US2329635A

US2329635A - Permeability tuner operating mechanism

Info

Publication number: US2329635A
Application number: US392657A
Authority: US
Inventors: Philip K Mcgall
Original assignee: Johnson Laboratories Inc
Current assignee: Johnson Laboratories Inc
Priority date: 1937-12-24
Filing date: 1941-05-09
Publication date: 1943-09-14
Anticipated expiration: 1960-09-14
Also published as: GB522946A; FR847978A; US2253304A

Description

Sept. 14, 1943. P. K. M GAL L 2,329,635

v PERM EABILITY TUNER OPERATING MECHANISM Original Filed Dec. 24, 1937 4 Sheets-Sheet l Z INVENTOR. v

PHILIP K.Mc6A1 L.

BY Muir/36w Sept. 14, 1943. I P. K. M GALL PERMEABILITY TUNER OPERATING MECHANISM 4 Sheets-Sheet 5 Original Filed Dec. 24, 1937 PHILIP Kf I IE G BEL Sept. 14, 1943. P; K. M GA LL PERMEABILITY TUNER OPERATING MECHANISM Sheets-Sheet 4 Original Filed Dec. 24, 1957 INVENTOR. PHILIP K. McGALL ple and inexpensive to manufacture.

Patented Sept. 14, 1945 PERMEABILITY TUNER OPERATING MECHANISM Philip K. McGall, Orange, N. J., assignor to Johnson Laboratories, Inc., Chicago, lll., a corporation of Illinois Original application December 24, 1937, Serial No. 181,674. Divided and this application May 9, 1941, Serial No. 392,657

11 Claims.

My invention relates to an improved construction of permeability tuner for radio receiving sets and similar purposes, comprising a plurality of combined capacitance and inductance units susceptible of being tuned to res onance at different frequencies, by changing the effective inductance of the inductance coils of said units. A tuner of the kind referred to may consist of as many stages as desired, and it has the advantage of small bulk per stage, adapting the tuner for use in receivers where the larger bulk of variable condensers would be undersirable, if not prohibitive.

My invention also includes improved operating means for simultaneously and similarly vary ing the efiective inductance of the inductance coils of said .tuner, to the end that the several tuner units or stages may be simultaneously tuned to resonance at any desired frequency of alternating current impulses, within the range of the tuner. Said operating mechanism thus constitutes a gang control for tuning said units, and it is characterized by smoothness of action, absence of lost motion, positive operation, and mi-crometric effect, at the same time being sim- Said operating mechanism is also adapted for use for other purposes, as will more fully appear below.

This is a divisional application of my copending application, Serial No. 181,674, filed December 24, 1937, now 'Patent No. 2,253,304.

My invention will be best understood by reference to the accompanying drawings illustrating a preferred embodiment thereof, in which,

Fig. 1 shows my improved tuner in plan view;

Fig. 2 is a side elevation of the construction shown in Fig. 1;

Fig. 3 is a bottom view of the construction shown in Fig. 1;

Fig. 4 is a vertical, sectional view of the parts illustrated in Figs. 1 and 3, taken along the line 4-4 in the latter figures;

Fig. 5 shows in a view similar to Fig. 4 and to an enlarged scale, a part of the operating mechanism of the tuner, consisting of the devices used to hold the operating rod in operative relation to the operated rods of said operating mechanism, said operated rods being above said operating rod instead of below the latter as illustrated in Fig. 4;

Fig. 6 is a vertical, sectional view of the parts shown in Fig. 5, taken along the line 6-6 in that figure;

Fig. 7 is a horizontal, sectional view to an enlarged scale, of a part of the construction shown in Fig. 1, taken along the line 1-'! in that Fig. 8 shows in a view similar to Fig. 5, a modified construction of operating mechanism, in which one operated rod is employed instead of two of said rods as shown in Fig. 5;

Fig. 9 is a vertical, sectional view of the parts shown in Fig. 8, taken along the line 99 in that figure;

Fig. 10 shows in a view similar to Fig. 5, a further modified construction of operating mechanism, in which two operated rods are moved simultaneously in opposite directions by the operating rod, instead of in the same direction as illustrated in Fig. 5;

Fig. 11 is a vertical, sectional view of the parts shown in Fig. 10, taken along the line H--H in that figure;

Fig. 12 is a right handend view to an enlarged scale, of one of the operated rods shown in Fig. 3, and illustrates the manner of connecting said rods with the movable plate connected in turn with the cores of magnetic material to operate the same;

Figs. 13, 14 and 15 show respectively, modifled means for connecting said operated rods with said movable plate;

Fig. 16 is a vertical, sectional view of the parts shown in Fig. 15, taken along the line l6l6 in that figure;

Fig. 17 is a horizontal, sectional view of the construction shown in Fig. 1, taken along the line ll-ll, excepting that in this view the shield of the sectioned tuner unit is shown in side elevation, and the cover of the tuner is shown in place;

Fig. 18 illustrates in a view similar to Fig. 17, the combination of two tuners of the construction illustrated in Figs. 1 to 4 inclusive, to illustrate the tuning of two multi-stage tuners, by means of a single operating rod;

Fig. 19 illustrates diagrammatically, the adaptation 'of my improved tuner to a remote control system; 7

Fig. 20 is a horizontal, sectional view of a part of the structure shown in Fig. 4, taken along the line 20-40 in that figure; and

Figs. 21 and 22 illustrate respectively in views similar to Fig. 5, modified forms of operated rods for actuation by the operating rod.

Similar numerals refer to similar throughout the several views.

As shown in Figs. 1 to 4 inclusive, my improved tuner consists of a housing comprising a bent sheet metal plate l0 forming the front parts and side walls of said housing, and a sheet metal shelf II having front and side flanges secured respectively to the front and side walls of the plate I0. the front flange of said shell" extending upwardly and its side flanges extending downwardly. Said shelf II is also provided with adownwardly extending flange at its rear edge. Above the shelf II, the front wall of the housing has secured to it a plurality of blocks I2 of insulating material, each of which blocks supports with a sliding fit, the front end of a tubular support I3 of insulating material on which the inductance coil I4 of the corresponding unit of the tuner, is wound. The rear end of each insulating tube I3 is supported with a sliding fit,v

in a small plate I5 of insulating material which is in turn supported from the shelf I I by a metal angle bracket I6. As shown in Fig. 20, the front end of the tube I3 contains a cross member I! connected at its ends with said tube, which cross member is connected by a stud I8 with the central portion of a flat spring I9 resting at its ends against the corresponding block I2. A screw 20 threaded through the front wall of the tuner housing, rests at its inner end against the midportion of the spring I9, said spring having a conformation moving the tube I3 to its extreme forward position when the screw 20 is turned to move it forwardly away from the block I2. The spring I9 and the parts described as co operating therewith, constitute a means for moving axially the tube I3 and the coil I4 carried thereby, to align said coils relatively to each other for effective and accurate gang operation of the inductance changing devices respectively associated with said coils, by the common operating mechanism below described.

Each of the tubes l3 contains a core ll of magnetic material, preferably cornminuted magnetic material compressed into solid form, which core may move freely axially in the tube I3 to change as desired, the effective permeability of the magnetic path through and around the corresponding coil I l, and correspondingly changes the inclucfance of said coil. The rear end of each core 2! isconnected with a short rod 22, the rear end of which is connected with and supported by a small plate of insulating material 23, which, as shown in Fig. 7, is rigidly connected with the upper portion of metal bracket 24 extending through a slot 25 therefor in the shelf II, shown in Figs. 1 and 3. As shown in Figs. 3 and 7, the lower portion of each bracket 24 extends through an opening therefor in an operating plate 26, and is rigidly secured below said plate to a flange 26a extending downwardly from the rear edge of said operating plate.

As shown in Figs. 1, 3 and 4, the shelf II has formed therefrom upwardly projecting ribs 21 extending from front to rear of said shelf between the coils I4, forming corresponding grooves in the lower surface of said shelf. As shown in Fig. 4, each of the ribs 21 engages the lower portions of adjacent shields 28 provided to enclose the coils I4 and their cores 2|, to hold said shields against lateral movement, and centrally around said coils I4. Each of said shields 28 is provided with a longitudinal slot 28a in its bottom wall, to clear the corresponding bracket 24 and to also clear the connection between the the bracket I8 serves as a guide in moving the shield around the coil I4, and holds the shield adjacent the shelf II. Each of the blocks I2 fits in the open end of the corresponding shield 28, as a result of which the shields when in place, are held at their front ends against lateral movement in any direction. The rear ends of said shields are held against movement, as below described.

The operating plate 26 as shown in Fig. 3, is

shorter from front to rear, than the shelf II, so that its operating movement is equal to the tuning movement to be imparted axially to the cores 2I. The plate 26 is provided with upwardly extending ribs'29 fitting the grooves in the ribs 27, to guide the plate 26 in its movement under the shelf II. As shown'in Figs. 3 and 4, bars 30 and 3I extend horizontally from the front wall of the tuner housing to the rear flange on the shelf II, to which their ends are rigidly secured, the upper. edges of said bars being spaced slightly from the operating plate 26, the flange 26a. of which is provided with apertures through which said bars extend with sliding fits. In the spaces between the bars 30 and 3I and the plate 26, flat springs 32 carried by said plate are disposed which press the plate against the shelf II and hold the ribs 29 in sliding engagement with the grooves in the ribs 21. The lower edges of the bars 30 and 3I are somewhat above the bottom of the housing In, to clear the cover of the latter, as below described. The plate 26 thus constitutes a means for imparting simultaneous and equal movement to the cores 2|, making gang tuning of the several inductances possible for different frequencies within the range of the tuner.

As indicated diagrammatically in Fig. 4, each ofthe blocks I2 carries a flat capacitor 33 having

terminals

34 and 35, for connection with the terminals of the corresponding coil I4, which

terminals

34 and 35 are also the terminals of the corresponding unit of the tuner for connection as desired, according to the requirements of the circuit or hook-up with which the tuner is used, whether superheterodyne, tuned radio fre quency, or otherwise. The capacitors 33 are of any kind well known in the art and preferably provided with sufficient adjustment for aligning purposes, but are otherwise fixed.

In constructing the tuner, the coils M are wound to have as nearly as possible, identical electricalcharacteristics, and the cores 2| are made as closely as possible, duplicates as to dimensions and permeability. The coils and cores are then mounted as described, and by aligning the coils by the screws 20, the same inductance relation is established between each coil and its core, as between each. other coil and its core. Then, preferably with the cores drawn to the limit of their movement from Within the coils, each unit of the tuner is tuned to resonance by aligning adjustment of its capacitor 33, and the tuner as to all of its units or stages, is in tune or resonance for the highest frequency of the range of the tuner. Movement of the cores 2I into the coils I4 by the operating plate 26, equally increases the permeability of the magnetic paths of the several coils for any particular position of said cores, correspondingly and equally increasing the inductance of said coils and establishing a tuned or resonant condition of all of the units or stages of the tuner for any desired frequency within the range of the tuner, which is lower than the limiting high frequency of said range.

The means I employ to operate the plate 26, consists as shown in Figs. 3 and 4, of an operating rod 36 having rotary movement, which rod extends perpendicularly through one of the side walls of the housing l and through the bar 3|, a bushing 31 being mounted in said side wall to constitute a bearing for said rod, which rod is prevented from moving axially in said bearing by split rings 38 carried by said rod at the'ends of said bushing. Two operated rods 39 are mounted below the rod 36, between and parallel with the bars 30 and 3|, with their rear ends attached to the flange 26a. The rod 36 is provided with grooves 36a in line with the rods 39, in which grooves the rods 39 are held in frictional engagement by rollers 40 below said rods 39, said rollers 40 being pressed upwardly against said rods 39 and in turn pressing said rods upwardly into the grooves 36a, by a spring 4| extending at its mid-portion over and pressing downwardly against the rod 36, and at its ends extending under and pressing upwardly against the mid-portions of the rollers 40. In Figs. 5 and 6, the relation between the rod 36 and the rods 39 is more clearly shown. In these figures the rods 39 are above the rod 36 instead of below the latter rod as shown in Fig. 4, but the relation between said rods operatively, is the same in both cases. As shown in Fig. 5, the grooves 36a are provided with inclined side surfaces diverging outwardly, said grooves being deep enough to clear the surfaces of the rods 39 which are nearest the axis of the rod 36,

so that the rods 39 engage only said side surfaces. Between the grooves 36a, the rod 36 is provided with a groove 362) containing the midportion of the spring 4|, and the rollers 40 are provided at their mid-portions with groove 40a containing the end portions of said spring. The ends of the spring 4| are extended sufficiently around the rollers 40, so that in use, rotation of the rod 36 and the resultant longitudinal movement of the rods 39, will rotate the rollers and cause them to slip at their points of engagement with said spring, without changing the general relation of the spring to the rollers 4|]. By engaging the surfaces of the rod 36 and of the rollers 40 which are remote from the surfaces of engagement between the rod 36 and the rods 39, the tendency of the spring 4| to elongate or straighten, presses the rollers 40 towards the rod 36, and maintains the frictional engagement between the rod 36 and the rods 39. This produces a smooth and even longitudinal movement of the rods 39 by rotation of the rod 36, without any irregularity of action, which makes possible exact and smooth operation of the movable parts of the tuner, even in imperceptible amounts, 2. condition greatly to be desired in effecting exact tuning. As shown in Figs. 1 and 2, the rod 36 has secured to its outer end, an operating knob 42,. and the much greater diameter of the knob than the diameter of the surfaces of the rod 36 engaging the rods 39, gives the operating mechanism a micrometric action, which also facilitates exact tuning. It will be noted in Fig. 6, that the radius of curvature of the curved end portions of the spring 4| engaging the rollers 49, is substantially greater than the radius of curvature of the'surfaces of said rollers 4|] engaged by said spring. As a result, when the tuner is substantially in tune for. a desired frequency, and exact tuning is required, a small amount ctr-oiling action of the rollers on the spring 4| occurs without slippage of said parts on each other, which further facilitates effecting exact tuning, by lessening the drag on the operating rod 36.

With the operating mechanism described, several complete rotations of the rod 36 are required to move the plate 26 through its tuning range, and to afford an indication of the frequency for which the tuner is adjusted at any time, the plate '26 is provided with an arm 43 (Figs. 1, 2 and 3), extending through a slot 44 in a side wall of the housing |0 (Fig. 2), which arm is connected with an indicating pointer 45 adjacent a scale 46 on the housing, calibrated in any desired units. Obviously, any equivalent indicating means operated by the arm 43 may be employed as desired, depending upon the location of the tuner and the parts associated therewith in any case.

To enclose the operating mechanism, a cover plate 41 (Fig. 17) is employed. With the unit shields 28 in place as above described, the upper rear flange 41a of.the cover plateis located on top of the rear ends of said shields, the rear wall 411: of the said cover plate extends adjacent the rear end walls of the shields 28, and the bottom wall 410 of said cover plate extends horizontally in the bottom plane of the tuner housing ID, a front flange 41d on said cover plate extending. upwardly just inside of the front wall of the plate In of the tuner housing. The cover plate is of a width equal .to the distance between the side walls of the plate i0,

encloses the tuner, and produces a self-contained 7 structure that is much more compact than is possible by the use of conventional interleaved variable capacitors, which structure is a com plete multi-stage tuner that is thoroughly shielded and entirely enclosed, and requires in addition, only suitable radio tubes, a suitable current source, and wiring therefor, connected with the tuner in accordance with a desired hook- Lip or circuit, to make an operative tuning sys- It will be understood that I do not limit myself in constructing the tuners described, to the particular number of units illustrated, since each tuner may consist of as many units or stages as desired. In Fig. 18 I illustrate means that may be employed to operate and tune two complete tuners of the kind described, by a single operating rod. Part of a first-tuner as above described, is shown, having a housing It], a shelf shields 28, an operating plate 26 and an operating rod 36. A second similar tuner is shown, having a housing Illa, a" shelf Ila. shields 28b and an operating plate 26b, but no operating rod. The bottom edges of the housing H) are held against the bottom edges of the housing Illa, by a cover plate 48 secured to the rear flanges of the shelves II and Na, which cover plate has upper and lower flanges 48a extending over the end portions of the shields 28 and 28b. The front walls of the housings l0 and Illa are held together by a connecting plate 49 secured to said front walls. The

flanges

26a and 260 of the operating plates 26 and 26b respectively, are connected by plates 50 secured to said flanges as indicated. The operating devices connecting the operating rod 36 with the operating plate 26, are the same as above described. and are omitted in Fig. 18 for the sake oi clearness. As a result of the construction shown in Fig. 18, rotation of the rod 36 operates the plate 28 with the results above described, and at the same time operates the operating plate 26b of the second tuner with similar results as to the second tuner, and all of the units or stages of both tuners are thus simultaneously operated and tuned by means of a single operating rod. Thus a plurality of tuners, each complete for its intended purpose and consisting of as many stages as desired, may be simultaneously tuned by a single .operating rod, and said complete tuners may be severally used for any purposes desired and either simultaneously or alternately, for example, as tuning means for different frequency bands.

As illustrated in Fig. 19, my tuner described,

is adapted for use in any case where the tuning units must have one location and the operating means or controlling devices must have a second location which may be remote from said flrst location. In this figure my tuner is shown diagrammatically at H], its operating rod 36 being connected by a flexible shaft 5| with an operating knob 52 on a control board 53 remote from the tuner H]. The arm 43 of the tuner, is connected with a wire 54 extending through a tube 55 to the control board 53, where said wire is connected with a pointer 56 movable by said wire along a scale 51 carried by said control board. The ends of the tube 55 are supported by

brackets

58 and 59 carried respectively by the tuner l0 and the control board 53.

The manner of operating the frequency indicating pointer 56 as described, gives a correct indication at any time of the frequency to which the units of the tuner are tuned, in the system of units used in laying out the scale 51, regardless of whether there is slippage in the friction mechanism above described between the operating rod 36 and the cores 21, since the knob 52 is not relied upon to indicate by its angular posi- .tion, the frequency for which the tuner is set at any time. Although there is little probability of slippage between the operating rod 36 and the operated rods 39 described in connection with Figs. 3 to 6 inclusive, such slippage is possible unless prevented. I eliminate the possibility of such slippage to an appreciable extent, by securing to the inner end of the rod 36, a pinion 50 (Figs. 3 and 4), meshing with a rack 6| disposed parallel with the operated rods 39 which rack is rigidly secured at one end to the flange 26a. The other end 61a of the rack BI is in sliding engagement with the upper surface of the bar 30, thereby holding the rack in mesh with the pinion 60. The pitch diameter of the pinion 69 should equal the diameter of the contact circles in the grooves 36a with the rods 39 to insure against slippage between the operating rod 36 and the operated rods 39, due to the action of said pinion. I

The operated rods 39 may be connected with the flange 26a of the operating plate 26, in any one of a number of ways, several of which are shown in Figs. 12 to 16 inclusive. In each of these cases, each of the rods 39 is provided with a circumferential groove 39a near its end to facilitate said connection. In Fig. 12 the flange 26a is provided with an edge slot 26d fitting the groove 39a, and after the rod 39 is pressed to the bottom of said slot, an edge tongue 26s of the flange 26a adjacent said slot, is forced over and into the slot 26d and into the groove 39a, locking the rod 39 in said slot. In Fig. 13 the flange 26f is provided with clearance holes 269 for the rods 39, and after they are inserted in said holes with the adjacent parts of the flange 26) in the grooves 39a, the rods 39 are held in the position shown in Fig. 13 by a spring 62 bent at its midportion to go over the edge of the flange 26f with the ends of said spring on opposite sides of said flange and extending under and partly around and pressing upwardly on the rods 39 respectively. In Fig. 14, the flange 26h is provided with edge slots 26 fitting the grooves 39a in the rods 39, and when said rods are pressed to the bottoms of said slots, they are held in the position shown in Fig. 14 by a spring 63 bent at its midportion to go through a hole 291' in the flange, with the ends of said spring extending on opposite sides of said flange and over and pressing downwardly on said rods 39 respectively. As shown in Figs. 15 and 16, the flange 2670 is provided with a clearance aperture 26m for each of the rods 39, and a U-shaped metal clip 64 having similar clearance apertures through its legs, is employed. The clip is placed on the flange with the clip apertures in line' with the flange aperture 26m, the grooved end of a rod 39 is inserted through said apertures with the groove 39a in line with the flange 26k, and a set screw 65 threaded through the mid-portion of the clip 64 and resting against the edge of the flange 26k, is tightened, drawing the clip 64 and the rod 39 downwardly until the groove 39a is tightly against the bottom of the aperture 26m, in which position the parts are held by the set screw.

In constructing the operating mechanism above described, I do not limit myself to the form and detail shown, since said mechanism may be made in many equivalent ways as far as operation and results are concerned, without departing from my invention in its generic aspect. Essentially my improved operating mechanism includes a rotary operating rod, an operated rod to which movement is imparted axially by angular movement of said operating rod, there being frictional engagement between said rods resulting preferably from substantially opposed surfaces of or carried by one of said rods engaging correspondingly opposed side surfaces of a groove in or carried by the other of said rods, said surfaces being held in frictional engagement with each other by pressure of an amount determined by the degreeof said frictional engagement required by the purpose for which said operating mechanism is used. It will be understood that said operating mechanism may be used for any purpose requiring the changing of angular motion into translatory or axial motion of an operated member or rod, as long as the force so transferred is within the limits of the frictional engagement referred to.

In Figs. 8 and 9 I show a modified form of operating mechanism in which but one pressure roller and one operated rod are used, instead of two of said rollers and two of said rods, a illustrated in Figs. 3, 4, 5 and 6. As shown in Fig. 8, the operating rod 360 is provided with a groove 36d having outwardly diverging side walls and engaging an operated rod 391) in said groove, in the same manner that each of the grooves 36a engages a corresponding rod 39 as above described in connection with Figs. 5 and 6. On each side of the groove 36d, the rod 360 is provided with a groove 36c containing one end portion of a spring 66,-the other end portion of which is in a groove 61a in a roller 61, which roller is provided with a central groove 61b receiving the operated rod 39b. The form of the springs 66 which press the roller 6'! against the'operated rod 391) and so press the operated rod into the groove 36d, is shown in Fig. 9, which also shows the position of the roller 61 immediately over the operating rod 360, this View further illustrating the shape of the end portions of each of the springs 66, which permits a small amount of rolling movement of the roller 61 on said springs, in making accurate adjustments of the rod 39b. This construction is adapted to move not only rigid operated rods, but also operated rods that are more or less flexible, whereas the construction shown in Figs. and 6 is adapted particularly for use with operated rods that are rigid and have little flexibility. A further advantage of the construction shown in Figs. 8 and 9, is

that greater pressure of the operated rod against the operating rod may readily be obtained, as a result of using two springs per roller and per operated rod, instead of one spring as shown in Figs. 5 and 6. I

In Figs. 10 and 11 I Show a modification of the operating mechanism last described, in which two operated rods 3% arein frictional engagement with the inclined side walls of the groove 36d in the operating rod 360, one of said rods 39b being above and the other being below the operating rod, and each of said operated rods 3% being held in engagement with the operating rod 36c by a pair of springs 66 inthe manner described in connection with Figs. 8 and 9. The two grooves 36c in the operating rod 360, receive the end portions of both'sets of springs, the parts being of the same construction and operating in the same manner as described in connection with Figs. 8 and 9, and ing that two operated rods 39b are employed. This construction provides for moving operated mechanisms in different directions from each other, by a single angular movement of an operating rod.

While I have so far illustrated the operated rods as having circular cross-sections, it will be understood that they may be of any form of cross-section that will effect frictional engagement of the kind described, with an operating rod. For example, in Fig. 21 I illustrate a fiat operated rod 68 having frictional engagement at-its edge portions, with the outwardly diverging side walls of a groove 69a in an operating rod 69, it being understood that the rod 68 may be held in said frictional engagement, by. any of the means above described and not shown in Fig. 21, to avoid needless duplication. In Fig. 22 I show a modification of the construction shown in Fig.

which a flat operated rod 10 and an operating rod H are employed, which have the same frictional relation to each other as the

rods

68 and 69 shown in Fig. 21, and in addition, the

groove Ha in the rod II, which frictionally engages the edge portions of the rod 10, carries at its mid-portion, outwardly extending gear teeth 1 lb meshing with corresponding rack teeth 10a. in the lower surface of the rod I0, to prevent relative displacement between the rods I0 and II due to slippage at their surfaces of frictional engagement, thereby avoiding the need for additional gear and a separate rack for that purtially exerted between each operated rod and the the only difference be-- operating rod by the springs and rollers described, and in this case the lateral pressures developed by the small inclination of the side walls of the groove or grooves in the operating rod, pro'duce forces which are balanced and self-contained in the operating rod, and also produce balanced lateral forces which are self-contained in the operated rod or rods, the spring pressure exerted in holding the rods together 'being balanced against the operating and operated rods so that the said forces are balanced within the operating mechanism considered as a whole.

With this construction the only force required M to move the operating mechanism, is that re- .quired to overcome the friction between the operated rod and the side walls of the groove of the operating rod.

While I have shown my inventionin the particular embodiment above described, it will be understood that I do not limit myself thereto, as I may employ equivalents thereof known to the art at the time of the filing of this application, without departing from the scope of the appended claims.

Having thus described my invention, claim is:

1. In an operating mechanism, the combination of a plurality of elements mounted for simultaneous reciprocating movement, a member connected and movable with said elements, an operating rod having a groove with outwardly diverging side walls, an operated rod secured to said member and extending across said operating rod what I with its opposite side surfaces in engagement with said groove side walls, a roller crossing and engaging the side ofsaid operated rod remote from said operating rod, and spring means engaging and pressing with equal and opposite pressure against relatively remote sides of said roller and said operating rod and tending to move said roller and said operating rod towards each other.

2. In an operating mechanism, the combination of a plurality of elements mounted for simultaneous reciprocating movement, a member connected and movable with said elements, an operating rod having a diverging side walls, an operated rod secured to said member and extending across said operating rod with its opposite side surfaces in engagement with said groove side walls, a roller crossing and engaging the side of said operated rod remote from said operating rod, and spring means enoperating rod having a groove with outwardly diverging side walls, an operated rod secured to said member and extending across said operating rod with its opposite side surfaces in engagement with said groove side walls, a roller crossing and engaging the side of said operated rod remote from said operating rod, and spring means engaging and pressing with equal and opposite pressures against relatively remote sides of said roller and said operating rod and tending to groove with outwardly I move said roller and said operating rod towards each other, said spring means having an end conformation retaining said roller in engagement with said spring means and affording a limited range of rolling movement of said roller on said spring means.

4. In an operating mechanism, the combination of an operating rod having a circumferential groove, an operated rod in said groove and extending across said operating rod, a roller crossing and engaging the side of said operated rod remote from said operating rod, and spring means engaging and pressing with equal and opposite pressures against relatively remote sides of said roller and said operating rod and tending to move said roller and said operating rod towards each other.

5. In an operating mechanism, the combination of an operating rod having a circumferential groove, an operated rod in said groove and extending across said operating rod, a roller crossing and engaging the side of said operated rod remote from said operating rod, and spring means engaging and pressing with equal and opposite pressures against relatively remote sides of said roller and said operating rod and tending to move said roller and said operating rod towards each other, said spring means having an end conformation retaining said roller in engagement with said spring means.

6. In an operating mechanism, the combination of an operating rod having a circumferential groove, an operated rod in said groove and extending across said operating rod, a roller crossing and engaging the side of said operated rod remote from said operating rod, and spring means engaging and pressing with equal and opposite pressures against relatively remote sides of said roller and said operating rod and tending to move said roller and said operating rod towards each other, said spring means having an end conformation retaining said roller in engagement with said spring means and affording a limited range of rolling movement of said roller on said spring means.

'7. In an operating mechanism, the combination of an operating rod having a circumferential groove, an operated rod in said groove and extending across said operating rod, said groove having outwardly diverging side walls, and said operated rod having engagement with said side walls and being otherwise free from engagement with said operating rod, a roller crossing and engaging the side of said operated rod remote from said operating rod, and spring means engaging and pressing with equal and opposite pressures against relatively remote sides of said roller and said operating rod and tending to move said roller and said operating rod towards each other.

8. In an operating mechanism, the combination of an operating rod having a circumferential groove, an operated rod in said groove and extending across said operating rod, said groove having outwardly diverging side walls, and said operated rod having engagement with said side walls and being otherwise free from engagement with said operating rod, a roller crossing and engaging the side of said operated rod remote from said operating rod, and spring means engaging and pressing with equal and opposite pressures against relatively remote sides of said roller and said operating rod and tending to move said roller and said operating rod towards each other, said spring means having an'end conformation retaining said roller in engagement with said spring means.

9. In an operating mechanism, the combination of an operating rod having a circumferential groove, an operated rod in said groove and extending across said operating rod, said groove having outwardly divering side walls, and said operated rod having engagement with said side walls and being otherwise free from engagement with said operating rod, a roller crossing and engaging the side of said operated rod remote from said operating rod, and spring means engaging and pressing with equal and opposite pressures against relatively remote sides of said roller and said operating rod and tending to move said roller and 'said operating rod towards each other, said spring means having an end conformation retaining said roller in engagement with said spring means and affording a limited range of rolling movement of said roller on said spring means.

10. In an operating mechanism, the combination of an operating rod having a circumferential groove, operated rods in said groove on opposite sides of and extending across said operating rod, a roller crossing and engaging the side of each of said operated rods remote from said operating rod, and spring means engaging and pressing with equal and opposite pressures against relatively remote sides of each of said rollers and said operating rod and holding the corresponding operated rod in engagement with said operating rod, said groove having outwardly diverging side walls, and each of said operated rods having engagement with said side walls and being otherwise free from engagement with said operating rod.

11. In an operating mechanism, the combination of an operating rod having a circumferential groove, operated rods in said groove on opposite sides of and extending across said operating rod, a roller crossing and engaging the side of each of said operated rods remote from said operating rod, and spring means engaging and pressing with equal and opposite pressures against relatively remote sides of each of said rollers and said operating rod and holding the corresponding operated rod in engagement with said operating rod, said groove having outwardly diverging side walls, and each of said operated rods having en'- gagement with said side walls and being otherwise free from engagement with said operating rod, said spring means having end conformations retaining. said rollers respectively in engagement with said spring means.

PHILIP K. McGALL.

CERTIFICATE OF CORRECTION. Patent No. 2,529,655. .September lL 19b5,

PHILIP K. TICGALL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, first column, line MD, for "groove" read "grooves"; page 5, first column, line 70, after "for" insert --an; and second column, line 59, claim 1, for

pressure read -pressures; page 6, second column, line 16, claim 9. for

"divering" read "diverging-q and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

.Signed and sealed this 9th day of November, A. 1'). 191g.

' v a Henry Van Arsdale, (Seal) Acting Commissioner of Patents.