Title:
MULTIPOSITION BI-DIRECTIONAL ROTARY MEANS FOR A SWITCH OR THE LIKE
Document Type and Number:
United States Patent 3748915
Abstract:
Multiposition bi-directional rotary means for a switch or the like includes a rotary ratchet operated by two actuating push levers. Two advance levers or pawls are slidably and pivotally mounted and engage this ratchet from opposite radial directions. Each advance lever has means for engaging the ratchet to rotate the ratchet one step to an adjacent position and means to engage the ratchet and releasably hold it in a position. One lever rotates it in one direction the other lever rotates it the opposite direction. A single spring engages both advance levers to urge them radially inward toward the ratchet. Other springs urge the advance levers or pawls tangentially of the ratchet toward projected at-rest positions. The push levers have projections to engage the advance levers for effecting lineal sliding movement and permitting pivoting of such advance levers relative to the ratchet and the push levers.
Inventors:
Winter, Ronald C. (Johnson Creek, WI)
Knief, Enno A. (Watertown, WI)
Application Number:
05/228895
Publication Date:
07/31/1973
Assignee:
Cutler-Hammer, Inc. (Milwaukee, WI)
International Classes:
F16H31/00; G05G7/08; H01H19/00; G05G7/00; F16H27/02
Field of Search:
74/128,129,142,143 335/140,123
US Patent References:
| 2841119 | Operating mechanism | July 1958 | Hard | |
| 3408879 | Ratchet drive for workpiece conveying apparatus | November 1968 | Modder | |
| 3626452 | MULTIPOSITION BIDIRECTIONAL ROTARY MEANS FOR A SWITCH OR THE LIKE | December 1971 | Winter et al. | |
Primary Examiner:
Myhre, Charles J.
Assistant Examiner:
Ratliff Jr., Wesley S.
Claims:
We claim
1. A multiposition bi-directional rotary means for a switch or the like comprising:
2. A multiposition bi-directional rotary means as set forth in claim 1 in which:
Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to multiposition bi-directional rotary means including a rotary ratchet operated selectively by actuating push levers. The rotary ratchet controls the position of a switch or other like member and if desired operates a visible position indicator. The actuating push levers and advance levers or pawls are spring controlled and so related that operation of the ratchet is accomplished without resilient deflection of either of the levers. This increases the life of the device, minimizes friction and provides it with uniform predetermined values.
2. Description of the Prior Art
U.S. Pat. No. 3,626,452 issued to applicant's assignee on Dec. 7, 1971 shows and describes multi-positioned bi-directionary rotary means for a switch or the like which utilizes independent slidably and pviotally mounted spring biased actuating levers or pawls. This patent however does not teach or disclose the use of a single C-shaped spring which urges such actuating levers or pawls radially inwardly toward the rotary ratchet. Neither does this patent utilize a ratchet engaging shape on the actuating levers or pawls which engages two teeth spaced by a third tooth on the ratchet to provide the locking means by one pawl during the retracting action of the other pawl from its ratchet advance position.
Other prior art is set forth and briefly described in U.S. Pat. No. 3,626,452.
IN THE DRAWING
FIG. 1 is a schematic plan view showing the mechanical layout, with the rotary ratchet, actuating levers or pawls and advance levers embodying the present invention in the fully projected at-rest position; and
FIG. 2 is a view similar to that of FIG. 1 with one actuating lever or pawl and its associated advance lever activated to the inner position after advancing the ratchet one step counterclockwise.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawing by reference numerals, the multiposition bi-directional rotary means embodying this invention has its basic components shown and described in U.S. Pat. No. 3,626,452 and such showing and description is incorporated herein by reference. Some of the basic components will be designated herein by the same reference numbers as in such patent. The switch or the like is rotated by a rotary ratchet 12, one tooth of which is identified by an indexing dot 13. The rotary ratchet 12 is mounted on a spindle 18 which may be formed as an integral part of a base 14. As shown, the ratchet 12 may take the form of a multiple tooth star wheel.
In order to advance the ratchet one step at a time in either direction, there is slidably mounted in the base 14 a pair of advance levers or pawls 22 and 24. Each of these pawls are positioned to engage the ratchet from essentially opposite radial directions. These pawls 22 and 24 are shaped as shown in FIGS. 1 and 2. Each one has: (a) a smooth bearing portion 26 which is guided by ribs 28, 30 formed up from the base 14; (b) a spring seat guide pin 32 against which a compression spring 34 reacts; (c) a ratchet engaging arm 36, the outer end of which has ratchet hook 38; (d) a notch 42 by which they are pivotally associated with actuating push levers 44 and 46; (e) a notch 43 which spacedly accommodates a tooth of the star wheel or rotary ratchet 12 in the at-rest position; and (f) smooth ends 51 which are guided by ribs 53 formed up from the base 14.
Each of the actuating push levers 44 and 46 have: (a) portions 48 which extend through openings in the end wall of the base to be manually engaged for operating the actuating push levers; (b) guide portions 50 which slide against the inner face of wall of the base 14; (c) fingers 52 providing pivots which cooperate with the notches 42 of the advance levers or pawls; and (d) abutments 54 which limit the outward movement of the actuating push levers.
The at-rest or fully retracted position of the rotary means is shown in FIG. 1. In this position the springs 34 have caused each advance push lever to be moved outward to the limit provided by the abutments 54. A C-shaped spring 35 engages the outer sides of the pawls 22 and 24 to urge them radially inwardly toward the ratchet 12 so that two teeth on said pawl spaced by an intermediate or in-between-tooth are strongly engaged by sloping surfaces 45 (see FIG. 1) while the intermediate tooth is spacedly accommodated by the notch 43. The bearing surfaces which slidably guide all the levers are those provided by: (a) the portions 48 and the sides of the respective openings through which they project; (b) the guide portions 50 and the respective inner surfaces of the wall of the base 14; (c) the bearing portions 26 and the respective surfaces of the ribs 28 and 30; and (d) the smooth ends 51 and the respective surfaces of ribs 53.
When for example, the plus sign actuating push lever 46 is pressed inwardly (see FIG. 2) the hook 38 on advance lever or pawl 24 will engage the dot marked tooth on the ratchet 12 and advance the ratchet one step counterclockwise. The position of the parts at the completion of such advance is shown in FIG. 2. During this advance, the other advance lever or pawl 22 is cammed outwardly against the force of spring 35 by the approaching tooth until such tooth drops into the notch 43. This frees the intermediate tooth within the confines of the notch 43. When the step is completed the teeth spaced by such approaching tooth will be engaged by the sloping sides 45 as the pawl 22 is forced inwardly by the spring 35 shown in FIG. 2 and lock the ratchet 12 against rotation as the plus sign actuating push lever 46 is moved outwardly to the at-rest position by the spring 34.
When the minus sign actuating push lever 44 is pressed inwardly, it will cause the advance push lever 22 to rotate the ratchet 12 one step in a clockwise direction in the same manner as previously described for the operation of the plus sign push lever 46 with the respective parts functioning in the same manner but in opposite directions.
An important feature of the arrangement described above is that there is no resilient deflection of any of the advance or actuating levers. The only resilient deflection occurs in the springs 34 and the spring 35. Thus these levers, the base, and the ratchet may be formed from rigid materials which will permit these parts to be molded or cast without requiring any machining. The material selected may also have inherent lubricating characteristics which keeps friction to a minimum. Since the only deflection is in the springs 34, calibrations can be easily controlled within close tolerance and uniformity of multitudes of manufactured rotary means easily maintained. Another important feature resides in the locking action accomplished by the C-shaped spring 35 and the tooth engaging sloping sides 45. This locking action is sufficient to prevent unwanted rotation of the ratchet with a minimum of the frictional resistance to be overcome by the step-by-step advance.