Electrical sunshade assembly for shielding a window of an automobile

An electrical sunshade assembly includes a tubular mounting unit adapted to be secured in an automobile adjacent to a window of the latter and formed with a longitudinally extending slot. A pinion is disposed rotatably in the mounting unit and is driven to rotate in opposite first and second directions. Two racks are disposed movably in the mounting unit on two sides of the pinion. Each rack meshes with the pinion and has a connecting end portion. Rotation of the pinion in the first direction causes the connecting end portions of the racks to move away from each other, while rotation of the pinion in the second direction causes the connecting end portions to move toward each other. A screen unit is located adjacent to the slot of the mounting unit and includes a sun screen and an axially rotatable roller which is biased to wind the sun screen normally thereon. Each of two linking rods has a first end portion connected pivotally to the sun screen and a second end portion connected pivotally to the connecting end portion of a respective one of the racks such that movement of the connecting end portions of the racks away from each other causes unwinding of the sun screen from the roller to shield the window and such that movement of the connecting end portions toward each other causes winding of the screen on the roller.

BACKGROUND OF THE INVENTION 
1. Field Of The Invention 
This invention relates to an electrical sunshade assembly for shielding a 
window of an automobile, more particularly to an electrical sunshade 
assembly which is easy to assemble and which can be manufactured at a 
relatively low cost. 
2. Description Of The Related Art 
Most conventional sunshades for shielding a window of an automobile are 
operated manually. However, such sunshades are inconvenient to use, 
especially by the driver. 
To overcome the problem of inconvenient operation of the conventional 
sunshades, an electrical sunshade assembly has been proposed. The known 
electrical sunshade assembly includes a tubular mounting unit adapted to 
be mounted securely in the automobile adjacent to the window. The mounting 
unit is formed with a longitudinally extending slot. A longitudinally 
extending rotatable shaft extends rotatably in the mounting unit between 
two ends of the mounting unit. The shaft has two opposed end portions that 
are threaded in opposite directions. Two movable members are mounted 
respectively and threadably on the end portions of the shaft and are 
restricted to rotate synchronously with the shaft such that rotation of 
the shaft results in movement of the movable members along the shaft. The 
electrical sunshade assembly is provided with a driving unit which 
includes a bidirectional motor unit for driving the shaft to rotate in 
opposed first and second direction. Rotation of the shaft in the first 
direction causes movement of the movable members away from each other, 
while rotation of the shaft in the second direction causes movement of the 
movable members toward each other. A screen unit is located adjacent to 
the slot of the mounting unit and is parallel to the mounting unit. The 
screen unit includes an axially rotatable roller and a sun screen which 
has a first end portion connected to the roller and a second end portion. 
The roller is biased to wind the sun screen normally thereon. Each of two 
linking rods has a first end portion connected pivotally to the second end 
portion of the sun screen at a respective one of two opposed edges of the 
sun screen, and a second end portion connected pivotally to a respective 
one of the movable members such that movement of the movable members away 
from each other causes unwinding of the sun screen from the roller to 
shield the window and such that movement of the movable members toward 
each other causes winding of the sun screen on the roller. 
It should be noted that the manufacturing cost of the shaft is relatively 
high, thereby increasing the manufacturing cost of the known electrical 
sunshade assembly. 
SUMMARY OF THE INVENTION 
Therefore, the objective of the present invention is to provide an 
electrical sunshade assembly for shielding a window of an automobile, 
which electrical sunshade assembly can be manufactured at a lower cost. 
According to the present invention, an electrical sunshade assembly for 
shielding a window of an automobile includes a tubular mounting unit 
adapted to be mounted securely in the automobile adjacent to the window. 
The mounting unit is formed with a longitudinally extending slot. A 
driving unit includes a pinion which is disposed rotatably in an 
intermediate portion of the mounting unit and which has an axis of 
rotation transverse to a longitudinal axis of the mounting unit, and a 
bidirectional motor unit for driving the pinion to rotate in opposite 
first and second directions. First and second racks are disposed movably 
in the mounting unit on two sides of the pinion. Each of the racks meshes 
with the pinion and has a connecting end portion. Rotation of the pinion 
in the first direction causes the connecting end portions of the racks to 
move away from each other. Rotation of the pinion in the second direction 
causes the connecting end portions to move toward each other. A screen 
unit is located adjacent to the slot of the mounting unit and is parallel 
to the mounting unit. The screen unit includes an axially rotatable roller 
and a sun screen which has a first end portion connected to the roller and 
a second end portion. The roller is biased to wind the sun screen normally 
thereon. Each of two linking rods has a first end portion connected 
pivotally to the second end portion of the sun screen at a respective one 
of two opposed edges of the sun screen, and a second end portion connected 
pivotally to the connecting end portion of a respective one of the racks 
such that movement of the connecting end portions of the racks away from 
each other causes unwinding of the sun screen from the roller to shield 
the window and such that movement of the connecting end portions of the 
racks toward each other causes winding of the sun screen on the roller.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIGS. 1 and 2, an electrical sunshade assembly for shielding a 
window (not shown) of an automobile (not shown) in accordance with a first 
embodiment of the present invention includes a tubular mounting unit 1, a 
driving unit 2, first and second racks 31,32, a screen unit 4 and a pair 
of elongated linking rods 51,52. 
The tubular mounting unit 1 is adapted to be mounted securely in the 
automobile adjacent to the window. For example, the mounting unit 1 can be 
positioned on the rear shelf covering (not shown) or on the door (not 
shown). The mounting unit 1 is formed with a longitudinally extending slot 
10 and has opposite interior surfaces 11 on two sides of the slot 10. Each 
of the interior surfaces 11 is formed with longitudinally extending first 
groove 110 and a longitudinally extending second groove 111 which is 
located farther away from the slot 10 than the first groove 110. The 
mounting unit 1 is provided with a clamping unit 12 which includes two 
spaced C-shaped clamps 120 that extend respectively from two ends of the 
mounting unit 1 and that are adjacent to the slot 10. 
The driving unit 2 includes a bidirectional motor unit 20 and a pinion 21. 
In the present embodiment, the bidirectional motor unit 20 includes a 
bidirectional motor 200 which is mounted on the mounting unit 1 opposite 
to the slot 10 and which has a driving shaft 201 that extends in a 
direction parallel to a longitudinal axis of the mounting unit 1. The 
motor 200 is connected electrically to a power source (not shown) of the 
automobile via a switch unit 2001. A first bevel gear 202 is secured 
axially on the driving shaft 201. A rotatable shaft 204 has an axis of 
rotation transverse to the longitudinal axis of the mounting unit 1 and 
extends rotatably into the mounting unit 1 such that a first end portion 
of the rotatable shaft 204 is disposed at an intermediate portion of the 
mounting unit 1 and such that a second end portion of the rotatable shaft 
204 extends out of the mounting unit 1 and is adjacent to the first bevel 
gear 202. A second bevel gear 203 is secured axially on the second end 
portion of the rotatable shaft 204 and meshes with the first bevel gear 
203. The pinion 21 is secured axially on the first end portion of the 
rotatable shaft 204. Thus, the pinion 21 can be driven to rotate in 
opposite first and second directions by the motor 200 through the rotation 
of the first and second bevel gears, 202 and 203. 
The first and second racks, 31 and 32, are disposed movably in the mounting 
unit 1 on two sides of the pinion 21. Each of the racks 31,32 meshes with 
the pinion 21 and has a connecting end portion 310,320 and a distal end 
portion 311,321 opposite to the connecting end portion 310,320. Each of 
the racks 31,32 further has two slide pieces 33 which are secured 
respectively to the connecting and distal end portions, 310,320 and 
311,321, thereof by means of screws 34. The slide pieces 33 of the first 
rack 31 extend slidably into the first grooves 110 to guide movement of 
the first rack 31 in the mounting unit 1. The slide pieces 33 of the 
second rack 32 extend slidably into the second grooves 111 to guide 
movement of the second rack 32 in the mounting unit 1. 
The screen unit 4 includes a housing 40 which is clamped by the clamping 
unit 12 so as to be located adjacent to the slot 10 of the mounting unit 1 
and which is parallel to the mounting unit 1. An axially rotatable roller 
41 is disposed rotatably in the housing 40. A sun screen 42 has a first 
end portion which is connected to the roller 41 and a second end portion. 
The roller 41 is biased to wind the sun screen 42 normally thereon. The 
housing 40 is formed with a longitudinally extending slot 401 via which 
the second end portion of the sun screen 42 extends out of the housing 40. 
Each of the linking rods 51,52 has a first end portion which is connected 
pivotally to the second end portion of the sun screen 42 at a respective 
one of two opposed edges of the sun screen 42, and a second end portion 
which is connected pivotally to the connecting end portion 310,320 of a 
respective one of the racks 31,32 such that movement of the connecting end 
portions 310,320 of the racks 31,32 away each other causes unwinding of 
the sun screen 42 from the roller 41 to shield the window of the 
automobile, and such that movement of the connecting end portions 310,320 
of the racks 31,32 toward each other causes winding of the sun screen 42 
on the roller 41. 
Referring now to FIGS. 2, 3 and 4, supposing that the sun screen 42 is 
initially wound on the roller selective operation of the switch unit 2001 
causes the motor unit 20 to drive the pinion 21 to rotate in the first 
direction, thereby causing the connecting end portions 310,320 to move 
away from each other. Since the first end portion of each linking rod 
51,52 is connected pivotally to the second end portion of the sun screen 
42, and since the second end portion of each linking rod 51,52 is 
connected pivotally to the connecting end portion 310,320 of a respective 
one of the racks 31,32, movement of the connecting end portions 310,320 of 
the racks 31,32 away from each other unwinds the sun screen 42 from the 
roller 41 to shield the window of the automobile. As best shown in FIG. 4, 
the linking rods 51,52 are generally perpendicular to the mounting unit 1 
when the sun screen 42 is unwound fully from the roller 41. 
Referring now to FIGS. 5 and 6, a second embodiment of the present 
invention is shown. In the present embodiment, each of the linking rods 
(51A,52A) is telescopic in order to suit the window size of any automobile 
model. Each of the linking rods (51A,52A) includes a first rod section 
(510A,520A) which is formed with a row of longitudinally spaced engaging 
holes (511A,521A), and a second rod section (512A,522A) on which the first 
rod section (510A,520A) is sleeved movably. The second rod section 
(512A,522A) of each linking rod (51A,52A) is provided with a spring-loaded 
projection (513A,523A) which engages selectively one of the engaging holes 
(511A,521A) so as to vary the length of the linking rod (51A,52A). 
The mounting unit 1 of the electrical sunshade assembly of the present 
invention can be mounted pivotally to a positioning unit (not shown) which 
is fixed in the automobile so as to permit variation of the angle formed 
between the sun screen 42 and the window of the automobile in order to be 
compatible with any model of automobile. 
It should be appreciated that, since the electrical sunshade assembly of 
the present invention employs inexpensive racks, the manufacturing cost of 
the present invention is thus lower when compared with the previously 
described prior art. 
While the present invention has been described in connection with what is 
considered the most practical and preferred embodiments, it is understood 
that this invention is not limited to the disclosed embodiments, but is 
intended to cover various arrangements included within the spirit and 
scope of the broadest interpretation so as to encompass all such 
modifications and equivalent arrangements.