Abstract:
Restraining device intends to protect the workman from falling while working at higher environments. The device consists of a fixed cable stretched along the area of interest. A gripping clamp which slides along the cable is attached permanently to the workman's belt. Clamp consists of a pivotal arm which, when a downward load is applied at the point of attachment of the belt, exerts a frictional force on the cable, sufficient to immediately terminate workman's fall.
Inventors:
Kleine, Richard A. (Peoria, IL)
Byers, Warren J. (Morton, IL)
Wright, Charles A. (Peoria, IL)
Application Number:
05/412169
Publication Date:
09/30/1975
Assignee:
Unarco Industries, Inc. (Chicago, IL)
International Classes:
E06C7/18; E06C7/00; E06C5/36
Field of Search:
182/3,4,5,6,7,8,9,190,191,192,193
US Patent References:
| 1955473 | Safety appliance for brakemen | April 1934 | Raymer | |
| 3006431 | Apparatus connecting the safety belt with the safety appliance | October 1961 | Meyer | |
| 3179994 | Safety appliance | April 1965 | Meyer | |
| 3250515 | Movement control device | May 1966 | Hudnall | |
| 3317971 | Rope safety clamp device | May 1967 | Meyer | |
Primary Examiner:
Machado, Reinaldo P.
Attorney, Agent or Firm:
Hill, Gross, Simpson, Van Santen, Steadman, Chiara & Simpson
Claims:
What we claim as our invention
1. A safety device comprising:
2. The safety device of claim 1 further characterized by;
3. A safety device according to claim 1 comprising:
4. A safety device according to claim 1 wherein said gripping clamp comprises:
5. A safety device according to claim 1, wherein said gripping clamp comprises;
6. A safety device according to claim 5, wherein said gripping clamp comprises:
7. A safety device according to claim 5, wherein said constraint means comprises:
8. A safety device including a gripping clamp which comprises:
9. A safety device according to claim 8, wherein said constraint pin further comprises:
10. A safety device according to claim 9, wherein said constraint pin further comprises:
11. A safety device including a gripping clamp which comprises
Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention
Safety clamp intended to restrain the user from falling without loss of facility or mobility.
2. Prior Art
Safety clamps are well-known to the art. These normally consist of a belt, clamp and a cable, tube or formed metal extended over the area of interest. Current state of the art utilizes a safety clamp separate from the belt. This particular design feature was necessitated because the clamps utilized called for permanent fixture, and as a result, were captive on the cable.
Portable clamps do exist and feature improved mobility. Disassembly, however, is laborious, necessitating the use of both hands, and consequently such clamps are not conducive to such operation at higher elevations.
Current state of the art clamps offer strictly a one-degree of freedom mobility. It is difficult, if not extremely hazardous, to disengage and change cables with the current state of the art clamp while operating in higher environments.
Taller structures require intermediate cable restraints to prevent harmonics in the cable resulting from wind or body movement. Current clamps made for this purpose must be opened and the cable removed to allow the clamp to pass. This necessitates the workman to hold on with one hand while trying to reconstruct this apparatus; an operation which should utilize both hands.
SUMMARY OF THE INVENTION
In order to overcome the problems encountered in prior art safety clamps, the present invention proposed to utilize an integrated clamp-belt unit.
An important advantage of the present invention is in the clamp. The gripping clamp is so designed that the user can remove the clamp from the cable and move to other ladders or work areas. The clamp can be removed from the cable at any point, such as rest stops or immediate work platforms, provided along the ladders.
The removal or transfer of the clamp of this invention does not necessitate the usage of both hands as was required with prior art mechanisms. Such ease of removal and subsequent reengagement of the mechanism on the same or different cable facilitates manipulations at higher elevations.
A further advantage of the invention is that it avoids any necessity to open or disassemble the clamp upon encountering an intermediate cable restraint. The clamp glides over the restraint and avoids the problems inherent in the prior art clamps.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmented, functional view of a ladder, equipped with a safety cable and showing the use of a safety belt equipped with a safety clamp embodying features of the invention.
FIG. 2 is a perspective view of the safety belt with the safety clamp in a position for attachment to a cable.
FIG. 2A is a perspective view showing the safety clamp in an at-rest position on the belt.
FIG. 3 is an enlarged fragmentary isometric view of the safety clamp, the cable and the intermediate cable restraint.
FIG. 4 is a sectional view taken substantially along the line III--III of FIG. 3.
FIG. 5 is a vertical sectional detailed view taken substantially on line V--V in FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a representative embodiment of the invention, and depicts in phantom a workman straddling a restraint cable 1 while wearing a safety belt 4 attached to a gripping clamp 3. The clamp 3 slides along a safety member such as the cable 1 which extends along the entire length of the ladder. Intermediate cable restraints 2 are located at intervals along the cable to prevent harmonic oscillations in the cable resulting from wind or body movements. The cable 1 could be a rod, pipe, wire or track. The geometry of the cable may be round, oval or rectangular, and may be of any suitable material of sufficient strength. The cable is held in place by two cable anchors 9 located at the top and bottom of the ladder. The top cable anchor 9 extends above the top of the ladder, thus facilitating the users disembarkment. The bottom cable anchor 9 has a yieldable tension device 10, spring loaded to allow for minor variations in both the ladder and the cable.
The safety belt 4 comprises a harness 15, (FIG. 2) an anchor web 16 and a bracket 17 attached to the harness 15. The gripping clamp 3 is permanently fastened to the safety belt through an extended gripping arm 5, (FIG. 5) which pivots on a pivot pin 6.
The gripping clamp 3 comprises a body 11 and the gripping arm 5 contained in the internal cavity resulting from the intersection of a longitudinal slot 12 and a vertical slot 13 and a bore 14. The longitudinal slot 12 of width greater than that of the cable is dimensioned to provide clearance for the intermediate cable restraint 2 and facilitates the engagement and disengagement of the clamp.
The gripping arm 5 is an elongate arm, constructed with a suitably, geometrically contoured internal end, preferably arcuately shaped, to allow for minor variations in the cable diameter and passage of the intermediate cable restraint while keeping pressure on the cable constant, containing hole 7 and terminating in a means at the end remote from body 11 and is engaged on the web 16 and thereby anchored to the harness 15 of the safety belt. The gripping arm 5 can be locked in two positions by inserting the constraint pin 8 into hole 7 or hole 7--7A, respectively. When not in use, the gripping arm is locked in a vertical position with the constraint pin 8 to hole 7--7A and the gripping clamp 3 stored along the periphery of the belt in the bracket 17 as illustrated in FIG. 2A.
While utilized, pulling the constraint pin 8 allows the gripping arm 5 to move to the near vertical position and enables the cable 1 to be received through the longitudinal slot 12 into the bore 14 in the body 11 as shown in FIGS. 3 through 5. The constraint pin 8 is then reinserted in hole 7--7A. The position of the pin is such that it acts as a limiting constraint on the amplitude of a slotted opening resulting from the interaction of the pivotal motion of the gripping arm 5 and the longitudinal slot 12 and thus precludes inadvertent entrance of cable 1 into the longitudinal slot 12 resulting in a release. The constraint pin 8 is fitted with a detent 18 at the leading end. The detent serves as a locking device, constructed to allow for detraction from and subsequent reinsertion of the constraint pin 8 into body 11.
A loop in a gripping arm 5 is attached to the safety belt 4 by sewing it between the harness and the web of the belt. Should the workman lose his footing, the weight of his body applies a downward load on the arm 5 at the point of attachment to the belt. The resultant, angular motion of the gripping arm 5 induces a compressional and a frictional grip on the cable, sufficient to cause an immediate breaking of the workman's fall.