US2573930A - Farm silo personnel elevator - Google Patents

Description

Nov. 6, 1951 Filed Sept. 22, 1949 A. c. RADTKE 2,573,930 FARM SILO PERSONNEL ELEVATOR 5 Sheets-Sheet 1 FIGI.

INVENTOR ADELBERT c. RADTKE May M ATT'Y Nov. 6, 1951 A. c. RADTKE FARM SILO PERSONNEL ELEVATOR 3 Sheets-Sheet 2 Filed Sept. 22, 1949 FIGB.

INVENTOR DELBERT C. RADTKE ATT'Y.

Nov. 6, 1951 A. c. RADTKE FARM SILO PERSONNEL ELEVATOR 3 Sheets-Sheet 3 Filed Sept. 22 1949 INVENTOR ADELBER T C. RADTKE' PM FIGT.

Patented Nov. 6, 1951 I FARM SILO PERSONNEL ELEVATOR Adelbert o. meme, Oak Park, 111., assignor to International Harvester Company, a corporation of New Jersey Application September 22, 1949, Serial No. 117,175

This invention relates generally to an improvement in farm silos, and more particularly to a personnel elevator especially constructed and arranged within the silo ac cess chute to readily enable the farmer to ascend and descend the silo safely and quickly. v

'Farm' .silos generally have an upright access chute into which the discharge openings of the silo proper open at different points in the height of the silo and the access chutehas an outlet ordischarge openingat the bottom. Heretofore, it was necessary for the farmer when withdrawing a quantity of ensilage from the silo to climb the interior of the access chute to the proper discharge opening, and upon entering the silo take the desired quantity of ensila'ge therefrom and allow it to drop through the access chute to the outlet or discharge opening at the bottom of the access chute. Inasmuch as it is neces--- sary to use the silo ladder to gain access tothe silo, oftentimes the operation is dangerou'sbee cause of the accumulation of Wet ensilage 'on'the rungs of the ladder. Hence, the primary objective of this invention is to provide a new and improved personnelelevator. for silos whereby the farmer may safely ascend and descend the silo without using the silo ladder. l Another object is the provision of a novel automatic safety device which eifectively stops descent of the elevator car upon failure of the supporting chain track. A still further object is the provision of means whereby the ensilage may be taken from the silo at any particular unloading point, and delivered to the bottom of the accesschute without the discharge of ensilage being hampered by the ele Vator car.

A further object is the provision of novel guide means for the elevator car which also serves as a braking surface for an automatic safety device carried by the elevator car. a

The foregoing and other important objects and desirable features inherent in and encompassed by the invention, togetherwith many of the purposes and uses thereof, will become readily apparent from a reading ofthe ensuing description in conjunction withthe annexed drawings, in which: Fig. 1 is a side elevational view of a farm silo showing the preferred embodiment of the invention positioned within the silo access chute;

Fig. 2 is a plan view of the access chute with the top of the access chute cut away to show the elevator car;

Fig. 3 .is a side elevational view showing the 12 Claims.

, 2 safety device and driving mechanism in detail;

Fig. 4 is a side elevational view showing the elevator platform in a vertical position;

Fig. 5 is a detail view of the motor controlling switches;

Fig. 6 is a sectional view taken substantially along the line 66 of Fig. 2; and

-Fig. '7 is a sectional view taken substantially along line 7--1 of Fig. 2.

Referring to the drawings, in which like reference characters designate like elements throughout the various views, a conventional farm silo I0 is shown having a Vertically extending opening 1 I substantially along the entire height of the silo. The vertical opening H is closed by a series of removable boards or plates l2 which may be individually removed to provide a plurality of discharge openings along the height of the silo l0. Positioned over the vertical opening II is a substantially semi-circular access chute l3 having an outlet or discharge opening I 4 at its bottom. A plurality of horizontal reinforcing rods or bars I5 are structurally held in the vertical opening II to provide ladderrungs for ascending or descending the silo Iil. Fastened within the access chute 13 as by means of a plurality of horizontal brackets l6 secured to certain of the bars l5 are a pair of guide rails l1 preferably formed of angle iron strips.

An elevator car, designated generally by refer- A ence character [8, is adapted for sliding vertical movement along the guide rails I! within the access chute [3. The car 18 includes a semicircular back portion 19 made of sheet metal or like material curved to conform to the interior wall 20 of the access chute It. A pair of vertically extending members 2| preferably having an L-shaped cross-section are secured to the back portion l9 adjacent the guide rails I! whereby the surfaces 22 of members 2| will abut the surfaces 23 of the guide rails I1. The members 2! depend downwardly below the lowermost edge 24 of the back portion 19 and hingedly support a platform 25 upon which the elevator operator stands when operating the elevator car [8. A pair of chains 26 have one of their ends-fastened to platform 25 and their other ends attached to a pair of hand grips 21 secured on the members 2| within the back portion is to support the platform 25 in a horizontal position as shown in Fig. 1. A coil spring 59 continually urges the platform 25 to a vertical position as shown in Figure 4. The turning force of spring 59 is of a magnitude which is easily overcome by the weight of the farmer standing upon the platform 25. It

will be appreciated from a reading of the foregoing structure that the farmer may convenient ly stand upon the platform 25 and ascend to the level desired whereupon he can enter the silo l and discharge a quantity of ensilage from within. silo to the bottom of the access chute l3 without being hampered by the elevator car l8 in the discharging operation. The platform is easily pivoted to a vertical position as shown in Fig. f when operator steps away from car removing his weight from platform 25 by spring 59,'and thus permits the ensilage to be freely discharged through the elevator car l8; It will be noted that the back portion I9 is curvedto allow the maximum possible discharge area through the elevator car l8. 1 j

The elevator car I8 is continually maintained in sliding contact with the guide rails H by means of a plurality of vertically spaced L-shaped brackets 28 rigidly fastened to the members 2|. One leg 29 of each bracket 28 abuts a surface 30 opposite a surface 23 of each guide rail whereby the guide rail I1 is confined or embraced between the bracket 28 and the vertically extending member 2|.

Positioned above and secured tothe elevator car I8 is a frame designated by reference character 3| which comprises a plurality of horizontally and vertically disposed bars 32 welded together and to the elevator car to provide a supporting structure for various parts to be described hereinafter.

An electric motor 33 for raising and lowering the elevator car I8 is mounted on the frame 3| and is equipped with an automatic brake (not shown) which prevents rotation of the rotor shaft 34 when the motor is not energized. A speed reducer 35 is drivingly coupled to the motor 33. by means of a belt sheave 38 keyed to rotor shaft 34, a belt sheave 31 keyed to the input shaft 38 of the speed reducer, and an endless belt 39 connecting the sheaves 36 and 31 Positioned adjacent the motor 33 is a self-winding reel 40 of the conventional type which automatically takes up slack in the electric cord 4|, which has one end attached to an electric outlet (not shown) in the vicinity of the mid point of car travel in the access chute I3. It will be noted that an electrical circuit diagram, not shown, includes leads from the reel 40, a pushbutton switch 42 and a reversing switch 43. The switches 42, 43 are mounted on a horizontal bar 44 held between the vertical members 2| near the top of the elevator car [8 and are normally in a circuit-open position. It will be apparent that in order to energize the motor 33 both switches must be actuated to a circuit-closed position and since the switches are horizontally spaced from each other it will be necessary to actuate each switch with; a different hand. Hence, a very simple interlock device is provided which effectively prevents the elevator operator from having his hands projecting from the elevator car I8 when in motion.

The input shaft 38 of the sped reducer 35 drives an output shaft 45 at a reduced speed through suitable gearing (not shown) Keyed on the output shaft 45 is a chain sheave 45 adapted to mesh'with a chain track 47. The chain track 4'! is anchored near the top of the access chute l3 by means of braces 48 secured to the silo rungs l5 and depends downwardly therefrom.

A safety device 49 is mounted on the frame 3| from falling if the supporting chain track 41 should break or become loose from its anchorage. The safety device 49 includes a shaft 50 horizontally mounted for rotation in the frame 3|. Each end of the shaft 50 adjacent the guide rails I1 is provided with a cam member 5| adapted to be rotated into wedging engagement with the guide rails. Spaced approximately midway between the cam members 5| on the shaft 50 is asubstantially L-shaped arm 52 mounted for rotation therewith. An idler chain sheave 53 is rotatably supported on one leg 54 of the arm 52.

' It will be noted thatthe rotational axis of the chain sheave 53 is coincident with the longitudinal axis of the leg. A helical tension spring 55 has one end 53 anchored to the frame 3| and the other end attached to the leg 51 of the arm 49. It will be apparent that the spring 55 tends to rotate the shaft 50 and, therefore, the cam members 5| in a clockwise direction as viewed in Fig. 3, whereby the cam members 5| act as a brake on the guide rails IT. The supporting chain track 41 is trained beneath chain sheave 53, over chain sheave 46, and then over an idler chain sheave 58' rotatably supported by the frame 3|. It will be appreciated that the weight of the elevator car l8 acting through the arm 52 will overcome the biasing action of the spring 55 and rotate the shaft 50 in a counterclockwise direction. In this position, which is the normal operating position, the cam members 5| are rotated out of wedging engagement with the guide rails However, it will be obvious if the supporting chain track 41 should fail, the spring 55 will be free to rotate the cam members 5| into wedging engagement with the guide rails H to effectively stop downward movement of the elevator car I8.

Attention is drawn to the fact that the entire elevator assembly including the guide rails and chain track is designed to be readily attached or detached solely to or from the reinforcing rods or bars l5 of the silo vertical opening The embodiment of the invention chosen for the purposes of illustration and description herein is that preferred as-the result of selective tests based upon requirementsffor achieving the objects of the invention and developing the utility thereof in the most desirable manner, due regard being had to existing factors of economy, simplicity of design and construction, and the improvements sought to be effected. 7 It will be appreciated, therefore, that the particular structural and functional aspects emphasized herein are not intended to exclude, but rather'to suggest, such other adaptations and modifications of the invention as fall within the spirit and scope of the invention as defined in the appended claims.

What isclaimed is: V

1. In a farm silo personnel elevator, the combination comprising a vertically extending semicircular access chute; a pair of horizontally spaced guide rails extending substantially along 33 which effectively prevents the elevator car l8 the entire length of said access chute; an elevator car adapted for sliding vertical movement along said guide rails within said access chute, said elevator car including a semi-circular back portion adapted to conform to the semi-circular access chute, and a pair of vertically extending members secured to said back portion adjacent said guide rails adapted to abut a first surface of said guide rails, said member s ha ving a platform pivotally mounted between their lowermo t end and a p ura ity of I--shaped aeration site": said firstsurface to confinesaid. guiderails between said members andisaidi second; legs; a

frame: positionedv above said car; electric means: to: raise and lower said car. including; an. electric. motor supported on said: frame and aospeeda reducer drivingly connected tosaid motor havingan output-shaft for drivinga first chainsheave; an automatic safetydevice mounted on, said: frame, adjacentsaid motor comprising a r tatable shaft having a cam member ateach end adjacent said guide rails anda. substantially L-sllaped arm: rigid with. said shaft, said arm having a. secondchain sheave rotatably supported on one leg thereof and: a spring acting on; the other-leg adaptedto rotate said. cam membersin-to wedging engagement with; said. guide railsy'and a longitudinally extending chain track. depending from an upper portion of' said. access chute adapted to be trained-beneath said second chain sheave and over said first chain sheave whereby, the:- weight of said car overcomes the action ofsaid spring and rotates saidrjshaft to; disengage said cam members. from saiidguide rails.

2. In; a farm silo personnel elevator, the com,-

bination comprising a longitudinally extending) accesschute; a pair of transversely spaced, guide rails extending substantially along the, entire length of said access; chute; an elevator car adapted for longitudinal sliding movement along said guide railswithin said access chute; a frame positioned above said car; electric means to raise and lower saidcar including a first chain sheave driven by an electric motor; an automatic safety device mounted onlsaid frame comprising a rotatable shaft having a cam member at each end adjacent said guide rails and a substantially L-shaped arm rigid with said, shaft, said arm having a second chain sheave rotatably supported on one leg thereof and aspring acting on the other leg adapted to rotate said cam members into: wedging engagement with said guide rails; and a longitudinally extending chain track depending from an upper portion of said access chute adapted to be trained beneath said second sheave and over said first sheave whereby the weight of said car overcomes the action of said spring and rotates said shaft to disengage said cam members from said guide rails.

3. In a farm silo personnel elevator, the combination comprising a pair of longitudinally extending transversely spaced guide rails; an elevator car adapted for longitudinal sliding movement along said guide rails; a frame positioned above said car; electric means to raise and lower said car including a first chain sheave driven by an electric motor; an automatic safety device mounted on said frame comprising a rotatable shaft having a cam member at each end adjacent said guide rails and a substantially L-shaped arm rigid with said shaft, said arm having a second chain sheave rotatably supported on one leg thereof and a spring acting on the other leg adapted to rotate said cam members into engagement with said guide rails; and a longitudinally extending supporting chain track adapted to be trained beneath said second sheave and over said first sheave whereby the Weight of said car overcomes the action of said spring and rotates said shaft to disengage said cam members from said guide rails.

4. In a farm silo personnel elevator, the combination comprising a pair of vertical guide rails; an elevator car adapted for sliding movement 6; along, said guide rails; a frame carried on top; of; said can m ans. to raiseand. low r.- a car including, an. electric motor drivinely connected; to, afirst-chain sheave; a safety device mounted. on said frame comprisin a rot ab e Shaft having a; cam member at each endadj acent said guide rails anda substantially L-shaped arm rigid with saidshaft, saidarm having a second chain sheave rotatably supported on one leg thereof and a spring acting on; the other leg adapted to rotate said cam, members into engagement with said guide rails; and a upporting chain ck;ad pt tobe trainedbenea h id con sheav a ver said firstv sheave whereby the weight of said car rotatessaid shaft to disengage said cam members from said ui rails,

5., In a\ farm silo personnel elevator, the com-.- bination comprisinga pair of vertical guide rails; an elevator car adapted for sliding vertical movement along said guide rails; a frame carried on top of said car; a safety device mounted on said frame including a rotatable shaft having a cam member at each end adjacent said guide rails and a substantially L-shaped arm rigid with said shaft, said arm, having a chain sheave rotatably supported on one leg thereof and a spring acting on the other leg adapted to rotate said cam members into engagement with said guide rails; and a supporting chain track adapted to be trained beneathsaid sheave to support said car wherebythe weight of said car rotates said shaft to disengage said cam members from said guide rails.

6. In a personnel elevator, the combination comprising a, pair of transversely spaced longi tudinally extending guide rails; an elevator car adapted to move longitudinally on said guide rails a frame mounted on top of said car; a rotatable shaft transversely journalled in said frame, said shaft having a cam member on each endadapted to normally engage said guide rails; an arm mounted on said shaft having a chain sheave rotatably mounted thereon; and a chain adapted tobe trained beneath said sheave to support said car whereby the weight of said car rotates said shaft to disengage said cam members from said guide rails.

'7. In a farm silo elevator, a pair of guide rails; an elevator car movable in said guide rails; a safety device pivotally mounted on said car adapted to be raised into engagement with said guide rails, said safety device including a shaft transversely journalled on said car carrying an arm having a chain sheave rotatably mounted thereon, and a supporting chain track passing under said chain sheave whereby said safety device is normally prevented from engaging said guide rails.

8. In a farm silo elevator, the combination comprising a pair of guide rails; an elevator car movable in said guide rails; a safety device pivotally mounted on said car, said safety device including a rotatable shaft mounted on said car having a pair of cam members on each end, an arm rigid with said shaft having a chain sheave rotatably mounted thereon, and a spring acting on said arm for rotating said cam members into engagement with said guide rails; and a supporting chain track passing around said chain sheave whereby said cam members are normally prevented from engaging said guide rails.

9. In a farm silo personnel elevator, the combination comprising longitudinally extending guide means; an elevator car adapted to move longitudinally along said guide means; a frame mounted on top of said elevator car; means mounted on said frame to impart longitudinal movement to said elevator car including an electric motor drivingly connected to a horizontal output shaft, said shaft having a first chain sheave secured thereto; a safety device mounted on said frame including a rotatable shaft longitudinally and horizontally spaced from said output shaft, said rotatable shaft having a cam member at each end adjacent said guide means and an arm rigid with said shaft, said arm having a second chain sheave rotatably supported thereon along the longitudinal axis, and a spring acting on said arm adapted to rotate said cam members into engagement with saidguide means whereby the rotative axes of said first and second chain sheaves are not in parallel horizontal planes; and a supporting chain track adapted to be trained beneath said second chain sheave and over said first chain sheave whereby the weight of said car rotates said rotatable shaft to disengage said cam members from said guide means and the rotative axes of said sheaves are in substantially parallel horizontal planes.

10. In an elevator, the combination comprising a pair of vertical extending guide rails; an elevator car adapted to slide on said guide rails; an open frame on top of said car; a shaft journalled in said frame; cams carried on the ends of said shaft adapted to move into and out of engagement with said guide rails; a spring biasing said shaft to cause said cams to engage said guide rails; an arm mounted on said shaft having an idler chain sheave rotatably mounted thereon; a chain sheave vertically spaced from said idler chain sheave; a chain to provide a track for said driving chain sheave, said chain being anchored at one end and trained under said idler chain sheave and over said driving chain sheave whereby said spring is overcome and said shaft and cams are rotatated to disengage said cams.

11. In a silo having a longitudinally extending access chute, the combination comprising a pair of transversely spaced guide rails extending substantially along the entire length of said access chute; an elevator car adapted for sliding vertical movement within said access chute; means for' guiding said elevator car including a pair of longitudinally extending frame members secured to said elevator car adjacent said guide rails adapted to abut a first surface of said guide rails,

and a plurality of brackets secured to said frame. members, each having a portion adapted to abut a second surface of said guide rails whereby said guide rails are confined between said brackets and said frame members.

12. In a silo having a plurality of longitudinally spaced discharge openings arranged along the height of the silo and a semi-circular access chute positioned over said openings and providing an outlet opening at its bottom, the

combination comprising an elevator car adapted for longitudinal movement within said access chute, said elevator car including a semi-circular REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Datev 751,328 McDonald Feb. 2, 1904 1,470,292 Scheunert Oct. 9, 1923

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