Printed circuit board mounting bracket

Bracket for connection to a chassis of an electronic apparatus without the use of screws is described. The bracket may feature a support arm having at least one connection means, a ledge portion connected to the top of the support arm, and a flexible section connected to the ledge portion. The flexible section may extend at an angle to the ledge portion to impart a tension force on the chassis when installed, and contains an engagement device for attachment to a chassis connection element. In a described embodiment, when installed, a protrusion of the flexible section engages a pre-existing hole in the chassis of the electronic apparatus, and the flexible section exerts a bias force against the chassis to ensure a secure connection. The bracket may also include a handle attached to the flexible section, to permit a person to disengage the engagement device of the flexible section from the chassis connection element.

BACKGROUND OF THE INVENTION 
The invention pertains to a printed circuit board mounting bracket. In 
particular, the bracket is designed to facilitate mounting printed circuit 
boards to the chassis of a personal computer without using screws. 
Manufacturers of electronic equipment, such as personal computers, 
continuously strive to improve the methods used to assemble component 
parts in order to reduce costs. Printed-circuit boards (PC boards), also 
known as cards, must be connected to a motherboard and secured to a 
chassis quickly and efficiently while still ensuring good electrical 
connections. The PC boards include one or more integrated circuit 
components mounted to a stiff substrate, and conventionally include a 
circuit board edge connector for connection to an ISA, PCI, AGP or other 
connector receptacle on the motherboard. 
Before final assembly of the electronic equipment, each PC board is 
typically mounted on a bracket. The bracket and PC board are then lowered 
into a chassis so that the edge connector of the PC board is inserted into 
a motherboard connector and holes in the bracket are aligned with 
pre-drilled holes in the chassis. Screws are then inserted into the holes 
to secure the bracket to the computer chassis. Therefore, screws and a 
torque drive tool are required to complete the assembly. Such installation 
requirements take time, which adds to manufacturing costs. Also, the use 
of screws makes it difficult for a consumer to later remove a PC board in 
order to upgrade the system or to perform a repair. 
SUMMARY OF THE INVENTION 
In general, a bracket for supporting a PC board in accordance with the 
invention connects to a chassis without the use of screws. An embodiment 
of the bracket includes a support arm having a top and a bottom, and at 
least one printed circuit board connection element. A ledge portion having 
a first end is connected to the top of the support arm. The invention 
provides a flexible section that extends at an angle to the ledge portion 
to impart a tension force on the chassis when installed. The flexible 
section includes an engaging device for attachment to a chassis connection 
element. 
Certain implementations of the invention may include one or more of the 
following features. The bracket may comprise a tab element protruding from 
the ledge portion for engaging a pre-existing slot in the chassis. A 
flange may be formed at the bottom of the support arm, for engaging a 
holder in the chassis. In addition, a handle may be attached to the 
flexible section, to enable a user to disengage the engaging device from 
the chassis connection element. The angle of extension of the flexible 
portion to the ledge portion may be greater than ninety degrees. 
The engaging device of the flexible section may be a protrusion, and the 
chassis connection element may be a pre-existing hole in the chassis. 
Alternately, the engaging device may be a hole in the flexible section, 
and the chassis connection element may be a protrusion on the chassis. 
In another implementation, generally, the invention features a one-piece 
printed circuit board mounting bracket for connection to a chassis without 
the use of screws. The bracket includes a support arm having a top and 
bottom, and at least one printed circuit board connection means extending 
from the support arm. A ledge portion extends from the top of the support 
arm. A flexible section contains an engaging device for engaging a chassis 
connection element, and the flexible section extends from the ledge 
portion to impart a tension force on the chassis when installed. 
Yet another embodiment, generally, features a bracket for connection to a 
chassis and to a PC board bracket assembly. The bracket includes a support 
arm having a top and a bottom. At least one connection element is 
connected to the support arm for attachment to a PC board bracket 
assembly. A ledge portion has a first end connected to the top of the 
support arm, and has a second end. A flexible section is connected to the 
second end of the ledge portion and includes an engaging device for 
attachment to a chassis connection element. The flexible section extends 
at an angle to the ledge portion, so that a tension force is imparted on 
the chassis when the bracket is installed. 
A further aspect features, generally, a method for mounting a printed 
circuit board to a chassis without using screws. The technique includes 
connecting the printed circuit board to a support arm of a bracket, 
wherein the bracket includes a flexible member having an engaging device. 
The support arm of the bracket is then aligned along a chassis wall so 
that an edge connector of the printed circuit board aligns with a 
receptacle on a motherboard. In addition, the engaging device of the 
flexible member is aligned with a chassis connection element in the 
chassis. The engaging device is then engaged with the chassis connection 
element and the edge connector engages with the receptacle. 
Certain implementations of the method according to the invention may 
include one or more of the following features. A tab of the bracket may be 
engaged with a pre-existing slot on the chassis. A flange of the bracket 
may be engaged with a holder inside the chassis. A handle of the bracket 
may be depressed to disengage the engaging device from the chassis 
connection element, and then the bracket and the printed circuit board may 
be removed from the chassis. 
The use of a bracket according to an implementation of the invention 
reduces the total number of screws required to install PC boards into an 
electronic device, such as a personal computer. In addition, the bracket 
eliminates the need to use a torque driving tool, such as a screwdriver to 
install or remove the PC board. Thus, a time savings in the manufacturing 
process is realized. Furthermore, an engaging device, such as a 
protrusion, located on a pre-loaded flexible section of the bracket, snaps 
into the hole of the chassis upon connection. The protrusion seated in the 
hole provides an indication of proper connection, while the flexible 
section creates a restraining load on the bracket and PC board which acts 
to secure the board. The restraining load also ensures a tight fit and 
good electrical connection of the PC board to the motherboard. 
Furthermore, the handle attached to the flexible section of the bracket 
enables a consumer or assembly worker to easily remove a PC board without 
the use of a screwdriver or some other torque driving tool. 
The details of several implementations of the invention are set forth in 
the accompanying drawings and the description below. Other features and 
advantages of the invention will be apparent from the description and the 
drawings, and from the claims.

Like reference numbers and designations in the various figures denote like 
elements. 
DETAILED DESCRIPTION 
FIG. 1A is a side view of an implementation of a bracket 1 for supporting a 
printed-circuit board (PC Board) which contains one or more integrated 
circuit components. The bracket 1 may be of one-piece construction and be 
made of a flexible metal, such as twenty-gauge zinc-plated steel. The 
bracket may also be made of a composite material, such as a metallized 
plastic, which may include a conductive material to provide adequate 
grounding. 
Referring to FIG. 1A, a support arm section 2 contains an upper connection 
tab 4a and a lower connection tab 4b. The tabs 4a and 4b are spaced a 
distance apart "d" of approximately 3.36 inches to connect to a 
standard-sized PC Board. Although two connection tabs are shown, it should 
be understood that only one or a greater number of such connection means 
may be required. A ledge portion 6 extends at approximately a ninety 
degree angle from the top of the support arm. The ledge portion fits into 
a lip portion of the computer chassis (discussed below with regard to FIG. 
2A) and includes a tab 7 that projects downward. Extending from the end of 
the ledge portion is a flexible section 8 having a protrusion 9. Extending 
from the end of the flexible section is a handle portion 10. 
The protrusion 9 on the flexible portion 8 may be spherically shaped, and 
may be a dimple designed to fit into a hole on the side wall above the lip 
of the personal computer chassis. The protrusion 9 may have a spherical 
radius of approximately 12 degrees, and may be formed by pressing an auger 
tool into the flexible member, or may be a separately attached element. In 
a similar manner, the tab 7 may be rectangular in cross-section, and may 
be designed to fit into a slot in the chassis. Of course, instead of a 
protrusion and tab, the bracket 1 may contain an alternate engaging 
element such as slots or holes designed to accept a connection device on 
the chassis such as a protrusion or tab. 
As shown in the implementation of FIG. 1A, in the rest position, the 
flexible section 8 of the bracket may be at a one-hundred and nine degree 
angle from the plane of the ledge portion 6. The size of the angle between 
the flexible section and ledge portion may be greater or less than 
one-hundred and nine degrees, depending on the material composition of the 
bracket and/or tensioning requirements. However, in most cases, this angle 
should be greater than ninety degrees to provide a pre-load tension force 
when the bracket is mounted to the chassis to ensure a secure fit, as will 
be explained below. 
FIG. 1B is a front view of the bracket 1 of FIG. 1A. The width "W" of the 
bracket may be approximately 0.725 inches, and the length "L" of the 
support arm may be approximately 4.725 inches. The ledge portion 6 may be 
approximately 0.75 inch in length, and the tab 7 may extend from near one 
end of the ledge so that it will engage a slot of the chassis. The 
flexible section 8 may be approximately 0.5 inch long and the protrusion 9 
may be positioned to engage with a hole in the chassis. These dimensions 
of the bracket sections correspond to those required to fit into a 
standard size personal computer chassis. However, one skilled in the art 
could easily modify the dimensions of the bracket sections to be longer or 
shorter, wider or thinner, so that the bracket will fit other chassis 
types. 
Referring to FIG. 1B, the bottom end of the support arm 2 contains a flange 
12. The width "f" of the flange 12 may be approximately 0.40 inches, and 
may be designed to fit into a holder (shown in FIG. 2B) that may be 
mounted within the chassis of the personal computer. 
As shown in FIG. 1B, the PC Board connector tabs 4a and 4b are integral 
parts of the bracket 1 in this embodiment, and are approximately 
perpendicular to the plane of the front of the support arm. In addition, 
the dotted line, cross-hatched area 5 represents the approximate area 
occupied by the integrated circuit components of a PC board when connected 
to the bracket, behind the front of the support arm 2. The bracket and 
attached PC board can therefore be installed in the chassis without having 
any of the PC board components touch the chassis. 
FIG. 2A is a side view of a card assembly 16 which includes the bracket 1 
connected to a PC Board 15 via the upper and lower tab connectors 4a and 
4b. In addition to containing one or more integrated circuit components, 
the PC board includes a circuit board edge connector 17. The edge 
connector is designed to fit into a receptacle in a motherboard located 
inside a chassis. 
Referring to FIG. 2A, a rivet or screw could be used to fasten the PC board 
to the tab connectors 4a and 4b of the bracket. Alternately, the PC board 
may contain one or more areas corresponding to the positions of the tab 
connectors so that an adhesive or solder connection may be formed. 
FIG. 2B is a partial cutaway side view of a personal computer chassis 18 to 
illustrate the mounting of a card assembly 16 therein. In the mounted 
position, the support arm 2 of the bracket is substantially parallel to 
the side wall 20 of the chassis, the tab 7 is engaged in a slot 27 of the 
chassis lip 22, and the protrusion 9 is seated in a screw hole 23 in 
chassis rim 24 (see FIG. 2C). In addition, the flange 12 of the bracket is 
seated in a holder 26 located in the interior of the chassis, and the PC 
Board edge connector 17 (shown in dotted line) is seated in a card 
connector receptacle 19 of the motherboard 21. 
FIG. 2C is an enlarged, cutaway view of the circular dotted-line area 30 of 
FIG. 2A. In particular, the detailed view 30 depicts the protrusion 9 
seated in a hole 23 in the rim 24. In this location, a prior art bracket 
would be secured to the chassis by use of a screw. The tab 7 is seated in 
a slot or aperture 27 of the lip 22 of the chassis. As shown, the ledge 6 
of the bracket is substantially parallel to the lip 22, and the flexible 
section 8 now conforms to the rim 24. However, the flexible section 8 has 
been forced into this position from its rest position shown in FIG. 1A, to 
now be in a position that it is approximately ninety degrees from the 
plane of the ledge portion 6. Therefore, when the protrusion 9 is seated 
in the hole 23, the flexible portion 8 provides a spring-like tension 
force against the rim 24, and also exerts a spring-like tension force 
causing the ledge 6 and tab 7 to press against the lip 22. In addition, a 
slight bias force is exerted on the support arm 2 in a direction towards 
the chassis side wall 20, and on the PC Board 15 in a generally downward 
direction. These forces may be beneficial because they promote good 
electrical contact between the circuit board edge connector 17 and 
connector receptacle 19 (see FIG. 2B). 
FIGS. 3A to 3C depict how a card assembly 16 may be connected to the 
chassis 18 of a personal computer. In FIG. 3A, the arrow 35 depicts the 
insertion direction of the card assembly 16 into the chassis 18. The 
pre-loaded, flexible section 8 of the bracket 1 is in its rest position as 
the support arm 2 of the bracket is lowered to slide along the inside of 
chassis wall 22. As the bracket is lowered, the flexible section 8 
approaches the chassis rim 24, the tab 7 approaches the aperture in the 
lip 22 of the chassis, the flange 12 approaches the bracket holder 26, and 
the PC Board edge connector 17 approaches the connector receptacle 19 of 
the motherboard 21. In order to better align the bracket during insertion, 
the inside walls of the chassis may contain channels to guide the edges of 
the support arm 2. When the bracket 1 reaches the position shown in FIG. 
3B, the protrusion 9 of the flexible section 8 snaps into the hole in the 
rim 24 of the chassis, the tab 7 seats in the slot in the lip 22, and the 
flange 12 seats in the holder 26. The circuit board edge connector 17 also 
seats in the connector receptacle 19. The installer may hear an audible 
"snap" sound, and/or feel the protrusion 9 entering the hole in the 
chassis rim 24 when the bracket is correctly inserted, as well as feel the 
edge connector 17 enter the receptacle 19, which indicate that the bracket 
and PC Board have been properly aligned. 
Referring to FIG. 3C, to remove the bracket and PC Board assembly, service 
personnel or a consumer pushes the handle 10 of the bracket 1 in a 
generally downward direction as shown by the arrow 37. This operation 
disengages the protrusion 9 from the hole 23 in the rim 24 and permits the 
bracket and PC Board assembly to be removed in the direction of the arrow 
39. A technique for removing the assembly involves grasping the PC Board 
about the top connector 4a with one hand and depressing the handle 10 with 
the other hand so that the dimple disengages from the hole 23, and then 
pulling upward in the direction of arrow 39. In this manner the support 
arm 2 of bracket 1 slides along the inner wall of the chassis 18 as the 
tab 7, flange 12, and PC board connector 17 disengage from the chassis 
and/or their respective holders. 
It should be understood that the handle 10 may not be required on a bracket 
according to the invention. In the absence of a handle, a tool could be 
used to push the protrusion of the flexible element away from the hole in 
the chassis or to push the flexible element away from the chassis wall. 
For example, in some implementations, it may be possible to use a pen or 
pencil to disengage the protrusion from the hole so that the bracket can 
be removed. 
Embodiments of the-present invention have been described, and it will be 
understood that various modifications may be made without departing from 
the spirit and scope of the invention. For example, while a generally 
circular protrusion 9 has been shown, the protrusion may be conical or may 
be of other suitable shapes to fit into a pre-existing hole. Similarly, 
the tab and flange may be of different shapes, depending upon the slot 
and/or holders into which these elements are to engage. 
Furthermore, while a bracket of certain dimensions has been described, the 
bracket may be larger or smaller depending on proposed use. Yet further, 
although the bracket has been depicted connected directly to a PC board, 
the bracket could be easily modified to connect to an already existing 
bracket. Such a device may contain bracket connection elements, such as 
clips or other connectors, to enable attachment to existing PC board and 
bracket assemblies. Such bracket connection elements are within the 
knowledge of one skilled in the art. Connection to an existing bracket may 
enable a manufacturer to enjoy the benefits of the present invention 
without having to disassemble already existing PC board and bracket 
assemblies. 
In addition, although the described implementation of the bracket is of 
one-piece construction, it could be manufactured of two or more pieces. 
For example, a rigid, L-shaped support arm and ledge portion could be 
attached to a flexible member by one or more rivets or by spot welding, 
wherein the flexible member would include a protrusion element.