US2386849A

US2386849A - Automatic grip for lifesaving devices

Info

Publication number: US2386849A
Application number: US543069A
Authority: US
Inventors: Frankel Jack
Original assignee: Individual
Current assignee: Individual
Priority date: 1944-07-01
Filing date: 1944-07-01
Publication date: 1945-10-16
Anticipated expiration: 1962-10-16

Description

Oct. 16, 1945. J, FRANKEL AUTOMATIC GRIP FOR LIFE SAVING DEVICES Filed July 1, 1944 5 Sheets-Sheet 1 Oc t. FRANKEL I 7 AUTOMATIC GRIP FOR LIFE SAVING DEVICES Filed July 1, 1944 5 Sheets-Sheet 2 INVENTOR. Jck Han Eel ATTORNEY Oct. 16, 1945. J. FRANKEL 2,386,849

AUTOMATIC GRIP FOR LIFE SAVING DEVICES Fild July 1, 1944 5 Sheets-Sheet -3 IN V EN TOR.

v zck Wankel A TTORNEVY Oct. 16, 1945. J, FRANKEL 2,386,849

AUTOMATIC GRIP FOR LIFE SAVING DEVICES Filed July 1, 1944 5 Sheets-Sheet 4 l N VEN TOR.

ATTORNEY Oct. 16, 1945. J, FRANKEL 2,386,849

' AUTOMATIC GRIP FOR LIFE SAVING DEVICES Filed July 1, 1944 5 Sheets-Sheet 5 INVENTOR.

Jack We Take! P. 1m I ATTORNEY Patented Get. 16, 1945 AUTOMATIC GRIP FOR .LIFESAVING DEVICES Jack Frankel, Brooklyn, N. Y.

Application July 1, 1944, Serial No. 543,069

11 Claims.

This invention relates to new and useful improvements in a life saving device.

More specifically, the invention proposes the construction of a novel type of clamp for use in a life saving device for persons working in elevated positions on scaffolds and the like and arranged in a manner to be engageable with a safety belt and an adjacent guy rope.

Still further it is proposed to characterize the clamp by a bracket supporting movable jaws engageable against opposite sides of the guy rope.

A further object of the invention proposes -a novel means for supporting the movable jaws upon the bracket in a manner to be movable towards each other for rigidly clamping the guy rope.

Still further, it is proposed to provide novel means for moving the slidably mounted jaws toward each other and which is arranged in a manner to permit the clamping action to be quickly effected.

Still further the invention contemplates a clamp as aforesaid having an adjustable jaw and an automatically'closable jaw.

Still further the invention contemplates an.

automatic clamping device which will automatically reclose one slidably mounted jaw onto the guy rope, forcing it into. engagement with'the adjustably mounted jaw in the event of an emergency. With this arrangement it is impossible for a person using the device to experience a fall of any distance. If a fall should'start, it would be arrested immediately.

For further comprehension of the invention, and of the objects and advantages thereo-treference 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. 1 is a perspective view of a clamp or a device constructed in accordance with this invention. g

Fig. 2 is a rear View of the clamp of Fig. 1.

Fig. 3 is a plan view of the clamp of Fig. 1.

Fig. 4 is an end view of the left .side .of the clamp shown in Fig. 1. v

Fig. 5 is a perspective view of one of the jaws of the clamp of the present invention.

Fig. 6 is a section on the line 6 -6 of Fig. 1.

Fig. '7 is a section on the line l-l ofFig. 1.

Fig. 8 is a perspective view illustrating a man standing upon a scaffold and using a lifesaving device constructed in accordance with .this invention.

Fig. 9 is a perspective view of the assembled life saving device per .se.

Fig. 10 is a developed view of the waist engaging belt, per se.

Fig. .11 is an end view showing a clamp constructed in accordance with a modification of .this

invention, the view being taken from the left side of the clamp.

Fig. 12 is a section on the line I2.l2 of Fig. 11.

The life saving device, in accordance with this invention, includes a belt I B for engagement about the waist of a person operating from a suspended scafiold H. The belt It] is of conventional construction and includes a buckle l2 on one end. The buckle l2 has a pivotal tongue l3 selectively engageable with one of a plurality of openings 14 formed in the other end of the belt. Attached at spaced positions along the length of the belt I0 there is provided a pair of leg engaging straps [5 which are arranged to engage the top of the wear ers legs immediately adjacent the crotch. The positioning of the belt Ill and straps I5 upon the waist of a person is clearly illustrated in Fig. 8 of the drawings.

A clamp i6 is adapted to be attached to :the belt 1) and a guyrope l'l projected downwards adjacent the scaffold ll. The clamp I6 is characterized by a base or bracket 18 having a pair of downwardly extending eye pieces 19. Each of the eye piecesis provided with a downwardly extending fastening means by which the bracket 18 is attached to the .belt Ill.

Each of the fastening means is characterized by a flexible cable 20 projected through and having its .ends secured to arigid tube member .2! which acts to encase its cables. Mounted upon each of the cables adjacent the lower end of the tube members 2! there is a clamp 22 having .a spring closed jaw 2.3. These clamps 22 are engaged with complementary .rings 24 securely mounted upon the belt H] at points adjacent the straps-l5. e

Clamp 16 further has an end wall 25 bolted to the bracket 18. A threaded orifice 26;is formed in .wall 25and a screw 2! is threaded through this orifice. A set screw .28 is provided :for selectively locking and unlocking screw .21 in .orlfice 2B. A handle 29 is fastened to one end-of the screw 21 anda YIIIOVflblQ jaw is mounted on the other .end of the screw 2-!, screw 21 having an annular slot 3.! in which .a pin 32 projects, securing the jaw on the screw '21 :but permitting the .screw to rotate relative to 'thejaw.

Jaw 38 has slots 33 in which are disposed bolts 34 screwed into the bracket I 8 and slidably mounting the jaw on the bracket. Washers 35 are provided adjacent the slots. A rope-engaging serrated vertical groove 36 for engaging one side of the guy rope I1 is provided in one side face of the jaw.

A similar but oppositely directed jaw 31 is secured to the bracket I8 by bolts 34' disposed in slots 33':. However, a shaft 38 is secured in jaw 31 instead of a screw 21. Shaft 38 extends to the end of the clamp l6 remote from the handle 29 and is journalled at this end in an end wall 39 secured to two vertically spaced members 48 which in turn are bolted to the rear face of the adjacent end of the bracket l8.

Wall 39 has an inwardly extending boss 4| in which is the orifice forming the bearing for the adjacent end of shaft 38. A collar 42 is journalled on shaft 38 adjacent boss 4! and a movable handle 43 is secured to this collar. A stationary handle 44 is bolted to the back of the members 48 in line with handle 43. A torsion spring 45 is mounted on shaft 38 with one end secured to collar 42 by a bolt 46. A coil spring 41 is connected at one end to the top member 48 bya screw 48 in line with collar 42 and at the other end to the bolt 46 by a pin 49. Spring 41 augments spring 45. The other end of spring 45 is secured by a bolt 58 to an end wall similarto wall 25 and bolted to bracket 18 at the adjacent end thereof. While wall 5| is an end wall of the bracket 18 it is an intermediate wall of the clamp. However, as members 48 may be, if desired, parts of bracket l8, in the appended

claims walls

25 and 38 will be considered the endwalls of the bracket and wall 5| an intermediate wall.

A cam 52 is secured to shaft 38 by a pin 53 adjacent wall 5| and a cam 54 is rotatably mounted on shaft 38 and secured to jaw 31. Two small tension springs 55 connected to jaw 31 and end wall 5| operate to hold

cams

52 and 54 in engagement.

The operation of the device is as follows:

A person about to work upon a scaffold similar to that shown at I I in the drawings, engages the belt i8 about his waist. When the straps l5 are engaged about the top of the persons legs the clamps 22 of the clamp l6 are then engaged with the rings 24 mounted on the belt ID. The set screw 28' is then loosened and the jaws separated so that the guy rope I! can be placed between the

jaws

38 and 31 of the clamp l6. The handle 29 is then turned to move the screw 21 inwardly and thus move the jaw 38 towards the law 3'! to firmly rip the guy rope between the jaws whereupon the set screw 28 is screwed in again. The springs 45 and 41 maintain the'jaw 31 in position so that the guy rope is firmly gripped by the two jaws, jaw 31 bein prevented from moving due to the engagement of the earns 52 and 54. With the lift saving device thus assembled, it will be noted that it is practically impossible to fall to the ground in the event that a person loses his foot hold on the scaffold, or if one of the ropes from the scaffold should break, as the guy rope is firmly held by the clamp 16, the serrations of the jaws forming a tight grip.

If it is desired to hoist or lower the scaffold and it. becomes necessary for the clamp 16 to be moved upward or downward upon the guy rope l7, itis merely necessary for the person to which the clamp I6 is attached to grip the

handles

43 and 44 and squeeze them'together. This can be done with one hand. This operation will rotate collar 42, tighten spring 45, stretch spring 41, rotate shaft 38 and cam 52. Rotation of cam 52 will cause a space to be formed between the cams and the springs 55, which are under tension, will move jaw 31 away from jaw 38, freeing rope H in the jaws so that the clamp l6 may be slid relative to the rope without the rope leaving the aws. a

When the clamp has been moved to its new proper position, the person using the clamp need only release the

handles

43 and 44 to cause the clamp l6 to again grip the rope 11. That is to say, the regripping of the rope by the jaws is automatic, which is an important feature of the present invention, for should the user of the clamp fall while adjusting the clamp on the guy rope, he need only release his grip on the handles to make the clamp 16 regrip the guy rope to stop the fall. This automatic regripping is caused by the unwinding of the spring 45 and the return of spring 41 to normal position, which rotates shaft 38 backward and causes cam 52 to rotate and reengage cam 54, moving jaw 31 toward jaw 38.

It is contemplated that when handles 43 and 44 are gripped and moved together to free rope l1 for sliding, rope I! is nevertheless maintained in the

grooves

36 and 36 and the jaws do not open suificiently to permit the rope to move out of the jaws. This is an added safety feature of the present device.

Springs 45 and 41 augment each other and either of these springs may be eliminated if desired, although it is a desirable safety feature to include both springs so that a positive spring action will always be present and the failure of either spring will not make the device inoperative.

The pressure exerted on the rope by the springs 45 and 41 is always constant. However, the effective pressure that these springs exert may be controlled by the movable jaw 38. That is to say, jaw 38 may be moved to a position nearer jaw 31 to increase the pressure with which the guy rope is held or moved away to decrease the pressure. It further provides for better operation on ropes of different diameters.

In the modification of the invention shown in Figs. 11 and 12, a clamp is shown which is substantially like the clamp I6 except that the handle 43' is connected to an internally toothed ring gear 56 having slots 51 in which are disposed bolts 58 securing the ring gear to the end wall 38 for limited rotation relative thereto. A gear 59 is secured on the end of shaft 38 in engagement with the teeth of ring gear 56. Rotation of the handle 43 rotates ring gear and thereby gear 59 and shaft 38, this rotation of shaft 38' being accompanied by the same results as the rotation of shaft 38 and no further description thereof is deemed necessary.

While I have illustrated and described the preferred embodiments of my invention, it is to be understood that I do not limit myself to the precise constructions herein disclosed and the right is reserved to all changes and modifications coming within the scope of the invention as definedin the appended claims; y

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

1. In a device of the class described, a clamp,

. comprising abracket, a jaw having a serrated bracket, a screw threaded into a part of said bracket and rotatably secured to said jaw for adjusting the position of said jaw, another jaw having a serrated rope-engaging groove complementary to said first mentioned groove movably mounted on said bracket, a shaft rotatably journalled at one end in said other jaw and at its other end in a part of said bracket, a cam rotatably mounted on said shaft and secured to said other jaw, another cam rigidly secured on said shaft and adapted to engage said jaw cam for moving said other jaw toward said adjustable jaw, a handle secured to said shaft for rotating same manually to disengage said cams to permit said other jaw to move away from said adjustable jaw, and a spring means operatively connected to said shaft and to said bracket for automatically rotating said shaft in a reverse direction when said handle is released to move said other jaw toward said adjustable jaw.

2. In a device of the class described, a clamp, comprising a bracket, a jaw having a serrated rope-engaging groove movably mounted on said bracket, a screw threaded into a part of said bracket and rotatably secured to said jaw for adjusting the position of said jaw, another having a serrated rope-engaging groove complementary to said first mentioned groove movably mounted on said bracket, a shaft rotatably journalled at one end in said other jaw and at its other end in a part of said bracket, a cam rotatably mounted on said shaft and secured to said other jaw, another cam rigidly secured on said shaft and adapted to engage said jaw cam for moving said other jaw toward said adjustable jaw, a handle secured to said shaft for rotating same manually to disengage said cams to permit said other jaw to move away from said adjustable jaw, and a spring means operatively connected to said shaft and to said bracket for automatically rotating said shaft in a reverse direction when said handle is released to move said other jaw toward said adjustable jaw, said spring means including a torsion spring disposed around said shaft.

3. In a device of the class described, a clamp, comprising a bracket, a jaw having a serrated rope-engaging groove movably mounted on said bracket, a screw threaded into a part of said bracket and rotatably secured to said jaw for adjusting the position of said jaw, another having a serrated rope-engaging groove complementary to said first mentioned groove movably mounted on said bracket, a shaft rotatably journalled at one end in said other jaw and at its other end in a part of said bracket, a cam rotatably mounted on said shaft and secured to said other jaw, another cam rigidly secured on said shaft and adapted to engage said jaw cam for moving said other jaw toward said adjustable jaw, a handle secured to said shaft for rotating same manually to disengage said cams to permit said other jaw to move away from said adjustable jaw, and a spring means operatively connected to said shaft and to said bracket for automatically rotating said shaft in a reverse direction when said handle is released to move said other jaw toward said adjustable jaw, said spring means including a coil tension spring.

4. In a device of the class described, a clamp, comprising a bracket, a jaw having a serrated rope-engaging groove movably mounted on said bracket, a screw threaded into a part of said bracket and rotatably secured to said jaw for adjusting the position of said jaw, another having a. serrated rope-engaging groove complement'ary to said first mentioned groove movably mounted on said bracket, a shaft rotatably journalled at one end in said other jaw andat its other endin a part of said bracket, a cam rotatably mounted on said shaft'and secured to said other jaw, another cam rigidly secured on said shaft and adapted to engage said jaw cam for moving said other jaw toward said adjustable jaw, a handle secured to said shaft for rotating same manually to disengage said cams to permit said other jaw to move away from said adjustable jaw, and a spring means operatively con nected to said shaft and to said bracket for automatically rotating said shaft in a reverse direction when said handle is released to move said other jaw toward said adjustable jaw, said spring means including a torsion spring disposed around said shaft and a coil tension spring.

5. In a device of the class described, a clamp, comprising a bracket having'a back, end walls and an intermediate wall, a jaw having a serrated rope-engaging groove movably mounted on said bracket back wall, a screw threaded through one of said bracket end Walls and rotatably secured to said jaw for adjusting the posi tion of said jaw, another jaw having a serrated rope-{engagin groove complementary to said first mentioned groove movably mounted on said bracket back wall, a shaft rotatably journalled and secured at one end in said other jaw and at its other end journalled in the other end wall of said bracket, and passing through said intermediate wall, a cam rotatably mounted on said shaft and secured to said other jaw, another cam rigidly secured on said shaft and adapted to engage said jaw cam for moving said other jaw toward said adjustable jaw, a collar secured to said shaft adjacent said other end wall, a handle secured to said collar for rotating said shaft manually to disengage said cams to permit said other jaw to move away from said adjustable jaw, and spring means operatively connected to said shaft and to said bracket for automatically rotating said shaft in a reverse direction when said handle is released to move said other jaw toward said adjustable jaw.

6. In a device of the class described, a clamp, comprising a bracket having a back, end walls and an intermediate wall, a jaw having a serrated rope-engaging groove movably mounted on said bracket back wall, a screw threaded through one of said bracket end walls and rotatably secured to said jaw for adjusting the position of said jaw, another jaw having a serrated rope-engaging groove complementary to said first mentioned groove movably mounted on said bracket back wall, a shaft rotatably journalled and secured at one end in said other jaw and at its other end journalled in the other end wall of said bracket, and. passing through said intermediate wall, a cam rotatably mounted on said shaft and secured to said other jaw, another cam rigidly'secured on said shaft and adapted to engage said jaw cam for moving said other jaw toward said adjustablejaw, a collar secured to said shaft adjacent said other end wall, a handle secured to said collar shaft for rotating said shaft same manually to disengage said cams to permit said other jaw to move away from said adjustable jaw, and spring means operatively connected to said shaft and to said bracket for automatically rotating said shaft in a reverse direction when said handle is released to move said other jaw toward said adjustable jaw, said spring means including a torsion'spring ;sur-' rounding said shaft and secured at one end vto said collar and at the other end to said inter-v mediate wall.

- '7. In a device of the class described,,a clamp, comprising a bracket having a back, end walls and an intermediate wall, a jaw having 'a serrate rope-engaging groove movably mounted on said bracket back wall, a screw threaded through one of said bracket end walls and rotatably secured to said jaw for adjusting the position of said jaw, another jaw having a serrated ropeengaging groove complementary to said first mentioned groove "movably mounted on said bracket back wall, a shaft' rotatably journalled and secured at one end in said other jaw and at its other end journalled in the other end wall of said bracket, and passing through said intermediate wall, a cam rotatably mounted on said shaft and secured to said other jaw, another cam rigidly secured on said shaft and adapted to engage said jaw cam for moving said other jaw toward said adjustable jaw, a collar secured to said shaft adjacent said other end wall, a handle secured to said collar shaft for rotating said shaft same manually to disengage said cams to permit said other jaw to move away from said adjustable jaw, and spring means operatively connected to said shaft and to said bracket for automatically rotating said shaft in a reverse direction when said handle is released to move said other jaw toward said adjustable jaw, said spring means including a torsion spring surrounding said shaft and secured at one end to said collar and at the other end to said intermediate wall, and a tension spring connected at one end to said collar and at the other end to said bracket.

8. In a device of the class described, a clamp, comprising a bracket, a jaw having a serrated rope-engaging groove movably mounted on said bracket, a screw threaded into a part of said bracket and rotatably secured to said jawfor adjusting the position of said jaw, another jaw having a serrated rope-engaging groove complementary to said first mentioned groove movably mounted on said bracket, a shaft rotatably journalled at, one end in said other jaw and at its other end in a part of said bracket, a cam rotatably mounted on said shaft and secured to said other jaw, another cam rigidly secured on said shaft and adapted to engage said jaw cam for moving said other;j aw toward said adjustable jaw, an internally toothed ring gear secured to said last mentioned part for limited rotative movement relative thereto, a gear secured to said shaft in engagement with said ring gear, a handle secured to said ring gear for rotating said shaft manually to disengage said cams to permit said other jaw to move away from said adjustable jaw, and spring means operatively connected to said shaft and to said bracket for automatically rotating said shaft in a reverse direction when said handle is released to move said other jaw toward said adjustable jaw.

9. In a device of the class described a clamp, comprising a bracket, a jaw having. a serrated rope-engaging groove movably mounted on said bracket, a' screw threaded into a part of said bracket and rotatably secured to said jaw for adjusting the position of said jaw, another jaw having a serrated rope-engaging groove complementary to said first mentioned groove movably mounted on said bracket, a shaft rotatably journalled at one end in said other jaw and at its other end in a part of said bracket, a cam rotatably mounted on said shaft and secured to said other jaw, another cam rigidly secured on said shaft and adapted to engage said jaw cam for moving said other jaw toward said adjustable jaw, a handle secured to said shaft for rotating same manually to disengage said cams to permit said other jaw to move away from said adjustable jaw, and a spring means operatively connected to said shaft and to said bracket for automatically rotating said shaft in a reverse direction when said handle is released to move said other jaw toward said adjustable jaw, and tension spring connected to said other jaw and to a part of said bracket on the side of said other jaw remote from said adjustable jaw.

10; A safety device for gripping a rope or the like comprising a base, a jaw movably mounted on said base, a screw threaded into a part of said base and rotatably secured to said jaw for adjusting the position of said jaw, another jaw movably mounted on said base, a shaft rotatably journalled at one end in said other jaw and at its other end ina part of said base, a cam rotatably mounted on said shaft and secured to said other jaw, another cam rigidly secured on said shaft and adapted to engage said jaw cam for moving said other jaw toward said adjustable jaw, a handle secured to said shaft for rotating same manually to disengage said cams to permit said other jaw to move away from said adjustable jaw, and spring means secured to said shaft and to said base for automatically rotating said shaft in a reverse direction when said. handle is released to move said other jaw toward said adjusted jaw.

11. A safety device for gripping a rope or the like comprisin a base, a jaw slidably mounted on said base, a screw threaded into a part of said base and rotatably secured to said jaw for adjusting the position of said jaw, a handle secured to said screw for manually operating same, a set screw in a part of said base for coacting with said screw for locking said screw in an adjusted position, another jaw slidably mounted on said base, a shaft rotatably journalled at one end in said other jaw and at its other end in a part of said base, a cam rotatably mounted on said shaft and secured to said other jaw, another cam rigidly secured on said shaft and adapted to engage said jaw cam for moving said other jaw toward said adjustable jaw, a handle secured to said shaft for rotating same manually to disengage said cams to permit said other jaw to move away from said adjustable jaw, and spring means secured to said shaft and to said base for automatically rotating said shaft in a reverse direction when said handle is released to move said other jaw toward said adjusted jaw.

JACK FRANKEL.