US3680015A

US3680015A - Improved hinge means for a rotary solenoid armature

Info

Publication number: US3680015A
Application number: US93157A
Authority: US
Inventors: Raymond J Ganowsky
Original assignee: Cliftronics Inc
Current assignee: Cliftronics Inc
Priority date: 1970-11-27
Filing date: 1970-11-27
Publication date: 1972-07-25
Anticipated expiration: 1989-07-25

Abstract

In a rotary solenoid having a hinged armature and converter means between the armature and a rotary shaft for transmitting arcuate pivotal movement of the armature into rotary movement of the shaft, the improvement wherein the hinge is a flexible hinge, preferably a one-piece thin metal strip, connected at one side thereof to the armature and at the other side thereof to a solenoid casing.

Description

United States Patent Ganowsk Jul 25 1972 s41 IMPROVED HINGE MEANS FOR A 3,048,749 8/1962 Koehler ..33s/274 ROTARY E ID A M TUR 3,505,629 4/1970 Krautwald et a1 ..335/276 X [72] Inventor: Raymond J. Ganowsky, Clifton Springs, Primary Examiner George Harris Attorney-Schovee & Boston [73] Assignee: Cliitronics, Inc., Clifton Springs, NY. 22 Filed: Nov. 27, 1970 [57] ABSTRACT {21] AppL No; 93 157 In a rotary solenoid having a hinged armature and converter means between the armature and a rotary shaft for transmitting arcuate pivotal movement of the armature into rotary [52] :LS. CII ..335/228, movement of the shaft the improvement wherein the hinge is {g 274 276 a flexible hinge, preferably a one-piece thin metal strip, con. 21 5 nected at one side thereof to the armature and at the other side thereof to a solenoid casing. [56] References Cited UNITED STATES PATENTS 12 Claims, 3 Drawing figures 3,419,831 12/1968 Ganowsky ..335/272 X IO 78 7 0 4 4e 4 40 68 6O 52 50 "II 42 N I l6 I 36 I4 HINGE MEANS FOR A ROTARY SOLENOID ARMATURE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to rotary solenoids of the hinged armature type and more particularly to an improved hinge for use therein.

2. Description of the Prior Art In the rotary solenoid described in U.S. Pat. No. 3,419,831, the armature is connected to the solenoid housing by a pin hinge. This construction is expensive in that the solenoid housing has to have two broach or mill cuts on the open end, so that two ears are left, and then the ears have to be drilled and then de-burred. The dimension separating the ears is critical due to the fact that said dimension locates the armature in the lateral direction, which in turn locates the armature cam race in relationship to the output shaft. lfthe armature cam race is not located in the proper position in relationship to the cam race in the output shaft, the ball will not track properly, thereby reducing life and torque of the solenoid. The dimension between the center line of the drilled holes in the ears to the axis of the shaft is also critical. This dimension also locates the armature with respect to the shaft and has a similar effect on solenoid performance and operation as does the abovementioned dimension between the ears. The armature itself also has a critical dimension in the dimension between the outer surfaces of the two extensions, because this also affects the cam location. If the armature extensions fit too loosely within the housing ears, the armature can shift from side to side causing cam mismatch and stroke position change. If the armature extensions fit too tightly in the housing ears, large amounts of solenoid force are used in overcoming the friction, and the solenoid return spring has to be set at too high a torque value for returning the armature. In summation, it can be stated that the various inter-relationships of the various critical dimensions is complex and results in a solenoid difficult and expensive to control in production. Even if all parts initially fit properly, wear would cause the solenoid to loosen up and the various dimensions to change.

It is therefore an object of the present invention to provide an armature hinge which is easy to locate on the housing so that the cam will be located correctly.

It is another object of the present invention to provide an armature hinge that cannot shift from side to side and is not affected by long life wear.

It is a further object of the present invention to provide a hinge that is stable, has long life characteristics, has no dimensional inter-relationships which prevent the cam from being located perfectly every time, and which will not wear dimensionally, so that the stroke position will not change during the life of the solenoid.

SUMMARY OF THE PRESENT INVENTION A solenoid housing or casing is machined with a flat top surface to receive the armature and the flexible hinge assembly of the present invention; thus all drilling, breaching, and hand de-burring of the housing is eliminated. The armature is a simple stamping with a'broach or mill cut on the top rear section to form an angle nest, to which the armature side of the flexible hinge assembly of the present invention will be projection welded. The hinge assembly of the present invention includes a flexible metal strip and retainer blocks. In the housing side of the hinge assembly, the metal strip is held between a pair of retainer blocks comprising a lower housing block (to be welded to the solenoid housing) and an upper hinge block. The hinge block overlies a rear edge of the armature, and the housing block abuts the armature, whereby the hinge block keeps the rear edge of the armature from lifting up when the solenoid is energized. After the housing and hinge blocks are connected to the housing side of the metal strip, the armature side of the hinge assembly is connected to the armature. This is done in a fixture which butts the armature up tight against the housing block, and then an armature block is positioned over the metal strip and is welded to the flexible hinge and to the armature, holding the hinge assembly tightly to the armature. The flexible hinge has holes through which projections on the retainer blocks protrude, so that when the welds are made, excess material fills the holes locking the hinge in place. This insures that there will be a minimum of heat applied to the metal strip which could cause warping. The armature is then precisely located, prior to welding to the solenoid housing, by inserting a close fitting plug into the bore of the solenoid coil having a matching male ball or cam race to match the cam race in the armature. The armature is then clamped in the welder and welded, holding the correct position. In this manner, all production tolerances are eliminated.

BRIEF DESCRIPTION OF THE DRAWING hinge assembly of DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT With reference now in detail to the drawing, FIG. 1 shows a rotary solenoid 10 using a flexible hinge 12 according to the present invention. Before describing the details of the hinge l2, brief reference will first be made, for convenience, to the construction of the preferred rotary solenoid in which the hinge 12 of the present invention is used. Except for the hinge 12, the other parts of the solenoid 10 are known, see for example, U.S. Pat. No. 3,419,831.

The solenoid 10 comprises generally a machined or formed housing 14 provided with annular groove 16 in a top surface 18 thereof. A suitable annular solenoid coil winding 20, at least partly encapsulated in an epoxy resin layer 22, is positioned in the groove 16. Rigidly aflixed to the bottom of the housing 14 are a pair of suitable mounting bolts or lugs 24. Mounted on the bottom of the housing 14 is a torsion return spring 26 suitable for attachment to a rotary output shaft 28, for returning the output shaft 28 to its arcuate orientation, shown in FIG. 1, which it occupies when the solenoid 10 is not energized. A spring retainer 30 holds the spring 26 onto a bottom surface 32 of the housing 14.

The output shaft 28 is rotatably mounted, by suitable bearing means, in a suitable output shaft cylindrical bushing or bearing 34, which bearing is wedged within a central opening 36 of the housing 14.

A clapper l8 armature 40 is hingedly connected to the top surface 30 of the housing 14 by means of the flexible hinge 12 of the present invention. A dustcover 42 is connected to the housing 14 and encloses the armature 40. The armature 40 includes an opening 44 through which an adjustable limit screw or post 46 extends, for limiting the upward movement of the armature 40, and for varying the rotary stroke of the output shaft 28. Converter means 48 are provided between the armature 40 and the output shaft 28 for imparting rotary movement to the shaft 28 in response to arcuate movement of the armature 40 when the solenoid 10 is energized. The converter means 48 are preferably of the same type described in detail in U.S. Pat. No. 3,419,831. The converter means 48 comprises a single ball 49 that coacts with a pair of oppositely inclining converter

ball race cams

50 and 52 in the lower surface of the armature 40 and in the upper surface of the output shaft 28, respectively.

Referring now in detail to the hinge 12 of the present invention, the hinge 12 comprises a thin, flexible metal strip 60 of generally rectangular shape connected adjacent one side 62 thereof to the armature 40 and adjacent another side 64 thereof to the top surface 18 of the housing 14. The flexible hinge 12 comprises the thin metal strip 60 and a plurality of retainer blocks, including a housing block 66, a hinge block 68 and an armature block 70. As is shown in FIG. 1, the hinge block 68 is mounted with a slight overlap over the armature 40 to restrain a rear edge 72 of the armature 40 to keep it from lifting up when the solenoid is energized. ln assembling the hinge 12, the housing block 66 is positioned in a fixture, the thin metal strip 60 is then positioned over the housing block 66, with two openings in the strip 60 in register with two small projections on the housing block 66. The hinge block 68 is then positioned in overlying relationship to the thin metal strip 60 and the assembly is projection or spotwelded together. This assembly is then welded to the armature 40 by positioning the thin metal strip 60 in a fixture and positioning the armature upside down and against the strip 60 and with the rear edge 72 of the armature 40 abutting the housing block 66. Then the armature block 70 is placed over the strip 60 adjacent the side 62 thereof and the block 70 and strip 60 are welded to the armature 40. The block 70 is placed in register with the strip 60 such that three projections in the armature block 70 (see projection 74 in FIG. 3) extend into three holes in the metal strip 60 (see hole 76 in FIG. 3). The projection 74 in FIG. 3 is shown for disclosure purposes as it appears prior to the projection welding step, after projection welding, the material of the projection 74 fills the hole 76. The hinge 12 must be welded tightly to the armature 40 to prevent any movement of the armature under load which would cause buckling of the thin metal strip 60 and sideways movement of the armature 40. The buckling of the strip 60 causes fatigue in the metal eventually cracking it and once cracking occurs the crack will probably propagate causing hinge failure. As already mentioned above, the strip 60 has holes therethrough through which projections on the retainer blocks protrude so that when the weld is made, the excess material fills the hole locking the strip 60 in place. Also the pressure exerted by the welder causes a clamping action between the parts so that when the weld cools, the spring is. clamped, for example, between the housing block 66 and the hinge block 68. This design provides for a minimum of heat being applied to the strip 60 which could cause warping. If the welding were attempted without these holes in the strip 60, or if the holes were too small, an excess amount of heat could be generated burning the strip 60 and/or annealing and warping could ensue causing eventual failure. On the other hand, if the holes are too large, reliance could only be placed on the clamping which could cause the strip 60 to work loose allowing the armature 40 to shift and resulting in degradation of solenoid performance. In the final assembly of the armature 40 to the casing 14, it must be stated that for the best performance, the cam 50 in the armature 40 must line up with the cam 52 in the output shaft 28, i.e., the ball 49 must track on the designed cam radius; if the radii are different, the forces cannot be transmitted through the center line of the ball due to cam angle mismatch, therefore, the ball would have to skid to make up for the distance it has to travel, and the skidding can cause extreme temperature increase on the surface of the ball causing pitting and eventual ball and cam failure. It is therefore imperative that the cams match as close as possible. By having a floating armature, and a flat surface to weld upon at final assembly, the armature 40 can be located by a close fitting plug which is inserted into the shaft bore of the bushing 34. This plug has a matching male ball or cam race to match the cam race in the armature-40. This locates the armature 40 so that the cam races match perfectly. The armature is then clamped in the welder and welded holding the correct position. In this manner all production tolerances are eliminated.

The plane normal to the axis of the shaft 28 and extending through the pivot line of the hinge 12 and the plane normal to the centerline of the shaft 28 and extending through the center of the converter ball 49, should come as close as possible to being the same plane. This is why a taper 78 exists on the rear top surface of the armature 40, i.e., to drop the pivot line down as close as possible to the plane through the center of the ball 49 and normal to the output shaft 28 axis. Another solution is to insert the cam 50 further into the armature 40. The lower the pivot line, the less friction caused at the rear of the armature 40. The preferred material for the strip 60 is 300 series stainless steel spring stock. Other materials can be used.

The invention has been described in detail with particular reference to the preferred embodiment thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

I claim:

1. In a rotary solenoid having a housing, an annular solenoid coil winding within said housing, an output shaft mounted for rotary movement within said winding, an armature movably mounted relative to said shaft responsive to the magnetic field of said coil winding and being hingedly connected to said housing for arcuate movement relative to said shaft, and converter means between said armature and said shaft for converting arcuate movement of said armature to rotary movement of said shaft, the improvement comprising a flexible hinge connecting said armature to said housing, and a plurality of retainer blocks connecting said hinge to said armature and said housing for preventing said armature from rocking from side to side and for preventing the hinged end of said armature from lifiing up when said solenoid is energized.

2. The apparatus according to claim 1 wherein said flexible hinge is a single thin metal strip welded at one side to said armature and welded at the opposite side thereof to said housing.

3. The apparatus according to claim 1 wherein said converter means includes ball means and wherein the hinge line of said hinge is approximately in the plane passing through said ball means and normal to said shaft.

4. In a rotary solenoid having a housing, an annular solenoid coil winding within said housing, an output shaft mounted for rotary movement within said winding, an armature movably mounted relative to said shaft responsive to the magnetic field of said coil winding and being hingedly connected to said housing for arcuate movement relative to said shaft, and converter means between said armature and said shaft for converting arcuate movement of said armature to rotary movement of said shaft, the improvement comprising a flexible hinge connecting said armature to said housing, said converter means including ball means, the hinge line of said hinge being approximately in the plane passing through said ball means and normal to said shaft, and wherein said armature includes a top surface having an angle nest, and said angle nest tapers from a top surface of said armature down toward a bottom surface of said armature, whereby said hinge line of said flexible hinge can be positioned in the plane passing through said ball means and normal to said shaft.

5. In a rotary solenoid having a housing, an annular solenoid coil winding within said housing, an output shaft mounted for rotary movement within said winding, an armature movably mounted relative to said shaft responsive to the magnetic field of said coil winding and being hingedly connected to said housing for arcuate movement relative to said shaft, and converter means between said armature and said shaft for converting arcuate movement of said armature to rotary movement of said shaft, the improvement comprising a flexible hinge connecting said armature to said housing, said flexible hinge being a single thin metal strip of generally rectangular shape welded at one long side thereof to said armature and at the other long side thereof to said housing, and including retainer blocks welded to said strip adjacent both of said long sides of said strip for keeping the strain of flexure off of the weld points of said strip.

6. The apparatus according to claim 5 wherein said retainer blocks include an armature block overlying said one side of said strip, and a housing block underlying said other side of said strip and abutting said armature and a hinge block overlying said other side of said strip.

7. The apparatus according to claim 6 wherein said hinge block overlaps said housing block to overlie the adjacent end of said armature to prevent said adjacent end of said armature from rising up when said solenoid is energized.

8. The apparatus according to claim 7 wherein said metal strip includes holes therethrough in register with projections on said blocks, and wherein the relative size of said holes and projections is such that excess weld material from said projections just fills said holes.

9. The apparatus according to claim 1 wherein said flexible hinge is a one-piece thin metal spring hinge.

10. The apparatus according to claim 1 wherein said housing is cylindrical and wherein said armature is substantially disc-shaped, having substantially the same circumference as that of said housing, wherein said housing includes a flat top surface and said armature includes a flat bottom surface overlying said flat top surface of said housing, said armature having a circular periphery except for a straight section, said hinge being connected to said armature adjacent said straight section, and said hinge being connected to said top surface of said housing at a portion thereof not overlain by said armature.

11. In a rotary solenoid having a housing, an annular solenoid coil winding within said housing, an output shaft mounted for rotary movement within said winding, an annature movably mounted relative to said shaft responsive to the magnetic field of said coil winding and being hingedly connected to said housing for arcuate movement relative to said shaft, and converter means between said armature and said shaft for converting arcuate movement of said armature to rotary movement of said shaft, the improvement comprising a flexible hinge connecting said armature to said housing, said housing being cylindrical, said armature being substantially disc-shaped, having substantially the same circumference as that of said housing, said housing including a flat top surface and said armature including a flat bottom surface overlying said flat top surface of said housing, said armature having a circular periphery except for a straight section, said hinge being connected to said armature adjacent said straight section, and said hinge being connected to said top surface of said housing at a portion thereof not overlain by said armature, said converter means including a ball, the top surface of said armature tapering down towards said flat bottom surface of said armature adjacent said straight section, and wherein said hinge is connected to said tapering portion of said armature for positioning the pivoting hinge line of said hinge in approximately the plane passing through the center of said ball and normal to the axis of said shaft.

12. An armature and hinge assembly for use in a rotary solenoid comprising a flat, disc-shaped armature having a top surface and a bottom surface, and having a straight edge peripheral section, a ball cam race recess in said bottom surface, an angle nest in said top surface comprising a surface section tapering downwardly from said top surface toward said bottom surface adjacent said straight edge section, and a flexible hinge welded to said armature at said tapering surface section and including a generally rectangular, flexible metal strip welded at one long side thereof to said armature and having another long side thereof projecting beyond said straight section, and an armature retainer block overlying said strip and welded to said armature and strip at said one side of said strip, and a housing retainer block underlying said another side of said strip and a hinge block overlying said another side of said strip, said housing and hinge blocks being welded together and to said strip with said housing block abutting said straight section of said armature and said hinge block slightly overlapping said straight section of said armature.

Claims

1. In a rotary solenoid having a housing, an annular solenoid coil winding within said housing, an output shaft mounted for rotary movement within said winding, an armature movably mounted relative to said shaft responsive to the magnetic field of said coil winding and being hingedly connected to said housing for arcuate movement relative to said shaft, and converter means between said armature and said shaft for converting arcuate movement of said armature to rotary movement of said shaft, the improvement comprising a flexible hinge connecting said armature to said housing, and a plurality of retainer blocks connecting said hinge to said armature and said housing for preventing said armature from rocking from side to side and for preventing the hinged end of said armature from lifting up when said solenoid is energized.

11. In a rotary solenoid having a housing, an annular solenoid coil winding within said housing, an output shaft mounted for rotary movement within said winding, an armature movably mounted relative to said shaft responsive to the magnetic field of said coil winding and being hingedly connected to said housing for arcuate movement relative to said shaft, and converter means between said armature and said shaft for converting arcuate movement of said armature to rotary movement of said shaft, the improvement comprising a flexible hinge connecting said armature to said housing, said housing being cylindrical, said armature being substantially disc-shaped, having substantially the same circumference as that of said housing, said housing including a flat top surface and said armature including a flat bottom surface overlying said flat top surface of said housing, said armature having a circular periphery except for a straight section, said hinge being connected to said armature adjacent said straight section, and said hinge being connected to said top surface of said housing at a portion thereof not overlain by said armature, said converter means incluDing a ball, the top surface of said armature tapering down towards said flat bottom surface of said armature adjacent said straight section, and wherein said hinge is connected to said tapering portion of said armature for positioning the pivoting hinge line of said hinge in approximately the plane passing through the center of said ball and normal to the axis of said shaft.