US3424416A - Strain relief - Google Patents

Description

Jan. 28, 1969 H. J. DELL ET Al. 3,424,416

STRAIN RELIEF Filed Feb. 2l, 1967 United States Patent O 7 Claims ABSTRACT OF THE DISCLOSURE A device for surrounding a wire conductor or similar rod-like member to prevent strain thereon. The device serves to distribute the stress on the conductor over a relatively large area and further to serve as a means for mounting a conductor within a panel aperture and for preventing axial movement of the conductor relative to the aperture; The device is formed of an elastomeric material and comprises a body member having an interior surface and an exterior surface, the exterior surface being joined at its opposite ends to the interior surface and being spaced at its intermediate position from the interior surface.

BACKGROUND OF THE INVENTION Field of the invention Strain relieving means for electrical conductors or similar rod-like members.

Description of the prior art Various means are known for providing strain relief for wire conductors. These known devices, however, are Vgenerally limited in that they are designed to accommodate one conductor size or a relatively small range of con* ductor sizes. This is a considerable drawback since it requires a rather large inventory of parts to accommodate a broad range of conductor sizes. IFurther the known devices are generally designed for use with one panel aperture size and do not permit adjustability of the device to accommodate a range of aperture sizes.

SUMMARY OF THE INVENTION This invention provides a device which accommodates a broad range of conductor sizes and provides a strain relief for such conductors. The device is mountable within a panel aperture and prevents axial movement of the conductor relative to the aperture. The device may be supplied in strip form and may be cut to length to suit any desired panel aperture size.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a perspective view of a strain relief device shown in successive stages of production and made in accordance with the teachings of the present invention;

FIGURE 2 is a perspective View showing the device of FIGURE l partially surrounding a wire conductor;

FIGURE 3 is a perspective view illustrating the strain relief device mounted in a panel aperture and surrounding a wire conductor;

^ FIGURE 4 is a sectional view showing the strain relief device prior to insertion in a panel; and

FIGURE 5 is asectional view showing the device after insertion in a panel.

DESCRIPTION OF THE PREFERRED EMBODIMENT The attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings in which there is shown and described an illustrative embodiment of the invention; it is to be ICC understood, however, that this embodiment is not intended to be exhaustive nor limiting of the invention but is given for purpose of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use.

Turning lirst to FIGURE l there is shown a strip ofmaterial 10 which may conveniently be supplied in extruded form and made from a suitable elastomeric material. Thestrip 10` is of indefinite length and is severed to an appropriate length depending on a particular use. When a strain relief is desired for use with a particular aperture in a panel, board, or similar article the circumference of the aperture is determined and the end ofstrip 10 is then severed to a dimension equal to the circumference of the panel aperture.Section 12 shown in FIGURE l represents a portion ofstrip 10 for use with a particular aperture size.

Thesection 12 has a generally diamond-shaped crosssectional configuration. A pair ofinterior surfaces 14 and 16 are provided and have a plurality ofridges 18 disposed therealong which constitute gripping surfaces as described hereafter. A pair ofexterior surfaces 20 and 22 are also provided and are joined to theinterior surfaces 14 and 16 alongedges 24 and 26 respectively.Surfaces 20 and 22 are joined by a channel-shaped groove 218 which mates with a panel aperture in a manner to be described.

Section 12 is adapted to be wrapped around an electrical conductor or the like in a manner as shown in FIGURE 2. Since the conductor diameter is necessarily smaller than the diameter of the aperture through which the conductor will extend, the length of theinterior surfaces 14 and 16 must be less than that of theexterior surfaces 20 and 22. The circumference of the electrical conductor to be mounted in the panel aperture is deter mined and this dimension is used to determine the size ofsurfaces 14 and 16.Section 30 is shown in FIGURE 1 and is identical tosection 12 except that the interior surfaces have been severed to appropriate length to accommodate the electrical conductor. Thechannel 28 is the only portion ofsection 12 which remains at a dimension equal to that of the panel aperture circumference. The strain relief device is shown in FIGURE 4 completely surrounding aconductor 32 and prepared for entry into theaperture 34 located in thepanel 36. The conductor 32., together with thedevice 30, is then inserted through thepanel aperture 34 during which insertion the device is caused to be radially compressed, such compression being possible due to the space provided between the interior and exterior surfaces of the device. When the conductor is sufficiently moved in an axial direction through theaperture 34 thedevice 30 will snap into place within the aperture and thechannel 28 will be located at the panel to maintain the device in position. Theaperture 34 will exert a pressure on thedevice 30 in a radially inward direction which will cause the device to rmly grip the conductor by means of thegripping surfaces 18. `In this maner the conductor is prevented from moving in an axial direction and further thedevice 30 serves to prevent rupturing of the conductor due to torsional stresses.

It can be seen that the strip ofmaterial 10 may be selectively severed to provide a strain relieving device capable of use with various size conductors and various size panel apertures. It is also apparent that by making the device slightly oversize relative to a panel aperture it is possible to produce increased pressure within the strain relief device to thereby provide a firmer `frictional connection between the device and the electrical conductor -to thereby further prevent against axial movement of the conductor relative to the panel.

Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be m-ade without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective against the prior art.

We claim:

1- A strip of material adapted to be formed into strain relieving means, said strip of material comprising a rst pair of surfaces extending longitudinally along said strip, said first pair of surfaces being joined to each other along their longitudinal extent and being disposed at an angle to each other, means disposed along the juncture of said rst pair of surfaces for engaging a panel aperture, a second pair of surfaces extending longitudinally along said strip, said second pair of surfaces being separated from each other and being joined to said rst pair of surfaces, each of said second pair of surfaces being angularly disposed relative to said rst pair of surfaces and to each other whereby said strip is of generally open quadrilateral configuration, and gripping means disposed along said second pair of surfaces for engaging rod-like means ad-apted to extend through said panel aperture.

2. A strip as set forth inclaim 1 wherein said first and second pairs of surfaces are formed of an elastomeric material.

3. A strip as set forth inclaim 1 wherein said aperture engaging means comprises a channel extending longitudinally along said strip.

4. Strain relieving means comprising in combination a panel having an aperture therein, cylindrical means extending through said aperture, and exible means disposed between said cylindrical means and said aperture, said flexible means comprising an interior surface in engagement with s aid cylindrical means and an exterior surface in engagement with said aperture, said exterior surface being joined at its opposite ends to said interior surface, said surfaces having portions thereof spaced from each other and movable toward and away from each other.

5. Strain relieving means as set forth in claim I4 further compnsing gripping means on said interior surface for engaging said cylindrical means.

6. Strain relieving means as set forth inclaim 4 further comprising channel means disposed along said exterior surface for receiving said aperture.

7. Strain relieving means as set forth inclaim 4 wherein said flexible means is split in the directionvof the axis of said cylindrical means.

References Cited UNITED STATES PATENTS 1,204,625 11/ 1916 Wheelock. 1,817,774 8/1931 Sipe. 1,967,466 7/1934 Damsel 285-373 X 2,377,510 6/1945 Newell 285-373 X 2,3 87,295 10/ 1945 Robertson. 2,417,741 3/ 1947 Dillon 285-373 2,420,826 5/ 1947 Irrgang. 2,449,795 9/ 1948 Stillwagon 285-373 X 2,451,354 10/1948 Ohls 285-373 X 2,912,712 11/1959 Shamban et al. 3,288,407 11/1966 Downer et al. 248-56 LARAMIE E. ASKIN, Prmmy Examiner.

U.S. Cl. X.R.

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