US3847377A

US3847377A - Safety lowering device

Info

Publication number: US3847377A
Application number: US00367732A
Authority: US
Inventors: C Byrd
Original assignee: Safety Devices Inc
Current assignee: Safety Devices Inc
Priority date: 1973-06-07
Filing date: 1973-06-07
Publication date: 1974-11-12
Anticipated expiration: 1991-11-12

Abstract

A safety device utilizing a drum and cable arrangement for lowering a person or load at a substantially constant speed. A plurality of radially displaceable vanes or blades rotate with the drum and are positioned within a fluid-filled, sealed housing. A fixed plate is secured within the housing to depress the vanes upon movement past the plate to control rotation of the drum.

Description

lll tates Patent H Byrd [ Nova 12, 1974 [541 SAFETY LOWERING DEVICE FOREIGN PATENTS OR APPLICATIONS 1 1 1.093606 12/1967 Great Britain.........i........, 193/35 A Primary Examiner-Stanley H. Tollhcrg Assistant ExaminerNorman L. Stack [73] Assignee:

[22] Filed:

[57] ABSTRA C'll A safety device utilizing a drum and cable arrangc- 5 5 ment for lowering a person or load at a substantially 2 1/12 constant speed. A plurality of radially displaceahle 193/35 254/136 158 vanes or blades rotate with the drum and are positioned within a fluid-filled, sealed housing. A fixed plate is secured within the housing to depress the [51] lnt. [58] Field of Search References Cited UNITED STATES PATENTS 254/158 254/158 9 Claims, 4 Drawing Figures 516,117 3/1894 1,099,834 6/1914 Baldwin et a i' SAFETY LOWERING DEVICE BRIEF SUMMARY AND OBJECTS or INVENTION THE The device may be used for the safe lowering of various bodies and objects. Particularly, the device may be secured to an upper story of a building or other structure for useas a tire escape for safely lowering persons to the ground from the upper stories of a building.

Briefly, the device includes a fluid type housing assembly which houses a plurality of rotatable vanes in a fluid. The vanes are connected for rotation with a rotor and displaceable relative thereto. The rotor is secured to a shaft which extends through the housing assembly and has a pair of drums fixed to the opposite ends of the shaft for rotation with a rotor. Each drum has a cable or line attached thereto, the cables being wound on the drums in opposite directions such that as one cable is unwound from a drum, the other cable is wound upon the other drum. Upon rotor rotation, the vanes are displaced inwardly by a plate from a position normally in engagement with the housing inner periphery. The speed of the drums is regulated by the liquid compressed upon vane rotation and by the small openings provided in the vanes.

One of the primary objects of the invention is the provision of anew and improved safety device for lowering persons or loads at a generally constant speed.

Another object of the invention is the provision of a safety lowering device employing two drums and two cables, the cables being oppositely wound on the drums whereby a person lowered by a first cable automatically raises the second cable to an operative position for a second operation.

Still another object of the invention is the provision of a device which is reliable, and of relatively small, simple construction.

Other objects and advantages of the invention will become apparent when considered in view of the following detailed description.

BRIEF DESCRIPTIONOF THE DRAWING FIG. I is a schematic, perspective view of the safety device of the present invention;

FIG. 2 is a front elevational view of the present invenby circular plates 24. The plates 24 may be secured by j a pluralityof suitable fasteners 26. Secured on the inner periphery of the annular member 22 is a plate member 28, FIGS. 3 and 4. The plate member 28 is a segment of a circular plate having an arcuate face in engagement with the inner periphery of the annular member 22 and a flatface 30. The plate member 22 is generally the same width as the annular member 22 and is fixedly secured thereto by fasteners 32.

The annular. member 22 of the housing 12 is a mounted, as by welding or other suitable means, to a support block 34 which is, in turn, attached to a plate 36. Openings 38 are provided in the plate 36 for facilivtating mounting of the safety device 10 to a wall or housing 12 by means of the bearings 40.

tion illustrating one line being wound upon a drum as the other line is unwound from a drum;

FIG. 3 is a side elevational view, partly in section, of the safety apparatus illustrating the rotor, blades and stationary plate within the fluid-filled housing; and

FIG. 4 is an exploded, perspective view of the housing and rotor assembly.

DETAILED DESCRIPTION'OF THE INVENTION Referring to the drawing, and particularly to FIG. 1,

Each blade or vane 46 is generally rectangular having a width substantially corresponding to the width of the annular member 22 and is slidably mounted within a radial groove in the rotor 42. Normally the blade 46 is biased by a spring48, or other means, radially outwardly into sliding engagement with the inner periphcry of the annular member 22. Upon rotation of rotor 42, each blade 46 is depressed radially inwardly compressing the spring 48 as the blade moves over the face 30 of the vane engaging cam or plate member 28. The vane engaging cam being a projecting segment of less than 10 in an angular rotation.

Each drum l8 and 20, including a barrel portion 50 and spaced flanges '52, is secured to the elongated shaft 44 by a key or other r'neans. A cable 54 is wound upon each drum. One cable end is secured to the drum while the free end may be attached to a sling, strap or other means 56, FIG. 2, for supporting or attachment to a load or body.

In the operation of the device, the sealed housing 12 is filled with a suitable fluid 58 such as oil. The device 10 may be mounted upon a structure such that the cables 54 extending from the

drums

18, 20 generally are in a vertical plane. It is to be noted that the cables 54 are wound upon the drums in opposite directions such that as one cable unwinds, the other cable is wound upon a drum.

The free end of the cable is attached to a person or other load for lowering. The lowering speed is retarded to a predetermined speed due to the rotation of the blades 46 within the fluid-filled housing 12 which functions as a fluid brake. The blades 46 also frictionally engage the inner periphery of the housing annular member 22 and the face 30 of the plate 28. The face 30 is positioned such that it is spaced at very small distance from the outer periphery of the rotor 42, as shown by FIG. 3. As the blades 46 rotate in the fluid, the fluid immediately forwardly of the rotating blade is compressed as the blade approaches the stop member 28. A small opening or groove 60 is provided in each blade 46 to permit fluid to flow from one side of the blade to the opposite side as the blade rotates. As the rotor and drums rotate to safety lower a person, a second cable is wound upon the other drum to permit a second person to be immediately lowered by means of the second cable.

I claim:

1. Apparatus for controlling the rate of descent of a load comprising,'a rotatable shaft, a drum mounted upon said shaft for rotation therewith to wind or pay out a line attached to the drum, support means, a fluidfilled, sealed housing assembly mounted upon said support means, said housing assembly'rotatably supporting said shaft, rotor means, including a plurality of vanes, attached to said shaft for rotation therewith and vane engaging cam means projecting within a segment of less than 90 within said housing assembly for displacing said vanes relative to said rotor means upon rotation thereof whereby said vanes are projected radially substantially the same extent during rotation of said rotor means until engagement with said vane engaging cam means.

2. Apparatus asrecited in claim 1, wherein said two drums, each having a line attached thereto, are secured to said shaft for rotation therewith, one line being unwound from one drum and a second line being wound upon the other drum upon rotation of the rotor means.

3. Apparatus as recited in claim 2, said rotor means including a rotor member mounted for rotation with said shaft, said member defining a plurality of radially directed slots, said vanes being slidably mounted within said slots.

4. Apparatus as recited in claim 3, and further including means biasing said vanes radially outwardly into engagement with said housing assembly.

5. Apparatus as recited in claim 4, said means within said housing assembly including a plate having a face for radially displacing inwardly said vanes as they r0- tate passed said plate.

6. Apparatus as recited in claim 5, wherein each vane defines an opening to permit fluid to flow from one side of the vane to the other side.

7. Apparatus as recited in claim 6, wherein the width of said vanes correspond substantiallyto the internal width of said housing assembly and said vanes normally extend from said rotor member outwardly into frictional, sliding engagement with said housing assembly.

8. Apparatus as recited in claim 1, said rotor means including a rotor member mounted for rotation with said shaft, said member defining a plurality of radially directed slots, said vanes being slidably mounted within said slots.

9. Apparatus as recited in claim 8, said means within said housing assembly including a plate having a face for radially displacing inwardly said vanes as they rotate passed said plate, each vane defining an opening to permit fluid to flow from one side of the vane to the

Claims

1. Apparatus for controlling the rate of descent of a load comprising, a rotatable shaft, a drum mounted upon said shaft for rotation therewith to wind or pay out a line attached to the drum, support means, a fluid-filled, sealed housing assembly mounted upon said support means, said housing assembly rotatably supporting said shaft, rotor means, including a plurality of vanes, attached to said shaft for rotation therewith and vane engaging cam means projecting within a segment of less than 90* within said housing assembly for displacing said vanes relative to said roTor means upon rotation thereof whereby said vanes are projected radially substantially the same extent during rotation of said rotor means until engagement with said vane engaging cam means.

2. Apparatus as recited in claim 1, wherein said two drums, each having a line attached thereto, are secured to said shaft for rotation therewith, one line being unwound from one drum and a second line being wound upon the other drum upon rotation of the rotor means.

5. Apparatus as recited in claim 4, said means within said housing assembly including a plate having a face for radially displacing inwardly said vanes as they rotate passed said plate.

7. Apparatus as recited in claim 6, wherein the width of said vanes correspond substantially to the internal width of said housing assembly and said vanes normally extend from said rotor member outwardly into frictional, sliding engagement with said housing assembly.

9. Apparatus as recited in claim 8, said means within said housing assembly including a plate having a face for radially displacing inwardly said vanes as they rotate passed said plate, each vane defining an opening to permit fluid to flow from one side of the vane to the other.