RESTRAINTDEVICEFORELECTRICALWIRESANDCABLES
BACKGROUNDOFTHEINVENTION
[0001] The present invention relates to a restraining device for wires and/or cables and, more particularly, to a restraining device for providing strain relief and preventing unintentional disconnection of electrical wires, especially computer accessory wires and/or cables.
[0002] Personal computers, for example, those of the desktop and notebook types, have been well developed and are commercially available. Many computer systems, including personal computers, workstations and servers, are designed to have multiple peripheral devices included in the system. Generally, a typical personal computer system includes a number of peripheral devices that provide input and output (I/O) for the system. Such peripheral devices include compact disc read only memory (CD-ROM) drives, hard disc drives (HDD), floppy disc drives, digital versatile disk drives (DVD), keyboards, mouses and printers.
[0003] The primary method of expanding the functional ability of personal computers is through the use of external devices that connect to the personal computer via a signal transmission device. The most common signal transmission devices are wires or cables that connect to the personal computer, such as a power cord, a USB cable, an IEEE 1394 cable, etc. Such wires and/or cables are subject to pulls in everyday use that place strain on the connectors, resulting in unintentional disconnection of the wire and/or cable and damage to the connectors. This is especially true of computers that operate in a rugged environment, such as in military service.
[0004] Known devices include the PCMCIA card cable strain relief mechanism used J, and wire routing Kwik Klips manufactured by Richco. These devices use a
loop under which the cables are placed, the loop then being pushed closed and held in place by ratcheting features in the loop and a base. However, the PCMCIA card cable strain relief mechanism is too large physically for the available areas in some applications, and the Kwik Klips are mounted by pressure sensitive adhesive, which does not meet the life expectancy requirements of some applications and does not work with cables having small diameters.
SUMMARY OF THE INVENTION
[0005] An object of the present invention is to provide a restraint device that securely holds computer accessory wires and/or cables for strain relief and for preventing unintentional disconnection of the wires and/or cables and damage to the connectors in which the wires and/or cables terminate. The restraint device according to the present invention has the features of compact size, secure mounting method, easy operation and ability to maintain its functionality for the lifetime of the equipment with which it is used. In providing strain relief, the restraint device according to the present invention is capable of withstanding a static force of 5 pounds and a dynamic force of 10 pounds for 500 milliseconds.
[0006] The present invention comprises a housing containing a finger-operated, spring-loaded, sliding movable member or clamping device. The movable member slides on a shaft in the housing to provide an opening for a computer accessory wire and/or cable to enter, whereby the wire and/or cable is positioned under a catch. The housing also contains a spring to cause the movable member to apply a clamping force against the computer accessory wire and/or cable. This arrangement provides strain relief and securely holds the wire and/or cable in position under the catch. The clamping force prevents the wire and/or cable from being disconnected unintentionally. In accordance with the present invention, one or more restraint devices are secured to a mounting member to define a restraint apparatus
mountable as a unit. The present invention also comprises a method of restraining a wire from movement.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Figure 1 is a front elevation of a restraint device according to the present invention mounted on a casing of, for example, a computer;
[0008] Figure 2 is a right side elevation of the restraint device of Figure 1 ;
[0009] Figure 3 is a top plan view of the restraint device of Figure 1 ;
[0010] Figure 4 is an isometric view, taken from the front, top and left side, of the restraint device of Figure 1;
[0011] Figure 5 is an isometric view, taken from the rear, top and right side, of the restraint device of Figure 1 ;
[0012] Figure 6 is an isometric view, taken from the front, bottom and right side, of the restraint device of Figure 1, without a casing; and
[0013] Figure 7 is an isometric view of a plurality of the restraint devices of Figure 1 secured on a mounting member mounted on a computer casing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] As can be seen from Figure 1 , a restraint device according to the present invention, which is designated generally by the reference numeral 10, is in the form of a clamping device and is mounted on a casing 12 of, for example, a computer. Only a portion of a wall of the casing 12 is shown, and it is broken away. A plurality of the restraint devices can be mounted on the casing 12. Alternatively, one or more of the restraint devices can be
mounted on a plate or other member to define a restraint device according to the present invention that is secured in or across an opening in the casing 12.
[0015] The restraint device 10 according to the present invention comprises a housing 14 containing a movable member 16 in the form of a finger-operated, spring-loaded, sliding first clamping element. The movable member 16 slides on a shaft 18 in the housing 14 to provide an opening for a computer accessory wire 19 and/or cable to enter a space S defined by and positioned under a catch 20. For simplicity of expression, the term "wire" will be used alone hereinafter, it being understood that "wire" is intended to encompass any wire, cable, or similar device, especially any such device designed to conduct electrical current, and most especially in connection with a computer. The housing 14 also contains an urging structure 22, for example, a spring, to apply a clamping force against the wire 19 that provides strain relief and securely holds the wire in position under the catch 20. The clamping force prevents the wire 19 from being disconnected unintentionally from the computer or other electrical device to which it is connected.
[0016] The movable member 16 is mounted for movement relative to the catch 20 between a first position, in which the movable member is spaced from the catch, such that the wire 19 is able to be inserted sideways into the space S defined by the catch, and a second position, in which the movable member prevents the wire from being inserted sideways into the space. The urging structure 22 resiliently urges the movable member 16 toward the second position. The urging structure 22 can include a spring, either as a distinct member, as shown in Figure 6, or formed in one piece with a member on which the movable member 16 is mounted. When the wire 19 is in the space S, and the movable member 16 is in its second position, the movable member clamps the wire against the catch 20. The space S has a perimeter, the catch 20 borders approximately half of the perimeter of the space, and the
space receives the wire 19 sideways, that is, in a direction generally perpendicular to the length of the wire.
[0017] As can be appreciated from Figure 3, at least one of the catch 20 and the movable member 16 has a friction-enhancing surface 24 facing the space S. The friction- enhancing surface 24 can take a variety of forms, including a roughened surface, a tacky surface, ridges, and the like. In the illustrated embodiment, each of the catch 20 and the movable member 16 has at least one ridge extending transverse to the length of the wire 19 and parallel to the perimeter of the space. In the second position of the movable member 16, the ridges engage the sides of the wire 19 and help prevent the wire from being pulled lengthwise.
[0018] The catch 20 has a first surface 26, and a second surface 28 extending at angle from the first surface, the first and second surfaces bordering the space S, and the second surface having a dimension parallel to the perimeter of the space. The friction- enhancing surface 24 of the movable member 16 is on a side of the movable member facing the space S; the side has a front surface 30 having a dimension parallel to the perimeter of the space; and the dimension of the front surface of the movable member is generally equal to the dimension of the first surface of the catch 20. The front surface 30 is on a protruding portion 32 of the side of the movable member 16 facing the space, and the second surface 28 of the catch 20 has a free end adjacent to the movable member. If the diameter of the wire 19 is smaller than the dimension of the second surface 28 of the catch 20 in a direction parallel to the perimeter of the space S, the protruding portion 32 of the movable member overlaps the free end of the second surface of the catch. The side of the movable member 16 facing the space has a shoulder 34, and, in the second position of the movable member, the shoulder engages the free end of the second surface 28 of the catch 20.
[0019] The movable member 16 is movably mounted on a base member 36, and the catch 20 is connected to the base member. The base member 36 includes the housing 14; the movable member 16 is movably mounted in the housing; and the urging structure 22 is positioned in the housing. The base member 36 further includes mounting flanges 38, 40 and 42 extending from the housing 14, the base member being secured to the casing 12 of an electrical device, or to a mounting member, by screws 44 or other fasteners extending through the mounting flanges. The catch 20 is connected to the base member 36 by the screws 44 extending through the mounting flange 42, the base member contacting one surface of the casing or a mounting member, and the catch contacting an opposite surface. The catch 20 and the movable member 16 protrude from said opposite surface of the casing or mounting member.
[0020] The space S is also defined by the surface of the casing or mounting member from which the catch 20 and the movable member 16 protrude. The catch 20 borders approximately half of the perimeter of the space and has a free end, which is also the free end of the second surface 28. A gap is defined between the free end of the catch 20 and the surface of the casing or mounting member, and, in the first position of the movable member 16, the wire 19 is insertable sideways through the gap and into the space S. In the second position of the movable member 16, the movable member closes the gap, unless the wire 19 is so large as to protrude from the space S.
[0021] The movable member 16 is movably mounted in the housing 14, and the urging structure 22 is positioned in the housing. As can be seen from Figure 6, in the illustrated embodiment, the urging structure 22 comprises a coil spring, and the coil spring is positioned around a shaft 46 extending from one wall of the housing 14 into a chamber 48 defined in the housing. A body portion 50 of the movable member 16 is also positioned in 8, adjacent to the urging structure 22, and is mounted for sliding on the shaft
46. The urging structure 22 engages the body portion 50 and resiliently biases the movable member 16 away from the wall of the housing 14 on which the shaft 46 is mounted and toward the catch 20. The movable member 16 is designed to be engaged by a finger to be moved against the force of the urging structure 22. In this regard, the movable member 16 has a friction-enhancing surface to help keep a finger from slipping. In the illustrated embodiment, the friction-enhancing surface comprises a plurality of ridges 52 extending transverse to the line of movement of the movable member 16 between the first and second positions. The friction-enhancing surface extends beyond the catch 20 in a direction away from the base member 36 of the restraining device 10. The friction-enhancing surface designed to help keep a finger from slipping can take a variety of other forms, including a roughened surface, a tacky surface, a single ridge, and the like.
[0022] As can be seen in Figure 7, two of the restraint devices 10 can be secured to a mounting member 56 in the form of, for example, a plate or panel that is mounted in or across an opening in a casing 58 of a computer or other electrical device. The restraint devices 10 are shown restraining wires 60 that terminate in connectors 62 electrically connecting the wires to the computer. It can be appreciated that the mounting member 56 can take other forms and/or that any number of restraint devices 10, including one, can be secured to the mounting member.
[0023] In a method according to the present invention for restraining the wire 19 from movement, an encircling structure that comprises, for example, the movable member 16, the catch 22 and either the casing of an electrical device or a mounting member, encircles a space S through which the wire can extend. The encircling structure is opened by moving a portion of the encircling structure, for example, the movable member 16, away from the space against the force of an urging structure 22 that urges the portion toward the space, ng an opening in the encircling structure. The wire 19 is inserted sideways
through the opening and into the space, and the moved portion is released to enable the force of the urging structure 22 to move the portion toward the space and to clamp the wire between the portion and the rest of the encircling structure. The encircling structure is connected to an electrical device, such as a computer, to which the wire is electrically connected.
[0024] It will be apparent to those skilled in the art, and it is contemplated, that variations and/or changes in the embodiments illustrated and described herein may be made without departure from the present invention. Accordingly, it is intended that the foregoing description is illustrative only, not limiting, and that the true spirit and scope of the present invention will be determined by the appended claims.