Abstract:
A drive mechanism for converting rotary movement to an oscillatory movement for operating switches, valves, pumps and light implements wherein the oscillating member is a flexible rod having a curved profile from which to attach output levers positioned in a simple manner to vary the amplitude, phase timing, and duration of stroke of individual output levers; whereby numerous output functions may be performed from a single rotary input source.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to devices for converting rotary movement into oscillating movement, specifically to such devices that require selectively adjustable output. 
     Vertical axis windmills of the type disclosed in U.S. Pat. No. 5,823,749 to Green (1998) for aeration of ponds require a transmission that can convert vertical axis rotary movement into reciprocating movement to operate multiple air pumps. It is desirable for these pumps to be arranged conveniently and economically, and provide means for seasonally adjusting the stroke of the pumps to accommodate changes in wind conditions. In low wind conditions, a shorter stroke will create less resistance and allow easier starting. It is further desirable that in other circumstances where rotary motion is to be converted to reciprocating movement, that the output be easily adjusted to selectively choose the amplitude, phase timing and duration of individual output levers. 
     U.S. Pat. No. 1,715,735 to Banning (1929) discloses a multiple pump design activated by an oscillating rod. However, this pump entails expensive manufacturing methods and complicated lubrication requirements, and the amplitude of stroke of Bannings pump is not adjustable. In addition, the oscillating, rigid rod disclosed has a single angle over its length. Therefore, attached output levers will oscillate with the same angle even though they are attached at different positions along the rod. 
     U.S. patent to Oosterling (1976) discloses an adjustable stroke conversion device that has an output adjustment mechanism. In this device, an adjustment may be made to the amplitude of a single output and does not anticipate the need for a means to selectively adjust individual magnitude, timing and duration of multiple reciprocating outputs from the same rotary source. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is a device for converting rotary movement into reciprocating movement. A flexible rod is employed to oscillate levers for the operation of a variety of implements. These implements may include electrical switches, valves, pumps, animated advertising displays, animated garden ornaments, toys, and robots. Some of these applications may require activation of multiple elements at different intervals of timing, different amplitude, and different duration of movement from a single rotating input source. It is object of the invention to provide a simple means to achieve complex reciprocal output with minimal structure. 
     It is further object of the invention to provide a novel structure that has versatility of use. That use may include but not limited to the operation of the mechanical and electrical apparatus before mentioned; and that the conversion device of the present invention may be powered by various power sources. 
     It is further object of this invention to provide versatility of output with compactness and economy of structure. The structure of the present invention is intended to provide convenient arrangement for implementation, whereby, input and output are disposed linearly, and the manufacturing requirements are uncomplicated and economical. 
    
    
     Other objects and advantages of this invention will become apparent in the detailed description of the rotary to oscillating conversion mechanism as follows. 
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     FIG. 1 is a perspective view of a pump mechanism constructed in accordance with the invention 
     FIG. 2 is a perspective view of the invention showing the adjustment detail of the flexible rod transmission 
     FIG. 3 is a perspective view of the invention applied to windmill air pumps 
     FIG. 4 is a perspective view of the invention designed to operate a plurality of adjustable valves, switches, or light mechanical apparatus 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings in general, the invention embodied therein comprises a reciprocating mechanism including a driving rotary means  11  upon which is mounted a slotted crank arm generally designated  12 . In accordance with the invention, crank arm  12  is provided with a curved profile and a slot  13  through the center of crank member  12  along its length. Captured in slot  13  of crank member  12  is a journal  14 . Journal  14  is provided with an adjustment means  14   a  to selectively change its position closer, or farther from driving means  11  whereby the eccentricity of an oscillating member journalled in crank arm  12  may be adjusted. An oscillating member is provided and consists of a flexible rod  15 , having concentric layers of helically wound, hardened wires of the type that has properties that resist twisting, but is adaptable to being easily flexed. 
     The wire structure of flexible rod  15  oscillating member is typically used in flexible drive shafts. In the embodiment of the preferred structure, the oscillating member is fixedly secured at a distance from, but in the same axis as rotary means  11 . Stationary bracket  16  is provided for the support and attachment of flexible rod  15 . Flexible rod  15  oscillates by means of the eccentric rotary movement of crank arm  12  but is prevented from twisting by its concentrically wound wire structure and compression fitting  25   b , through which flexible rod  15  is securely fastened. Journal  14  allows frictionless movement of crank arm  12  while oscillating flexible rod  15 . Levers  17  refer to the first power takeoff structure. 
     Referring to the drawings in particular, FIG. 1 shows an air pump mechanism wherein three piston type air pumps perform pumping action with a predetermined phase difference. Crank arm  12  revolves with rotary shaft  11 . Output rod  15   a  consists of a solid rod fixed rigidly to lever bracket  22 . Output rod  15   a  is freely oscillated through journal  14 . Levers  17  extend outward from lever bracket  22  to create pumping action through universal joints  19  and piston shafts  20 . Flexible rod  15  is clearly shown in this preferred embodiment. Pump cylinders  23  are shown in partial view. 
     Numerals  25   a  and  25   b  show compression fittings that secure flexible rod  15  rigidly to lever bracket  22  and stationary bracket  16 . Stationary bracket  16  provides attachment of flexible rod  15  to a stationary structure. 
     FIG. 2 shows a detail view of the pump arrangement shown in FIG. 1, wherein rotary driving shaft  11  revolves through bearing mount  10  to rotate slotted crank arm  12 . Journal  14  is clearly shown captured in slot  13  wherein it may be adjusted to change magnitude of oscillation of levers  17 . Numeral  14   a  shows a positioning nut to secure journal  14  at selective positions within slot  13 . Solid output rod  15   a  can be seen protruding through journal  14 . Flexible rod  15  can be seen through lever bracket  22  fastened to stationary bracket  16  with compression fitting  25   b.    
     FIG. 3 is a full view of the windmill operated air pump system showing its convenient arrangement. Pumps  23  are powered by windmill  24  through bearing mount  10  and rotary shaft  11  to oscillate flexible rod  15 . Stationary bracket  16  is secured to windmill tower structure  26 . Pump cylinders  23  are flexibly secured to tower structure  26  by pump bracket  28 . Air is discharged through collective hoses  29 . 
     FIG. 4 shows a variant of the adjustable rod transmission wherein input is rotary but may be selected from any appropriate source including non-rotary manipulation. Output may be selective in amplitude, timing, duration and direction. 
     In accordance with the invention, bearing mount  10  through which input shaft  11  rotates slotted crank arm  12  and adjustable journal  14  to oscillate flexible rod  15 . Flexible rod  15  is shown extending through journal  14  and terminating in compression fitting  25   b , which is secured fixedly to stationary bracket  16 . Numeral  17  shows takeoff levers of various lengths and positions selectively secured along flexible rod  15 . Wire cables  31  are shown attached to levers  17  with set screws  33 . Cable stops  31   a  are provided to allow slippage of wire cable  31  for determining duration of stroke. Wire cables  31  are guided through cable guides  32  to operate valves, switches or light mechanical apparatus. Cable guides  32  are held stationary by the provision of set screws  34  in stationary bracket  16 . 
     An advantage of the invention is that the output levers may be easily placed in various positions along and around flexible rod  15  to achieve different or synchronous oscillatory periods and amplitude. 
     Unlike prior oscillating devices, the flexible rod oscillating member of the present invention has a curved profile. This novel feature provides a selection of locations from which to place output levers that provide different degrees of oscillation. Therefore, a single rotary input may be employed to operate a plurality of output levers with selective output properties. 
     Another advantage of the invention is that in addition to selecting amplitude of oscillation of individual output levers, total amplitude of all output levers may be selectively adjusted by moving journal  14  in slotted crank arm  12 . Although the preferred embodiment shows an adjustably journalled crank member, a fixed journal may be employed without departing from the principles of the present invention. 
     An improvement of the present invention is that the number of parts required for basic operation of the conversion device is reduced and the remaining elements are simple and have few lubrication requirements. Because of these improvements, the cost of operation and manufacture is substantially reduced. 
     While a specific embodiment of the invention has been shown and described in detail to illustrate the principles, it will be understood that the invention may be embodied otherwise without departing from such principles.