US1888612A

US1888612A - Lifting mechanism

Info

Publication number: US1888612A
Application number: US564181A
Authority: US
Inventors: David P Anderson
Original assignee: Individual
Current assignee: Individual
Priority date: 1931-09-21
Filing date: 1931-09-21
Publication date: 1932-11-22
Anticipated expiration: 1949-11-22

Description

Nov. 22, 1932. D. P. ANDERSON 1,888,612

LIFTING MECHANISM Filed sept. 21, 1951 2 sheets-sheet 1 @j /2' ff lzvedor:

j DHV/ P HNDEESO/v, 8

Nov. 22, 1982. D R ANDERSON y 1,888,612

L'IFTING MECHANISM Filed Sept. 21, 18.31 2 sheets-sheet 2 FCQIZ.

/ Warneys.

Patented Nov. 212, 1.931?l UNITED-STATES LIFTING MricHNrsM Application ined september 21,1931, serial n. 564,181. i 'l This is an invention for a lifting mechanism adapted to operate furnace doors, valves, blast furnace bells and the like. The inventor intends to provide a mechanism which is simple and sturdy, no gears, brakes nor'limit switches beingl necessary.

Having reference to the accompanying drawings:

Figure 1 is a side elevation of an example of the invention arranged to operate a re# generative furnace door.

Figure 2 is a top plan of Figure 1.

Figure 3 is an end elevation of Figure V1.

Figure 4 is a cross-section on the line IV-IV of Figure 1. f

In detail the `above show a regenerative furnace door 1 raised and lowered by means of a chain 2 passing over a pulley 3, a lifting mechanism constructed according to the pres- 20 ent invention being connected to this chain.

This mechanism comprises a pair of differently sized sheaves .4 and 5 commonly mounted on the armature shaft 6 of an electric motor 7 with an endless cable 8 arranged from one of these sheaves to the other in the manner of a differential pulley, forming a horizontal loop 9 and a vertical loop 10.

A pulley 11, carried by the free end of the horizontal loop 9, has its housing connected to the chain 2, and a second pulley 12 is carried by the free end of the vertical loop 10, this latter pulley having a heavy thick-walled housing 13 which substantially counter-balances the door. A pair of chains 14 pass over pulleys 15 to resiliently interconnect the pulleys 1l and 12 through compression springs 16 carried by draw bolts 17. Preferably this is adjusted so that the compression springs carry part of the weight of the door.

Although not shown by the drawings, it is to be assumed that this lifting mechanism is located at the top rear end of a bank of furnaces having a number of doors similar to that shown and that there will be a lifting '45 mechanism for each door. The cable 8 is of a length which permits its vertical loop portion 10 to drop the pulley 12 and housing 13 onto a stop 18, which may be the floor or a shelf arrangement, whenV theV `door 1 is in raised 0 position. When this occurs the cable 8 is slacked sothat'ther'e is not sufficient friction i between it and the sheaves 4 and 5 for. driv-` ing'purpose`vvhereby a safetystoppage oc- `curs when the operator-.fails .to cutoff the motor 7 vwhen thedoor'reaches a fully? raised position. v f 1 Thisoperation isepo'sitive and immediate and works `without the `-aid :of delicate `limit switches or other fragiletparts, such las are usually employed A*in lifting mechanisms.

After this'stoppage'has-occurred the cable 8 will immediately tauten `when. the motor A7 is cut off, due to the drag of the door 1,\.so'that upon reversal of this motor this door will bey lowered. lNo brakesy are needed-because the y sa friction lof the door andfits frame willjbeV suliicient to preventany overrunningi: .The

chains -14 serve toprevent the doorfallingfor the pulleys 11' and '12c'aus'ingdamage should the Cable-Sbreak-in service. They further serve as a means for adjusting the tension'ofA thiscable-through'thedrawbolts 17. Y i While a specific example of the invention has been shown and described in accordance with the patent statutes, it is not intended to,` limit the scope of the invention exactly thereto, except as defined inthe appended claims.

2. A lifting mechanism including a pair j of interconnected differently sized sheaves, an endless `cable arranged from one of said sheaves to the othervin Vtwo looped portions,

a pulley carried by the free end of one of said looped portions for connection to the object to be lifted, a weighted pulley carried by the free end of the other of said looped portions this portion being vertically ar-` ranged and means for stopping the movement of said last named pulley when said'firstilO' V 2 s Y, Y 1,888,612

named pulley has moved to a predetermined position. Y Y Y 3.Y A lifting mechanism comprising a pair of interconnecteddiferently sized sheaves, an endless'cable arranged from one of said sheaves to the other in two looped portions, a pulley carried Aby the free end of one of said loopedeportions for ,connection tothe object to be lifted, a second pulley weighted to substantially counterbalance said object f and carried by the other of said looped por-r tions this portion beingverti'cally arranged,A means for interconnecting said" pulleys, f means for stopping the movement of said,V 15 last named pulley when' said drst namedv pulley has moved to a predetermined position and means for rotating said sheaves. Y 4. A lifting mechanism comprising a pair ofinterconnected differently sized sheaves, an endless cableiarranged from one of said sheaves to the other in'respectively horizontally and vertically looped portions, a .pulley carried by the free ,end of saidvhorizontally loopedv portion for connection to the object to be lifted, a second pulley c arried by said vertically looped portion and weighted to substantially, counterbalance said object, chainsresiliently connected between said pulleys and arranged substantially parallel to I v fig() the sides'of said looped portions, means for stopping the movement o said second named pulley whenl said `first named pulley' has "moved tol a .l predetermined positionwand g means forrotating said sheaves.

355' 5 In' testimony whereof, I have hereunto set fmyhand.Y f.

Y. yDAID 'PQANDERSON