Mother board structure with fitting holes

A mother board for a computer provided with a plurality of keyhole shaped fitting holes with protective elements extending around and downwardly from the peripheral edges of the large elliptical portions for preventing the annular slots of posts used in securing a PC board to the mother board from seizing the edges of the large elliptical portions during removal of the PC board. An interface rack is integrally formed with the mother board and provided with a plurality of main slots for receiving interfaces therein, each main slot terminating in an insertion slot formed between a positioning plate and the bottom of the interface rack for guiding and securing the interface to the rack.

BACKGROUND OF THE INVENTION 
The present invention relates to an improved mother board structure having 
fitting holes and an interface rack and particularly fitting holes for the 
fitting and removal of posts for installation of a PC board, and an 
interface rack for insertion of interfaces in a computer. 
Generally, as shown in FIGS. 1 and 2, a mother board (2) for a computer has 
to be incorporated with a number of posts (3) for installation of a PC 
board (4). For such installation, the upper end of each post is fixed to a 
corresponding hole in the PC board (4), and an annular slot formed at the 
lower end of the post is placed in a large elliptical portion (211) of the 
corresponding fitting hole at the mother board (2) and then moved 
transversely for retaining by a small elliptical portion (212) in order to 
fix the PC board (4) in place. However, upon removal of the PC board, a 
slight deviation in direction of movement will cause the slot (31) of the 
post to be seized by the peripheral edge of the large elliptical portion 
(211) of the fitting hole, and make removal of the PC board difficult. 
Moreover, an interface rack is normally provided at the back of the motor 
board for installation of interfaces, and generally a cavity is formed at 
the bottom of the interface rack for receiving a projected portion of a 
plate connected to the interface and then the plate is secured to the rack 
by a bolt at the top of the interface rack. Such a design cannot assure 
close insertion of the interface, and the interface may become loosened. 
In view of the above defects, the inventor has created an improved mother 
board structure to eliminate the above defects. 
SUMMARY OF THE INVENTION 
The present invention provides an improved structure for a mother board, 
particularly a structure to facilitate removal of posts for a PC board and 
installation of interfaces. It includes a plurality of fitting holes at 
the mother board, each hole having a protecting element extending 
downwardly from a large elliptical portion of the fitting hole to prevent 
the posts for installation of a PC board on the mother board from seizing 
on the mother board when the PC board is being removed, and an interface 
rack having a positioning plate extending perpendicularly from the bottom 
of each slot and having a guide element to guide an interface during 
insertion into an insertion slot. Moreover, the flexibility of the 
positioning plate can firmly secure the interface to the interface rack, 
and the interface rack is integrally formed with the mother board to 
assure accurate fitting and to provide additional strength.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
As shown in FIGS. 3, 4 and 5, the present invention includes a plurality of 
fitting holes (5) in a mother board (1). Each fitting hole (5) is designed 
in a substantially keyhole shape defined by a large substantially 
elliptical portion (51) at one side which reduces gradually to form a 
small substantially elliptical portion (52) at another side. There is a 
protective element (53) extending around and downwardly from the 
circumference or peripheral edge of the large elliptical portion (51) so 
that the edge of large elliptical portion (51) will not be seized by an 
annular slot (31) of the post (3). 
As shown in FIGS. 3, 6 and 7, an interface rack (6), which is integrally 
formed with mother board (1), comprises a plurality of main slots (61), 
each main slot (61) is incorporated with a positioning plate (62) 
extending perpendicularly and inwardly from its bottom. The upper end of 
each positioning plate (62) is bent inwardly to form a guide element 
(621). An insertion slot (63) is thus formed between the positioning plate 
(62) and the bottom of the interface rack (6). 
With reference to the above structure, the features of the present 
invention are described below: 
As shown in FIGS. 4 and 5, because there is a protective element (53) 
around the circumference or peripheral edge of the large elliptical 
portion (51) of each fitting hole (5) at the mother board, a PC board (4) 
fixed to the mother board (1) by the post (3) can be easily removed 
because the annular slot (31) of the post (3) is prevented from seizing 
the peripheral edge of portion (51)--a main feature of the present 
invention. Please refer to FIGS. 3, 6 and 7 for another feature of the 
present invention. With the positioning plate (62) at the bottom of the 
interface rack (6), the interface can be smoothly inserted into the 
insertion slot (63) through guidance of the guide element (621) and then 
secured by the positioning plate (62) which firmly closes the main slot 
(61) of the interface rack (6). As shown in FIG. 3, the interface rack (6) 
is integrally formed with the mother board (1) to provide additional 
strength, save production cost and time, and provide an accurate fitting 
which eliminates the requirement in assembling the interface rack to the 
mother board as normally practiced in the prior art. 
Characteristics and merits of the present inventions are summarized as 
follows: 
(1) The fitting holes in the mother board are designed with protective 
elements to prevent the posts for installation of PC board from being 
seized by the fitting holes upon removal of the PC board, and hence 
facilitate removal of the PC board. 
(2) The interface rack is designed with positioning plates having guide 
elements to guide insertion of interfaces, and the flexibility of such 
positioning plates can secure the respective interfaces to the interface 
rack tightly without seams or looseness. 
(3) The present invention permits easy installation and removal of a PC 
board and interfaces to save labor and time. 
(4) The present invention has a simple structure and is an improvement of 
the prior art.