US1867452A - Combined indicator and limit switch actuator - Google Patents

Description

y 12, 1932- H. E. HALLENBECK I 1,867,452

COMBINED INDICATOR AND LIMIT SWITCH ACTUATOR Filed Dec. 12, 1951 5 Sheets-Sheet l Q ill-14m n! L j T R w- 0 I F I A N q I mm 5 "F." s g i v t i g N i i H E N 0 as 0 q v 23 INVENTOR ATTORNEY 1932- H. ETHALLENBECK 1,867,452

COMBINED INDICATOR AND LIMIT SWITCH ACTUATOR Filed Dec. 12, 1951 3 Sheets-Sheet 2 S mil" Ill. I! l y 12, 1932- H. E. HALLENBECK 1,867,452

COMBINED INDICATOR AND LIMIT SWITCH ACTUATOR Filed Dec. 12, 1951 3 Sheets-Sheet 3 INVENTOR 4 f liflffallmad ATTORNEY Patented July 12, 1932 units-o STATES PATENT oFFic-I:

HAROLD E. narnnunncn, or Henson, NEW YCEK, ASSIGNOR To eir ro'nn-woon coir- PATTY, or nunsou, new YORK, A conronATron or new YORK COMBINED IivnrcATon AND LIMIT SWITCH ACTUATOR This invention relates to improvements in limit switches for electrically operated traversing hoists and among other objects, aims to provide a very simple and compact limit switch actuator preferably, but not necessarily, combined with indicating means, and so constructed and arranged that the traverse motor is automatically stopped at the predetermined limits of travel of the load carrier operated by said motor. The invention particularly aims to improve upon known trolley bucket systems by providing a motor control unit of such few parts that it may be manufactured and installed very economically, and hence may be sold at a low price; also to provide a. unit rotatable for ease of adjustment and adaptability to various trav-.

ersing hoist installations. The invention has other objec'tswhichwill appear during the following description of the preferred embodiment thereof which is shown in the accompanying drawings.

In said drawings,-- 1 Fig. 1 is a plan view of. a motor-powered traversing hoist unit equipped with an actuator for limit switches;

Fig. 2 is an elevation, on a somewhat larger scale, of the mechanism for driving the limit switches and indicating means;

F i g. 3 is a side elevation of the mechanism Fig. 2; and Figs. 4 and 5 are vertical sections, at right angles to each other and both on the same enlarged scale, of the limit switch casing and actuating parts. I

The motors of the described power unit are preferably used in an automatic electric control system such. as is dc. cribcd and claimed in my pending application, Ser. No. 491,53a, filed October 27, 1930.; although the invention will be equally useful in atrolley bucket system controlled by hand. The wiring and connect-ions are such that the bucket is automatically hoisted, when loaded, to a point adjacent the underside of'th e trolley, whereupon hoisting automatically stops and traverse movement in a predetermined direction begins. When the trolley-has reached a point over thespot where the load of the bucket is to bedischa'rged, it is automatically Application filed December 12, 1931, Serial N5. 580,686.

stopped, and loweringofthe bucket automatically takes place. Dumping of the contents of the bucket is eiiected as soonas -the bucket strikes an obstruction, as disclosed the Bennett Patent llo. 1,7 l1,123 of December 2st, 1929, and substantially instantaneous reversal of the bucket takes place, so that the bucket starts up to the trolley as its load discharges. Ls soon, as the bucket reachesthe trolley, hoisting automatically ceases, traverse begins and continues until the trolley is over the pointwhere the bucket is to be lowered for another load; then traverse is stopped, the bucket is automatically lowered and brought to a stopat the loading point. I deferring particularly to Fig.1, there is shown a machine base on which all the parts to be described are supported, so that the entire mechanism may be shipped and installed as a unit. Journaled in bearings 11 secured to the frame is a drum-shaft-12 on which hoist drum 13 and trolley or traverse drum 14 are mounted for independent rotation. Hoist drum 13 is loose on shaft 12 and is driven by a gear 15 fixed thereto and meshing with a pinion 16 on a countershaft 17 journaled in bearings 18. Countershaft 17 is driven by a gear 19 which meshes with motor pinion 20 of the hoist motor 21 which is on base 10. Obviously rotation jOf the hoist motor inopposite directions will drive hoist drum 13 in opposite directions at a reduced speed, thereby winding or unwinding hoist cable 22 (which is dead-ended to the drum) to raise or lower the bucket or other load carrier, not shown. I

The traverse or trolley drum 14 is fixed on shaft 12 and hence is rotated by gear 23 which is secured to said shaft. Gear 23 is driven by pinion 2 1 which is secured to gear 25 loosely mounted on countershaft 17, and gear 25 is driven by pinion 26 of the traverse or trolley motor 27 mounted on the base 10. Reverse rotation of motor 27 will obviously rotate drum 1 1 in opposite directions, at a reduced speed, to move the traverse-cable 28 in opposite directions. On the shafts of the motors 21, 27 are solenoid brakes 29, 30 re spectively, said brakes acting automatically to stop the motors and hence the drums and cables whenever the power is cut 05 from the motors. In the aforesaid pending application, I have shown means whereby power is automatically out off from and applied to the meters at the proper intervals.

As shown in Fig. 1, there is a sheave 31 mounted to rotate in a vertical plane on a sheave stand 32 secured to machine base 10, and the traverse or trolley cable 28, after being wrapped several times about drum 14, is passed around sheave 31 and brought back around the drum 14 again. The cable 28 extends upwardly to the trolley (not shown) to which its ends are lined, so that rotation of drum 14 in opposite directions will move the trolley in opposite directions, thus moving the bucket, which is suspended from the trolley by the hoist line. It will be clear that the trolley is moved solely because of friction between the cable 28 and drum 14. This friction is enhanced by wrapping the cable around sheave 31 and then bringing it back to and around the drum, as the cable tends to hug the drum more tightly when passed at an intermediate point around a sheave spaced from the drum shaft but parallel to the medial plane of the drum.

The sheave 31 is not only useful for increasing the frictional grip of the traverse cable on its drum; it is also used to drive the indicator (to be described) which shows the position of the trolley and also the limit switch mechanism (to be described) which controls two limit switches governing the traverse of the trolley through its motor 27, As the cable 28 drives sheave 31 by friction only, and as said cable is directly secured at both ends to the trolley, it follows that only actual movement of the trolley effects move ment of the trolley indicator and of the trolley-governing limit switch actuating mechanisms, which are driven only when sheave 31 is rotated. Therefore, slippage of the drum 14 relative to cable 28 may take place without affecting the accuracy of the indicator and withoutalfecting the proper working (in point of time) of the limit switches. Only slippage or movement of cable 28 relative to sheave 31 would make the indicator and limit switches inaccurate. and such slippage or relative movement will not occur except under extraordinary circumstances because the load on sheave 31 is very light, and cable 28 presses against it very tightly.

Referring to Figs. 2 and 3, which best show the indicator, it is seen that sheave 31 drives a shaft 33 on which there is a bevel gear 34 meshing with bevel gear 35 on a vertical shaft 36. WVhile an idler or rope driven sheave 31 is greatly to be preferred, for the illustrative traversing hoist unit, it is within the scope of my invention to provide a gear drive for shaft 33, and hence for shaft 36, which may be done whenever the load carrier has no slippage relative to the drum which operates it, for example, when the indicator and limit switches are to be used with a hoist drum. The vertical shaft 36 is enclosed in a tubular housing 37 supported by a bracket 38 on the upper end of sheave stand 32, and said housing 37 provides a standard, fixed upon the machine base, by which the indicator or dial plate 39 and limit switch housing 40 are supported. See, also, Fig. 1. Through a reduction gearing, to be described, vertical shaft 36 drives a horizontal shaft 41 on which a pointer 42 is fixed, the pointer thus rotating slowly in one direction or the other as the trolley moves back and forth on its track. By selecting the proper reduction gearing and arranging the indicia 43 properly, it is clear that the position of the bucket may be ascertained at any time in its traverse by noting the pointers position relative to the dial.

Obviously, in the described embodiment,

the pointer will rotate not more than one revolution for the greatest possible traverse of the bucket from the loading point; but if desired, the indicator may be of a different type. as like the indicator of the H. V. Harding Patent No. 1,705,973 dated March 19, V

1929, in which event the speed reduction need not be so. great, and traverse over a large plant may be accurately indicated. For small plants, however, the described embodiment is ideally fitted, as it is quite economical to make, install and maintain in service. As shaft 41 is also a limit switch actuating shaft, it follows that the only eX- tra parts necessary for the indicator are the pointer 42 and dial 39.

At the upper end of standard 37, a collar 44 fitting over said upper end is secured by a set screw 45 (Figs. 2 and 3), said collar thus permitting rotation of the indicator assembly to turn the dial toward the operators position, whatever it may be. Thus the indicator is adaptable to a wide variety of conditions without any change in its con- StlUCtlOIl.

Referring to Figs. 4 and 5, it is seen that the upper end of vertical shaft 36 is within the housing 40 and carries a worm 46 meshing with worm gear 47 fast on shaft 41, the pointer 42 being secured to shaft 41 by a nut 48 and by parts to be described. Obviously, at the start of traverse, the pointer should be at the zero position, but if not, the sheave 31 is rotated by hand, with cable 28 stationary, until the pointer is exactly at the Zero mark. Thus the indicator may be set accurately without difficulty.

lVithin the casing or housing 40 are two limit switches 49 of standard construction, being supported by bracket 50 in such posi tion that their pivoted switch arms 51 are moved by cams 52 which are fast to shaft 41. Preferably the cams 52 are of bakelite traverse motor. 10 i V i efl e i ns ma anese fee t i ree i he r s 'b ly amend ng th im t weet. w th it ind fie ti tefida pivoted switchfarms 51 are held pressed against the switch contacts '53 springs 54 ex ept vlan earns 52 push them away w the em e asie h s' l ane of the sptrings, thus breaking the circ uit offthe I p v Each switc'h arm is insulated from the mac-seem and casing {l0 and has a ciol'itactfhl which touches one of adjustable c' ont'ac t's when the'circuit controlledf said switch arm is closed. Contacts 53 'itrescf animate for adjustrnent, so tlia't thecirouit may be properly brokenby each cam. Further details ,iof the limitswitchejs are not disclosed because "the specificconstrliction of said switches forms no partbfi'ny invention.

Asf'sho'w'n, shaft-41 isjournaled in aushaped bearingbracketeti securedto the bottom of housing 40. Each earn 52 isan-gularly adjustable upon and is secured to sli'aftitl by means which will now be described. Itestran e) thefl'efthand cam in-Fig. 5, there are screws 56 secured to said cam and passing ltlirough'spa c'in g 'niembersb'l', 58, being parallel to shi'ftfl tl, Shaft tl carries two bushings 59, 60, bushing 59 being fixed to the shaftand bu'sl'ii'n g 60 being loose-upon it, and both bushings, 'having 'a-"circular end flange. The flange 'of bu'shing 59 m serve-"to space cain-52(which surrdunds said bushing) from theadjacer'ltj'wall of the'be'aring bracket 55', as shown, thuspreve'nting movement of the cam in onediirection onthe shaft,'the spacing members 57, 58j an'd nut ls preventing move- "nhent "in "the or'rposit'e direction; It will also be clear that shaft &1 is prevented from moving ldng it'iidinallyin one direction by the end flange of bushing 59. The flange of bushing 60 not only provides an abutment for the outside spacing member 58 but also provides convenient means for securing the pointer 42 to bushing 60, this being done by screws 61. Both bushings are cut away at their meeting ends, as clearly shown, so that bushing 60 may be locked against rotation relative to bushing 59 (and hence relative to shaft 41) whenever said ends engage in the manner illustrated. Such engagement is effected by tightening nut 48, which thrusts bushing 60 along shaft 41 toward bushing 59. However, the angular position of the cam with respect to shaft l1 may be changed at any time by loosening nut 48, whereupon the assembly consisting of the two spacing members 57, 58 and cam 52 may be turned on said shaft. This operation obviously varies the time at which the left-hand limit switch will operate, and hence varies the amount of traverse of the load carrier in one direction.

Referring now to the construction at the right side of Fig. 5, it will be clear that the right-hand cam 52 is adjustable relative to shaft-41in the same manners-site left hand cam; shortpointer 62 is clamped'by nut 'd3 to't'hepshaft, just as the 'long pointen fflis'; This short pointer provides a convenient means for determining the'adjustmen t which has been made at the othe'r side of the casing and will enable the operator to "duplicate the adjustment on the'r'i'ght-handside. The p0 sition of pointer 62 maybe marked-byiising V a sharp implement on spacingmem'ber 5"8,*'or

said member may be initially marked with indicia, not shown, Thusboth cams maybe moved angularly as often as desired, until it is determined by experiment that thyaefiu: ate the limit switches to bring the trolley to a stop at theproper point. Obviously, the a'd justment of both cams is Very uickly and easily efi'ected. g p

The described construction is easily-iii stalled and adjusted andeconomical com bined indicator and limitsiv'itch actuator for a small trolley bucket plant. I

Obviously, the present invention not restricted to the particular embodiment thereof hereinshown an'ddescrib'ed. More0ver,'it is not indispensable that all the features of the invention'be used conjointly, sincethey may be employed advantageously in various combinations andsub-combinations;

.1. A combined actuatorjfor limit switches and for an indicatorcomprising, in combination, ashaft driven through a reduction gearing; 'a pointer on the shaft; a pair of flimit switches -adjacent the shaft; a p'air of cams carried onthe shaft in position to actt'i- 'at-ez said limitsw'itchesf; and man anese to hold the pointer and also meetin immovable relative to the shaft, said'lnea'ns being] idiserrg 'ageable to permit angular ad justinerit of-eachcam and also the-pointer relativeto'the 'shaft.

I Ajcdmbified actuator for limit switches nd for anf'i ndicator comprising, in com;- bination, I a driven shaft; a worm on said shaft; 'aworm gear driven bysaid worm"; a second shaft driven by said worm gear; said second shaft being screw-threaded at its o-p 'posite ends; a nut on each end of the second then; a pair 'of'limit switches adjacent the second shaft; a 'pair of spacedcanis carried on the 'second'shaft in position toactuate said limit switches; a pair of pointers also on said shaft; and means on the-shaft providing abutments against which the two camsfa-nd the two pointers maybe pressed soas to clamp them to the shaft whenever said nuts are tightened.

? 31 A combined actuator for limit switches and for an indicator comprising, incombin'ation, a driven shaft; awornfi on saidshaft'; a worm gear'driven by said wor a-"second shaft driven by said worm ge'am safd'seegfid start bing screw threa'ded its opposite *encisg a nut on-each end of the second "shaft;

its

cams and the outer end flanges; the inner bushings being fast to the shaft and the outer bushings being interlocked with the inner bushings when the nuts are tightened.

4. An actuator for limit switches and for an indicator comprising, in combination, a shaft; means for driving the shaft at a very slow speed; a pair of bushings fixed to the shaft and having flanges at their inner ends; a. pair of cams loose on said shaft, surrounding said bushings, and abutted against said flanges; a second pair of bushings slidable on said shaft but interlocked with the first pair so that they rotate with the shaft, when in position; nuts screw-threaded on the 0pposite ends of said shaft; and pointers secured to the outer ends of the second pair of bushings, with the nuts located outside said pointers, so as to thrust said second bush ings inwardly when tightened.

5. An actuator for limit switches comprising, in combination, a shaft; means for driving the shaft at a very slow speed; a pair of cams at spaced points on said shaft; a pair of bushings secured to the shaft with the cams surrounding them; a second pair of bushings on the shaft interlocked with the first pair of bushings yet removable therefrom by pulling longitudinally of the shaft; a pair of nuts screw-threaded on opposite ends of said shaft; said nuts, when tightened, thrusting the second pair of bushings into interlocking engagement with the first pair; said cams being individually clamped to the shaft when the corresponding nuts are tightened.

6. An actuator for limit switches comprising, in combination, a casing; a U-shaped bearing bracket intermediate two opposite walls of the casing; a shaft rotatably supportshaft supported by the, sheave stand and driven by the sheave; a standard enclosing said shaft and supported by the sheave stand; a worm on the upper end of the vertical shaft; a worm gear driven by the worm; a horizontal shaft driven by the work gear; a dial plate secured to said standard; and a pointer fixed to said horizontal shaft and movable over the face of the dial plate.

8. A unitary indicator comprising, in combination, a sheave; a sheave stand; a vertical shaft supported by the sheave stand and driven by the sheave; a standard enclosing said shaft and supported by the sheave stand; a casing rotatably supported at the top of said standard; a worm on the upper end of the vertical shaft, within said casing; a worm gear within the casing driven by said worm; a dial plate fixed to said casing on the outside; a horizontal shaft driven by said worm gear; and a pointer fixed to said horizontal shaft'and movable on the face of the dial plate.

9. A unitary indicator comprising, in combination, a vertical standard; a powerdriven shaft within the standard; a casing; a collar fixed to the underside of the casing and rotatably mounted on the upper end of the standard; a set screw'holding the collar and casing in any desired angular position; an indicator dial fixed to the casing; reduction gearing within the casing driven by said shaft; a second shaft within the casing driven at: a slow speed by said reduction gearing; and a pointer secured to said second shaft and movable over said dial.

In testimony, that I claim the foregoing as my own, I have hereto afiixed my signature.

HAROLD E. HALLENBECK.

ed by said bearing bracket; a worm gear fixed V to the shaft between the two arms of said bearing bracket; a power-actuated worm for driving said worm gear; bushings fixed to said shaft on each side of the bearing bracket and each having an end flange abutting against the outer wall of the bearing bracket;

a cam loosely surrounding each of said bushings; spacing means outside of each cam but loose on said shaft; and nuts screw-threaded on each end of the shaft and clamping said cams on the shaft by thrusting the same, through the spacing means, against the aforesaid end flanges.

7. A unitary indicator comprising, in combination, a sheave; a sheave stand; a vertical

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