US830159A - Variable-speed gear. - Google Patents

Description

No. 830,159. BATENTED SEPT. 4, 1906.

W. E. MARX.

VARIABLE SPEED GEAR. APPLIOATION FILED BEPT.17.1904.-

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PATENTED SEPT. 4, 1906.

W. E. MARX. VARIABLE SPEED GEAR. APPLICATION I'I'LED SEPT, 17,1904.

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WILHELM EDUARD MAR-X, OF LEIPSIG, GERMANY.

VARIABLE-SPEED GEAR.

Specification of Letters Patent.

Patented Sept. 4, 1906.

Application filed September 17, 1904. Serial No. 224.887.

To all whom, it may concern:

Be it known that I, \VILHELM EDUARD hIARX, engineer, a subject of the King of Saxony, residing at Leipsie, in the Kingdom of Saxony and German Empire, have invented certain new and useful Improvements in Variable-Speed Gears for Engines and Vehicles, of which the following is a full, clear, and exact description.

This invention relates to an improvement in variable-speed gears for engines and vehicles by means of which the rotary speed can be varied without interrupting the continuity of the driving action.

In carrying my invention into effect I proceed in or in ab out the following manner, making reference to the accompanying drawings, wherein Figure 1 shows a side view, partly in section on line 1 1, Fig. 2, of one form of this speedgear; Fig. 2, a view from below of this form. Fig. 3 is the longitudinal section of a sleeve and a cross-piece attached to it. Fig. 4 is the cross-section of the sleeve, the crosspiece, and two roller-holders. Fig. 5 is a ,plan view of. the crosspicce; Fig. 6, a side view of a modified construction; Figs. 7 and 8, views of the lower portion of this modification from below. Fig. 7 is shown partly in section. Fig. 9 is partly a central cross-section, partly an end elevation, of this modified form. Fig. 10 is a central horizontal section of the sleeve of the modified construction. Fig. 11 is the cross-piece of it. Fig. 12 is a doubleforked guide; Fig. 13, a slide-frame in longitudinal section, and Fig. 14 this frame in central crosssection.

To carry this invention into effect, I arrange a shaft 1, firmly seated in bearingblocks, and loosely on this shaft I provide two independent step-pulleys 2 3 in such a manner that the pulleys with the largest diameter are close to each other, as is shown in the form of this variable-speed gear illustrated by Figs. 1. and 2. In order to facilitate the action of this gear, the single steps of the pulleys pass into each other by the conieal planes Beyond the step-pulleys 2 3 and sliding upon a guide-shaft 10 there is mounted a sleeve 11, which can be moved in direction of the arrows A B by the shaft 9, firmly seated in the sleeve. The sleeve of the form represented in Figs. 1 and 2 is mounted above a cross-piece 14, which is slidably set on a vertical bolt 26, secured to the sleeve preferably.

The vertical movement of the cross-piece is effected by screws 22 when the tension of the bolt 4 is to be increased. The female threads of these screws are cut into the ends of the longitudinal portion of cross-piece 14. The free ends of the screws engage with pans 27, provided at the bottom of the sleeve 11. The other arms of the cross-piece 14 are provided with two roller-holders 13 13, which are pivotally suspended from the above-mom tioned cross-arms by bolts 15. These rollerholders are capable of being turned on their bolts 15, and they carry guide-rollers 5 to 8, pivotally arranged on pins 12. For transmitting, the rotary motion on the endless belt 4 is provided, which runs over the step-pulleys 2 3 and the rollers 5 to 8. On the shaft 1 is loosely mounted a pulley 25 and close to it a pulley 28, which is firmly connected to the step-pulley 2. After having stretched the endless belt 4 by means of the screws 22 the gear (represented in Figs. 1 and 2) acts thus: hen the sleeve 11 is moved by the shaft 9 in direction of the arrow A, the endless belt 4 slips down to the following smaller step of the step-pulley 2. At the same time the belt when being in motion will creep up to the following larger step ofthe step-pulley 3. As before mentioned, this creeping movement of the belt onto the larger step of pulley 3 is facilitated by the cones 33.

Now it is clear that the steppulley'2,being coupled with the driving-pulley 28 and having a uniform motion, will cause the rotary movement of the step-pulley 3 to diminish as soon as the sleeve 11 has been moved in the direction of the arrow A. If the displacement of the belt, on the contrary, takes place in the direction of the arrow B, the speed of the step-pulley 3 will be increased, for now the endless belt 4 slips over the smaller step of the step-pulley 3 and creeps up to the larger step of the step-pulley 2.

The modification represented in Figs. 6 to 14 is characterized by the fact that the steppulleys 2 3 are loosely arranged on the shaft 1 in such a manner that the pulley-steps with the smallest diameter are close to one another. Parts of the guide-shaft 10, which carries the sleeve 11, are provided on both sides with teeth 30, which engage with toothed wheels 31, pivotally mounted in the sleeve 11 on pins 19. These wheels 31 are in engagement with driving-wheels 18, the latter being firmly connected with two pins 15, which unite two guide-frames 13 with the cross-piece 14. A bolt 26 is screwed into sleeve 1 1, which forms a vertical guide for the cross-piece 14:, allowing it a limited movement in vertical direction. The guide-forks 13 carry slide-frames 20, which have guiderollers 5 to 9 seated rotatably on pipe 12. When the belt 4 has been put in place, the sliding frames 20 are by thetension of the belt, with their shoulders 29 against cams 16 17, which are firmly connected to the two pins 15.

In order that the action of the modification represented in Figs. 6 to 14 may be better understood, I refer to the position shown in Fig. 6. In this figure the two cams have a position such as represented in Fig. 7, where it may be seen that the adj oined pieces 29 of all four sliding frames 20 stand against the shorter ends 16 of the cams in consequence of the tension of the belt 4. The indentations and the diameter of the graduated circle of the bolts 15 and extensions 18 18 are so calculated that when the sleeve is moved in the longitudinal direction of the step-pulleys to the extentof one-half the width ofa step the cams 16 16 are rotated ninety degrees. The distance between the guide-rollers 5 7 and 6 8 depends on the size and form of the cams 17, by which said rollers are moved to the intended distanoeviz., a full step of the steppulley. According to this action the two guide-rollers 7 8 do not advance, so that the belt remains in its position on that step on which it has been before the movement of the sleeve 11 began. It is easily understood that the belt lying above the two guide- rollers 5 and 6 will creep up to the following higher step if said guide-rollers are moved a whole step forward. If the sleeve 11 be further moved in the same direction to the extent of half a step, the two cams 16 16 are rotated once more to the extent of ninety degrees, and consequently the pulleys 5 6 retain their position, but the guide-rollers 7 8 travel a whole step forward. The belt lying above these two pulleys will therefore slip down to the following smaller step.

In the speed-gear shown the pulley 32 is firmly connected with the step-pulley 3 in order to transfer the movement. The construction may, however, be changed in such manner that theshaft 1, that is firmly connected with the step-pulley 3, is seated r'otary.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is 1. A variabl-speed-transmission gear comprising a pair of stepped cone-pulleys coaxially arranged and having their bases opposite one another, a carriage movable parallel to said pulleys, and having a pair of swinging arms thereon, idler-pulleys on said arms, and a belt extending over said idler-pulleys and said cone-pulleys and arranged to direct said idler-pulleys into alinement with the particu-' lar cone-pulley opposite which they are located, by the tension of the belt.

2. In a variable-Speed-transmission gear, apair of stepped cone-pulleys in axial alinement and having, their bases opposite one another, a carriage arranged to move parallel to said pulleys, idlers on said carriage, a belt extending over said idlers and said pulleys, means whereby said idlers are guided to have a forward and back movement independent of the carriage, and cam means for imparting such movement when the carriage is shifted, whereby the forward idler-pulleys shift the belt to a smaller step of one of the cone-pub leys before the rear idler-pulleys shift the belt to a larger step of the other cone-pulley.

In witness whereof I subscribe my signature in presence of two witnesses.

WILHELM EDUARD MARX.

Witnesses ARNo KREBS, RUDOLPH FRICKE.

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