Background of the Invention
Numerous electrically operated rotary actuator devices have been created. However, so far as is known, all of the prior art rotary actuator devices have, by necessity, been built for a predetermined degree of rotative or angular operation and have not been adjustable in degree of rotative angular movement. Therefore, in known prior art devices, a different rotary actuator device is required for each different desired angle of rotative operation.
Also, known rotary actuator devices have included magnetizable circuits which are relatively inefficient.
Known rotary actuator devices have employed involved means for attempting to maintain all movable elements in proper relative positions.
In known rotary actuator devices problems frequently occur in the mechanism when the device is electrically deenergized prior to completion of its cycle of operation or is mechanically prevented from completion of its cycle of operation.
Thus, an object of this invention is to provide rotary actuator mechanism in which all of the components thereof are maintained in a simple manner in proper relative positions, regardless of the degree of angular movement between members thereof.
Another object of this invention is to provide rotary actuator mechanism which can rotatively move through a maximum angle of operation and which can be adjusted to rotatively operate through any angle less than the maximum angle.
Another object of this invention is to provide electrically operable rotary actuator mechanism which has a very high degree of efficiency in the magnetizable circuit thereof.
Other objects and advantages of this invention reside in the construction of parts, the combination thereof, the method of production, and the mode of operation, as will become more apparent from the following description.
Brief Description of the Views of the Drawing
FIG. 1 is a perspective view showing rotary actuator mechanism of this invention.
FIG. 2 is an exploded perspective view of the mechanism of FIG. 1.
FIG. 3 is an enlarged fragmentary sectional view taken substantially on line 3--3 of FIG. 2.
FIG. 4 is an enlarged end elevational view of the rotary actuator mechanism of FIGS. 1 and 2.
FIG. 5 is a sectional view taken substantially on line 5--5 of FIG. 4.
FIG. 6 is a sectional view taken substantially on line 6--6 of FIG. 4.
FIG. 7 is a sectional view similar to FIG. 6 but showing the mechanism in still another position of operation.
FIG. 8 is a fragmentary sectional view of a portion of the mechanism illustrated in FIGS. 6 and 7, but with the elements in another position of operation.
FIG. 9 is a layout type of view showing the ball members and the elements engaged thereby.
FIG. 10 is a layout type of view, similar to FIG. 9 but illustrating the elements shown therein in another position of operation.
Detailed Description of the Mechanism of the Invention
The rotary actuator mechanism of this invention comprises a magnetizable cup-shaped base member 20, which has mounting studs 22 extending from a wall 24 thereof. Secured to the wall 24 and positioned within the base member 20 is a tubular core 28. Within the tubular core 28 is any suitable bearing member, herein shown as being a sleeve bearing 30. Extending through the sleeve bearing 30 is a shaft 34, which is rotatably and axially movable within the sleeve bearing 30. The shaft 34 is of non-magnetizable material. Threadedly positioned upon the shaft 34, exterior of the base member 20, is an adjustment nut 36 and a jam nut 38.
Within the base member 20 and encompassing the tubular core 28 is a coil 40, having connection leads 42 extending therefrom. Encompassing the base member 20 integral therewith or secured thereto by suitable means such as welds 43 or the like, is an annular engagement member 44. The engagement member 44 has a plurality of substantially parallel inclined engagement surfaces 50. One end of each of the inclined engagement surfaces 50 is connected by an arcuate notch 51 to an edge surface 52. The other end of each of the inclined engagement surfaces 50 is connected by an arcuate notch 56 to an intermediate surface 58. Each intermediate surface 58 is also joined to the adjacent edge surface 52 by an offset 60.
Also encompassing the base member 20 is an annular magnetizable engagement member 64 which has an end wall 66. The engagement member 64 has a plurality of inclined engagement surfaces 68, which are substantially parallel to the inclined engagement surfaces 50 of the engagement member 44. One end of each inclined engagement surface 68 is connected to an edge surface 70 by an arcuate notch 72. The other end of each of the inclined engagement surfaces 68 is connected to an intermediate edge surface 74 by an arcuate portion 75. Each intermediate edge surface 74 is also joined to the adjacent edge surface 70 by an offset 76.
A ball 80 is normally positioned between each inclined engagement surface 50 of the engagement member 44 and one of the inclined engagement surfaces 68 of the engagement member 64. The balls 80 are rotatively supported at the periphery of an annular carrier 81.
The end wall 66 of the engagement member 64 has an output shaft 84 secured thereto or integral therewith and extending therefrom. Also secured to the wall 66 or integral therewith and at least partially positioned within the annular coil 40 is a magnetizable plunger 86. The plunger 86 is coaxial with the shaft 34 and is joined thereto by any suitable means, such as by means of a pin 88 which extends through the plunger 86 and the shaft 34.
Encompassing the engagement members 44 and 64 is a coil spring 90 which has one end attached to the engagement member 44 by any suitable means, such as by means of an annular strip 92 which encompasses the engagement member 44 and which is attached thereto in any suitable manner. The coil spring 90 has an end portion 94 which is attached to the strip 92. The coil spring 90 has an opposite end 95 which is attached to a tab 96. Intermediate portions of the coil spring 90 extend through guide members 100 and 102.
As best shown in FIG. 4, the exterior surface of the wall 66 may, if desired, be provided with degree number indicia. A pointer 110 is carried by a stem 112 which is attached by any suitable means to the engagement member 44. The pointer 110 is positioned adjacent the degree number indicia on the exterior surface of the wall 66.
Operation
The mounting studs 22 are adapted to be secured to any suitable stationary structure for support of the rotary actuator mechanism of this invention. The shaft 84 is adapted to be attached to a suitable load for rotative or angular movement thereof.
When the coil 40 is electrically energized through the leads 42, such energization causes magnetization of the core 28, the plunger 86, the base member 20, the wall 24, the engagement member 44, the engagement member 64 and the wall 66. Thus, such magnetization causes movement of the plunger 86 toward the core 28 and movement of the engagement member 64 toward the engagement member 44. However, such movement of the engagement member 64 toward the engagement member 44 results in rotative movement of the engagement member 64 with respect to the engagement member 44, due to the fact that the inclined engagement surfaces 68 and 50 with the balls 80 therebetween permit axial movement of the engagement member 64 with respect to the engagement member 44 only if rotative movement therebetween also occurs.
Thus, upon energization of the coil 40, the engagement member 64 rotatively moves in a counter-clockwise direction, as illustrated in FIGS. 4 and 7. When such rotative movement occurs, the balls 80 rotatively move upon the inclined engagement surfaces 50 and 68. FIGS. 5, 6, and 9 show the engagement member 64 in a deactuated position. In the de-energized position the nut 36 is in engagement with the core 28, as shown in FIG. 5. When energization of the coil 40 occurs, the engagement member 64 begins to rotatively move counter-clockwise from the position thereof shown in FIG. 6, to the position thereof shown in FIG. 7.
As this rotative movement of the engagement member 64 occurs, each of the balls 80 rotatively moves the arcuate notches 56 and 75 toward the arcuate notches 51 and 72. Thus, each ball 80 moves along an inclined engagement surface 50 of the engagement member 44 and along an inclined engagement surface 68 of the engagement member 64. Thus, there is relative rotative movement between the engagement member 44 and the engagement member 64.
FIG. 8 illustrates an intermediate rotative position of the engagement member 64 and one of the balls 80.
For maximum rotative movement, the engagement member 64 rotatively moves until each ball 80 is positioned within an arcuate notch 72 of the engagement member 64 and an arcuate notch 51 of the engagement member 44, as shown in FIG. 7.
At this rotative position of the engagement member 64, the "0.degree." indicia shown in FIG. 4 on the outer surface of the wall 66 is in position directly below the pointer 110. Also in this position of the engagement member 64, the shaft 34 has moved axially and rotatively within the bearing 30, so that the nut 36 is spaced a maximum distance from the core 28, as illustrated in FIG. 7.
With such rotative movement of the engagement member 64, the output shaft 84 also rotatively moves. Thus, a work element attached to the output shaft 84 is rotatively moved through the same angle as is in the engagement member 64. Such rotative movement of the engagement member 64 is against the forces of the coil spring 90. Thus, when the electrical coil 40 is de-energized, the coil spring 90 causes the engagement member 64 to rotatively move in a clockwise direction until the nut 36 again engages the core 28, as shown in FIG. 5. It is to be understood, however, that any suitable means, other than the coil spring 90, may be employed for return movement of the engagement member 64.
If it is desired to limit the rotative movement of the engagement member 64 and thus limit the rotative movement of the output shaft 84, the nut 36 is threadedly moved upon the shaft 34 so that when the engagement member 64 is in its deactivated position, the degree indicia below the pointer 110 is less than the maximum degree. Such position of the engagement member 64 may be substantially as shown in FIG. 8. In such position, each of the balls 80 is located in an intermediate position.
After the nut 36 is threadedly moved to its desired adjusted position to establish the operative angle of rotative movement of the engagement member 64, the jam nut 38 is threadedly moved into engagement with the nut 36 to lock the nut 36 in position upon the shaft 34.
Thus, it is understood that rotary actuator mechanism of this invention is operable through a large angle. The maximum angle may be at least 115.degree. or 120.degree. degrees. Furthermore, the rotary actuator mechanism of this invention may be adjusted to rotatively operate a load to any desired degree less than the maximum. Thus, one actuator device of this invention can be employed for operation of any one of numerous types of rotary loads.
Due to the fact that the balls 80 are secured in relative positions and rotatively carried by the annular carrier 81, the relative positions of the balls 80 cannot change. Thus, the angular movement between the engagement members 64 and 44 can be stopped an any desired position without interference with the proper relative positions of the balls 80 and the other elements of the rotary actuator mechanism of this invention. Thus, the desired angle of rotative movement can be adjusted. Also, if for any reason the movable engagement member should be prevented from movement to its fully adjusted angle of movement, no trouble is involved within the actuator mechanism.
Due to the fact that magnetic airgap formations within the mechanism of this invention are a minimum in length, very high magnetic efficiencies are possible in the rotary actuator mechanism of this invention.
Although the preferred embodiment of the device has been described, it will be understood that within the purview of this invention various changes may be made in the form, details, proportion and arrangement of parts, the combination thereof, and mode of operation, which generally stated consist in a device capable of carrying out the objects set forth, as disclosed and defined in the appended claims.