US 3710055 A
A locomotive controller in which a throttle handle assembly is selectively capable of operating as an engine power control or as a dynamic brake control as controlled by the action of a selector lever. The mechanism incorporates detent means which are effective only during action of the throttle handle as an engine power control to position the handle in any selected one of the predetermined throttle positions. An escapement mechanism acts to prevent continuous power increasing movement of the throttle handle past at least the first and second throttle positions when in the power mode. The escapement is disconnected from the throttle handle assembly when the dynamic brake mode is selected, thus providing an unmistakable indication to the operator, when he advances the throttle handle, of whether the unit is operating in the power or dynamic brake mode without requiring his observation of the control panel.
Claims available in
Description (OCR text may contain errors)
United States Patent 1191 Blonn, Sr.
1 51 Jan. 9, 1973  Inventor: George W. Blonn, Sr., Downers  Field of Search ..200/5 R, 5 EA, 1 TX, 153 R, 200/18; 74/483 R  References Cited UNITED STATES PATENTS 2,497,416 2 1950 Peckham ..200 5 EA ux 2,784,265 3/1957 3,281,544 10/1966 Bailey et al ..200l5 EA Primary ExaminerJ. R. Scott Attorney-J. L. Carpenter et al.
 ABSTRACT A locomotive controller in which a throttle handle assembly is selectively capable of operating as an engine power control or as a dynamic brake control as controlled by the action Of a selector lever. The mechanism incorporates detent means which are effective only during action of the throttle handle as an engine power control to position the handle in any selected one of the predetermined throttle positions. An escapement mechanism acts to prevent continuous power increasing movement of the throttle handle past at least the first and second throttle positions when in the power mode. The escapement is disconnected from the throttle handle assembly when the dynamic brake mode is selected, thus providing an unmistakable indication to the operator, when he advances the throttle handle, of whether the unit is operating in the power or dynamic brake mode without requiring his observation of the control panel.
7 Claims, 7 Drawing Figures PATENTEDJAN 9197s 3 710 055 SHEET 1 OF 3 REVERSE NEK QRAL FORWARD Q J 0 V o /25; BY Geoz e %f o kfz (MM A T TORNEY PATENTEDJAN 9 ma SHEET 2 UF 3 INVENTOR. 96059:: la /0224.32
ATTORNEY LOCOMOTIVE CONTROLLER WITH THROTTLE ESCAPEMENT FIELD OF THE INVENTION This invention relates generally to an electromechanical control and, more particularly, to an improved master controller intended primarily for use on diesel electric locomotives, although capable of other applications.
DESCRIPTION OF THE PRIOR ART The use of relatively complex electro-mechanical mechanisms to control many of the operating functions of die-sel-electric locomotives and the like is well.
tioned patent includes three main control levers. These are a directionalcontrol handle which is movable to select power operation of the unit in the forward or reverse direction; a selector handle which is movable to select either power operation or dynamic braking operation of the unit and a throttle handle which is selectively operable depending upon the position of the selector handle to either control the power output of the locomotive engine by movement into any one of a number of predeterminedthrottle operating positions or to control the degree of dynamic braking by connection with, and operation of, a dynamic braking control rheostat.
The throttle handle assembly of this prior art controller is provided with detent means which, through action of the selector lever,-are moved into operating position when the throttle handle is set to act as a power control lever. These detent means act primarily to properly position the throttle lever in the desired one of the throttle operating positions selected by the operator. Movement of the selector lever to the dynamic braking position moves the detent mechanism to a non-operating position and thus provides a different feel to the action of the throttle lever when it is operating as a dynamic brake control from the feel it has when operating as an engine power control.
In spite of the distinguishing feel created by the throttle handle detent means in its two modes of operation, occasions have arisen where it is believed locomotive engineers have mistakenly applied power by movement of the throttle handle while believing they were applying the dynamic brakes. The possibility of the occurrence of such an error during a time of stress or inattentiveness on the part of the engineer, in spite of the provision in the prior art mechanism of visual indicating means, as well as the above mentioned difference in throttle handle feel to indicate the actual mode of operation, suggested the desirability of incorporating in the controller means unmistakable by the operator to draw his attention to the fact of operation in the power mode.
v 2 SUMMARY OF THE INVENTION The present invention provides a controller mechanism having a throttle handle assembly capable of performing the dual function of engine power control and dynamic brake control and wherein escapement means are provided to act upon the throttle handle assembly in the power control mode so that the handle may not be advanced continuously past the first throttle position or any desired number of subsequent throttle positions. Instead, movement of the throttle handle above the first throttle position requires that the operator release pressure on the handle, allowing it to back up slightly, after which the throttle may be advanced to the next throttle position.
The escapement mechanism is arranged to be moved out of engagement with the throttle handle assembly by actuation of the selector handle to place the throttle lever in the dynamic brake control mode. The throttle handle assembly is then capable of free continuous movement through its entire range when operating in the dynamic brake mode.
In this way, the differences in the operatingcharacteristics of the handle in the dynamic brake and power control modes are sufficient to give the operator positive notice, by feel, of the mode of operation of the handle assembly. This notice is in addition to visual means incorporated in the controller and operative in conjunction with the various control handles, as well as the previously known use of a detent mechanism in conjunction with the operation of the throttle lever in the power control mode.
These and other features of the invention may be more thoroughly understood from the following description of certain preferred embodiments of the invention, taken together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:
FIG. 1 is a front view of a preferred embodiment of controller having escapement means according to the invention;
FIG. 2 is a top view of the controller of FIG. 1 having certain portions broken away to disclose the escapement mechanism;
FIGS. 2a, 2b and 2c are views supplementing FIG. 2 and illustrating the operation of the escapement mechanism;
FIG. 3 is another front view of the controller of FIGS. 1 and 2, in which the front cover is removed and DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings in detail, numeral 10 generally indicates a controller assembly formed according to the invention. Controller 10 is generally similar in construction to and has many of its basic con- 'cepts identical with the controller described and claimed in U. S. Pat. No. 2,784,265 Weide. Since the basic construction features disclosed in the above-mentioned patent form no part of the present invention, a description of these features is not believed necessary except to the extent necessary to describe the novel features of the present invention.
Controller includes three manually operated control handles arranged for actuation by the locomotive engineer. These include a directional control handle 11, a throttle handle 12 and a selector handle 14. The construction and operation of the handle assembly mechanisms operated by these three handles is essentially the same as that described for the corresponding handles of the controller arrangement of the above mentioned patent.
Thus, the directional handle 11 includes forward, reverse and neutral positions into which it is movable to control the direction of powered operation of the locomotive.
The throttle handle 12 is, in one mode, operable as an engine power control. In this mode, the throttle handle is movable through a predetermined range of sequential engine speed and power controlling throttle positions, in this instance eight in number, plus positions for engine idle and engine stop. These throttle positions are indicated by an indicating quadrant 15 which is visible to the engineer through a viewing window 16 provided in the front cover 18 of the controller. In another operating mode, throttle handle 12 acts as a dynamic brake control lever and operates a brake control rheostat. Operation of the throttle handle in both modes is as described in the above-mentioned patent.
Selector handle 14 is movable from the neutral position shown to either power or brake positions so as to select the mode of operation of the throttle control handle as the engine power control mode or dynamic braking mode, respectively. The handle 14 includes position indicating means 19 which visually indicate to the engineer the operating position of the handle.
The mechanism connected with the selector handle 14 differs from that described in the above-mentioned patent in, that there is no provision for moving the selector drum beyond the first power position, as was previously provided to manually control the traction motor electrical connections, a function commonly referred to as transition. In current locomotive models, this function is taken care of automatically or is dispensed with entirely and thus such provision is not currently required. However, it would be possible, if desired, to incorporate the concepts of the present invention on previous controllers having the manual transition provision.
The three control handles of controller 10 are interlocked through mechanism of the type described in the above mentioned patent so as to prevent the improper operation of the locomotive controls by the engineer. In addition, the mechanism provided includes detent means as described in the above mentioned patent, which are effective in the engine power control mode I to positively position the throttle handle in any of the selected ones of the eight predetermined throttle power positions, as well as the idle position. The mechanism is arranged in known manner to be moved out of actuating position by movement of the selector handle 14 to the brake position so that the throttle control handle moves freely in the brake mode through its entire range of movement.
Having discussed certain portions of the controller assembly 10 which are the same as or similar to the prior art controller, there will now be described the novel construction features of the present invention which provide the improved operation thereof.
In the embodiment of FIGS. 1 3, there is provided an escapement mechanism including a partially toothed segment or escape wheel 20. Escape wheel 20 is secured by clamp means 21 to a shaft 22 that is connected to and rotates with movement of the throttle handle 12. Associated with escape wheel 20 are other components of the escapement mechanism, comprising a bell crank 24, stop pawl 25, connecting rod 26, escape pawl 28 and compression spring 29. In addition, a stop plate 30 and adjustable stops 32 and 33 are fixed to the frame of the controller assembly and adjustable stop screw 34 is mounted on connecting rod 26 for cooperation with the various components of the escape mechanism, as will be subsequently described.
Bell crank 24 is pivotally carried adjacent the end of the shaft 35 which is connected with and rotates upon movement of the selector handle 14. Stop pawl 25 in turn pivots around its connection at 36 with bell crank 24, while connecting rod 26 pivots around its connection at 37 with'stop pawl 25. Escape pawl 28 is likewise pivotally connected at 39 to the connecting rod 26. Spring 29 acts between the bell crank 24 and escape pawl 28 and urges each of the escape pawl 28, connecting rod 26 and stop pawl 25 to rotate in a clockwise direction and around their respective pivots.
In addition, themechanism includes a cam plate or finger 40 which is fixed to the end of shaft 35 and rotates therewith into and out of engagement with the pivot pin 39 on which the escape pawl 28 is mounted.
Operation of the embodiment of FIGS. 1 3 is as follows. Movement of selector lever 14 into the brake position rotates the cam plate 40 clockwise from its position shown in FIG. 2 into full engagement with pivot pin 39. This moves the pivot pin rightwardly, as shown in the figure, pulling the escape pawl 28 completely out of engaging position with the teeth of the escape wheel 20 and rendering the escapement mechanism ineffective to act upon movement of the throttle lever 12. Accordingly,'the throttle lever moves freely throughout its full travel in the dynamic brake mode.
Movement of selector lever 14 to the power position moves the cam plate 40 counterclockwise from the position shown in FIG. 2, completely freeing the escapement mechanism and leaving it in substantially the position shown in FIG. 2. In this condition, the escape pawl 28 is in position opposite the end tooth of escape wheel 20, the connecting rod 26 is rotated clockwise into engagement with the end of stop-plate 30 and the bell crank 24 is rotated counterclockwise into engagement with the adjustable stop 32. It is assumed that the throttle handle 12 is in the idle position,
as shown in FIGS. 1, 2 and 3.
Movement of the throttle handle 12 from the idle position to the first throttle position changes the position of the escapement mechanism as shown in FIG. 2a. The escape wheel 20 has rotated clockwise, urging escape pawl 28 against the stop screw 34 and acting through connecting rod 26 to pull the stop pawl 25 into one of the spaces between teeth on escape wheel 20. The mechanism in no way restricts this throttle movement, however, and the throttle handle moves freely from idle to the first throttle position.
An attempt to move the throttle handle 12 from the first to the second throttle position, causes the mechanism to change to the position indicated in FIG. 2b. It should be understood that the clearances involved have been accentuated for clarity and in actuality are made only large enough to provide for proper operation of the mechanism. As is shown in FIG. 2b, a tooth of escape wheel 20 has engaged the stop pawl 25, forcing it to the right and urging bell crank 24 against adjustable stop 33, preventing further rotation of the escape wheel and, accordingly, stopping movement of the throttle handle from the first throttle position. The motion of the mechanism also causes the connecting rod to be urged in a counterclockwise direction around its pivot pin 37 by the stop plate 30. This movement compresses the spring 29 and draws the escape pawl 28 out of engagement with the escape wheel 20.
In order, then, to continue movement of the throttle handle from the first to the second throttle position, the operator must release pressure on the handle so as to permit the spring 29 to force the connecting rod 26 clockwise. This action, as illustrated in FIG. 20, causes the escape pawl 28 to engage the second of the teeth at the end of the escape wheel 20 and forces the stop pawl 25 in a clockwise direction out of engagement with the escape wheel. At the same time, bell crank 24 is rotated counterclockwise away from stop 33 and into engagement with stop 32.
When this condition is reached, the operator may then again apply rotational pressure to the throttle handle l2 and cause it to move from the first to the second throttle position. This movement will then affect the escapement mechanism in generally the same manner as shown in FIG. 2a except that the escape pawl and the stop pawl will each be engaged in the next tooth space of the escape wheel 20 from that in which they are shown engaged in FIG. 2a. In this condition, then, the mechanism will be ready to undergo a like sequence of actions in order to provide for movement of the throttle lever from the second to the third throttle position.
After the third throttle position is reached, the absence of teeth on the escape wheel permits further movement to higher throttle positions without any restricting action of the escapement mechanism. In addition, the operator may at any time move the throttle handle in a power reducing direction from any higher to any lower throttle position and, if desired, through to the stop position without any restrictive action by the escape mechanism.
FIG. 4 illustrates an alternative embodiment of escapement mechanism which may be applied to a controller of the type described. This embodiment will accomplish substantially the same function as the mechanism just described with the exception that the alternative embodiment is shown as providing a completely toothed escape segment 42. This causes the escapement mechanism to effectively prevent continuous advance of the throttle handle as previously described, over the complete range of throttle positions rather than only the first few.
The embodiment of FIG. 4 includes certain elements which are identical to or modifications of elements of the conventional portions of the prior art controller disclosed in the above mentioned U. S. Pat. No. 2,784,265, of which particular reference is made to FIG. 9 for a comparative illustration. The corresponding elements in FIG. 4 are the throttle interlocking plate 44, which corresponds to member 262 of the patent, link 45 which corresponds to element 310 of the patent, roller 46 which corresponds to element 304 of the patent, bell crank 47 which corresponds to element 294 of the patent, and stud 48 which corresponds to element 296 of the patent. Additions to the prior mechanism include the escape segment 42, which is attached to the throttle interlocking plate 44. Also, bell crank 47 includes an end portion 49 which is fixedly attached thereto and pivots with the bell crank member around stud 48. Added to these are a stop pawl 50 pivotally attached to the bell crank at 52, a connecting rod 53 pivotally attached to the stop pawl at 54 and an escape pawl 56 pivotally attached to the connecting rod at 57. A compression spring 58 acts between the bell crank 47 and connecting rod 53, urging both in clockwise directions around their respective pivot points. A tension spring 60 acts between the stop pawl 50 and escape pawl 56, urging the latter in a clockwise direction around its pivot. The construction additionally includes fixed stop members 61 and 62, which are engagable by the stop pawl 50 and connecting rod vided between link 45 and the roller 46. This movement, in connection with the engagement of connecting rod 53 with the stop 62 moves the connecting rod counterclockwise, releasing the escape pawl 56.
Thereafter, release of pressure on the throttle handle causes the escape pawl to engage the next tooth in the escape segment and disengages the stop pawl 50 from the escape segment. The mechanism is then in position for advancement to the next throttle position.
When the selector lever is moved to the dynamic brake position, the right end of link 45 is moved upwardly, which slides the link rightwardly, causing bell crank 47 to pivot clockwise, retracting the escape mechanism from engagement with the escape segment 42. This provides free movement of the throttle handle through its entire range in the dynamic brake mode, as is the case in the embodiment of FIGS. 1 3.
It should be apparent that either of the embodiments shown could be arranged to have any desired number of teeth in the escape segment so that the restriction of advancement of the throttle handle could be applied over any desired number of throttle position changes. Additionally, numerous other changes could be made within the scope of the invention in applying its concepts to various types of control devices, wherein the advantages previously mentioned may be desired. Accordingly, the invention is intended to be limited only by the language of the following claims.
l. A locomotive controller having a throttle handle assembly selectively operable as a throttle position control or a dynamic braking control and movable in either condition through a predetermined range of operating positions, an escapement mechanism engagable with said throttle handle assembly and operative when so engaged to prevent continuous movement of said throttle handle assembly in a throttle opening direction through at least certain predetermined throttle positions, and selector means having first and second operating positions and being connected with said throttle handle assembly and said escapement mechanism such that movement of said selector means to said first operating position is effective to engage said escapement mechanism with said throttle handle assembly and to cause the latter to operate as a throttle position control, while movement of said selector means to said second operating position is effective to disengage said escapement mechanism from said throttle handle assembly and to cause the latter to act as dynamic braking control.
2. The combination of claim 1 wherein said escapement mechanism includes means operative to prevent a continuous throttle opening movement of said throttle handle assembly from its idle position past the first power position of the throttle handle assembly adjacent said idle position.
3. The combination of claim 2 wherein the effective range of limiting action of said escapementmechanism on said throttle handle assembly is confined to the movements in the lower half of the total range of throttle handle assembly positions.
4. In a locomotive controller of the type having a throttle handle assembly selectively operable as a throttle position control or a dynamic braking control and a selector handle assembly having power and dynamic braking positions and interconnected with said throttle handle assembly such that selection of the power position causes the throttle handleassembly to control throttle position while selection of the dynamic braking position causes the throttle handle assembly to control dynamic braking, the improvement comprising an escapement mechanism connected with said selector handle assembly and engagable with said throttle handle assembly to prevent its continuous and uninterrupted movement in a throttle opening direction through at least certain predetermined throttle positions, said escapement mechanism including positioning means movable with said selector handle assembly to position said escapement mechanism in engagement with the throttle handle assembly when said selector handle assembly is in the power position and to retract said escapement mechanism from engagement with the throttle handle assembly when said selector handle assembly is in the dynamic braking position, whereby said throttle handle assembly may be freely moved throughout its total travel while it is operable to control dynamic braking but said throttle handle assembly is restricted to intermittent advancement through at least certain of said throttle positions when it is operable as a throttle position control.
5. The combination of claim 4 wherein said escapement mechanism comprises a toothed escape wheel fixed to and oscillatible with said throttle handle assembly,
a bell crank within said controller and arranged for limited oscillation about a fixed axis,
a stop pawl, pivotally connected with said bell crank at a first point spaced from said axis,
a connecting rod pivotally connected with said stop pawl at a second point spaced from said first point and said axis,
an escape pawl pivotally connected with said connecting rod at a third point spaced from said first and second points and said axis,
fixed stop means engagable by said connecting rod at a point opposite said escape pawl from said second point, and
means biasing said escape pawl toward engagement with said toothed escape wheel, said connecting rod toward engagement with said fixed stop means and said stop pawl away from engagement with said toothed wheel,
said mechanism being arranged such that when said selector handle is in the power position and said escape pawl is in engagement with said toothed wheel, movement of said throttle handle assembly in a throttle opening direction causes the escape pawl and connecting rod to move against said biasing means, drawing said stop pawl into engagement with a tooth of said toothed wheel, further uninterrupted opening movement of said throttle handle assembly being limited to the amount of movement permitted of said stop pawl by said limited oscillation of said bell crank, such movement forcing said rocker arm against said fixed stop and pivoting said arm so as to move said escape pawl out of engagement with said escape wheel, subsequent release of the opening movement force on said throttle handle assembly being required to permit said biasing means to return said mechanism elements to their initial positions but with said escape pawl engaging the tooth of the escape wheel adjacent that initially engaged and the throttle handle assembly being advanced one step, said mechanism being then in position to permit a further one step uninterrupted advance of said throttle assembly.
6. The combination of claim 5 wherein said positioning means comprise a cam plate connected with said selector handle assembly and engaging said connecting rod to retract said escape pawl from engagement with said escape wheel upon movement of said selector handle assembly to the dynamic brake position, said cam plate being moved out of engagement with said connecting rod, permitting engagement of said escape pawl vwith said escape wheel when said selector handle is moved into the power position.
7. The combination of claim 5 wherein said positioning means comprises link means connecting said rocker arm with said selector handle assembly and operative to move said rocker arm beyond the normal limit of oscillation and to a position retracting said escapement mechanism and the escape pawl thereof from engagement with said escape wheel when said selector lever assembly is moved to the dynamic brake position, said link means acting to return said rocker arm to its operating position of limited oscillation wherein said escape pawl may engage said escape wheel when said selector lever is moved to the power position.