 1916 1,709,233 Schroeder s- Apr. 16, 1929 1,985,918 De Lancey Jan. 1, 1935 2,111,996 Slye Mar. 22, 1938 2,476,275 Bliss July 19, 1949

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