US2664755A - Timer and control mechanism - Google Patents

Description

TIMER AND CONTROL MECHANISM Filed March 11, 1949 2 SheetsSheet l V INVENTOR. 1 262 M 44 2 K. M. KlEL 2,664,755

Jan. 5, 1954 K. M. KIEL 2,664,755

TIMER AND CONTROL MECHANISM Filed March '11, 1949 2 Sheets-Sheet 2 I INVEN TOR. I 'We/HW Z W7 #ZLEZ i'L/ BY Patented Jan. 5, 1954 TIMER AND CONTROL MECHANISM Kenneth M. Kiel, Ann Arbor, Mich, assignor to King-Seeley Corporation, Ann Arbor, Mich., a

corporation of Michigan Application March 11, 1949, Serial No. 80,861

6 Claims.

This invention relates to control mechanisms and, in particular, refers to mechanisms that may be both manually and automatically operated.

A specific usage of control mechanisms of the general type herein described is in automatic gas stoves. In this application a manually set control member is employed to hold the gas valve in open position and, in certain stoves, to also hold the oven vent flaps in open position. A controlling element is provided to lock the control member in the set or on position. The control member may be either manually or automatically tripped or released to the off position.

With particular reference to control mechanisms of this general type that have been known heretofore, the present invention provides a number of improved and advantageous features. First, the component parts may be almost exclusively formed by comparatively inexpensive press operations. Additionally, the mechanism is small and compact in size and regular in shape :so that it is easily adaptable to a variety of applications and locations. Furthermore, by virtue of a novel locking connection between the controlled and controlling members, permissible dimensional tolerances have been appreciably expanded so that there is no need for costly hand fitting and finishing on each unit to enable it to give satisfactory performance.

plied to the controlling element it provides a look which is incapable of disconnection by the load. Furthermore, the load provides a component which assists in unlocking so that when it.

is desired to unlatch very little torque is required. .As a further feature of importance, independent and noninterfering manual and automatic means are provided for releasing the controlled member. Manual actuating means for the controlling member is provided which is positive in its action so that there is no possibility that it will be ineffective to actuate. Resilient means serve to maintain the actuating means in a predetermined on position when the controlled memher is locked. In certain applications it may be convenient to use the controlled element as a cam and in these cases the invention provides cam follower which desirably is arranged to panying drawings in which:

Figural a front elevation of themechanism,

This connection is also of such a nature that when properly ap- 2 with parts removed, in the off or unlocked position;

Fig. 2 is a front elevation of the mechanism, with parts removed, in the on or locked position;

Fig. 3 is a plan view of the mechanism;

Fig. 4 is a section taken on line 4-4 of Fig. 1; and

Fig. 5 is a rear view of the timer mechanism showing a novel dog leg connection between the timer and the tripping elements; and

Fig. 6 is a diagrammatic view of the locking connection between the sear surface andlocking The improved control mechanism is supported by a suitable frame which may comprise a back mounting plate I anda front mounting plate 3 spaced from the back plate but having rearwardly extending side arms '5 formed therefrom which are suitably secured to the back plate I, as shown at 1. The control mechanism and the actuating elements therefor are supported by and between the plates l and 3, thus forming a compact and easily mountable assembly. The mechanism 9, shown in the left half of Figs. 1, 2 and 3, comprises the operating mechanism and manual means for actuating the same while the mechanism H appearing in the right half of these figures comprises automatic means, specifically a clock mechanism, for actuating the operating mechanism independently of the manual actuating means.

The central element of the control mechanism is the plate 13 which, to suit it to the present application, has a. peripheral cam surface l4 formed thereon and will thus be referred to hereinafter as a cam plate, though it will be understood that the improved results of the present invention are not dependent upon the specific use of the plate l3. A shaft [5 is journaled in the back and front plates I and 3 and extends out-side of the front plate where it has secured thereto the knob 1'! so that it may be manually rotated. The cam plate l3 ismounted on the shaft i5 for rotation relative thereto but its axial position thereon is fixed by suitable means. For this latter purpose, the cam plate l3 may be staked upon a hub or bushing member l9, as'shown best in Fig. 4. The hub I 9 is freely rotatable on the shaft [5 but is restrained from forward movement by a clip 2| which fits in'a suitable peripheral groove in the shaft l-5.- The hub I3 is restrained from rearward movement by abutment with the actuator plate 23 which is coaxially secured to the shaft l5, as by means of an engaging flat surface 25, and bears on its 3 rear side against a suitable journal boss provided in the back plate I.

The actuator plate 23 is the medium through which the cam plate I3 is rotated manually by knob I? in a clockwise direction. For this purpose the plate 23 is provided with a radial shoulder 21 and this is engaged by a. rearwardly formed ear 29 on the cam plate It. Thus, when the shaft I5 is rotated in a clockwise direction the radial shoulder 21 of actuator 23 is also rotated in the same direction and drives the cam plate ear 29 before it so that the cam plate 13 is rotated from the position of Fig. '1 to that of Fig. 2.

When the cam plate I3 reaches the position of Fig. 2, it is locked against further rotary movement in either direction by virtue of the latch plate 3| acting in conjunction with the actuator plate 23. The latch plate 3| is pivoted at 33 to a boss 35 extending forwardly from the back plate I, the pivot connection 33 being upwardly and sidewardly spaced from the shaft l5 and the latch plate 3| being slightly forward of the cam plate l3. The actuator plate 23 and the latch plate 3| have mutually contacting surfaces which, when engaged, cause the plates to rotate together about their respective axes. In order to effect unitary clockwise rotation, the actuator plate 23 has a generally radial arm 31 and to the right thereof the latch plate has a rearwardly extending car 39 above its pivot point 3 which crosses the rotary path of the arm 31 and may therefore be driven before it in a clockwise direction. In order to effect counterclockwise rotation of the latch plate 3|, the actuator 23 is provided with a second radial arm 4| which is on the right of the latchplate and has a forwardly extending ear 43 that contacts the edge of an upward extension '45 on the latchplate above the pivot point 33.

As will be more readily evident hereinafter, pivotal movement of the latch plate 3| serves to engage or disengage its looking or sear surface 41 and a forwardly extending pin 49 which is affixed to the cam plate l3. The surface 41 is arranged to intersect the locus or circular path followed by pin 49 as the latter is rotated counterclockwise with the cam plate l3. As best indicated in Fig. 6, the sear surface 41 may be in the form of a circular arc struck from the center 50, this center being displaced slightly on the right or unlatching side of the axis of pivot 33. It will be evident that radii to successive points a, b, and c, which the pin 49 contacts as latch 3| is rotated in a counterclockwise or unlatching direction, decrease in length so that the pin 49 is actually sliding down an inclined surface, this surface being the sear surface '41. The angle included between the radius and the normal to each point of contact corres'ponds to the wedge angle of the inclined surface. The wedge angle, of course, must be sufliciently low .so that frictional forces hold the pin on the surface. On the other hand it provides means whereby the force of the load applied to cam plate l3 assists in 'u'nlatching so that only very small torque applied to plate 3| is required to overcome it and unlock the surfaces. The magnitude of this torque and its constancy or variation at different contact positions a, b, c is dependent upon the value of the wedge angle, the torque increasing as the wedge angle decreases. Instead of a simple circular arc, a

compound are, or a fiat surface may be employed as the sear surface. In all cases, however, Where it is desired to take advantage of the assistance the loadon cam plate |3 provides in unlatching, the normals to the surface 41 should pass to the right of the axis of pivot 33. This construction centralizes the critical dimensions, 1. e., those defining surface 41, in one piece, the latch plate 3|, and rather wide dimensional tolerances are permissible in the adjoining members, thus providing a marked saving and facility in manufacturing.

If the operating mechanism is in the position of Fig. L, clockwise rotation of the cam plate I3 alone cannot ordinarily be depended upon to engage the'pin 49 and surface 41 in the manner shown in Fig. 2, and clockwise rotation of the latch plate 3| is desirable to effect this engagement. This is accomplished by arranging the arm 31 on the actuator plate 23 so that it contacts the latch plate ear 39 when the pin 49 has passed the adjacent edge of the surface 41. Clockwise rotation of the arm 31 results in a positive clockwise rotation of the latch plate 3|, and this causes the surface 41 to cross the path or locus of the pin 49 behind the pin so that counterclockwise return movement of the pin is blocked by mutual contact of pin and surface. Since no amount of counterclockwise torque on cam plate l3 can disengage the pin 49 from the surface 41, the latch plate 3| must be rotated in a counterclockwise direction to effect disengagement. As described above, this may be done manually by turning the knob H to rotate the shaft l5 and attached actuator 23 in the counterclockwise direction. When this is done, the actuator ear 43 engages the latch extension 45 to pivot the latch plate 3| and unlock the cam plate l3. Counterclockwise rotation of the latch plate 3| to unlock the pin 49 of the cam plate l3 may also be effected automatically, as will be presently described. It should be noted again that an important advantage of the wedgerounded surface locking connection between the latch plate 3| and pin 49 on cam plate l3 resides in the ease with which the connection may be broken. The pin 49 is literally sliding down the incline of the surface 41 and only insignificant torque on latch plate 3| is required to overcome the frictional contact which looks the pin and surface together.

If desired, the head 5| of the pin 49 may be enlarged and provided with a groove to receive one of a torsion spring 53. The spring 53 surrounds the shaft l5 and its other end is inserted in a hole 55 therein, the end connections of the spring being made so that it has initial set or stress. When the shaft I5 is rotated in a counterclockwise direction, the Stress on the spring is increased until the car 43 reaches the latch extension 45 and then upon disengagement of the pin and surface 41 forces the cam plate 13, which is freely rotatable on the shaft iii, to rotate in a counterclockwise direction until its ear 2.9 strikes actuator shoulder 21, as shown in Fig. 1.

An important function of the spring 53 is to yieldably hold the shaft I5 and thus the knob H in a predetermined position so long as the cam plate |3 is locked to the latch plate 3|. Thus, if the actuator plate 23 is rotated an insufficient amount in a counterclockwise direction to disconnect the latch and cam plates, it, the shaft l5, and knob 11 will be automatically returned by the spring 53 to the on position of Fig. 2.

The latch plate 3| may also have a pair of aeca'rtt spaced cars 51, and 59 formed thereon which are adapted to abut the surface of the hub I9.

- These ears serve as safety elements to prevent In normal operation, the cam plate I3 is forced by the load over rotation of the latch plate 3|.

in such a manner that it exerts little or no component to rotate the cam plate |3 in the clockwise direction which is the only direction in which, ,7

the plate 5 3 is free to rotate, it being held against counterclockwise rotation by abutment of its ear 29 with the shoulder 27 of the actuator 23 which member is stopped by abutment of its ear 43 with the latch plate extension 35. However, if the cam plate l3 lags behind the latch plate 3| in counterclockwise rotation, the pin 49 is not available as a stop but in this case the ear E'lwill abut the hub Hi to prevent'excessive rotation of the latch plate 3|. The same considerations apply to rotation in the clockwise direction and the ear 59 serves to limit such movement of the latch plate 3|. The ear 59 may also limit clockwise movement of the pin 49, though ordinarily this is accomplished by engagement of the actuator shoulder 3'| with the latch plate 3| which is itself locked by abutment of a peripheral edge 62 with the pin 49.

' The foregoing description has shown how the cam plate I3 may be-locked in a predetermined position by manually rotating it in a clockwise plished automatically by the timer mechanism 1 which operates independently of and does not interfere with the manual controls just described. The automatic control includes a suitable clock mechanism 63 which may be actuated and set by a knob 64. An extension arm 65 is controlled by the clock 53 and for this purpose it is pivoted at '65 to a hub arm 66 that is directly connected to and controlled by the clock mechanism 63 by virtue of the pivotal connection 65 which it has therewith. When the clock 63 is running, the arms 85 and 66 are in the dotted line position of Fig. 5 and locked by the clock mechanism against movement to the right in this figure or in a counterclockwise direction when viewed from the front of the timer. The arm 63 effectuates movement of the arm 65 to the dotted, cocked position by abutment with a lateral ear 63 on the arm 65 and when it is released by the timer mechanism at the expiration of a predetermined period, spring means to be described returns the arms to the uncooked position.

A trip arm 69 is pivotally connected at 61 to the extension arm 65. The connection 6'! may include a slot H in the arm 69 to permit adjustment but in actual operation there is no movement in the slot. Means are provided to yieldably bias the arms 65 and 69 in the counterclockwise direction, and this may include a spring 13 that is anchored at one end to an ear on the trip arm 69 and at the other to a forwardly struck car 17 extending from the back mounting plate i. It will be apparent that when the timing mechanism 63 releases the arms 65 and 65, the arm 65 and the trip arm 69 will move quickly to the left (counterclockwise) under the influence -holds it there, as shown in Fig. l.

striking the shoulder 85.

of the spring 13. The extent of this movement may be regulated by an adjustable stop 19 on the back of the clock '63 which engages with the side of the arm 65.

The movement by spring 13 of the trip arm 69 which has been just described is employed to rotate the latch plate 3| in a counterclockwise or unlocking direction. For this purpose, the extreme end portion 8| of the trip arm 69 is somewhat narrower than the adjacent inner portion 83 so as to provide a shoulder 85 which separates these portions and is substantially normal to the underside surfaces thereof. The latch plate 3| has a'forwardly extending ear 8'! formed on its upward extension 45 which lies in the path of movement of the shoulder 85 so that when en- I gaged thereby the trip arm 69 will force counterclockwise rotation of the latch plate.

A further connection is provided between the trip arm 69 and the latch plate 3| so that the relative movement therebetween may take place freely-under all condition except the one just described, viz., latch plate 3| in its extreme clockwise position and trip arm 69 moving leftwardly. This connection therefore prevents interference during manual locking of the control mechanism 9. It includes an'upwardly extending web 89 that is connected to, but laterally spaced from, the latch plate extension 45 by a web 9|. The Web 89 has a guide slot 93 through which the triparm 69 extends/and that serves to limit upward and lateral movement of the trip arm. The'lower end of the web is rebent and inclined upwardly to the right to provide a support ear 95 that engages the underside of the trip arm 69 when the latch plate 3| is in counterclockwisemost range of its movement. When the operating mechanism 9-is cocked and the timer mechanism set, as in Fig. 2, the undersurface of the trip arm portion lies on the latch plate ear 8? and the tripping shoulder 85 is spaced slightly from the ear. Afterthe clock 63 releases the arm, the shoulder 85 strikes the ear 81 so that the operating mechanism is unlocked by counterclockwise rotation of the latch plate 3|. This movement of the latch plate 3| causes the support car 95 to rise and it engages the underside of the trip arm and lifts the shoulder 85 over the ear 81 and It will be evident that subsequent clockwise movement of the latch plate 3| will occur freely, since there is no possibility of interference due to the ear 8? It will also be evident that in the event the operating mechanism 9 is locked but the timer mechanism i is not used, so that counterclockwise rotation of the latch plate 3i under manual force is desired, there is also no possibility of interference. In this case, the trip arm remains in the position of Fig. l and the latch plate ear 81 rotates underneath the trip arm portion 83 so that the shoulder 85 is elevated above a position of possible interfering contact with the ear 81.

As already indicated, the cam plate It can be adapted to control a variety of devices and it is not intended to limit the invention in that respect. It is often possible to make the connections between the devices and the cam plate i3 in such a manner thatthey exert a counterclockwise torque on the plate H which is in itself sufficient to drive the cam plate, when unlocked,-

formed on the cam plate. tion includes a-cam follower H1 which comprises an elongated channel member I09 that is pivotally mounted at a point intermediate its ends to 31 213051] H that extends between the front and rear plates 3 and I. A tension spring H3 is attached to the right end of the member I09 and is anchored to the rear plate I so that it tends to rotate the cam follower in a clockwise direction. The other .end of the member rotatably carries a roller 1 l5 that engages the cam surface M to the right of the mid plane of cam plate :3 so that the force of spring H3 not only holds the roller in contact with the cam surface, but also tends to rotate the cam plate in a counterclockwise direction. The cam follower Nil may on its underside engage the plunger l i! of a valve H79 and depress the same to permit flow through fluid lines i2'l and I23 when the cam plate is in the locked position of Fig. 2.

In operation, the control mechanism is in the off position when the parts are arranged as shown in Fig. 1. It is set or cocked by manual clockwise rotation of the knob IT. This torque is transmitted to the actuator 23 through the operating shaft !5. The actuator shoulder ii is in engagement with the ear 29 of the controlled member or cam plate [3 so that the latter is rotated on the shaft l5 despite the fact that it is .journaled thereon through the medium of the hub 19. It will be recognized that the coaxial arrangement of shaft 15, actuator 23, and cam plate 13 serves to minimize the space required by the mechanism and provide a compact working assembly.

The cam plate 13 carries a lock element in the form of pin 49 which upon cocking movement may ride on the periphery 6| of the latch 3i and tend to rotate it in the counterclockwise direction. However, latch 3! is positively rotated in the cleckwise direction by the actuator arm 3? which engages the latch ear 3% after the pin passes the wedge-like or inclined sear surface 47 to force this surface to cross the locus of the pin 49. Clockwise rotation of the cam plate I3 (and of shaft i5) is limited by this clockwise rotation of the latch plate 3! which forces the surface 52 against the pin 49, any overrotation of the latch plate 3! being prevented by abutment of the ear 59 with the hub E9. The pin 59 is therefore confined so that neither clockwise nor counterclockwise torque on the cam plate is will free it from the latch plate 3!. Thus, in the position of Fig. 2, the control mechanism is in the on or set position. While, as indicated, clockwise rotation of the shaft is and knob I! is blocked, counterclockwise rotation thereof is, of course, not blocked. It takes place, however, against the resistance of spring 53 so that if it is insufficient to disconnect the cam plate 13 and latch plate '31, the spring will return the shaft and knob to the predetermined on position to clearly indicate the condition of the mechanism to the user.

The operating mechanism may be tripped or released from its cocked position of Fig. 2 either manually or automatically. To trip it manually the knob I! is rotated in the counterclockwise direction and this torque is transmitted through the shaft [5 to actuator 23 so that the actuator car 43 is moved upwardly against the resistance of spring 53 to engage the extension 45 of the latch plate 3|. Further rotation of the actuator 23 results in counterclockwise rotation of the latch plate 3i and the sear surface 41 is backed The other connecoff thepin 49. From the standpoint of relative movement, it will be evident-that the pin 49 is in effect moving down the incline of the surface :21, hence for reasons indicated-above, very little counterclockwise torque need be applied to the latch plate 3| in order to effect disengagement or tripping of the mechanism. At the instant tripping occurs, the knob ll, shaft 15, actuator 23 and latch plate 3| are in substantially their extreme counterclockwise position. When tripping occurs, the cam plate I3 is rotated sharply in the counterclockwise direction by the combined action of spring 53 and the forces applied by-rod [0i andcam follower i92 Excessive overrotation of the latch plate 3 1 before the cam plate It reaches the position of Fig. 1 is prevented by the ear 5? which may abut the hub l9, Whereas counterclockwise rotation of the actuator 23, shaft l5, and cam plate I3 is limited by abutment of actuator arm ll with the post 35. In this manner the mechanism is returned to the predetermined off position and is ready for actuation again by clockwise rotation of the knob H as just described.

When it is desired to trip the operating mechanism e automatically, the automatic control mechanism I i may be cocked or set either before or after the knob I1 is turned to the on.position of Fig. 2. Before the control mechanism ii is set, the under-surface of portion 83 of its trip arm 69 rests on the latch ear and if the mechanism l l is not set, the arm 69 remains supported on ear Bl through the cycle of manual op eration that has just been described. There is, therefore, no danger of its interference with the movements of the latch plate 3!. When an automatic control mechanism H such as the timer mechanism 63 is employed, the knob 64 is suitably actuated to rotate the arms 65 and 66 to the right until the arm 65 is locked in position by the arm 66. The arm 55 carries the trip arm 69 rightwardly with it so that the undersurface of the trip arm portion 83 drops from the ear 8? to put the shoulder 85 in operative alignment therewith. When the timer mechanism releases the arm 55, the spring it pulls the trip arm 69 to the left so that the shoulder 85 strikes the ear 8? to rotate the latch plate 3? in the counterclockwise direction and effectuate tripping. In its leftward movement after tripping the underside of portion 33 of the arm 69 is engaged by the latch car and as the latch 31 is rotated this car lifts the arm 69 so that the underside of portion 83 is in a position of noninterference with further movements of the latch plate 3i From the foregoing description many of the advantageous mechanical features of operation of the improved control mechanism will be apparent to those in the art. When considered from the standpoint of manufacturing and application, the device has further advantages. It will be recognized for example, that most of the parts can be formed by press operations from sheet metal and that they may be rather easily assem bled. Furthermore, the novel wedge-shaped sear surface t! centralizes all the critical dimensions in one piece, the latch 3 I, and makes it unnecessary to maintain exacting dimensional tolerances in manufacture and assembly of the other parts. This is demonstrated in Fig. 6, which shows that for a circular sear surface d'i variations in the distances between pivots 33 and is resulting in variations a, b, and c in the points of contact do not appreciably affect the angle between the normal to the point of contact and the radius from pivot 33 to the point of contact. However, despite relaxation of dimensional tolerances, the surface 41 is arranged to provide a positive lock or barrier to movement of the pin 49. The mechanism as a whole is small and compact and regular in shape so that it can be attached to many devices without appreciable alteration or waste space,

Other advantages and features of the invention as well as modifications thereof will appear upon further consideration, hence it is not intended to limit the invention to the specific construction described.

What is claimed is:

1. In a control mechanism of the type described, the combination of a pivotal controlled member having a rounded surface, a controlling member pivoted about an axis spaced from that of the controlled member and having an inclined surface capable of frictional locking engagement with the rounded surface, said members being arranged so that when the surfaces are engaged counterclockwise torque on the controlled member tends to overcome the frictional engagement between the members, an actuator for pivoting the controlled member in a clockwise direction to engage the surfaces and for pivoting the controlling member in a counterclockwise direction to disengage the surfaces, and resilient means for holding the actuator in a predetermined position when the surfaces are engaged.

2. In a control mechanism of the type described, the combination of a rotatable controlled member having a lock element thereon, a rotatable controlling member having a sear surface thereon coactive with the element to prevent counterclockwise rotation of the controlled memher, an operating shaft, an actuator coaxially and operably secured to the shaft for rotating the members in the clockwise direction to effect locking engagement and for rotating the controlling member in the counterclockwise direction to effect disengagement, and spring means between the controlled member and the shaft energized by counterclockwise rotation of the shaft when the members are locked and eifective to return the shaft to a predetermined position in the event counterclockwise rotation does not effect disengagement of the members.

3. In a control mechanism of the type described, the combination of a movable controlled member, a movable controlling member adapted to lock the controlled member in a predetermined position, means whereby predetermined movement of the controlling member releases the controlled member, manual means for moving the members to effect locking and unlocking, and second means operative without interference with the manual means for also moving the controlling member to release or unlock the controlled member, comprising a trip member having a predetermined uncocked position, automatically releasable lock means for holding the trip member in a cocked position, one-way abutment means on the trip member operatively engageable with the controlling member as the 10 trip member moves from the cocked position to the one position, and a shoulder slidably engageable with the trip member in said uncooked position to hold the abutment away from a position of interference with the controlling member.

4. The invention as ciaimed in claim 3 wherein an ear on the controlling member provides the last mentioned shoulder.

5. The invention as claimed in claim 4 wherein the abutment contacts the ear to cause release movement of the controlling member.

6. In a control mechanism, the combination of a pivotal controlled member having a latch pin thereon, a pivotal controlling member having a sear surface engageable with the pin and disengageable upon rotation in a counterclockwise direction, said surface being formed on an are having a center spaced on the disengaging side of the controlling members axis, the radii of said pin and surface to a point of mutual contact being in summation greater than the distance between the members axes whereby the sear blocks movement of the pin, an operating shaft, said con trolled member bein journaled on said shaft, an actuator coaxially secured to the shaft for rotation therewith, said actuator having an ear for engaging the controlled member to rotate it in a clockwise direction and angularly spaced ears for engaging the controlling member to rotate it in either direction, a torsion spring anchored to a the shaft and to the controlled member to yieldably resist relative rotation of the shaft and controlled member, stop means for limiting rotation of the controlling member in either direction, a trip arm having a shoulder thereon, resilient means biasing the arm to the uncooked position, an automatically releasable lock for holding the arm in cocked position, said controlling member having an ear lyin in the path of uncocking movement of the arm and engageable by the shoulder when the pin and surface are engaged so that said arm applies counterclockwise torque to the member to disengage the pin and surface, and shoulder means on the controlling member slidably engageable with the trip arm when the arm is in uncooked position to continuously hold the arm shoulder away from possible interfering engagement with the ear.

KENNETH M. KIEL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,532,212 Wilms Apr. 7, 1925 1,696,178 Ahlm Dec. 25, 1928 1,807,041 Lingal I- May 26, 1931 2,031,458 Bush Feb. 18, 1936 2,230,191 Knight Jan. 28, 1941 2,328,266 Durbin Aug. 31, 1943 2,342,816 Peek Feb. 29,1944 2,344,853 De Haes Mar. 21, 1944 2,386,402 Lilja Oct. 9, 1945 2,488,614 Antonevich Nov. 22, 1949 2,493,608 Willett Jan. 3, 1950 2,506,270 Kidd May 2, 1950 2,525,846 Wilson Oct. 17, 1950

Images