Window operator

A window operator has a prime mover for opening and closing of a window, with the prime mover being drivingly connected to a drive output member through an intermediate gear structure. A clutch device in the drive structure senses the torque applied to the drive output member in a window closing operation and a switch operable by the clutch is effective to deenergize the prime mover when the torque applied to the output member reaches a predetermined value. The switch can be adjustably located relative to the clutch whereby the predetermined value at which the motor will be deenergized may be varied in order to obtain a desired tension on a member connected to the closed sash of the window, such as a chain connected to the sash of a skylight window.

BACKGROUND OF THE INVENTION 
This invention pertains to a new and improved window operator and, more 
particularly, to a window operator for a window, such as a skylight 
window, wherein a power unit can cause extension and retraction of a chain 
connected to a movable sash of the window for causing opening and closing 
movement of the window sash. Window operators for skylight windows are 
known in the art. An example of such window operator is shown in the 
Tacheny et al. U.S. Pat. No. 4,521,993, owned by the assignee of this 
application. The window operator has a chain storable within a housing and 
with the chain being extended from and retracted into the housing by means 
of a rotatable drive sprocket having a toothed relation with the chain. 
The Tacheny et al. patent discloses a two-part housing with a housing base 
providing for chain storage, chain guiding, and rotatable mounting of the 
drive sprocket. An upper part of the housing mounts means for driving the 
rotatable drive sprocket which can either be a manually operable means or 
a motor drive, as shown in FIG. 5 of the patent. 
The invention disclosed herein relates to an improvement in a power drive 
for the window operator as shown in the Tacheny et al. patent and the 
disclosure of the Tacheny et al. patent is incorporated herein by 
reference. 
SUMMARY OF THE INVENTION 
A primary feature of the invention is to provide a new and improved window 
operator which provides for control of the opening and closing movements 
of the window sash wherein the torque on the chain-driving sprocket can be 
preset to a value corresponding to a desired chain tension for tight 
closing of the window. 
More particularly, an object of the invention is to provide a window 
operator which utilizes a prime mover for opening and closing of a window 
and which is drivingly connected to a drive output member, means in said 
drive connection sense the torque applied to the drive output member and 
means operated by the sensing means acts to stop the prime mover when the 
torque reaches a predetermined value in achieving closing of the window. 
The window operator as defined in the preceding paragraph has the sensing 
means in the form of a clutch with a clutch member movable proportionally 
to the torque when the torque exceeds a certain level and which is at a 
level below said predetermined value. This torque sensing is only operable 
in the closing mode. (The clutch is a one-way type clutch.) In one 
embodiment of the window operator, a movable clutch member as well as a 
second clutch member have coacting helical ramps. Separation of the clutch 
members by coaction between the helical ramps is resisted by spring means 
and with the spring means yielding to permit movement of the movable 
clutch member when the torque exceeds said certain level. 
The means for stopping the prime mover includes a switch operable by the 
movable clutch member and said predetermined value of torque at which the 
prime mover will be stopped is determined by adjustable positioning of the 
switch relative to the movable clutch member. The movable clutch member 
will move an increased distance with increasing torque applied to the 
drive output member and, therefore, the predetermined value of torque can 
be established by positioning of the limit switch at a level relative to 
the movable clutch member corresponding to the amount of separating 
movement of the clutch members which will result from the torque being of 
said predetermined value. 
Another object of the invention is to provide a window operator for moving 
a window component between fully open and closed positions and any desired 
position therebetween comprising, a rotatable drive output member, a 
rotatable drive input member, a gear train between said drive input and 
drive output members, means for rotating said drive input member, a switch 
for controlling operation of said rotating means, and means responsive to 
a closing torque applied to the rotatable drive output member in excess of 
a predetermined value for operating said switch to deenergize said 
rotating means. 
A further object of the invention is to provide a window operator 
comprising, a rotatable drive output member, a selectively operable motor, 
a speed-reducing gear train between said motor and drive output member, a 
clutch in said gear train including a pair of separable clutch members, 
means yieldably-holding said clutch members against said separating 
movement, torque-responsive coacting means on the clutch members for 
causing progressive increase in the separation of the clutch members 
against the action of the yieldable holding means as the torque applied to 
the output member increases above a certain amount, a motor-controlling 
switch positioned in the path of one of the clutch members, and means for 
adjustably positioning said switch whereby the amount of said torque 
effective to operate the switch can be set at a predetermined value.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The window operator, indicated generally at 10 in FIG. 1, is shown mounted 
for operation of a window and particularly a skylight window having a 
frame 11 and a sash 12 hinged to the frame at 13. The sash has a dome 
member 14 which transmits light. The window is shown in solid lines with 
the sash 12 in the closed position and in dashed lines with the sash 12 in 
the open position. 
The window operator 10, as shown in FIGS. 2-7, has a number of associated 
components that can be mounted to a base 15, such as the 
previously-described base of the Tacheny et al. patent. These components 
include a housing 16 with a flange 17 having suitable openings 18 for 
receiving attachment members for securing the housing 16 to the base 15. 
A prime mover power source, in the form of an electric motor 20, is mounted 
to the housing 16 at one end thereof and a panel 22, extending beyond the 
motor 20, mounts a slave controller 24. A wiring harness 26 is located at 
the opposite end of the housing 10 and with parts of the wiring being 
associated with the slave controller 24 and with wiring connections 
between the slave controller 24 and the electric motor 20. 
The electric motor 20 has a rotatable drive input member, in the form of a 
worm gear 30, positioned within the housing and which is geared to a 
speed-reducing gear train by mesh with a helical gear 32 rotatable on a 
shaft 34 and which has pinion gear 36 rotatable therewith. 
The speed-reducing gear train drivingly interconnects the motor 20 and worm 
gear 30 with a rotatable drive output member, in the form of a drive shaft 
40. This driving connection is through the helical gear 32 and the pinion 
gear 36, with the latter gear meshing with a spur gear 42. The spur gear 
42 is rotatable on a shaft 44 and has a pinion gear 46 which meshes with a 
spur gear 48 rotatable on a shaft 50. The spur gear 48 has a pinion gear 
52 fixed thereto which meshes with a spur gear 54 on an idler shaft 56. 
The spur gear 54 in addition to meshing with the gear 52 also meshes with 
the teeth of a peripheral gear 58 extending around the periphery of a 
lower clutch member 60 of a clutch to be further described. 
The clutch has the clutch member 60 which is the lower of two clutch 
members and also an upper clutch member 62. As seen in FIG. 5, the lower 
clutch member 60 has a circular opening 64 whereby the clutch member is 
freely rotatable on the drive output shaft 40. The upper clutch member 62 
has a rectangular opening 66 to fit on a portion of the drive output shaft 
which is rectangular in cross section, as seen in FIGS. 3 and 5. Because 
of this relation, the upper clutch member 62 has its rotation controlled 
by the rotational condition of the drive output shaft 40. If the drive 
output shaft cannot rotate, then the upper clutch member 62 cannot rotate, 
while the lower clutch member 60 is still free to rotate. The upper clutch 
member 62 is free to move lengthwise of the drive output shaft 40 and, in 
an up and down direction, as viewed in FIG. 4. 
The drive output shaft 40 is rotatably mounted in the housing by a pair of 
bushings including an upper bushing 70 and a lower bushing 72. A thrust 
washer 74 is positioned between the housing and the underside of the lower 
clutch member 60. 
The clutch members 60 and 62 have pairs of coacting helical ramps, with the 
lower clutch member 60 having the helical ramps 80 and 82 and the upper 
clutch member 62 having the helical ramps 84 and 86. The clutch members 
are urged toward each other with the helical ramps thereof in engagement 
by means of a wave spring 90 captured between the underside of a top part 
92 of the housing and the upper side of the upper clutch member 62. 
The drive shaft 40 has a drive nut 94 at its lower end and positioned 
beneath the underside of the housing 10 which is engageable within the 
hole of a drive sprocket for the chain, such as the drive sprocket 95 
shown in FIG. 2 and in the aforesaid Tacheny et al. patent which is 
incorporated herein by reference. 
In operation, energization of the motor 20 in a forward direction results 
in rotation of the drive output shaft 40 through the speed-reducing gear 
train and, with the window being closed, the resulting rotation of the 
drive output shaft results in extension of a chain 96 connected to the 
window sash 12 for opening movement of the window. The underside of the 
housing 16 mounts a limit switch 100 positioned for engagement by a 
suitable member positioned selectively along the chain 96 which will 
indicate the desired full-open position for the window and, when this 
member contacts the limit switch 100, the motor 20 will be deenergized. 
During the opening mode, the clutch members are drivingly locked together 
and will not separate in proportion to the applied torque. In the opening 
mode, vertical surfaces A and B on the clutch members 60 and 62 (FIG. 5) 
are in contact and directly drive the output shaft. There is no capability 
for the lower clutch member 60 to rotate relative to the upper clutch 
member 62 and "sense" the opening torque by elevation of the upper clutch 
member 62. 
When the window is to be closed, the motor 20 is energized for rotation in 
the opposite direction to achieve the reverse direction rotation of the 
drive output shaft 40, with resulting movement of the chain 96 into the 
base part of the housing. In order to achieve a desired chain tension for 
desired closing force on the window sash, the invention has means for 
sensing the torque on the chain-driving sprocket 95 and the drive output 
shaft 40 and when this torque reaches a predetermined value the motor 20 
is deenergized. The means for sensing the torque comprises the 
previously-described clutch, with the clutch members 60 and 62. As the 
window is being closed, the spring means 90 will maintain the helical 
ramps of the clutch members in engagement, as shown in FIG. 6, and without 
relative rotation between the clutch members. As soon as the window sash 
reaches closed position, there is an increase in torque resulting from 
rotation of the motor 20 which continues to drive the drive output shaft 
40 in a window-closing direction. As this torque increases to a certain 
level, the clutch members will start to separate, as shown in FIG. 7, 
because of the upper clutch member 62 being held against rotation by the 
drive output shaft 40 not being able to rotate, while the lower clutch 
member 60 continues to rotate. This climbing of the helical ramps on each 
other exerts axial forces axially of the drive output shaft 40 to raise 
the upper clutch member 62 against the spring means 90. 
When the torque on the drive output shaft reaches a predetermined level, as 
sensed by the upper clutch member 62 having moved to a certain level on 
the drive output shaft 40, means are effective to deenergize the motor. 
This means comprises a limit switch 110 having a contact member 112 
positioned in the path of the upper clutch member 62. Engagement of the 
contact member 112 by the upper clutch member 62 changes the condition of 
the switch 110, with the result that the motor 20 is deenergized. As the 
inertia of the motor is dissipated, there can be a slight further rise in 
the movement of the upper clutch member 62. 
The desired tension on the chain 96, which is indicated by the torque on 
the output drive shaft 40 reaching a predetermined level, can be varied 
and preselected by adjusting the level of the switch 110. The body of the 
switch 110 is suspended from the top of the housing by an adjusting screw 
114 with rotation of this screw providing for varying the level of the 
switch 110. As the level of the switch 110 is raised, there is a resulting 
increase in the predetermined value of torque, at which time the motor 20 
will be deenergized. This is because there is a requirement for a greater 
torque value to cause a greater upward movement of the upper clutch member 
62 prior to engaging the contact member 112 of the switch. 
The lower clutch member 60 includes vertical surfaces 120 and 122. The 
upper clutch member 62 includes similar vertical surfaces 124 and 126. The 
vertical surfaces 120 and 124, and 122 and 126 match each other and are in 
abutting relation to preclude relative rotation between the clutch members 
60 and 62 when there is an externally applied window component opening 
force, as by a burglar attempting to open the window. Specifically, any 
such force applied to the chain 96 tries to rotate the sprocket 95 and the 
drive nut 94 in the selected direction. However, the respective vertical 
surfaces engage one another and there is no axial movement of the upper 
clutch member 62.