US1625512A - Reversing mechanism - Google Patents

Description

April 19, 1927. v i E ET 1,625,512

REVERS ING MEQHANI SM Filed MarohS 1924 Patented Apr. 19, 1927.

SERGIUS VERNET, 0F BROOKLYN, NEW YORK.

nnvnnsrne MECHANISM.

Application filed Marche, 1924. Serial No. 696,983.

This invention relates to an improvement in reversing mechanism, more especially designed for use in windshield wipers and other reversing mechanism where compactness and delicacy are prime requisites of the mechanism but capable of use generally in reversing mechanism.

In my copending application Serial No. 641,853, filed May 28, 1923, I have disclosed a windshield wiper operating mechanism in which a warped reversing gear driven by a constantly rotating pinion is mounted so as to slide longitudinally back and forth on the wiper rock shaft to reverse the movements thereof. Due to the enforced smallness of the parts the necessity for keeping the power consumption at a minimum and the comparatively heavy load on the motor, considerable difficulty has been experienced in securing a uniform rotational drive on the. rock shaft near the end of its swing when the pinion is meshing with the warped portion of the reversing gear to shift the gear longitudinally of the shaft, with the result that the effective torque at the ends of the wiper swing may be so greatly reduced that the wiper will sometimes stick at or near the ends of the stroke and stall the motor,-especially if the windshield is gummy or covered with snow or ice. While this difficulty may be overcome by the use of properly designed gear teeth in the warped portion of the reversing gear, it has i been found that each tooth in the warped portion must be formed on a different cone and pitch angle and that such extreme accuracy is necessary as to render the pro-' duction of these gears very diflicult.

It is an object of the present invention to overcome this difficulty by providing a means for. permitting the shifting of reversing gear back a d forth on the rock shaft without causing any substantial rotational movement of the rock shaft, so that the torque at each end of the swing of the wiper or other mechanism carried by the rock shaft will be substantially as great or if desired greater than the torque. through the main portion of the swing.

Another object of the invention is to pro- 'ide a means for permitting reduced rotational drive and increased play between the driving pinion, reversing gear and rock shaft during the longitudinal shifting of the reversing gear on the rock shaft so as to reduce the wear on the guides and other parts of the mechanism and to reduce the power consumption at this point of the movement.

A more specific object of the invention is to provide a means which will insure a substantially fixed relation between the reversing gear and the rock shaft during the major portion of the swing of the rock shaft, but will permit a slight relative rotation between the rock shaft and the reversing gear near the end of the rock shaft swings when the reversing gear is being shifted longitudinally of the rock shaft.

Various other objects and advantages will appear as the description of the invention proceeds. 7

Referring now to the drawings which illustrate one form of mechanism by which the invention may be practiced.

Figure 1 is a side elevation of the reversing mechanism in about the middle of its swing.

Figure 2 is a plan view of the same.

Figure 3 a sectional view approximately on the line 3-3 of Figure 1.

In the form of embodiment illustrated 1 represents the rock shaft, to the end 1 of which is secured the windshield wiper or other device which it is desired to swing back and forth. A reversing gear illustrated at 2 is mounted on the rock shaft, and comprises the internal bevel gear sectors 3 and 4 connected at each end by integral Warped portions 5. A constantly rotating pinion 6 driven by means of a gear or worm wheel 7 preferably dished as illustrated, meshes with the reversing gear 2 to drive the same in all of its positions.

The reversing gear 2 is loosely mounted on the rock shaft 1, and to cause the rock shaft to turn with the gear 2 but permit the gear to shift longitudinally of the shaft, a substantially oval slot 8 is cut in the top of the gear and a pin or screw 9 is fixed'to the rock shaft and projectsinto the slot 8. To reduce friction between the pin 9 and the walls of the slot a roller 10 may be provided on the pin.

The wheel 7 and pinion G are mounted on a fixed stud shaft 11 which extends into the slot 12 formed between the feather l3 and the toothed portions 3, l and 5 of the gear 2, and guides the gear 2 in its rotational and longitudinal movement. The wheel 7 may be driven by suitable gearing from an electric motor or any other suitable source of power.

In the operation of the device, starting, from the position illustrated in Figure l, with the pinion G rotating in a counterclockwise direction, the sector I) and reel; shaft 1 is rotated to swing the wiper or other mechanism located on the end 1 of the reel; shaft in a counter-eloelvtwise direction. l l hen the pinion t3 reaches the warped portion 5 at the end of the gear :2 which shown in Figure 1, the stud shaft 11 is opposite the opening 123 between the end of the feather l3 and the warped portion 5 so that the gear may be shifted to the right on the reel; shaft to put the pinion 6 in mesh with the sector at to drive the rock shaft in a clockwise direction until the opposite end of the sector -11: is reacl ed where the gear is again shifted lo udinallv on the shaft to reverse the rotation of the shaft.

During the rotational or swinging movements of the shaft 1, the pin 9 and roller 10 occupy a position at one end of the slot h, so that the gear 2 and the rock shalt swing back and forth in a lixed relation, during the shifting movement of the gear on the shaft, however, the pin 9 and roller it) more out into the oval portion between the ends of the slot 8, which per-mite a slight relative rotational movement or plav of the gear on the reel; shaft, which according; to the shape of the slot El may he made to reduce or to eliminate entirely the dririnr of the roelc shaft during the longitudinal. sh ltiue; of the gear thereon. it will, therefore, he upjilltinii that; with the reduel ion or elimi nation of the drive on the I'Ut'li shaft during; the reversing movement it will no lulltlftl he i'leeessary to have sueh a2 aceurate mesh lietiveen the teeth of the pinion (S and the te th in the warped portion 5--and that depending on the shape of the slot .8 it may onh, he ueeessary to have sullieient contact hetween the warped portions 5 and the pinion ii to keep the teeth in mesh during the l agitudinal shifting of the gear 53 on the shalt, consequently the necessity for carefully formed teeth in the warped portion 5 no longer exists.

Various modifications may he made in the form of embodiments illustrated without de iarting from the spirit of the invention or the scope of the appended claims.

I claim 1. In a reversing mechanism of the type described, a rock shaft, a warped reversing gear thereon, means to drive the gear, in alternately reverse direction to oscillate the the rock shaft haul; and forth, and means to cause a reduction in the driving torque on the rock shaft during the reversing movements.

2. In a reversing mechanism of the type described, a rock shaft, :1 warped reversing gear, means to drive the gear to swing the rock shaft and to shift it longitudinally of the roclr shaft to offer; a reversal of the swings, and means to hold the gear iiXed on the shaft during the swinging movement and to release the gear for relative rotational movement of the gear on the shaftduring the reversing movement.

in a reversing; mechanism of the type described, a rock shalt, a moped reversing gear on said rock shaft, means to drive the gear, means to cause longitudinal movement of the gear on the rocl; shaft, means to hold the gear lined against rotational movement on the lOClI shaft when in either extreme of its longitudinal movement thereon, and means to relea.- -e the gear for a slight rota tional movement of the. gear on the rock shaft during the longitudinal movement of the gear on the reel; shalt.

la a reversing mechanism of the type desrrihed, a rot-l; shaft, a warped reversing gear loosely supported on said reel: shaft, an oval opening in the huh of said gear, and a pin on said roclc shalt. projecting into said opening.

5. in a reverting merhauism ot the type deecrihed, a rock shaft, :1 warped internal level gear loosely supported on said rocl: shaft, an oval opening through the huh of s id gear, a pin on the rock shaft project into the opening}; and a. roller bearing on until Pill.

(i. in a revereing n'uzchanism of the type described, a root: shaft, a Warped reversing; gear thereon, means to drive the gear to eause radial movement o if the reel: shaft, means to shift the gear longitudinally of the roclr shaft to reverse said mmcment, and means to eliminate the radial drive on the reel; shaft during ti o longitudinal ehi'lting of the gear.

in teetimon whereof I have aliixed my signature to this specification.

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