Patent Document

BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention pertains to the field of lifting devices, such as handles and the like, that are used to carry equipment from one point to another. More specifically, the handles may be selectively attached to electrical equipment and detached once the electrical equipment is installed, for example, in a sliding rack assembly where the attached handles protrude to interfere with sliding motion of the rack assembly. 
     2. Discussion of the Related Art 
     In commercial and research facilities, electronic equipment or instrumentation is commonly housed in boxes or chassis that are mounted in electrical equipment racks having standard dimensions. Each rack, according to United States industry standards established by the Electronic Industries Association (EIA), typically has dimensions of approximately seventy-two inches in height, twenty-seven inches in depth, and nineteen inches in width, which corresponds to a rack volume of about 21.4 cubic feet. Standards in other countries may differ. Roller slides are used to hold instruments in a stacked arrangement on the racks and to facilitate movement of each unit out of alignment for replacement, servicing and/or modification. Rack-mounting of equipment in this manner advantageously provides a compact, easy to maintain implementation in a common duty area. Due to dimensional standardization of dimensions, it is difficult to sell non-standard sized commercial or research equipment where the equipment fails to comply with standard dimensions because the equipment cannot be used in the EIA racks. 
     Electronic equipment manufacturers provide increasing levels of functionality from internal components that have smaller sizes. From time to time, system designers may find it desirable to offer a chassis having a maximum width dimension to incorporate more internal components; however, the equipment can also be quite heavy and may require handles for lifting purposes. Because the rear of the chassis may be inaccessible for lifting purposes and because ergonomics may preclude the attachment of handles to the front of the chassis, handles are sometimes most conveniently located on the sides of the chassis across the width dimension. These handles may protrude to a greater width dimension than does the overall chassis. A problem arises when the handles interfere with sliding motion of the roller-slide assembly by abutting vertical support members of the equipment rack. 
     U.S. Pat. No. 5,505,533 discloses a rackmount chassis that adapts a standard personal computer for rack usage by encapsulating the personal computer. A handle is built into the side of the chassis for lifting of the assembly. The handle is formed of a dual-pivoting assembly in which the grasping portion of the handle that pivots on its axis of elongation. At least four pivoting operations are required to deploy the handle for lifting operations. Due to the positioning of his handle, the lifting operations are ergonomically incorrect, as the lifter&#39;s strength and grip are significantly compromised due to the twisting and bending motion of the wrist. This weakening occurs because the lifter&#39;s hand must engage the side-mounted handle in a handshake configuration as the lifter pushes the chassis forward. 
     Handles for lifting of electronic equipment cease to be a mere convenience and become a necessity when heavier items are being installed. For example, network server packages can weigh from one hundred to five hundred pounds (45 to 230 kilograms). Team lifting of these heavier items is a necessity. In some instances, the chassis that is being lifted contains sunken handholds that facilitate lifting. These handholds impose a burden that the wrists of the lifters are not optimally aligned with the chassis. The handholds also create a significant risk of personal injury to the lifters and/or damage to the equipment. In other instances, handles are temporarily attached to the chassis. The handles are removed after the equipment is installed, and storage is inconvenient because the loose handles are generally regarded as clutter until they are needed. It is a significant inconvenience that the handles often cannot be found when it is time to remove the chassis from the rack or to reposition the chassis in the rack. Detachable handles are usually not interchangeable between different chassis styles, such as chassis having different length dimensions, so it is also difficult to find substitute handles. When the handles cannot be found, there is significant risk of injury to the lifters or equipment damage in the attempt to move the chassis with improper lifting equipment. 
     There remains a need to provide a carry handle assembly that can be selectively attached and detached for use in lifting operations, yet are adjustable for convenient storage. 
     SUMMARY 
     The adjustable carry handle assembly shown and described herein overcomes the problems outlined above by permitting selective adjustment to a plurality of overall lengths, for example, lengths that facilitate both lifting operations and convenience in storage. The carry handle assemblies may also be adjusted to a plurality of lengths for use in lifting a chassis of any length. 
     The carry handle assembly includes a first segment and a second segment that are telescopically interfitted in a manner that permits manual manipulation to achieve a plurality of overall lengths. The first segment contains at least one lengthwise receptacle, e.g., a channel, of sufficient dimensions for receiving at least part of the second segment. The second segment is at least partially received in the lengthwise receptacle to establish a telescoping interfit through which an overall length of the carry handle assembly can be adjusted by lengthwise shifting of the second segment within the lengthwise receptacle. At least one carry handle is attached to one of the first segment and the second segment. A mounting structure, such as pins, bayonet latches, clip fasteners, screws and bolts, is used for coupling the carry handle assembly with the chassis. The carry handle assembly may be attached for lifting purposes, removed, and adjusted to an overall length that permits storage on an electrical equipment rack. 
     The carry handle assembly may contain any number of handles. For example, a first handle may be attached to the first segment, and a second handle may be attached to the second segment. In this configuration, lengthwise shifting of the second segment within the lengthwise receptacle alters a length dimension between the first carry handle and the second carry handle. The carry handle assembly may be locked in a fixed length to prevent its removal from the chassis. Accordingly, threaded fasteners are not necessarily required to couple the carry handle assembly to the chassis. 
     A latch mechanism, such as a threaded fastener or a spring biased barrel lock, may be mounted on the carry handle assembly to lock the first segment and the second segment in a fixed overall length. While the latch mechanism is not necessarily required, it prevents collapse of the telescoping first and second segments and may be used to selectively attach the carry handle assembly to the chassis solely by virtue of this extension, for example, as pins on either end of the carry handle assembly are driven into engagement with the chassis when the carry handle assembly is extended. The latch mechanism may operate, for example, through use of a spring biased barrel lock that thrusts a plunger through a first hole in the first segment and a second hole on the second segment when the first and second holes are aligned to permit passage of the plunger. 
     The adjustable carry handle assembly may include a carry handle that contains a pivoting handle having a range of pivoting motion over a vertical arc. Pivoting the handle over the arc selectively increases or decreases a width of the carry handle assembly. An abutment may be provided that limits the range of the arc, e.g., from about 0° to 90°. Outward termination of the arc may occur, for example, at a point of maximum width, which is also the most favorable point of termination for lifting purposes 
     The mounting structure may optionally include a mounting structure abutment, such as a dogleg abutment, that requires mounting of the carry handle assembly in a predetermined orientation relative to the chassis. The dogleg abutment may, for example, be attached to one of the first segment and the second segment, and extend to a greater length dimension than the overall length dimension. 
     The mounting structure may also include a plurality of openings for receipt of pins. These openings may be oriented to receive the pins in a position where axes of elongation in the threaded fasteners are oriented in parallel with the overall length dimension of the carry handle assembly, such that extension of the carry handle assembly drives the pins into engagement with the chassis. 
     The aforementioned structure permits sliding the first segment and the second segment relative to one another to establish an overall length that is required for mounting the carry handle assembly on the chassis. The carry handle assembly may then be attached to the chassis through use of the mounting structure. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a left front isometric view of a chassis installed in an electrical equipment rack with carry handle assemblies stored on the electrical equipment rack for reattachment to the chassis and subsequent use in lifting operations; 
     FIG. 1A is a diagram showing additional detail with respect to the stored carry handles of FIG. 1; 
     FIG. 2 is an assembly view showing installation of the carry handle assemblies on the chassis; 
     FIG. 3 is a left side isometric view of a right side carry handle assembly also shown in FIG. 2; 
     FIG. 4 is a right side isometric view of the carry handle assembly shown in FIG. 3; 
     FIG. 5 is an isometric view of a dogleg abutment that prevents misoriented installation of the carry handle assembly; and 
     FIG. 6 depicts a mounting structure in the form of a threaded fastener that may be used to couple the carry handle assembly with the chassis. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 depicts a system  100  including an electrical equipment rack  102  that supports a chassis  104 . The electrical equipment rack  102  includes a plurality of upright posts, such as post  106 , which are supported by a base  108 . Paired roller slide assemblies  110  and  112 , form tracks that facilitate forward and rearward shifting motions shown by double headed arrow  114 . The roller slide assemblies  110  and  112  are bolted to the posts  106  at height intervals that permit installation of additional chassis above chassis  104 . As shown in FIG. 1, chassis  104  is shifted fully forward for maintenance operations and in this position may be removed from the equipment rack  102 . Full rearward motion exists when face  116  of chassis  104  is substantially even with front surface  118  of post  106 . The equipment rack  102  may have the standard dimensions and features defined by EIA, or the dimensions of any other type of electrical equipment rack. 
     The chassis  104  internally houses electrical equipment, such as a commercial or laboratory instrument, a telecommunications server or router, a computer, audio equipment, or any other form of electrical equipment. Roller slide assembly  110  bolts to chassis  104  along interval  120  beneath a removable side  122 . Chassis  104  does not include carry handles. There is insufficient clearance between the removable side  122  and post  106  such that, if side-protruding carry handles were installed, the handles would prevent full rearward motion of chassis  104  by abutting post  106 . 
     FIG. 1A provides additional detail with respect to FIG.  1  and the mounting of carry handle assemblies, such as carry handle assembly  124 . Carry handle assembly  124  is shown in a storage position mounted on equipment rack  102  with handles  128  protruding inward. Carry handle assembly  126  is shown in the process of being mounted for storage. Carry handle assemblies  124  and  126  are intended for team-lifting use when mounted on a side of chassis  104  remote from side  122 . Any number of carry handle assemblies  124  and  126  may be installed on chassis  104  for team lifting purposes. Carry handle assemblies  124  and  126  are mounted on opposed wing brackets  132  and  134  after being telescopically adjusted to an overall length L. A shoulder screw  136  passes through a keyway  138  and fully engages slot-neck  140  with full lengthwise extension of carry handle assembly  126  to the overall length L. In this storage position, inwardly protruding handles  128  and  130  do not interfere with sliding motion of chassis  104  on roller slide assemblies  110  and  112 , for example, due to the increased width dimension afforded by front edge  142  of front post  144 . 
     FIG. 2 is an assembly view that depicts installation of carry handle assemblies  200  and  202  onto chassis  104 . The carry handle assemblies  200  and  202  are temporarily installed, as needed, for lifting chassis  104  onto and off of rack  102 . Removable sides  122  and  204  slide rearwardly for removal from chassis  104 . A clip-mounted front panel  206  may be detached from chassis  104  by pulling the front panel  206  forward. The carry handle assemblies  202  and  204  are mirror images of one another. Removal of the carry handle assemblies from chassis  104  comprises movements opposite those shown in FIG.  2 . 
     FIG. 3 shows carry handle assembly  200  from a left side internal elevational perspective. Carry handle assembly  200  is formed of a generally rectangular first segment  300  and a generally rectangular second segment  302 . The first segment  300  is made, for example, of sheet metal that is bent to form a pair of opposed lengthwise channels  304  and  306 , each forming a channel receptacle that receives a portion of a corresponding lengthwise shoulder  308  or  310  of the second segment  302 . Thus, the second segment  302  is at least partially received in the lengthwise channels  304  and  306  to establish a telescoping interfit through which a variable overall length L of the carry handle assembly  200  can be adjusted by lengthwise shifting motion  312  of the second segment  302  within the lengthwise channels  304  and  306 . A pin  314  attached to the first segment  300  protrudes through a lengthwise slot  316  in the second segment  302  to prevent removal of the second segment  302  from the channels  304  and  306 . Optional reinforcing panels  318  and  320  are respectively riveted to the corresponding first segment  300  and the second segment  302  to provide increased support for forces imparted by carry handles  322  and  324 . 
     Cross-member stiffeners  326  and  328  are riveted to the channels  304  and  306  to provide structural support between the channels  304  and  306  of first segment  300 . Similarly, cross-member stiffeners  330  and  332  provide structural support between the shoulders  308  and  310  of second segment  302 . Pin bolts  334  and  336  protrude forward of cross-member stiffener  326  to facilitate bolt-coupling of the first segment  300  with wing  338  of chassis  104  (see FIGS.  1  and  2 ). A pin  340  protrudes outwardly from stiffener  332  a sufficient distance to slidingly engage raceway  343  in chassis  104  (see FIG.  2 ). 
     Apertures  344  and  346  are formed in the second segment  302  for receiving a spring-biased barrel bolt  348  that locks the carry handle assembly  200  into a fixed overall length L corresponding to the selective alignment of the spring-biased barrel bolt  348  with aperture  344  or aperture  346 . The capacity to vary the fixed overall length L in this manner, where the barrel bolt  348  is selectively engaged or disengaged, permits selective adjustment of the overall length L. Locking the carry handle assembly  200  into the longest fixed overall length L prevents removal of the carry handle assembly from chassis  104 , as described in more detail below. The spring-biased barrel bolt  348  is biased towards insertion through one of the apertures  344  or  346 . 
     A dogleg abutment  350  is riveted to the bottom of channel  306  to prevent installation of carry handle assembly  200  in an improper orientation with respect to chassis  104 . 
     Shoulder screws  352  and  353  engage keyways  342  and  354  in chassis  104  (See FIG. 2) at an overall length of full extension L to provide increased support for lifting operations. Pin  340  protrudes a greater distance that do the shoulder screws  352  and  353  such that pin  340  engages raceway  343  prior to the insertion of shoulder screws  353  and  353  into keyways  343  and  354 . Full lengthwise extension occurs with the shoulder screws  352  and  353  engaging keyways  342  and  354  while pin bolts  334  and  336  engage wing  338 , as shown in FIG.  5 . The carry handle assembly  200  is locked into a fixed length L by the insertion of barrel bolt  348  into aperture  344 . From this position, the carry handle assembly  200  cannot be removed from chassis  104  unless the barrel bolt  348  is withdrawn from aperture  344  for telescoping contracture of segments  300  and  302 . A shorter stowage length L is produced by the insertion of barrel bolt  348  within aperture  346 , as shown for example in FIG.  3 . 
     FIG. 4 shows the carry handle assembly  200  from a right side rear elevational perspective. This perspective shows external components of the barrel bolt  348  including a protruding segment  400  designed to be manually grasped. The carry handles  322  and  324  are optionally each identically formed of a central handle  402  connecting a pair of downwardly open U-brackets  404  and  406 . A pin  408  protrudes through each of the U-brackets  404  and  406  at the respective ends of handle  402  to permit pivoting motion of handle  402  along an arc  410  extending approximately 90° until, for example, a top surface  412  of handle  402  abuts the base  414  of U-bracket  404  to prevent further upward rotation of handle  402  along arc  410 . 
     FIG. 5 demonstrates the operation of dogleg abutment  350  in aligning carry handle assembly  200  with chassis  104  of FIG.  1 . The dogleg abutment  350  drops below and passes across the lower extremity  500  of wing  338 . This feature prevents installation of carry handle assembly  200  in a backwards or upside down configuration. 
     In operation, the carry handle assembly  200  is positioned against wing  338 . Pin bolts  334  and  336  affix the first segment  300  to wing  338 , as shown in FIG. 5, with the dogleg abutment assuring proper orientation of carry handle assembly  200 . The second section  302  is manually manipulated to slide lengthwise forming an overall length L with shoulder screw  352  positioned in slot  354 . With a plurality of carry handle assemblies, such as  124 ,  126 ,  200 , and  202 , installed, chassis  104  can be team-lifted from and onto the equipment rack  104 . When lifting is completed, the carry handle assemblies  124 ,  126 ,  200 , and  202  can be removed from chassis  104  and stowed on the equipment rack  102 , as shown in FIG.  1 A. 
     FIG. 6 is a midsectional view that depicts the installation of pin-bolt  334  in stiffener  326 . The pin-bolt  334  is elongated along axis  600  in parallel the overall length L of carry handle assembly  200 . A rounded head  602  functions as a pin that may be grasped to rotate the pin-bolt  334 . A wrench may be used to turn hexagonal shoulder  604  if manual grasping of the head  602  exerts insufficient force for this rotation. The hexagonal shoulder  604  may also abut wing  338 , as shown in FIG. 5, as the pin protrudes through wing  338  for retention of the first segment  300  on chassis  104 . A threaded base  606  is received in a press-fit nut  608 . Alternatively, pin-bolts  334  and  336  may be replaced by threaded fasteners; however, the installation described where lengthwise shifting of the carry handle assembly  200  locks the carry handle assembly in place on chassis  104  without the use of threaded fasteners is preferred for ease of use. 
     The foregoing discussion is intended to illustrate the concepts of the invention by way of example with emphasis upon the preferred embodiments and instrumentalities. Accordingly, the disclosed embodiments and instrumentalities are not exhaustive of all options or mannerisms for practicing the disclosed principles of the invention. The inventors hereby state their intention to rely upon the Doctrine of Equivalents in protecting the full scope and spirit of the invention.

Technology Category: 4