US2691478A

US2691478A - Lifesaving device for scaffolds

Info

Publication number: US2691478A
Application number: US272213A
Authority: US
Inventors: Frankel Jack
Original assignee: Individual
Current assignee: Individual
Priority date: 1952-02-18
Filing date: 1952-02-18
Publication date: 1954-10-12
Anticipated expiration: 1971-10-12

Description

-2 Sheets-Sheet l Filed Feb. 18, 1952 JNVENTOR JACK FRANKEL BY Oct. l2, 1954 J. FRANKEL LIFESAVING DEVICE FOR SCAFFOLDS 2 Sheets-Sheet 2 Filed Feb. 18, 1952 Y @Ew JNVENToR. JAcx FRANKSL Patented Oct. 12, 1954 UNITED STATES PATENT OFFICE 2,691,478 LIFESAVING DEVICE FOR SCAFFOLDS Jack Frankel, Brooklyn, N. Y. Application FebruaryvlS, 1952, Serial No. 272,213 v 2 Claims.

This invention relates to a life saving device, and more particularly to a mechanism for gripping a safety rope and for being attached to the safety belt of a person working at a dangerous height.

Many occupations are hazardous due to the height at which duties must be performed. Thus a worker on a scaffold is in a dangerous position, even though the scaffold itself is safe and secure. Many men have tripped and fallen from scaffolds, or been knocked off of scaifolds by falling objects or other workers. Many scaffolds have fallen, their ropes have broken, or one side has been suddenly dropped. 1n such instances, having a safety belt fastened to the scaffold is no protection.

The object of the present invention is to provide a device which can be used by a man working at a height on a scaffold, ladder, window ledge or the like, which device will prevent him from falling inadvertently from his support.

A further object is to provide a device as aforesaid, which consists primarily of a hanging rope or cable, a safety belt which can be buckled about the person, and a gripping device secured to said belt for gripping the cable to secure the person thereto, which gripping device can be slid, when desired, along the cable without danger that a fall may occur during such sliding adjustment.

Another object is to provide a device as aforesaid in which the person using the device can quickly change his vertical position without losing the benet of the safety cable, by merely squeezing two levers of the device to release the cable, the levers automatically being returned to cable-gripping position upon being released.

For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the following description and accompanying drawings, and to the 'appended claims in which the various novel features of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure:

Fig. l is a perspective View of a man working on a scaffold and employing the life saving device of the present invention.

Fig. 2 is a front View of the cable gripping device, the safety belt being omitted and the lever shown in its locked position.

Fig. 3 is a rear view of Fig. 2, the safety belt and links being omitted.

Fig. 4 is an elevational view of the clamping jaw of the device.

Fig. 5 is an enlarged sectional view taken'on line 5 5 of Fig. 2.

Fig. 6 is a side view of the device as viewed from the left of Fig. 2.

Fig. '7 is a side View of the stationary drum.

' Fig. 8 is another side view of the drum, rotated degrees from its position in Fig. '7. i,

Fig. 9 is a perspective view of the release arm, per se.

The life saving device Ill, iaccording to the present invention, is shown in the drawings used by a man I I working on a scaffold I2. The'device includes a safety belt I3 which is buckled about the mans waist.

The device II) includes a thick vertical plate I4, having downwardly and laterally extending lugs I5 having suitably located orifices I6 and a vertically elongated slot IE?L in each of which is fastened a swinging link I'l carrying a spring clip I8. The two outer clips I8 are fastened to the safety belt I3 and the center clip is available for fastening to any' other suitable element which it may be desired to secure to the safety cable. It may also be clipped to a fire belt, which would be a waist-type belt to be used in lowering a person down the cableI in case of fire, the device assuring that the person will not descend too rapidly or fall altogether.

The device is adapted to grip its lifeline or safety cable I9, which cable I9 will be rmly'secured to some anchorage above the person working on the scaffold. For example, a scaffold is usually fastened to a building coping or guard, and the cable I9 will be similarly anchored. A guide pulley 20 is rotatably mounted on a bolt` 2I secured at the top of the plate I4. The groove 22 of this pulley is deep enough to completely receive the cable I9, which is shown in this instance as a strong wire lexible'cable. ,Manila rope may be employed instead of wire cable if desired. Where rope is used, it will be thicker than wire cable, and consequently the pulleys used with the rope will have wider grooves 22 than the pulleys used with the wire cable. The

device is, however, of the same construction eX- ,y

cept as to dimensions for either wire cable and manila rope employment.

The cable I9 is guided by the rolling pulley 2EIA to a stationary drum 23 which is secured to the center of the plate I4 by a bolt 24. The drum is best shown in Figs. '7-8. 1t has an arbor 25, cylindrical in shape, and an outer end flange 26. The wire cable is wrapped about the arbor. As

seen in Fig. 2, the wire cable passes around they pulley 20 in a clockwise direction and about th arbor in a counterclockwise direction, and is- 3 guided to the pulley by a rigid arm 21 of an elbow secured to the plate I4 by rivets 28. The drum is secured to the plate I4 by a fitting 29 and the bolt 24. Adjacent the outer and inner ends of the arbor are oppositely running cams 30. Each cam is somewhat less than 180 degrees in length, and the cams are disposed opposite each other. The inner cam has its wide end in the vertical:centen:plane'y ofethe drum .atfthesbottom thereof. The outer .cam has its lwidegen'd ati-the top of the plane. The opposed faces 3l of the cams are inclined, see Fig. 8, so that the space longitudinally of the arbor between the cam is wedge-shaped for receiving the'iconvolutionsrof the cable I9. The outer cam is secured toctha flange 2S yand the inner cam is secured to the plate I4 by bolts 32.

The cable I9 is guided over one sidezoffthe pulley 20 to the other side of the drum, see Fig. 6, andV is given. two and one .half turns about thedruln so that it passesr from VNthe drum on the same side as itsfirst convolution. .The convolutlons are squeezed betweenthe .camsin the wedge-shaped spaces, and'this squeezekeeps the convolutions inplace andenhances'the resistance to movement of the cable produced by the friction of the .convclutionson the drum'arbor by assuring contact with 'the arbor. The more cable turns over the drum,.the more force will be'required to move the device relative to the stationarycable. .'The cams guide the cables into convolutions. If adead weight, as a man falling, was'imposecl on-the cable, stretching same, the squeeze in the wedge-shaped spaces wouldsbe reduced. 'The bottom edge of the inner .cam formsafshoulder which rubs Vwith friction contactagainst the cable.

Below'the drum is another guiding rollerlil, inline .with butinwardly of the top guiding roller, and this roller at the'bottom guides the cable to a clamp"33. .Clalnp'33 has a stationary jaw`34and a movable jaw 35. Jaw l34 issecured to. plate I4 by several bolts 34a, see Figs/3 and`5. It has a portion the thickness of plate I4 superposed thereon and a thickerportion which underlies the plate I4, see Fig. 6. v"Ihejawlld has avertical groove 36 for receiving the cable I), see Eig. 5. Jaw 95 has .a groove" 31 mating with groove'36. This jaw is. superposed on'ltheplate [4i and slides thereon.

.`"Jaw.35 includes an arcuatelegii38 which slides onthe plate I4 and ,ismaintained 'thereon'.by a curved slot 39 'working on .two fspaced bolts 4t screwed'intoitheplate I4. "Theleg' has a large slot `4I disposedover :a post"42 securedto the plate .I4. 'This post serves'asan, anchorage'for a coil compression spring 43, v.the other `end' being anchored Nagainst 4a )shoulder 44 of .the v.leg 38. The coil spring is .maintained in ,place by a curved rod 45 .extending` .from .the shoulder J4, see Fig. 4. At the .toppf the. legis an elongated hole .46 .engaged .by .aspin .41a vof aJpivoted :bell crank lever 41. This .bell crank.lever41.;is .fulcrumed .on a pin-48 ,carried `by l.a depending handle-[49 .rigidly secured .to the vplate I4. .At its lower end the handle 49 carriesv a. swinging link 50 andlever41..has-La.notch.5l atfts lowenend. When-lever 41.is swung toward handlelilthe link is adapted to'nflt `inthe notchkapreventing .the lever from being swung fawayffromthe.handle 49wby the spring 43.

AAt its free end, the releasearm.Bnhasaright angularly extended `bill .portion 6,2 which .extendsrearward over the top,of..the .link 50. .The

bill ,portion :62 has .a.:lower.cam .surfacewBZaar lzunderstood that the device is equally applicable to other uses, the `cable I9 is first secured at its "upper end, 'as aforesaid, and fastened to the devicewithi` as many turns on the drum as is necessary to bring the drum cams into wedging "action, A:Thedevice is secured to the mans safety safetybelt, the lever and handle are gripped and squeezed, the link 5l) is engaged with the notch 5| holding the movable `jaw 35 in an inoperative position. The cable I9 is pulled downwardly below the 'device until all slack has been taken up. 'The 'fullmovement of the lever by squeezing" it toward the handle 49 slides the leg `/38 upwardly along the screws 4t and moves the jaw portion 33 of themovable jaw 35 away from the jaw 34, the spring '43 being compressed by this movement. The cable I9 is accordingly released.

"Of course vthe scaffold will bechanged as to its vertical position from time to time. VFor instance, if a workman is painting asign on. a wall, he will ordinarily work from thetop and drop the scaffold as his work proceeds. lItl is during dropping of the scaffold'that the greatest risk of accident occurs. For example, '..the scaffold is usually held in place by ropes .at its ends working over pulleys, the ropes 'being tied to the scaffold. To drop the scaffold, the rope at one end is untied, and'this end ofthe scaffold is first dropped, assuming one man only is working on 'the scaffold. The scaffoldis then tilteddangerously until 'the other end is similarly dropped. 'During .the release of the rope,if'the man 'should loosehis'grip onthe rope, the scaffold would `drop vertically and be heldiat' one end. This, ofcourse, would'beverydangerous. But even if no accident such as the above occurs, the tilting ofthe scaffold lstillpresents danger, as the man must .climb .this tilted hanging walk'to getto .the 'other end. "The "life saving device eliminates. any danger lduring this operation.

.The'normalguse of the device,.assumingthat thelowering' of theiscaifold proceeds safely; perniitsV the .lowering of the device along thecable the` saine distance as'the"scaifold was lowered without at anytime taking Ythe deviceout'of operation. That` is' tozsay; atno time is the "life saving 'feature 'ofithe device nullied. 'During suclrnorrnal operation the cable slides past the openjaws'34 and35 .with the cable I9 'turning reluctantly .around the ldrum 23, maintaining fairly 'tight engagement therewith. Shouldthe man fallduring this operation, downward vmovement ofthe plate Ilirelative tofthe cable` I9 would ..be..irnpeded by the` engagement .of vthe cable. I 9V .withthe` drum..23. The. links I 'I .would be piilled downward relative .to .theplate I4 byY reason of .their engagement Awith thesafety belt .I3.:causing..the .link kI'I' vwhich engages the vertically elongated slot'v Ito move .downward relative `to the respective lug I5 .and .pivotthe release arm downwardcausing its billpor tion 62 AtosWing the link `Slitdownward` disengaging it from the notch 5I to release .thelever 41, which would be a natural incident to a fall, and such release will permit the return of the jaw 33 into tight cable-engaging relation With the jaw 34, thus checking the fall.

While I have illustrated and described the preferred embodiment of my invention, it is to be understood that I do not limit myself to the precise construction herein disclosed and the right is reserved to all changes and modications coming within the scope of the invention as deiined in the appended claims.

Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent is:

1. A life saving apparatus for preventing a man from accidentally falling from a high perch comprising, a cable adapted to be rigidly connected at its upper end to an anchorage, a safety belt adapted to be worn by the man, and a device for adjustably securing said belt to said cable, said device including a Vertical plate including a rigid stationary jaw secured to said plate, a guide secured to said plate, a post secured to said plate, a sliding jaw mounted on said guide and post, said jaws having mating grooves for said cable, a coil spring compressed between said post and a part of said sliding jaw for urging said sliding jaw toward said stationary jaw, a lever fulcrumed to said plate and connected to said sliding jaw for moving same away from said stationary jaw against the resistance of said spring, a rigid handle secured to said plate for use in manually moving said lever, said handle having a link for coacting with said lever for locking said lever in a retracted position of said sliding jaw, and release means for disengaging said link from said lever to free said sliding jaw to be urged into operative position with relation to said stationary jaw when the man wearing the safety belt starts falling, said release means comprising a pivotally mounted release arm having a bill portion engaging said link, and means controlled by the attachment of said plate to said safety belt for pivlever.

2. A life saving apparatus for preventing a man from accidently falling from a high perch comprising, a cable adapted to be rigidly connected at its upper end to an anchorage, means to secure a man to said cable, said means comprising, a vertical supporting plate, and a gripper including a rigid stationary jaw secured to said plate,'a guide secured to said plate, a post secured to said plate, a sliding jaw mounted on said guide and post, said jaws having mating grooves for said cable, a coil spring compressed between said post and a part of said sliding jaw for urging said sliding jaw toward said stationary jaw, a lever fulcrumed to said plate and connected to said sliding jaw for moving same away from said stationary jaw against the resistance of said spring, a handle secured to said plate, said handle having a link for coacting with said lever for locking said lever in a retracted position of said sliding jaw, and release means for disengaglng said link from said lever to free said sliding jaw to be urged into operative position with relation to said stationary jaw when the man wearing the safety belt startsfalling, said release means comprising a pivotally mounted release arm having a bill portion engaging said link, and means controlled by the attachment of said plate to said safety belt for pivoting said release arm to free said link from said lever.

References Cited in the le of this patent UNTTED STATES PATENTS Number Name Date 450,796 Olmsted Apr. 2l, 1891 456,532 Bliss July 21, 1891 785,432 Perkins Mar. 21, 1965 40 1,412,624 Lundgren Apr. 11, 1922 1,497,534 Bass June 10, 1924 2,386,849 Frankel Oct. 16, 1945 2,432,741 Frankel Dec. 16, 1947 2,544,964 Phelan Mar. 13, 1951