US2027284A - Drive for shaker conveyers - Google Patents

Description

Jan. 7, 1936.

R. MOORE DRI VE FOR SHAKER CONVEYERS Original Filed May 29, 1953 3 Sheets-Sheet l M+ fl'coemare Jan. 7, 1936. R. MOORE 2,027,284

DRIVE FOR SHAKER CONVEYERS Original Filed May 29, 1933 5 Sheets-Sheet 2 Jan. 7, 1936. v R MOORE 2927 284 DRIVE FOR SHAKER CONVEYERS Original Filed May 29, 1935 5 Sheet -SheetB Patented Jan. 7, 1936 UNITED STATES PATENT OFFICE Original application May 29, 1933, Serial No. 673,532. Divided and this application May 3, 1934, Serial No. 723,754

8 Claims.

This invention relates to drives for shaker conveyer's, and more particularly to a drive for shaker conveyers of the type employed in transporting materials from a mining point to a loading point in a mine, and is a division of my prior application Serial No. 673,532 filed May 29, 1933 for Shaker conveyer, which matured into Patent No. 1,997,495, Apr. 9, 1935.

It has heretofore been impossible to practically produce a shaker conveyer which would successfully elevate material up an incline of any appreciable grade, such devices being employed only after the placement for the conveyer is level or has a slight slope from the loading to the discharge point. For this reason it is necessary that these conveyers have some type of elevator associated therewith for elevating the material to a carloading position and the multiplicity of handlings thus necessary for the coal causes an excessive breakage thereof in addition to the eX- cessive cost in maintenance.

One of the principal reasons for the failure of the ordinary type of shaker conveyer to elevate material moving therealong through any appreciable incline lies in the fact that the operating mechanism employed with such conveyers is of such character that the material does not come to a complete rest between alternate advancing strokes, with the result that the frictional engagement between the material and the trough of the conveyer is reduced to a point where it is insufiicient to cause such elevation.

An important object of this invention is the provision of operating mechanism for shaker conveyers which will permit the material to come to complete rest in reference to the chute at the terminus of each stroke.

A further object of the invention is the provision in an apparatus of this character of an arrangement such that the operating mechanism may be employed either in its improved manner, or in the manner in which such devices ordinarily operate.

These and other objects I attain by the construction shown in the accompanying drawings wherein, for the purpose of illustration, I have shown a preferred embodiment of my invention and wherein:

Fig. 1 is a plan view of a shaker conveyer drive constructed in accordance with my invention, portions of the mechanism being broken away to expose certain novel details;

nism,

Fig. 2 is a side elevation of the drive mecha Fig. 3 is a view showing the drive mechanism connected with the conveyer;

Fig. i is a detail view illustrating the control switch;

Fig. 5 is a diagrammatic View showing the manner of making the connections for controlling the drive motor; and

Fig. 6 is a diagrammatic view comparing the operating stroke of the ordinary mechanism and the operating stroke of the improved mechanism.

Referring now more particularly to the drawings, the driving mechanism comprises a drive motor 44 connected through a train of gearing generally designated at 45 with a shaft 46 having cranks 41. A rock shaft 48 has arms 49 centrally connected thereto, one end of each arm being connected with a crank ll by a link 50 and the other end'thereof being connected to the conveyer through one of connecting rods 26.

The construction, so far described, is one fairly commonly employed in one form or another in the operating mechanisms of shaker conveyer troughs and sorting tables, and the connections between the arms 48 and the cranks are so proportioned and relatively positioned that the reciprocating stroke of the connecting rods 26 produced at each rotation of shaft 48 is of greater duration in one direction than in the other. In Fig. 6 I have diagrammatically illustrated both the mechanical operating mechanism and the stroke obtained thereby, this stroke being illustrated by the dotted line. In the diagram of the mechanism it will be noted that the advancing stroke extends through 255 degrees of rotation of shaft 45 while the idle stroke extends through only degrees. Obviously, material on the conveyer at the end of the advancing or working stroke, since its movement is accelerated, tends to continue its movement during the relatively short period of the idle stroke. During the first half of the idle stroke the material is still moving rapidly and during the latter half thereof it tends to slow down but not to become stationary, with the result that when the working stroke is repeated the material is still moving in the direction of the working stroke or in other state of unrest, and, accordingly, has little, if any, frictional engagement with the trough at this time.

While this condition is satisfactory in horizontal transportation by shaker conveyer methods, it is unsatisfactory and renders inoperative any shaker conveyer disposed upon an appreciahle incline. For this reason, I incorporate in the operating mechanism l4, means for increasing the duration of the return stroke and more particularly means for increasing the duration of the latter portion of this stroke by slowing down or stopping entirely the motor 3 during the latter part of the stroke. I have at present illustrated 5 shaft 46 as equipped with a cam 5! acting through a rocker 52 and a plunger 53 upon a. switch 54 which controls the operating coils 55 and 55-41 of interlocked switches 56 and 56a. 'Shunting the motor armature A of motor 44 is an adjustable resistance 5?. Switches 56 and 56-a alternately close this shunt and one side of the motor line. Through a double throw switch 58, the switch 55a may be employed to place the adjustable resistance 51 in series with the armature. The circuit of the 0011 55-11 of switch 58-11 maybe opened through a suitable switch 53. It will be obvious that with switch'59 open at I the motor will operate continuously and the only actuation of the conveyer will be that normally given to conveyers through the me- "chanical motion of the drive; Withswitch 59 closed at I and switch 58 in its solid line position, 1 each time the cam 5i releases switch 54 and thus closes switch 56a, switch 5a completes the circuit of the resistance about the armature of the :motor and opens the circuit to the line at switch 56. With switch 58 in its dotted line position at each closing operation of switch '55a through cam 5l and switch 5 the resistance is placed in- :series with the armature. With switch 58 in mid position, the armature circuit is opened at each closure of; switch 5 5a. Obviously, any of these arrangements will cause a slowing down of "the motor, one applying a dynamic braking thereto and the others a reduction or interruption of the input thereto. The particular type of dynamic braking herein illustrated may, of course, be varied and the switches 55 and 5Ea operated in various manners.

10 '--It is apparent that the adjustment of the resistance-5'! may be improper or some unusual fric- "tion'may-occur during the operation of this de- -vice causing the motor to come to rest with the rocker 52 bearing upon the depressed portion of ""-"'cam 5l, in which case the machine would fail to "start. Pilot device 5 3-41 with a time element *somewhat greater than one normal cycle will now gopen the circuit to switch 55-a and close switch iifi-causingthe motor to start. This pilot device may be any of the well known time element relays.

The resulting stroke is diagrammatically illus- '"-trated by the solid line in Fig. 6, the point X indieating approximately the point at which dynamic braking of the motor begins its operation. It

willbe noted by comparison of these stroke diagrams that the entire added length of the stroke iisconfined to the latter half of the'return or idle stroke, with the result that a sufficient interval is provided for the material to come to rest upon the trough so that it may move therewith. The

use of therheostat permits the duration of the idle stroke to be adjustably regulated so that the ==period is of just suihcient duration to permit the material to come to rest. This is necessary due =to the-fact that transportation systems embodytrough thegreater load is obviously imposed thereon which load, of itself, acts as a brake,

"necessitating the modification of the dynamic i braking applied at the motor.

"The operating mechanism further incorporates are'el 69, one end of which is provided with a ratchet 6| having associated therewith an operating pawl 52 mounted upon a rocker arm 63 operated by a link connection with one of the arms 49, as indicated at 65, and a holding pawl 85. Holding pawl 55 is withdrawable by a pedal 5 66, which pedal may be held in its released position by a latch cam 5'5. The actuating pawl 62 is normally held out of engagement with the ratchet'fil by a spring 58 and is engageable With the ratchet through an operating cord $9, pref- 10 erably including a spring 2'0. This operating cord may be extended to an operator station and a cable ii wound upon the reel may be connected to a train of cars which is to be moved past the discharge end of the conveyer. 15

WhileI have illustrated the apparatus in Fig. 5

as arranged for use with direct current, obviously alternating current may be employed by substitution of equivalent elements suitable for use therewith. 20

.Sincetl e, construction illustrated is obviously capable of considerable modification without in and 'means operating in timed relation to the mechanism for braking operationof the motor a during the later portion of the idle stroke of the mechanism. 535

.2. In ashaker conveyer including horizontal and'inclined sections, operating mechanism to re- Tciprocate the conveyor providing working and idle strokes of the conveyer of different duration,

and electric operating motor for the mechanism, ae4o switch operating in timed relation to the mechanism for dynamically braking the motor during 'thelater portion of the idle stroke.

3. In ashaker conveyer, including horizontal and inclined sections, operating mechanism toi-45 reciprocate the conveyor providing working and idle strokes-of the conveyer of different duration, an electric operating motor for, the mechanism, switch means operating in timed relation to the mechanism for braking the motor during the350 'lat'er portion of the idle stroke, and means to again start the motor in case of excessive braking or friction.

4. In a shaker conveyer including horizontal and inclined sections, operating mechanism to 5 reciprocate the conveyer providing idle strokes of the conveyer of difierent durations, an electric operating motor for the mechanism, switch -means to open the circuit of the motor and apply dynamicbraking to the motor during the later portion of the idle stroke, and means to restart Y the motor in event of stoppage thereof during the operation of said switch means.

5. Operating mechanism for a shaker conveyer comprising means to reciprocate the conveyer which when driven at a uniform rate provides .working and idle strokes of difierent duration, an

electric operating motor for the mechanism, and

a switch operating in timed relation to the mechanism for dynamically braking the motor during' the later portion of the idle'stroke.

6. Operating mechanism for a shaker conveyer comprising means to 7 reciprocate the conveyer which when driven at a uniform rate provides working and idle strokes of different duration, 2.11 7

electric operating motor for the mechanism, a resistance associated with the motor to vary the current delivery thereto and a switch operating in timed relation to the mechanism for inserting the resistance in and withdrawing the resistance from the motor circuit.

7. Operating mechanism for a shaker conveyer comprising means to reciprocate the conveyer which when driven at a uniform rate provides working and idle strokes of different duration, an electric operating motor for the mechanism, means for braking the motor during the later through the later portion of the shorter stroke 10 whereby to permit the conveyed material to come to rest prior to the inception of the longer stroke.

ROSCOE MOORE.

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