Electronic dart board

An electronic dart board includes an outer frame shell having a plurality of partition ribs defining a set of scoring chambers, and a set of base blocks respectively mounted in the scoring chambers, wherein a set of block holders are respectively nested in the scoring chambers to hold the base blocks in the respective scoring chambers, the block holders fitting the scoring chambers respectively, each block holder having a plurality of less at a bottom side and at least one locating rib respectively engaged into a respective locating groove on the base blocks.

BACKGROUND OF THE INVENTION 
(a) Field of the Invention: 
The present invention relates to electronic dart boards, and more 
particularly to such an electronic dart board in which the base blocks are 
boxed in a respective block holder and nested in a respective scoring 
chamber within the front frame shell of the dart board. 
(b) Description of the Prior Art: 
Regular electronic dart boards with automatic scoring function include two 
types, one having cells at the front side for receiving the dart, the 
other having upright pegs at the front side for retaining the dart. The 
cells or upright pegs are respectively integral with a respective base 
block. When the dart hits one base block, a pressure is given to a 
membrane switch below the corresponding base block, causing a scoring loop 
to automatically count the score. These electronic dart boards are 
functional. however they cannot be used with a dart having a metal tip. 
Because the metal tip may damage the membrane switch and the related 
circuit boards. 
SUMMARY OF THE INVENTION 
According to one aspect of the present invention, the electronic dart board 
comprises an outer frame shell having a plurality of partition ribs 
defining a set of scoring chambers, and a set of base blocks made of 
flexible material such as cardboard cork, foamed resin, etc., and 
respectively mounted in the scoring chambers, wherein a set of block 
holders are respectively nested in the scoring chambers to hold the base 
blocks in the respective scoring chambers, the block holders fitting the 
scoring chambers respectively. When one base block is damaged, it can be 
conveniently replaced with a new one. According to another aspect of the 
present invention, the block holders include at least one circular base 
block, each circular base block having an annular locating groove around 
the periphery, and the block holder which holds one of the at least one 
circular base block comprises a plurality of horizontal locating ribs on 
the inside for engaging into the annular locating groove at the periphery 
of the corresponding circular base block. According to another aspect of 
the present invention, the base blocks include at least one side-loading 
base block, each side-loading base block having two horizontal locating 
grooves at two opposite sides. The block holder which holds one of the at 
least one side-loading base block comprises two horizontal locating ribs 
on the inside respectively engaged into the horizontal locating grooves at 
the corresponding side-loading base block, and at least one extension tab 
horizontally outwardly extended from a bottom wall thereof and bent 
upwards to hold the corresponding side-loading base block in place. 
According to still another aspect of the present invention, the block 
holders can be respectively molded from plastics, or made of metal by 
stamping. A block holder which is made of metal has a peripheral top edge, 
which is hammered inwards to hold the corresponding base block in place.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1, an electronic dart board in accordance with the 
present invention is generally comprised of an outer frame shell 1, a base 
frame shell 2, a score display 3, and a set of base blocks 4 (a standard 
dart board is formed of 82 base blocks 4). The outer frame shell 1, the 
base frame shell 2 and the score display 3 are similar to that of 
conventional electronic dart boards. The outer frame shell 1 comprises a 
plurality of partition ribs 11 defining the holding space of the outer 
frame shell 1 into a set of scoring chambers in which block holders 7 are 
respectively nested to hold the base blocks 4 respectively. When the block 
holders 7 and the base blocks 4 are respectively fastened together and 
inserted into the respective scoring chambers within the outer frame shell 
1, the circuit boards 5,6 are pressed together (the circuit board 5,6 are 
insulated from each other by an insulative sheet 51, which is retained 
between the circuit boards 5,6 as shown in FIG. 6). 
Referring to FIGS. 2, 5 and 8 and FIG. 1 again, the base blocks 4 are 
respectively made of cardboard cord, foamed plastics. etc., having 
different shapes respectively fitting the scoring chambers within the 
outer frame shell 1. The base block 4 shown in FIG. 2 comprises an annular 
locating groove 41 around the periphery. The block holder 7 which matches 
the base block 4 shown in FIG. 2 comprises a plurality of legs 71 raised 
from the bottom side wall thereof, and a plurality of horizontal locating 
ribs 72 raised around the inside wall thereof The locating ribs 72 each 
have a sloping top side by which the locating ribs 72 can be conveniently 
engaged into the annular locating groove 41 on the base block 4. When the 
base block 4 and the block holder 7 are fastened together and inserted 
into the corresponding scoring chamber within the outer frame shell 1, the 
assembly of the base block 4 and the block holder 7 is retained in place 
by arrowhead-like flanges 111 at the partition ribs 11 (see FIG. 5). 
Referring to FIGS. 3 and 7, the base block 4A has two locating grooves 41A 
at two opposite vertical side walls thereof: the matching block holder 7A 
is designed for side loading, comprising a plurality of legs 71A 
downwardly extended from the bottom side wall thereof, two horizontal 
locating ribs 72A bilaterally disposed on the inside for engaging into the 
locating grooves 41A on the base block 4A. and at least one extension tab 
73A horizontally outwardly extended from the bottom wall. When the base 
block 4A is nested within the block holder 7A, the extension tab 73A is 
bent upwards to hold down the base block 4A in the block holder 7A. 
Referring to FIG. 4, the block holder 7A is made having a plurality of legs 
71A downwardly extended from the bottom side wall thereof, two inward 
locating flanges 72A' perpendicularly inwardly raised from the two 
vertical side walls thereof at the top, and at least one extension tab 73A 
horizontally outwardly extended from the bottom wall. When the matching 
base block 4A is inserted into the block holder 7A. the extension tab 73A 
is bent upwards, enabling the base block 4A to be held in place inside the 
block holder 7A by the extension tab 73A and the locating flanges 72A'. 
Referring to FIGS. 10 and 11, the block holder 7B is a top-open box made of 
metal (for example, aluminum film, iron sheet, tin sheet, etc.), having a 
plurality of legs 71B at the bottom side. The matching base block 4B is 
made of cardboard, cork, etc. After the base block 4B has been fitted into 
the block holder 7B, the peripheral top edge of the block holder 7B is 
hammered down, forming an inward flange hooked on the top side wall of the 
base block 4B. 
Referring to FIGS. 6, 8, 9 and 10. a sound absorbing (plastic or rubber) 
sheet 9 is arranged below the lower circuit board 6. and a flexible 
anti-skid sheet 8 (of about 0.5 mm.about.1 mm thick) is covered on the 
upper circuit board 5 and retained below the block holders 4,4A,4B. This 
arrangement eliminates the production of noise and prevents a displacement 
of the circuit boards 5,6 during playing.