Window regulator mechanism

A window regulator for operating a slidable window panel. The window regulator includes a drive drum mounted for rotation in a wire winding direction to wind a first wire having one end mounted on a window panel carrier and in a wire unwinding direction to unwind the first wire. A driven drum is mounted for rotation in a wire winding direction to wind a second wire having one end mounted to the carrier and in a wire unwinding direction to unwind the second wire. The drive and driven drums come into connection with each other for rotation of the driven drum in unison with the drive drum only when the drive drum rotates in its wire unwinding direction. A device is provided for making a connection between the drive and driven drums for rotation of the driven drum in unison with the drive drum in response to rotation of the drive drum in its wire winding direction.

BACKGROUND OF THE INVENTION 
This invention relates to a window regulator for operating a slidable 
window panel and, more particularly, to a window regulator of the type 
which moves the window panel by winding one of two wires each having one 
end mounted on a carrier secured on the window panel while retracting the 
other wire. While the general principles and teachings hereinafter 
disclosed are applicable to all slidable window regulators including 
sun-roof window regulators, the invention is hereinafter described in 
detail in connection with its application to an automotive vehicle door 
window regulator. 
For example, one type of window regulator has been developed which employs 
two wires each having one end mounted on a carrier secured on a slidable 
window panel. One of the wires is wound on and retracted from a drive drum 
operated by a handle. The drive drum has on its one side a ratchet with 
ratchet teeth that face in a wire unwinding direction. The other wire is 
wound on and retracted from a driven drum which has on its one side 
ratchet teeth that face in a wire unwinding direction. The driven drum is 
resiliently biased to retain its ratchet in resilient engagement with the 
ratchet of the drive drum. Rotation of the handle in opposite directions 
winding one of the wire on one of the drum while retracting the other wire 
from the other drum to raise and lower the slidable window panel. 
With such a conventional window regulator, however, tensile forces are 
residual on the wires and the residual tensile forces are accumulated to 
require a greater force to operate the handle as the window regulating 
operation is repeated, as will be described later in detail. Such 
accumulated tensile forces may be a cause of failure in window regulator 
parts, as the window regulating operation is repeated. These difficulties 
stem mainly from the current designs of the wire drive device. That is, in 
conventional window regulators, the driven drum is mounted for free 
rotation except when the drive drum rotates in its wire unwinding 
direction. 
Therefore, the present invention provides an improved window regulator 
which can minimize tensile forces residual on wires used to move a 
slidable window panel with a relatively small design change. 
SUMMARY OF THE INVENTION 
There is provided, in accordance with the present invention, a window 
regulator for operating a slidable window panel. The window regulator 
comprises a carrier secured on the window panel and mounted for movement 
along a guide member, a first wire having one end mounted on the carrier, 
a second wire having one end mounted on the carrier, and a drive unit for 
winding one of the wires to move the carrier in one direction and winding 
the other wire to move the carrier in the opposite direction. The drive 
unit includes drive and driven drums. The drive drum is mounted for 
rotation on and movement along a shaft. The drive drum has thereon a first 
ratchet having ratchet teeth facing in a direction to retract the first 
wire. The driven drum is mounted for rotation on and movement along the 
shaft. The driven drum has thereon a second ratchet having ratchet teeth 
facing in a direction to retract the second wire for engagement with the 
ratchet teech of the first ratchet. A winding spring urges the driven drum 
in a direction to wind the second wire on the driven drum. A resilient 
means urges one of the drive and driven drums to bring the first and 
second ratchets into resilient engagement with each other. A drive member 
is secured on the shaft for rotation in unison therewith ro rotate the 
drive drum in the same direction as the shaft rotates. A means is provided 
for preventing movement of the drive and driven drums along the shaft to 
hold the second ratchet in mesh engagement with the second ratchet.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Prior to the description of the preferred embodiments of the present 
invention, the prior art window regulator mechanism of FIGS. 1-5 is 
briefly described in order to specifically point out the difficulties 
attendant thereon. 
In FIG. 1, the window regulator mechanism is shown as incorporated in an 
automotive vehicle door structure 1 for operating a vertically slidable 
window panel 2. The door structure 1 comprises an inner panel 1a formed at 
its lower portion with a terminal flange over which the marginal portion 
of an outer panel is crimped to provide an integral structure having a 
space or well between the inner and outer panels. The window well has a 
slot or access opening through which the window panel 2 is slidden into 
and out of the well by the window regulaor mechanism positioned within the 
window well at the inner side of the path of travel of the window panel 2. 
The window regulator mechanism includes a carrier plate C secured on the 
lower portion of the window panel 2. The carrier C is mounted for sliding 
movement along a guide member 3 bolted on the inner panel 1a. A drive unit 
D is mounted on the inner panel 1a to aid in winding one of two wires W1 
and W2 and retracting the other wire so as to move up and down the carrier 
plate C. 
Referring to FIG. 2, the guide member 3 has two parallel guide flanges 
extending on the opposite sides of the guide member 3. The guide flanges 
engage slidingly within two grooves 4 formed in the respective projections 
extending from the rear surface of the carrier plate C. The guide member 3 
has at its lower end a semi-circular guide plate 7 secured thereon for 
guiding the wire W1 and at its upper end a guide roll 8 secured rotatably 
thereon for guiding the wire W2. The guide plate and roll 7 and 8 
constitute the limits of movement of the carrier plate C. The guide plate 
3 also has a guide opening 9 for guiding the wires W1 and W2 toward the 
drive unit D which is shown schematically as including drive and driven 
drums 14 and 15 housed within a casing 10. The carrier plate C is formed 
between the projections with an opening 5 within which one ends of the 
wires W1 and W2 are secured to the carrier plate C by retainers 6a and 6b, 
respectively. 
The wire W1 extends downward from the retainer 6a to the semi-circular 
guide plate 7 around which it extends upward to the guide opening 9 and 
hence through a guide tube 28a to the drive drum 14. The wire W2 extends 
upward from the retainer 6b to the guide roll 8 around which it extends to 
the guide opening 9 and hence through a guide tube 28b to the driven drum 
15. The driven drum 14 rotates with rotation of a handle H in a manner as 
described later. 
Referring to FIGS. 3 and 4, the casing 10 is comprised of a housing 11 and 
a cover 12 for attachment to the housing 11. The housing 11 has therein a 
recess for reception of the drive and driven drums 14 and 15, and 
clearances 11a and 11b through which the wires W1 and W2 are wound around 
and retracted from the corresponding drums. A drive shaft 13 is supported 
by the housing 11 and the cover 12 for rotation within the housing recess 
with rotation of the handle H. The drive and driven drums 14 and 15 are 
supported on the drive shaft 13 for free rotation about the drive shaft 13 
and free movement along the drive shaft 13. 
The drive drum 14 is formed in its peripheral surface with a cutout 23a at 
which the wire W1 is secured and also with a helical groove 22a in which 
the wire W1 is wound around the drive drum 14. The drive drum 14 has on 
its one side surface an extension 18 and on the other side surface a 
ratchet 20 having ratchet teeth that face in the wire unwinding direction 
of drum rotation. The wire unwinding direction is clockwise as viewed in 
FIG. 3. The driven drum 15 is formed in its peripheral surface with a 
cutout 23b at which the wire W2 is secured and also with a helical groove 
22b in which the wire W2 is wound around the driven drum 15. The driven 
drum 15 has on its one side surface a ratchet 21 which has ratchet teeth 
that face in the wire unwinding direction of drum rotation. The wire 
unwinding direction is counter-clockwise as viewed in FIG. 3. The driven 
drum 15 is formed in the other side surface with a recess 26 for reception 
of a windup spring 27 which urges the driven drum 15 in the wire winding 
direction. A resilient member such as a web washer 25 is located on the 
bottom of the housing recess to urge the driven drum ratchet 21 into 
resilient engagement with the drive drum ratchet 20 but permit movement of 
the driven drum 15 away from the drive drum 14 by a length (l) 
corresponding to the ratchet tooth height. 
A cup-shaped drive member 17 is secured intermediate its ends on the drive 
shaft 13. The cup-shaped drive member 17 opens toward the drive drum 14 
and has a cutout 16 in which the extension 18 is placed with a clearance 
(.delta.) in the direction of rotation of the drive member 17. A coil 
spring 19 is located around the cup-shaped drive member 17 and it has at 
its opposite ends hooked portions 19a and 19b located on the opposite 
sides of the extension 18. The coil spring 19 serves as a return lock 
which aids in locking the drive drum 14 against rotation when an external 
force is exerted to slide the window panel 2 up or down. That is, such an 
external force, which is transmitted through the wire to rotate the drive 
drum 14, causes the extension 18 to push one of the hooked portions 19a 
and 19b with the other hooked portion being stopped against one of the 
side edges of the cutout 16. As a result, the coil spring 19 has its 
diameter increased to come into resilient contact with the inner surface 
of the cup-shaped cover 12 so as to lock the drive drum 14 against 
rotation. 
The operation of the conventional window regulator mechanism is as follows: 
It is assumed first that there is no slack on the wires W1 and W2. When 
the handle H is rotated in the direction of arrow A to slide the window 
panel 2 down from its closed position, the drive shaft 13 rotates with the 
drive member 17 in the direction of arrow A. After a degree (.delta.) of 
rotation of the drive shaft 13, the drive member 17 engages with the 
extension 18 and starts rotating the drive drum 14 in the direction of 
arrow A to wind the wire W1 around the drive drum 14. As a result, the 
wire W1 pulls the carrier plate C downward along the guide member 3 to 
slide the window panel 2 in the direction of arrow A' of FIG. 2. This 
downward movement of the carrier plate C causes the wire W2 to retract 
from the driven drum 15 while rotating the driven drum 15 in the direction 
of arrow A. 
When the handle H is rotated in the direction of arrow B, the drive shaft 
13 rotates with the drive member 17 in the direction of arrow B. After a 
degree (.delta.) of rotation of the drive shaft 13, the drive member 17 
engages with the extension 18 and starts rotating the drive drum 14 in the 
direction of arrow B to retract the wire W1 from the drive drum 14. The 
driven drum 15, the ratchet 21 of which is held in engagement with the 
ratchet 20 of the drive drum 14, rotates together with the drive drum 14 
in the direction of arrow B to wind the wire W2 around it. As a result, 
the carrier plate C slides upward along the guide member 3 to move the 
window panel 2 in the direction of arrow B' of FIG. 2. 
In the presence of a slackened condition of the wire W1, the conventional 
window regulator mechanism operates as follows: When the handle H is 
rotated in the direction of arrow A, the drive member 17 engages with the 
extension 18 and starts rotating the drive drum 14 in the direction of 
arrow A to wind the wire W1 around the drive drum 14 after a degree 
(.delta.) of rotation of the drive shaft 13. The carrier plate C stands 
still and does not pull the wire W2 until the drive drum 14 rotates to 
wind up the slack on the wire W1 and provides a tension on the wire W1. 
The ratchet 20, which is rotating with the drive drum 14 in the direction 
of arrow A, comes into engagement with the ratchet 21 of the driven drum 
15 for rotation of the driven drum 15 in unison with the drive drum 14 to 
retract the wire W2 when the slack on the wire W1 is wound up around the 
drive drum 14. That is, the carrier plate C starts sliding downward along 
the guide member 3 to slide the window panel 2 in the direction of arrow 
A' of FIG. 2 when the drive drum 14 winds up the slack on the wire W1. 
With respect to a slack on the wire W2, the windup spring 27, which urges 
the driven drum 15 in the wire winding direction, rotates the driven drum 
15 until the driven drum 15 winds up the slack on the wire W2. 
FIG. 6 is a schematic diagram showing a balance of forces exerted on the 
wires W1 and W2 during the rotation of the drive drum 14 in the direction 
of arrow A after the drive drum 14 winds up the slack on the wire W1. As 
will be observed from this diagram, the tensile force T1 and T2 exerted on 
the respective wires W1 and W2 may be expressed as: 
EQU T1=X+T2, 
and 
EQU T2=Fs 
where X is the force of resistance to sliding movement of the carrier plate 
C along the guide member 3, and Fs is the resilient force of the windup 
spring 27. 
FIG. 7 is a graph of two curves representing wire resilient extension 
versus tensile force provided when the drive drum 14 is rotated to wind 
the wire W1. In FIG. 7, the letter d1 indicates the extenion of the wire 
W1 on which the tensile force T1 is exerted, and the letter d2 indicates 
the extenion of the wire W2 on which the tensile force T2 is exerted. As 
shown in FIG. 7, if the sum of the extensions d1 and d2 is greater than 
the pitch P of the ratchets 20 and 21, the drive drum 14 will rotate in 
the wire winding direction to wind a length of the wire W1, the length 
corresponding to integral multiples of the ratchet pitch P. Upon removal 
of the rotational force on the handle H, the sum of the extensions of the 
wires W1 and W2 which is not wound around the drive drum 14 returns to 
zero, although the sum of the extensions which is wound around the drive 
drum 14 is retained around the drive drum 15, causing a residual tensile 
force To on each of the wires W1 and W2. The residual tensile force will 
increase as the window regulating operation is repeated. 
FIG. 8 is a graph of two curves representing required handle operating 
force versus wire tensile force. Curve A represents a curve developed when 
the handle H is rotated in the direction of arrow A to slide the window 
panel 2 downward while curve B represents a curve developed when the 
handle H is rotated in the direction of arrow B to slide the window panel 
2 upward. As will be observed from this diagram, a greater force is 
required to operate the handle H to slide the window panel 2 as the 
tensile force increases on the wires. A great increase occurs in the 
residual tensile force particularly when the handle H is rotated in the 
direction of arrow A with the carrier plate C abutting on the 
semi-circular guide plate 7 which constitutes a lower limit of movement of 
the carrier plate C. Such increased residual tensile force on the wires W1 
and W2 may be a cause of failure in window regulator parts such as guide 
members and wires. 
Referring to FIGS. 9-11, there is illustrated one embodiment of the window 
regulator mechanism made in accordance with the present invention. The 
window regulator mechanism of the invention is identical in many respects 
to the conventional mechanism of FIGS. 1-5, and the same reference 
numerals are used to identify identical parts. 
In this embodiment, the web washer 25 is removed and instead a coil spring 
30 is positioned around the drive shaft 13. The coil spring 30 is seated 
between the drive drum 14 and the drive member 17 to urge the drive drum 
14 toward the driven drum 15 so as to maintain the drive drum ratchet 20 
in resilient engagement with the driven drum ratchet 21 but permit a 
length (l) of axial movement of the drive drum 14 away from the driven 
drum 15 so as to bring the drive drum ratchet 20 out of engagement with 
the driven drum ratchet 21, the length (l) corresponding to the ratchet 
tooth height. 
The drive member 14 has a pair of projections 31 and 32 secured on its one 
side facing to the drive member 17. Preferably, the projections 31 and 32 
are positioned on a diagonal line of the drive drum 14, as best shown in 
FIG. 11, so that these projections 31 and 32 comes into abutment with the 
opening edge of the cup-shaped drive member 17 to prevent axial movement 
of the drive drum 14 away from the driven drum 15 when the drive member 17 
rotates in the direction of arrow A to rotate the drive drum 14 in the 
wire winding direction of arrow m1. In order to facilitate this function, 
the projections 31 and 32 has inclined planes 31a and 32a, respectively, 
the inclined planes facing in the wire unwinding direction of arrow m2. 
The number of the projections which can be used in the practice of the 
invention is not necessarily limited to two and may be one, three or more. 
The operation of the window regulator mechanism of this invention will now 
be described. It is first assumed that the wire W1 has slack as indicated 
in the phantom line of FIG. 12. When the handle H is rotated in the 
direction of arrow A to slide the window panel 2 downward from its closed 
position, the drive shaft 13 rotates with the drive member 17 in the 
direction of arrow A. After a degree of rotation of the drive shaft 13, 
the drive member 17 abuts the spring hooked portion 19a on the extention 
18. At this time, the projections 31 and 32 are in abutment on the opening 
edge of the drive member 17 to prevent axial movement of the drive drum 14 
relative to the driven drum 15 so as to retain the drive drum ratchet 20 
in engagement with the driven drum ratchet 21. 
A further rotation of the handle H in the direction of arrow A causes the 
drive drum 14 to rotate in the wire winding direction of arrow m1 to wind 
the wire W1 around it and at the same time causes the driven drum 15 to 
rotate in unison with the drive drum 14 to retract the wire W2 from it 
since the drive drum ratchet 20 is held in engagement with the driven drum 
ratchet 21. The carrier plate C stands still until the drive drum 14 
rotates to wind up a length of wire W1 corresponding to the slack. Because 
of this, a slack appears on the wire W2, as indicated in the phantom line 
of FIG. 12, when the slack on the wire W1 disappears. 
When the handle H is further rotated in the direction of arrow A, the wire 
W1 is wound around the drive drum 14 to pull the carrier plate C downward, 
whereas the wire W2 is retracted from the driven drum 15 with the slack 
being left on the wire W2. If the handle H is further rotated in the 
direction of arrow A, the wire W1 is wound around the drive drum 14 to 
pull the carrier plate C downward, whereas the wire W2 is retracted from 
the driven drum 15 with the slack being left on the wire W2. If the handle 
H is further rotated in the direction of arrow A after the carrier plate C 
comes into contact with the lower limit, that is, the semi-circular guide 
plate 7, the drive drum ratchet 20 will rotate at a small angle in the 
direction of arrow m1 to cause the drive drum 14 to wind the wire W1 in a 
little amount resulting in a relatively little resilient extension and 
tensile force residual on the wire W1. 
When, under this condition, the handle H is rotated in the direction of 
arrow B, the drive shaft 13 rotates with the drive member 17 in the 
direction of arrow B. After a degree of rotation of the drive shaft 13, 
the drive member 17 abuts the spring hooked portion 19b on the extension 
18. At this time, the projections 31 and 32 are disengaged or released 
from the opening edge of the drive member 17 to allow axial movement of 
the drive and driven drum ratchets 20 and 21. As a result, the driven drum 
15 rotates in the wire winding direction under the resilient force of the 
windup spring 27 to absorb the residual slack on the wire W2 and at the 
same time release the residual tensile force from the wire W1. 
When the handle H is further rotated in the direction of arrow B, the drive 
drum 14 rotates in the wire unwinding direction of arrow m2 to retract the 
wire W1 with a predetermined tensile force while at the same time the 
driven drum 15 rotates in the wire winding direction in unison with the 
drive drum 14 to wind the wire W2 with a predetermined tensile force. 
In the embodiment, the projections 31 and 32 are positioned on a diagonal 
line of the drive drum 14 for abutment at two points on the opening edge 
of the cup-shaped drive member 17, with a resulting higher effect to 
ensure that the projections can prevent axial movement of the drive and 
driven drums 14 and 15 when they are in abutment on the drive member 17. 
In addition, the projections 31 and 32 are not subject to failure due to 
wear since the coil spring 30 resiliently maintain the distance between 
the drive drum 14 and the drive member 17 at a predetermined length such 
as to prevent the drive member 17 from sliding in a high frictional 
manner. Even if the accuracy with which the drive drum 14, the driven drum 
15 and the drive member 17 are produced and/or assembled in the drive unit 
D is too low to assure a sufficient distance between the drive drum and 
the drive member, the drive member 17 can be guided by the inclined planes 
31a and 32a and placed in accurate position. 
While the windup spring 27 is placed between the housing 11 and the driven 
drum 15, it is to be noted that the location of the windup spring may be 
changed to a position between the drive and driven drums 14 and 15, as 
shown in FIG. 13. 
The invention has been described in detail with reference to preferred 
embodiments thereof, but it will be understood that variations and 
modifications can be effected within the spirit and scope of the 
invention. For example, the projections 31 and 32 may be provided on the 
drive member 17 to provide the same effect as described hereinbefore. If 
desired, the drive drum ratchet 20 may have ratchet teeth that face in the 
wire winding direction of drum rotation. In addition, the coil spring 30 
may be removed and instead the web washer 25 may be used at its position 
illustrated. The invention has been described with respect to a 
hand-operated window regulator. However, it is to be appreciated that the 
invention is also applicable to motor-driven window regulators.