US2905011A

US2905011A - Minimum shaft positioning means

Info

Publication number: US2905011A
Application number: US635309A
Authority: US
Inventors: William J Armstrong; Pearlie K Myhre
Original assignee: Collins Radio Co
Current assignee: Collins Radio Co
Priority date: 1957-01-22
Filing date: 1957-01-22
Publication date: 1959-09-22
Anticipated expiration: 1976-09-22

Description

Sept. 22, 1959 w. J. ARMSTRONG ETAL 2,905,011

MINIMUM SHAFT POSITIONING MEANS Filed Jan. 22, 1957 6 0 26b 33b 2 a. 326

27a 52b 62a J/b A T'TORNE Y6 United States Patent 6) SHAFT Posmoun's'o 1 Application January 22:, 1957, Serial No. 635,309

5 C a ms This invention relates generally to means for positioning a pair of slideable members with a minimum. number of coupling devices.

Often, tunable plungers in an electronic waveguide must be separately positioned, and the positioning means must pass through electrical fields within portions of the waveguide. Patent application No. 579,639 titled U.H.F. 1mpedance Matching Means of Edwin N; Phillips describes such a waveguide device. It is, therefore, desirable to have a minimum number of positioning devices to minimize disturbances to the electrical field. The plunger s are adjusted cooperatively to positions that provide a required impedance situation in the waveguide.

A conventional way of positioning such plungers is to connect one or more shafts to each plunger, shafts connected to the first plunger slideably pass through openings in the second plunger. Thus, a ofone shaft is. conventionally required per plunger, with two positioning shafts being required'fortwo piungers. The sheits ere generally ma i ee dhe ih met i a ie 121eveht radiation ugh the openi n he eeeehd. plun er, but the conducting material eauses eleetrieai losses within the waveguide. e

h invention pe mit red e eh b in -hal e minimum numberof shafts necessary to. obtain the abovementiened yp of p et en- Thu th n enti n pe m ts a single shaft to independently position two plungers e invention u e a hr aded eheft w th e nsitudinal slot. The shaft threadedly passes through one ad: iusieble member (w ic ma e a wa e ui e Plunger) and i rotetebly e ve but axial y h red. n a o he eeli s member h the be; another a eguid plunger). Also, the shaft is threadedl y reoeived through a first driving means, which is rotatably held by a guide me t de b su p r s he st and. second ediusteble em see ed i ing me he e se supported rotatably with respect to the guide; the shaft slideably passes throughit, except that the longitudinal slot in the shaft slideably engages .a key member fixed to the second driving means.-

p e rotation of t e st nd seeeh dri ng means can independently p t n t e ir and 2 14. ediheiehl members through the single shaft Further je e t e an advan a es of this. i venn l be pp e t a pe so hi ed in the a t nen f r r u y of e pe fiee ieh end sin e. fi u e. h eh is a partially sectioned isometric view of a form of the invention.

NOW e e ng to t e aw n a u de .0. is ee p of an outer cylindrical member 11 and an inner cylindrical member 12 concentrically supported by an end member 13,. Guide may, for example, be a terminal part of a coaxial type of waveguide used for the transmission of radio-frequency energy. For electrical reasons, a pair of

plunger members

16 and 17 are required which must be separately positionable.

First plunger member 16 is a metallic disc having a central opening and is slideably received between the inner Pat n S p 22,, 9

n e t r e hdr e m mbe 2 en 11-. Se on p unger mpri e eh e metellie r ng n e er h telh n 21. and i mfn etr e meme: 23, Inner ring 21 is slideably received about inner cylin drical niernber'lzj and outer ring 22 is slideably received against the inner surfaoe of outer cylindrical member 11 A pair of shafts 26c; and 26b are provided to

position plungers

16 and 17. Here, the two, shafts obtain mechanb cal symmetry, due to the, central mechanical obstruction caused by inner conductor 12 However, only one of

shafts

26a and 26b is required for the positioning function taught by this invention. For example, if inner cylindrical member 12 were not there, a single shaft could be provided centrally with respect to the plunger members, which would have mechanical symmetry and could pro vide the entire required positioning functions. Any number of shafts may be used to provide mechanical symmetry. However, must always be realized that only one of such shafts is necessary for the positioning functions obtained by this invention.

Accordifighl, each of the shafts 26g and 26b is formed in the same manner; and the same reference numerais are used with respectfto each shaft, except for a diiferent letter sufiix. Each shaft is threaded throughout its length; except for its uppermost portion in the figure. Further, each shaft is forgrned with a longitudinal slot 271: or b which extends through most of its length. In the figure, the upper non-threaded portion of each shaft is rotatably' received by second plunger member 17*. This portion is formed with a pair of grooves which receive retaining rings 25 that are positioned against opposite sides of plunger 17 to bind them axially but topermit freerotation between them. The

shafts

26a and 26b are also threadedly received through first plunger 16. Thus, rotation of the shafts causes relative movementbetween them and first plunger 16.

First driving; members 2811 and 28b threadedly receive

shafts

26a and 26b and are supported axially by end member 13 through ball bearings 31, which are reoeived in races fixed with the respective members. Thus, first driving

members

28a and 28b are fixed axially with re spect to guide 10- but can rotate relative to it.

A gear 32a or b is fa stened to the bottom end of each first driving, member 2801 and 2819; and a pair .offianges 33a and b and 34a and b are fixed on opposite sidesiof gears 32a and b. A ring gear 36 is formed with inner and outerteeth, with its inner teeth engaging each of first driving members 32a and 32b. The flanges of the first driving member provide support for first ring gear 36. i

A first pinion 41 engages the outer teeth of first ring gear 36. A control shaft 42 is fixed to pinion 41 and is rotatably and axially supported by a bearing 43 fixed with respect to guide 10. A first control knob 44 is fixed to the end of shaft 42. i

A pair of second driving members 51a and 51b is also received about the respective shafts 26a and b. Unlike first driving

members

28a and 28b, each second driving member 51a and 51b does not threadedly engage its

shaft

26a or 26b. Rather, members 51a and 51b each have a key 52a or 52b fixed with it to slideably engage the longitudinal slot 27a or b formed init-s shaft 26a or b. A gear 50a or b. bounded by a pair of flanges 53a or b and 54a 01' b is fastened to an end of each second driving member- 5 1a or b. A second ring gear 56 has inner teeth which engage gears50a and 50b, I i

1 A e ie'p ien 57 engage h en r t e h et'sel eee ring gear 56 and has a flange 58 which provides support for second ring gear 56. A second control shaft 61 fixes a knob 62 to second pinion 57; and a bearing 63, fixed with respect to guide 10, rotatably supports: them.

The flange supports for the gears shown in the figure are merely illustrative, and it will be obvious to a person in the art, after an understanding of the invention is obtained, how to provide supporting means for the various gears in a given situation.

. In operation,

plunger members

16 and 17 can be independently positioned within guide by rotation of control knobs 44 and 62. Sufficient friction is assumed in the system so that either control knob can be rotated without causing rotation of the other control knob. If sufficient friction is not inherent in the system, drag means (not shown) such as well-known types of worm-gears can be provided for gears 41 and 57.

A positioning cycle is obtained by first positioning plunger member 16 with first knob 44. (Although rotation ofknob 44 also moves second plunger 17, its movement is unimportant at this time.) However, second plunger member 17 is then singularly positioned by rotation of second knob 62.

In more detail, when first knob 44 is rotated, second knob 62 is non-rotative due to friction, and

keys

52a and 52b are, therefore, non-rotative. Accordingly, threaded

shafts

26a and 26b cannot rotate relative to guide 10. Consequently, when first knob 44 is rotated under these conditions, it causes rotation of

first driving members

28a and 28b through pinion 41, ring gear 36 and gears 32a and b. Since the shafts cannot rotate, the threaded actuation between each of them and their

driving members

28a and 28b causes them to move longitudinally without rotation with respect to guide 10. Longitudinal movement Without rotation of

shafts

26a and 26b obviously moves first and

second plunger members

16 and 17 together, maintaining a fixed spacing between the plungthreadedly receiving said shaft, a second driving member, said shaft slideably received through said second driving member, a key fixed to said second driving member and slideably received in said shaft slot, first means for rotatably actuating said first driving member, and second means for rotatably actuating said second driving member.

2. Means for positioning a pair of plunger members slideably received in a guide, comprising a plurality of shafts, each threadedly engaging one of said plunger members and rotatably engaging the other of said plunger members, an axially-fixed connection being provided with said rotatable connections between said shafts and said other plunger member, a plurality of first driving members, each rotatably supported but axially fixed to said guide, said shafts respectively and threadedly received through said first driving members, a first plurality of gears coupling said first driving members, a plurality of second driving members, each slideably receiving a different one of said shafts, each of said shafts formed with a longitudinal groove, a plurality of keys fixed to said second driving members respectively and slideably engaging the respective slots of the received shafts, and a second 7 plurality of gears coupling said second driving members.

ers. Thus, first plunger member 16 can be positioned where required by rotating first knob 44.

When second knob 62 is rotated and first knob 44 is non-rotative due to friction, first driving members 28a and b are maintained non-rotative. Rotation of second knob 62, however, causes rotation of second driving members 51a and 51b through gears 50a and b, 56 and 57; and, accordingly,

shafts

26a and 26b are rotated because of their keyed connection to second driving members 51a and 51b. Since first driving

members

28a and 28b are now non-rotative, the rotation of the shafts through their threaded connections moves the shafts axially with respect to the guide 10. Accordingly, plunger member 17 moves with

shafts

26a and 26b because they are axially connected. However, first plunger member 16 does not move with respect to guide 10, because each unit of axial movement of

shafts

26a and 26b caused by their rotation in

first driving members

28a and 28b causes them to move second plunger 16 back relative to the shafts by an equal amount in the opposite direction, since the thread pitch is the same in each case. Accordingly, first plunger 16 does not move relative to guide 10. Hence, only second plunger member 17 is moved relative to guide 10 by the sole rotation of second knob 62.

Although this invention has been dwcribed with respect to a particular embodiment thereof, it is not to be so limited as changes and modifications may be made therein which are within the full intended scope of the invention as defined by the appended claims.

We claim:

1. Means for positioning a pair of plunger members with respect to a guide member, comprising a shaft received through and threadedly engaging one of said plunger members, said shaft rotatively received by the other of said plunger members, means axially fastening said shaft to said other plunger member, said shaft being formed with a longitudinal slot, a first driving member rotatably supported by but axially fixed to said guide and 3. Shaft positioning means comprising a guide member, first and second plungers slideably received by said guide member to enable relative linear movement, a threaded shaft formed with a longitudinal slot, said shaft rotatably received by and axially fixed to said second plunger, and said shaft threadedly engaging said first plunger, a first driving member rotatably received by and axially fixed to said guide member, said shaft being threadedly engaged by said first driving member, first means for selectably rotating said first driving member, a second driving member rotatably but axially fixed with respect to said guide member, said shaft passing through said second driving member, and a key locked with said second driving member and slideably engaging the longitudinal slot in said shaft, and second actuating means for selectably rotating said second driving member. 4. A coaxial wave-guide having first and second plungers slideably received therein, a plurality of shafts, each shaft rotatably supported but axially fixed to said second plunger, each shaft threadedly engaging said first plunger, and supporting means fastened to an end of said waveguide, a plurality of first driving members rotatably supported by but axially fixed to said supporting means, said first driving members threadedly engaging said shafts respectively, a plurality of first gears respectively coupled to said first driving members, a first ring gear simultaneously engaging said plurality of first gears, a plurality of second driving members, each being axially fixed but rotatable with respect to said wave-guide, said shafts respectively and slideably received through said second driving members, said shafts respectively formed with longitudinal slots, a plurality of keys locked respectively with said second driving members and slideably engaging the respective slots of their received shafts, a plurality of second gears respectively coupled with said second driving members, and a second ring gear simultaneously coupling said plurality of second gears.

5. Positioning means as defined in claim 4 having a first drive gear engaging said first ring gear, first knob means coupled to said first drive gear, a second drive gear engaging said second ring gear, and second knob means coupled to said second drive gear.

References Cited in the file of this patent UNITED STATES PATENTS 2,796,587 Phillips June 18, 1957