US3325147A - Personnel lowering devices - Google Patents

Description

June 13, 1967 J. H. CARLSON ETAL 3,325,147

PERSQNNEL LOWERING DEVICES Filed Feb. 7, 1966 v (5 Sheets-Sheet l 12 l" /n/mord Jo/m #Cdr-son Bru ce F/Da ul @MWL June 13, 1967 J. H. CARLSON ETAL 3,325,147

PERSONNEL LOWERING DEVICES Filed Feb,

3 Sheets-Sheet 2 'June 13, 1967 J. H. CARLSON ETAL 3,325,147

PERSONNEL LOWERING DEVICES 5 Sheets-Sheet 5 Filed Feb. 7, 1966 United States Patent O 3,325,147 PERSONNEL LOWERING DEVICES John H. Carlson, Danvers, and Bruce F. Paul, Ipswich,

Mass., assignors to United Shoe Machinery Corporation, Flemington, NJ., a corporation of New Jersey Filed Feb. 7, 1966, Ser. No. 525,750 2 Claims. (Cl. 254-154) ABSTRACT F THE DISCLOSURE A device for enabling a person to control his descent in an emergency. A pair of Icounter-wound reels have their relative rotation manually controllable by coacting friction surfaces, the degree of effectiveness of these surfaces being determined by `a nut-and-screw type arrangement for axially spacing the hubs of the reels.

This invention relates to devices for use by an individual in lowering himself from an elevated position t-o a place of relative safety.

Emergency escape means for lowering persons should be uncomplicated, readily usable with a minimum risk of injury, and available at reasonable cost. In descending with the aid of such a device one should be supported in a fairly upright position and be able to control his rate -of descent as well as determine his stopping positions. Too often earlier escape devices of this character have been unwieldy and not readily portable; moreover they have not been particularly reassuring to the user because somewhat unstable in operation and/-or the user could not know that the one device counted upon, perhaps to save his life, was then in good operating condition.

Summary of the invention In the light of the foregoing it is a primary object of this invention to provide an improved, one-hand controlled mechanism for safely suspending a person to be lowered, which mechanism, is compact, light weight, and operable to permit descent of the person progressively or in stages, and without his incurring unbalancing forces.

To this end the invention contemplates, in combination with a suitable slig or harness securable to the body of one to 'be lowered, a dual line pay out device comprising a pair of counterwound reels respectively carrying the lines, clutch means mounted on the reels and respectively having cooperative faces, means for urging the clutch faces into locking engagement to prevent counter-rotation of the reels due to the load of the one suspended in the harness, and means under the control of the one thus supported for changing the frictional drag 'between the clutch faces to permit equalized pay out of the lines from their respective reels.

It will be understood that the term line or lines as herein used is intended to designate any elongated material which is reelable and has a tensile strength of at least half the weight of the load to be lowered. As herein shown the lines preferably 'are of flat woven tape which is light in Weight, fire and abrasion resistant, strong and reusable. There may be factors favoring different types of lines for different purposes. For example, a .parachutist to be low ered from a tree or one descending in the open from a helicopter may fare better with flat tape, at least 200 ft. of which may be wound on each reel, While an apartment house or single residence of only a few floors height may employ safety devices in accordance with this invention using lesser lengths and of other than `a flat cross section.

Although counter-wound reels have hitherto been employed in lowering devices, a feature of the present invention resides in the combination therewith of a spring normally acting through threaded mating of a sleeve and 3,325,147 Patented June 13, 1967 shaft to urge the reels into non-rotative relation, and a control lever connected to one of t-he sleeve and shaft for overcoming the holding power of the spring means thus to permit descent at a selected rate. Accordingly, an advantage afforded -by the present construction is that it insures both stability and continuous control of descent.

Brief description ofthe drawings The foregoing and other features of the invention including novel details in construction, will now be more particularly described in connection with an illustrative embodiment, and with reference to the accompanying drawings thereof in which:

FIG. 1 is a view in side elevation of a personnel lowering device in operative condition, its transparent container having been ruptured;

FIG. 2 corresponds to a portion of FIG. 1 but shows the device in its preuse or unruptured condition;

FIG. 3 is an axial enlarged section of `a pair of dual line-carrying reels (only one of which is shown in FIG. 1), their lines being omitted to indicate a clutch means for controlling counterunreeling of the lines when wound thereon.

FIG. 4 is an exploded perspective View Vof the `reel and clutch assemblage; and

FIG. 5 is an enlarged side view correspon-ding to a portion of FIG. 1.

Description of the preferred embodiment The illustrative lowering device generally designatedllf) comprises `a U-shaped frame 12 (FIGS. 3-5) t-he upper ends of which are respectively formed `with coaxial bores 14, 16 (FIG. 3) for receiving `a tubular sleeve 18. The left-hand end of this sleeve, as viewed in FIG. 3, has its reduced circumferential edge peened outwardly into locking relation with the frame 12 after two sets of needle bearings 20, 22, respectively seated in the hu'bs 24 of a pair of coaxial line-carrying reels 2-6, 28, have been rotat ably mounted on the sleeve. For holding the dual reel 'assemblage axially together for operation in a manner later to be described, the sleeve 18 is internally threaded telescopically to receive a partly threaded stub shaft 30 that is integral with one side of a U-shaped clutch operating handle 32 (FIGS. l, 4, 5).

By means of manual rotation of the handle 32 about the axis of the stubshaft 30 thus to rotate the latterwith respect to the sleeve 18, axial pressure forcing the reels 26, 28 together is easily and efficiently changed as desired by reason of the consequent relative axial movement effected in the nut-and-screw type engagement of the parts 18, 30. Accordingly, for controlling pay out of lines 34, 36 (FIGS. l `and 4) which are counterwound on the respective reels 26, 28, annular friction material 38 (FIGS. 3 and 4), for example cork, secured to an inner face of one of the reels 26 or 28 is brought further into or out of cooperative engagement with a corresponding disk clutch surface 40 in the other of the reels 26er 28. Preferably a side 42 (FIG. 4) of .the clutch handle 32 is formed with an angular hole 44 for receiving .a correspondingly formed portion 46 of the stubshaft 30 thereby securing them in non-rotary relation. A nut 48 (FIGS. 3-5) threaded onto an end of the shaft 30 abuts the handle side 42 to retain it in locking engagement with one end of a torsion spring 50 (FIGS. 3-5), the other end of which is anchored in the frame 12. The arrangement is preferably such that when the handle: 32 has been swung downwardly from its usual horizontally extending position and yagainst resistance of the sprinlg 50 by a person being lowered to thereby decrease frictional drag between the material 38 and the coacting surface 40, by increasing their axial spacing and thereby increasing the rate of pay-out of both of the lines 34, 36, he may simply release the handle 32 to be automatically returned .to its horizontal position by the spring 50. The resulting relative rotation of the shaft 30 in the sleeve 18 axially forces the material 38 and .the clutch surface 40 together with `a force adequate, despite the load of a body being lowered, to stop or nearly stop reel rotation and hence line pay out. The spring S04 and its associated clutch mechanism therefor constitute a dead man brake.

As herein shown the lowering device 10 has the free or upper ends of its counterwound lines 34, 36 connected to suitable anchoring m'eans, for instance, a hook 52 (FIGS. 1,l 2), `and there is det-achably secured to a bracket 54 integral with the frame 12 a suitable body supporting harness 56 or other form of sling or Weight supporting means to be affixed to the person to be lowered.

In order to maintain the safety apparatus in convenient, ready-to-use condition, it is preferred that the device 10 with its lines 34, 36 pre-counterwound on their reels, and excepting the hook 52, the harness 56, and ends of the bracket 54, be contained in a tamper-proof, transparent plastic sealed envelope 60 as shown in FIG. 2. This package may, when out of use, be stored or suspended by its hook 52 in an easily reached position. Brief instructions on how to use in an emergency would be printed on the envelope. In case of emergency the harness, if not already being worn as military equipment, is applied to the body of one to be lowered and connected to the bracket 54, the hook 52 is secured to any suitable, relatively fixed structure such as a pipe, tree branch, etc., at the locality of descent, and the envelope 60 is ruptured by the initial unwinding of the lines 34, 36, the clutch control handle 32 being grasped through the plastic and operated even though the protective envelope 60l is not removed from the device.

,In swinging the handle 32 downwardly from `its initial or stationary (preferably horizontal) load-holding position to permit ones restrained descent under the influence of gravity, friction between the clutch material 38 and the surface 40 will be reduced in approximate proportion to the degree of angular movement of the handle 32 so that one being lowered can control his descent and, if desired, effect it in stages. By reason of the counterwinding of the lines 34, 36., which may be of nylon tape, for example, there is equal and opposite torque acting to rotate the reels 26, 28 oppositely and hence pay out the lines at equal rates. Should greater torque be momentarily exerted on one reel, there is an immediate and automatic adjustment so that the load on the lines is again equalized and equilibrium maintained. One unique 'advantage of the construction therefore is that, with the device in static or dynamic condition, and with the dead man brake or the clutch being suddenly operated, no unbalanced torque or harmful forces will be transmitted to the one to be lowered whereas, if he used a single wound drum device, he would be wrenched about a vertical axis due to -unbalanced torque. Moreover, the opposite rotation of the clutch disk 38 and the colacting surface 40 provides twice the relative speed between clutch surfaces as would be encountered in a device of corresponding size having a single wound drum, and accordingly only half as much braking or declutching effort must be manually exerted.

From the foregoing it will be apparent that the escape device is simple to operate, has relatively few and simple parts, and can be very light weight. A device of the type described, for example, and including aluminum reels having 200 ft. of flat woven tape per reel, may weigh on the order of four pounds, The device may .accordingly be relatively inexpensive and, when provided with its tamperproof envelope 60, should be reliably useful for many years.

Having `thus described our invention, what we claim as new and desire to secure by Letters Patent of the United States is:

1. For detachable connection to a body supporting means, an emergency device for enabling a person to lower himself in said supporting means, the `device comprising a U-shaped frame, a pair of reels respectively carrying cooperative, friction engageable surfaces on their adjacent side faces, a line wound on each reel in a direction opposite to that of the line wound on the other reel, mechanism mounted in the frame for coaxially and rotatably carrying the reels in selected axially spaced relation, said mechanism including a telescoping sleeve and shaft in threaded relation, and a control lever connected to one of the sleeve and the shaft and rotatable by the person for changing the effectiveness of the engagement between the friction surfaces.

2. The device las set forth in claim 1 wherein a Itorsion spring has one end anchored in .the frame and its other end affixed in said lever to urge said mechanism to force the friction surfaces together, the arrangement being such that the influence of the spring is multiplied in the threaded engagement of the sleeve and .the shaft to hold the reels against counter rotation when the person is suspended on said supporting means.

References Cited UNITED STATES PATENTS 194,471 8/1877 Schultz 254-154 392,999 11/1888 Esson 254-154 2,561,832 7/1951 Wilson 254-151 EVON C. BLUNK, Primary Examiner.

SAMUEL F. COLEMAN, Examiner.

H. C. HORNSBY, Assistant Examiner.

Claims (1)

1. FOR DETACHABLE CONNECTION TO A BODY SUPPORTING MEANS, AN EMERGENCY DEVICE FOR ENABLING A PERSON TO LOWER HIMSELF IN SAID SUPPORTING MEANS, THE DEVICE COMPRISING A U-SHAPED FRAME, A PAIR OF REELS RESPECTIVELY CARRYING COOPERATIVE, FRICTION ENGAGEABLE SURFACES ON THEIR ADJACENT SIDE FACES, A LINE WOUND ON EACH REEL IN A DIRECTION OPPOSITE TO THAT OF THE LINE WOUND ON THE OTHER REEL, MECHANISM MOUNTED IN THE FRAME FOR COAXIALLY AND ROTATABLY CARRYING THE REELS IN SELECTED AXIALLY SPACED RELATION, SAID MECHANISM INCLUDING A TELESCOPING SLEEVE AND SHAFT IN THREADED RELATION, AND A CONTROL LEVER CONNECTED TO ONE OF THE SLEEVE AND THE SHAFT AND ROTATABLE BY THE PERSON FOR CHANGING THE EFFECTIVENESS OF THE ENGAGEMENT BETWEEN THE FRICTION SURFACES.

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