US2635712A - Safety device - Google Patents

Description

I 1102/05 7 3 1. iii? 6 239. 7,1 E

1Q iliiltl fil i "a I 1 15 11 U 12 W t- April 21, 1953 A. M. WILLIAMSON I 2,635,712

SAFETY DEVICE Filed Jan. 5, 1950 INVENTOR M Ml/zmson ATTORNEY Patented Apr. 21, 1953 UNITED STATES PATENT OFFICE s FE'rY DEVICE Andrew M. Williamson, Atlanta, Ga.

Application January 5, 1950, Serial No. 136,947

10 Claims.

'IhisinVention relates to an improved safety "device particularly adaptable to hold the clutch jor'operating lever of a ho isting engine. customarily, in present day practice, the hoisting engine is usually located on the ground and is irra remote point from the tower or supporting structure of a cage or the like for lifting materials and workmen to various levels of a construction job. The operator of the engine stands in a position whereit is impossible for him always tosee the elevator, cage or platform, and particularly to see workmen 0n the'oageor on the construction levels immediately-adjacent the cage. The'customary practice is for the operator to be governed by a bell or light signal whichcan be given by anyone on any of the floors of a building under construction; While workmen are actually en-' gaged loading 'or unloading a V cage, or are otherwise located'in a position of danger, should thecage be moved, he oftentimes misunderstands the signal given or becomes confused and lowers 'or'raises the cage before the workmen have an opportunity to move to a position of safety. Consequently, many workmen have been injured and killed as a resultof such mistakes and misunderstandings. Therefore, one object of this'invention is to provide a safety device that will eliminate accidents resulting from errors of judgment or signal to the hoisting engine operator. p Furthermore, in current day practice wherein adequate and positive safety devices are not provided relative to the hoisting equipment, workmen are hampered by the psychological fear of being caught in a position whereinjury can occur, and consequentlytheiroperationsaround the cage are hampered by this psychological fear. Accordingly, another object of this invention is to provide a safety device for construction work that will eliminate this psychological hazard-and will permit the workmen to function more effiof several individuals located at several different points, suchas levels of a building under con- -s truction, r'emotely located from said clutch lever orsimilar control.

' These objects may be accomplished by a prefrred form embodying my invention, by providingapluraliiay of'cont rols','- such as switches or th'like, at'different located levels of'a building under construction, and connecting said controls 7 "tbs mechanismfsuch as a solenoid or the like;

drawings.

which mechanism in turn operates a holding means such as an arm that cooperates with the clutch lever of a hoisting engine in such a way as to lock said lever in an inoperative position. This enables a workman located at any one of the several levels of the building under construction to actuate the control or switch on the level at which he is working to lock or hold the clutch lever out of engagement.

Other objects and advantages of this invention will become apparent as the discussion proceeds and when considered in connection with the accompanying claims and drawings, in which:

Fig. 1 is an elevation, partly in sectionof a conventional elevator tower diagrammatically showing the switches and safety bars embodying my invention;

- Fig. 2 is a side elevation and diagrammatic view of that part of the safety device'embodying my invention, which holds the clutch lever in an inoperative position; 0

Fig. 3 is atop plan anddlagrammatic view of that part of the safety device shown in Fig. 2;

and

Fig. 4 is an enlarged section of the switch and safety bar embodying my invention, which are located on the several levels of the constructio job or the hoisting tower.

Turning now toa detailed description of the drawings, thenumeral 5 designates a skeleton tower of conventional design located in position against a buildingt, under construction. Open ings 1 are located at various levels of the tower 5 and at which an elevator cage or platform 8 is adapted to stop.

The elevator cage 8 is lowered and raised by means of a conventional cable .9 which is connected to an ordinary drum or the like, operated by a donkey or other hoisting engine, all of which is conventional and is not shown in detail in the A clutch operating lever 10, which may be operated by hand or by foot, is connected to the conventional clutch and hold mechanism located on the hoisting engine. Mounted upon the clutch operating lever I0 is a plate H, as shown in Figs. 2 and-3.

vA platform or other suitable sup-port I? is mounted adjacent the clutch lever l0, and pivotally supported thereon at 13 is a lever I4. Upon one end of the lever I4 is a laterally extending finger [5 which is adapted to swing into position behind the clutch lever Ill, as shownin Figs. 2 and 3. Iheplate I I carried upon the clutch lever Ill-prevents the finger I 5 from falling in front of weight. jform andshape, it ,is preferred to mount one :of .these bars across .each of theopenings 1 about from.

the clutch lever It! When it is in the operating position shown in dotted lines in Fig. 2, and can fall on the side of the lever l opposite the finger only when the clutch lever is in an inoperativeposition, shown in solid lines in Fig. 2.

The opposite end of the lever l 4 from the finger l5 pivotally carries a core l6 which slidably operates into a high voltage solenoid IT. A spring l8 holds the safety arm I4 normally in the dotted line position shown .in' Fig. 3 awayfrom the clutch arm [0. When thesolenoid H is energized, the core I6 is drawn into said solenoid and causes the lever M to move into the solid line position best shown in Fig. 3.

The electrical system for operating the solenoid l '1 consists of a plurality of switches 26 which may be of conventional design-and which are shown in detail here only for'the purpose of clearly illustrating my invention. Theswitches 2G are normally closed, and each is provided with ;a-ho\usin Ethavinga contact 22 therein that is insulated from the housing ,2i --and is connected ;to..one "side =o.f :azlow voltage line -23. .Pivotally mounted within the -housing ,2! is an arm -24 The housing .21 .is

A plunger 26 is slidably mounted within the housing 2 l, as showninFig.4,.and is pivotally connected at2 l to the-armzil. .Aspring or -other actuating means 28 constantly urges the plunger Zfiupwardin-respect to the housing 2: when viewed ,in the'positionshown in Fig. 4. Thereby the contacts 2.2 and .25 .areconstantly urged --into {a closed position.

Associated with each switch 20 is a safety .bar 39 which, preferably, should be of considerable While'said bar fikrnay 'vary widely in a hinge point 3! at one end, andto .positionthe bar so as :to rest upon theplunger 2%.at itsoppositeend. The bar3il maybemountedon pivot 3| and lowered and raised in front of .the opening], or-it:may beentirely-removable there- -It serves the dual purposeof an.obstruction to-theopening i when thecage is not ata level, in which position it holds the plunger 25 in: a depressed position with the switch .oontacts Hand-25 open.

'It issto'belherenoted that the switches 28 are iconnectedin parallel to the low voltage line .23. However, itisobvious to .thoseskilled in the art, that by slightly modifying the circuit, to be described hereinafter, the switches 2% .could be ,connectedin series with the low voltag line23,

the contacts 22 and'zfi being reversed so that they are "normally closed and the solenoid H and plunger 516 also reversed. Thus --modified, my invention would function equally as well as described herein.

Low voltage lines '23 are connected to a stepdown transformer I32 and are in series with a low voltage solenoid 33. The step-down transformer "32, preferably, should supply 24 volts or less to the low voltage line 23, and the primary thereof is connected to the customary 110-volt source .of electric current supply.

The solenoid 33 actuatesa core 34 upon which a switch member 35 is-carried, as shown in Fig. '2. The switch member 35 closes'contacts 36, which are in series with an electrical connection .31 running tonne side of the solenoid H. The ether side .of the solenoid 47 is connected to la iIineB-S- The lines 31 andjil mammoth-p nnected to the llO-volt source of electric current supply.

The operation of my safety device is explained as follows:

When any one of the bars 30 is lifted from the plunger 26, as shown in Fig. 1 at a level designated L, the switch contacts 22 and 25 will be closed. This will energize solenoid 33 and will cause the core 34 to be drawn thereinto, as shown .insolid' linesfin'Fig. 2. This will: close the bar 35 on the contacts' 36, andthus solenoid 11 will be energized, pulling core l6 thereinto, as shown in dotted lines in Fig. 3. When core Iii is pulled ,into the solenoid H, the lever I4 is caused to swing about its pivot l3 and to take the posi- :tionshown in the full lines in Fig. 3.

,Emvidedthe .clutch lever IE! is in its inoperative position shown in solid lines in Fig. 2, the .zfinger [5 will drop into place behind the clutch lever l9 and will remain there as long as solenoid i-i sis-energized. When finger 45 .is Josh-ind rclutchilever w it Will-be impossible for-theroperator to throwstheplutch-lever.Hl into itsoper- .ating positionandtherebystart the. lowering or raising of the: cage 8. I

When the workman at a 'fioor level-is ready to-have the-cage-8 moved, he again replaces the safety bar -30 and-.therebycpens the switch r20, which cuts off the current .to solenoid 33 and thereby, in turn, releases .the lever 14, which again permits the engine operator to throw the clutohlever 19 into its operating position and -cause the cage 8 .to-raisebr lower,--.as.desired.

.It will .beseen from the foregoingexplanation thatthe safetydevi-ceshown anddescribed above enables. a workman .on .anyilevel where. a switch .20 islocated to positively .lock theclutchlever 1E5. frombeingthrowninto its operating position once .it is .throwninto its inoperating position. Any workman located .onany floor .at which .the cage 8 is not locatedmay actuate the safety mechanism .merely .by raising the .bar '31] .and guaranteethat the .cage will .not be lowered onto, raised.to,.or..past, the level on which .heis working at any time .helfeels he .may be in a position of danger 1. relative to .said .cage 8.

.Modifications and changes in my invention .may be resorted .to without deviating 'from the spirit thereof,..such as adapting-the safety .device to an electric switch operating an electric .motor, ortoa valve lever of astem engine. A plurality of levers .!4 may be provided simultaneously-on jobs where there is more than .one hoisting tower with more .thanpne. hoisting denglue and lever .I 0. The voltages, types .of .sole- ,noids, and switches, may also be varied without departing-from the spirit of my invention.

Ivclaim:

;1. .A safety device for a :hoisting engine ;con;- trolling the movement of an elevator associated with a building under construction comprising :a clutch "lever for controlling said hoisting engine, a support adapted .to ibe'loca'ted adjacent said clutch lever, anarmpivotallymounted-on said support, afinger carried bys'said arm-adapted to lock :said clutch .lever .iniraninoperative :position, actuating :means connected to :said pivoted arm, .and ;a plurality of controls :connected to said actuating means, each of said controls adapted to be:located at a level "of .said building under construction remote from-said clutch lever whereby the clutch levercan be positively locked in an inoperative position from any level .of the building under construction.

, A -.sa.f.ety-.device .for a hoistin engine having a clutch lever controlling the movement of an elevator associated with a building under construction comprising a support adapted to be located adjacent said clutch lever, a pivoted arm mounted on said support, a finger carried by said arm adapted to lock said clutch lever in an inoperative position, a plate mounted on said clutch lever positioned to prevent said finger from looking said clutch lever in an operative position, actuating means connected to said pivoted arm, and a plurality of controls connected to said actuating means, each of said controls adapted to be located at a level of said building under construction remote from said clutch lever whereby the clutch lever can be positively locked in an inoperative position from any level of the building under construction.

3. A safety device for a hoisting engine controlling the movement of an elevator comprising a clutch lever for controlling said engine, solenoid actuated means for positively locking said clutch lever in an inoperative position, switch means for operating said solenoid and adapted to be located at a level of a structure, and electrical means connecting said switch means to said solenoid.

4. A safety device for a hoisting engine controlling the movement of an elevator associated with a building under construction comprising a clutch lever for controlling said engine, a support adapted to be located adjacent said clutch lever, an arm pivotally mounted on said support, a finger carried by said arm in position to lock said clutch lever in an inoperative position, a solenoid having a movable core therein connected to said arm, a switch adapted to be located at a level of the building under construction, and an electrical circuit connecting said switch to said solenoid.

5. A safety device for a hoisting engine having a clutch lever controlling the movement of an elevator associated with a building under construction comprising a support adapted to be located adjacent said clutch lever, an arm pivotally mounted on said support, a finger carried by said arm in position to lock said clutch lever in an inoperative position, a plate mounted on said clutch lever positioned to prevent said finger from looking said clutch lever in an operative position, a solenoid having a movable core therein connected to said arm, a plurality of switches adapted to be located at various levels of the building under construction, and an electrical circuit connecting said switches to said solenoid.

6. A safety device for a hoisting engine having a clutch lever controlling the movement of an elevator associated with a building under construction comprising a support adapted to be located adjacent said clutch lever, an arm mounted on said support, a finger carried by said arm in position to lock said clutch lever in an inoperative position, a high-voltage solenoid having a movable core therein connected to said arm, a low-voltage solenoid having a movable core therein, a switch operatively connected with said last-mentioned core, said switch being connected to said high-voltage solenoid.

7. A safety device for a hoisting engine having an operating lever controlling the movement of an elevator for hoisting materials to a building under construction, said building having openings therein located at different levels and communicating with landing levels of said elevator, comprising electrically actuated means for looking said lever in an inoperative position, switch means for operating said electrically actuated means and adapted to be located at the various openings, electrical means connecting said switch means to said electrically actuated means, and closure bars, associated with said switch means adapted to actuate said switch means and to close said openings.

8. A safety device for a hoisting engine having an operating lever controlling the starting and stopping of an elevator at openings located at various levels of a building under construction and remote from said hoisting engine, comprising a pivoted lever adapted to be mounted in cooperating relation with said operating lever, a finger carried upon one end of said pivoted lever adapted to positively lock the operating lever in an inoperative position, a plate mounted on said operating lever positioned to abut against said depending finger to prevent locking of the operating lever in an operative position, a plurality of switches, each of said switches adapted to be located at the several respective levels of said building under construction, a solenoid connected with said switches, a switch actuated by said solenoid, a second solenoid connected with said switch, means actuated by said last-mentioned solenoid and connected to the pivoted lever, and closure bars associated with the switches adapted to be located at the several respective levels of said building, each bar being adapted to actuate one of said first-mentioned switches and to close one of said openings.

9. A safety device for a hoisting engine adapted to control the starting and stopping of an elevator, comprising a lever having a catch on one end portion thereof, means pivotally supporting the lever intermediate the ends thereof, a normally deenergized electro-magnetic device connected with the opposite end portion of the lever for moving the lever in one direction, a spring connected with the lever at the opposite side of the pivotal support normally tending to move the lever in the opposite direction.

10. A safety device for a hoisting engine adapted to control the starting and stopping of an elevator, comprising a lever having a catch on one end portion thereof, means pivotally supporting the lever intermediate the ends thereof, a normally deenergized electro-magnetic device connected with the opposite end portion of the lever for moving the lever in one direction, a spring connected with the lever at the opposite side of the pivotal support normally tending to move the lever in the opposite direction, an electric circuit connected with the electro-magnetic device for operating said device, a switch connected in said electric circuit for controlling the operation thereof, an electro-magnetio device for controlling said switch, and a second circuit connected with the second electro-magnetic device for operating the latter.

ANDREW M. WILLIAMSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 231,743 Sawyer Aug. 31, 1880 389,853 O-ngley Sept. 18, 1888 579,024 Strohm Mar. 16, 1897 648,995 Potter May 8, 1900 705,479 Strohm July 22, 1902 740,570 Jenkins June 3, 1903

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