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This application is a continuation of Ser. No. 09/635,781, filed Aug. 11, 2000, now abandoned. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to window operators and, more particularly, to window operators which may be selectively motor driven or manually driven. 
   2. Description of the Prior Art 
   There are many types of fenestration products such as windows, skylights, doors with many of such windows and skylights being generally manually operated by turning a crank mechanically connected to the pivotable unit of the window or skylight, whereby various hardware, e.g. linkages, connect the crank to the pivotable unit thereby allowing for manually opening or closing of the window or skylight. Various motorized versions of such operators have been developed such that the pivotable unit can be opened or closed by way, for instance, of an electric motor. 
   U.S. Pat. No. 5,006,766 issued on Apr. 9, 1991 to Yuhas et al. discloses a motorized window operator which comprises a housing containing a motor in operative engagement with a gear train having an output gear. This output gear is engaged to the drive axle of the window such that the motor will cause the drive axle to rotate to either open or close the window depending on the direction of rotation of the motor. It is also possible to manually operate the drive axle by disengaging the gear train therefrom while simultaneously cutting off power to the motor. In this patent, the conventional lever or crank is replaced by the aforementioned housing which contains the motor. When the housing is in a lower position thereof, the output gear meshes with an engagement member mounted to the window&#39;s drive axle. The housing can also be displaced such as to disengage the output gear from the engagement member while engaging the latter to a tooth provided on a head member which is fixed within the housing such that, the housing may be rotated about the axis of the drive axle, in a way similar to a conventional lever or crank, thereby resulting in the manual rotation of the drive axle. Various sensors, including a rain sensor, can be interfaced with a controller adapted to issue instructions to the electric motor for appropriate operation thereof, to allow for automatic operation of the window in accordance with prescribed environmental parameters. 
   U.S. Pat. No. 5,493,813 issued on Feb. 27, 1996 to Vetter et al. discloses an electric window operator which can be engaged to a handle for manual operation of the window. 
   U.S. Pat. No. 5,313,737 issued on May 24, 1994 to Midas teaches a motorized operator encased within a housing mounted at the front of the frame of the window and which replaces the usual crank normally mounted to the window&#39;s operator shaft. In this patent, there does not seem to be any manual override. 
   U.S. Pat. No. 4,553,656 issued on Nov. 19, 1985 to Lense discloses a housing containing an electric motor for causing a driven member to be rotated, the driven member being connected to the sash of the window and being adapted to cause the sash to displace such as to open or close the window. A crank arm is displaceable between active and inactive positions such that when the arm is in its inactive position, the motor may turn the driven member, whereas, when the arm is in its active position, the motor is disconnected from the driven member and the crank arm can be used to manually operate the sash. The housing in which the electric motor is lodged is mounted on the window&#39;s casement. 
   U.S. Pat. No. 3,845,585 issued on Nov. 5, 1974 to Cecil discloses a motor positioned in the casement of the window and adapted to cause the rotation of a vertical pivot shaft disposed adjacent to vertical hollow window jamb and connected to a hinge mechanism substantially enclosed within the hollow jamb and to which the window assembly is mounted. Therefore, the motor causes the rotation of the pivot shaft which displaces the hinge mechanism in a sweeping movement such as to pivot the window assembly between open and closed positions thereof. 
   U.S. Pat. No. 4,895,048 issued on Jan. 23, 1990 to Key et al. discloses a powered actuator for opening and closing convertible tops, sunroofs, windows and the like, in motor vehicles. The powered actuator has a manual override to allow the actuator to be operated by hand. 
   U.S. Pat. No. 2,259,811 issued on Oct. 21, 1941 to Fregeau teaches a window operator adapted to allow for windows to be manually adjusted and for their remote controlled closing using an electromagnet and associated hardware. 
   SUMMARY OF THE INVENTION 
   It is therefore an aim of the present invention to provide a novel motorized operator for casement windows. 
   It is also an aim of the present invention to provide a novel motorized operator for casement windows, the operator being adapted to be selectively driven by a motor or manually. 
   Therefore, in accordance with the present invention, there is provided a motorized operator for opening and closing a window sash relative to a window frame via an arm mechanism and being adapted to be installed in a cavity defined in the window frame, comprising motor means, a drive axle adapted to be rotated by said motor means, gear means adapted to be rotatably driven by said drive axle and to so cause the arm mechanism to pivot upon rotation of said second gear for opening and closing the window sash relative to the window frame, and a manual operator displaceable between inoperational and operational positions; said gear means being manually displaceable between first and second positions, wherein in said first position, said gear means is rotated by said motor means via said drive axle for pivoting the arm mechanism and displacing the window sash, whereas in said second position, at least part of said gear means is mechanically disconnected from said drive axle such that said part of said gear means is not rotated by said motor means, said part of said gear means being connected to said arm means, whereby with said manual operator in said operational position, said manual operator is adapted to rotate said part of said gear means for causing the arm mechanism to pivot. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Having thus generally described the nature of the invention, reference will now be made to the accompanying drawings, showing by way of illustration a preferred embodiment thereof, and in which; 
       FIG. 1  is a schematic front elevational view of a casement window intended to be fitted with a motorized operator in accordance with the present invention; 
       FIG. 2  is a exploded view of the motorized operator of the present invention; 
       FIG. 3  is a top plan view showing the motorized operator installed on the casement window and connected to the pivotable window thereof; 
       FIG. 4  is a schematic, broken away, front elevational view of  FIG. 3 ; and 
       FIG. 5  is a schematic, broken away, side elevational view of the motorized operator installed in the casement window. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  illustrates a casement window C generally comprised of a frame F mounted to a wall of a dwelling and a window W pivotally mounted to the frame F in a conventional manner. As it is well known in the art, a crank provided with a linkage is normally used to displace the window W between open and closed positions thereof. 
   Now referring to  FIG. 2 , there is shown an exploded view of a motorized operator O in accordance with the present invention and adapted to render the opening and closing of the window W with respect to the frame F easier, practical and safe. The motorized operator O is electrically connected to a conventional 120 volt wall outlet or may obviously be connected to a similar power supply but in a hidden fashion, that is with the wires connected to the operator O running within the wall. 
   It is noted that all of the components of the present motorized operator O are hidden under the moldings of the frame F, except for some subsidiary components which will be described hereinafter. 
   Therefore, the present motorized operator O eliminates the prior art crank arm which has a configuration which contrasts somewhat with the traditional elegance of a casement window. 
   Now turning to the various components of the motorized operator O illustrated in  FIG. 2 , a main limit switch  10  is intended to be installed under and actuated by one of the two lever catches  12  mounted within the vertical molding of the window&#39;s frame F and which co-act with hooks  14  mounted on the window W to lock the latter with respect to the frame F. The main limit switch  10  is thus adjusted such that electric power cannot be fed to the other elements of the operator O when the window W is in a locked position by way of the mating engagement of the catches  12  with their respective hooks  14 . Accordingly, when the catches  12  are disengaged from the hooks  14 , as shown in  FIG. 1 , the window W is free to be pivoted towards the open or the closed position thereof, whereby the limit switch  10  is in a position to allow power to reach the motorized operator O such that the latter can be used to displace, under motor force, the window W with respect to the frame F. In  FIG. 1 , the general location of the main limit switch  10  is shown at location  16 . It is possible to provide a limit switch  10  for each catch  12  such as to ensure that power is fed to the operator O when both catches  12  are disengaged from the hooks  14 . 
   A switch assembly  18  is also provided with the motorized operator O. The switch assembly  18  comprises a toggle switch  20  and a pilot light  22 . When the pilot light  22  is illuminated, it indicates that the system is ready to be operated, that is that the window W can be pivoted by way of the motor force provided by the motorized operator O. This pilot light  22  can only be illuminated if the catches  12  are completely disengaged from the hooks  14 , whereby it is electrically linked to the main limit switch  10 . When the pilot light  22  is on, the toggle switch  20  can be actuated such as to operate the motorized operator O. For instance, by pressing the toggle switch in one direction, the window W will pivotally open, for instance, up to a maximum orientation of 55° with respect to a plane of the frame F. By pressing the toggle switch  20  in an opposite direction, the window W will close until the switch  20  is released and, for instance, until the window W is completely closed whereat the window W can then be locked by pivoting the catches  12  such that they lockingly engage the hooks  14  of the window W. 
   For instance, as indicated in  FIG. 1 , the switch assembly  18  is mounted at location  24  such that opening of the window is achieved by pressing on an upper portion of the toggle switch  20 , whereas, to close the window W, a lower portion of the toggle switch  20  is depressed. 
   Typically, the displacement of the window W is relatively slow, for instance 10 seconds to completely close the window W from a completely open position thereof, and this permits for an easy adjustment of the window W to a desired intermediate position thereof with respect to the frame F. The toggle switch  20  is biased towards a neutral position thereof such that the window W can only be displaced once force is manually applied on either the upper or lower portions of the toggle switch  20 , whereby once released, the toggle switch  20  returns to its neutral position, that is to an unoperational position such that no movement whatsoever is imparted to the window W by way of the motorized operator O. 
   Now turning to the motorized operator O itself, it is adapted to be installed in a conventional recessed chamber  26  (see  FIG. 4 ) defined in the lower horizontal section of the frame F. The operator O comprises a motor and its casing  28  which are of small dimensions (for instance, 4″×2¼″×2¼″) with the motor  28  being capable of rotation in opposite directions for opening and closing the window W. As also seen in  FIG. 2 , the operator O comprises a base plate  30  which is typically made of metal and which is carefully adjusted to the profile of the metallic support frame provided in the general window frame F. The base plate  30  acts as a support for the motor and casing  28  located in the recessed chamber  26  defined in the wooden framing of the frame F. For example, the recessed chamber may measure 4⅜″×2⅜″×2¾″. 
   A small first gear  32  (¾″ in diameter) is mounted on a transmission motor shaft  34  of the motor  28 . This first gear  32  transmits the rotation imparted thereto by the motor shaft  34  to a second gear  36  (1½″ in diameter) which itself meshes with a third gear  38  (2″ in diameter). A composite movement arm  40  is mounted at one end thereof to the third gear  38  using screws  41 , whereas the other end of the arm  40  is attached to a frame  42  (see  FIG. 1 ) of the window W by way of a bracket  44  and a pivot pin (not shown). The controlled rotational movement of the third gear  38  causes a pivot of the window W thereby opening or closing the same. 
   The motorized operator O also comprises first and second miniature lever switches  46  and  48 , respectively. The first switch  46  is actuated by a pin which protrudes from under the second gear  36  and which is adapted to interrupt power to the motor  28  once the window W has reached its completely open position. Therefore, this pin is adjusted on the second gear  36  such that after a given rotation of the second gear  36 , the pin actuates the first switch  46  and interrupts power to the motor  28 , thereby preventing any attempt to further open the window W. 
   The second switch  48  is actuated by a further pin which protrudes under the third gear  38  and which is adapted to interrupt power to the motor  28  once the window W has reached its completely closed position. In a way similar to the pin mounted to the second gear  36 , the pin mounted to the third year  38  is positioned such that after a given rotation of the third gear  38 , its pin actuates the second switch  48  and prevents any attempt to further close the window W. Once the second switch  48  has been tripped by the pin provided under the third gear  38 , the window W is completely closed whereby the catches  12  can be lowered to lock the window W to the frame F thereby simultaneously interrupting power to the motorized operator O and, more particularly, to the motor  28  for preventing any subsequent attempt to open the window W by way of the motorized operator without having previously unlocked the window W from the frame F by disengaging the catches  12  from the hooks  14 . 
   Short first and second shafts  50  and  52 , respectively are fixably mounted to the base plate  30  and constitute fixed pivots around which the second and third gears  36  and  38  can respectively rotate. Typically, the first and second shafts  50  and  52  are spot-welded to the base plate  30 . Accordingly, the second and third gears  36  and  38  are free to rotate around these first and second shafts  50  and  52  while being prevented from being upwardly removed by circlips. 
   In order to allow for the window W to be manually opened or closed in the event, for instance, of a power failure, the motorized operator O is provided with a disengagement mechanism which includes a spring  54  which is positioned around the motor shaft  34  driven by the motor  28 , this motor shaft  34  having herein a square shape with the opening in the first gear  32  being also square-shaped such that it rotates with the motor shaft  34 . This configuration further allows the first gear  32  to slide along the motor shaft  34 . The spring  54  is under compression under the first gear  32  and a circlip  56  is fixedly mounted around the motor shaft  34 , above the first gear  32 . Therefore, in a normal position, the spring  54  urges the first gear  32  upwardly against the circlip  56  and, in this position, the first gear  32  is disposed horizontally opposite the second gear  36  and is thus in meshed engagement therewith such that operation of the motor  28  causes the rotation of the first gear  32  by way of the motor shaft  34  and, in turn, the rotation of the second and third gears  36  and  38 , respectively, and the displacement of the arm  40  and of the window W. 
   If it becomes necessary to disengage the motor  28  from the arm  40  for allowing the window W to be opened or closed manually (again in the event of a power failure), one must first remove a small cap provided on a decorative cover  58  (see  FIG. 1 ) which conceals the motorized operator O. Then, a manual operator  60  can be used to manually open or close the window W. More particularly, the manual operator  60  comprises an elongated handle  62  defining, for instance, an hexagonal opening  64  at one end thereof, and a manual actuator  66  which is comprised of an upper cylindrical member  68  defining an upper hexagonal head  70  engageable through the hexagonal opening  64  of the handle  62  and a lower gear  72  which is mounted to the upper member  68  by way of its upper cylindrical section  73 . 
   Once the aforementioned cap has been removed from the cover  58 , the lower gear  72  of the manual operator  60  is introduced in the opening defined in the cover  58  and revealed by the removal of the cap. By doing so, the lower gear  72  will be aligned with the motor shaft  34  and, once the lower gear  72  becomes located around the upper end of the motor shaft  34 , a further lowering of the lower gear  72  along the motor shaft  34  will force the first gear  32  downwardly along the motor shaft  34  (as per arrows  80  in FIG.  4 ), against the spring force of spring  54 , thereby causing the unmeshing of the first gear  32  with the second gear  36 . At the end of the downward travel of the lower gear  72 , it lies horizontally opposite the second year  36  and, as the lower gear  72  is of similar dimensions to the first gear  32 , the lower gear  72  in that position meshes with the second gear  36 . As the lower gear  72  defines an inner opening such that it will be able to freely rotate around the motor shaft  34 , once the lower gear  72  meshes with the second gear, the motor shaft  34  is in fact disconnected from the second gear  36  and, in other words, the second and third gears  36  and  38  and the arm  40  are all disconnected from the motor  28 . 
   Furthermore, the upper member  68  of the manual actuator  66  includes an incorporated magnet (not shown) which is adapted to contact the upper end of the motor shaft  34  with the magnet force holding the manual actuator  66  and the motor shaft  34  together and compensating for the spring force of spring  54 ; in other words, the user does not need to continually press on the manual actuator  66  to keep its lower gear  72  in meshed engagement with the second gear  36  as the upward spring force of the spring  54  is compensated or overcome by the magnet force. 
   Then, the handle  62  is used to rotate the manual actuator  66  thereby causing its lower gear  72  to rotatably drive the second gear  36  and, in turn, the third gear  38  and the arm  40  for selectively opening or closing the window W. The manual actuator  66  can then be forced upwardly out of engagement with the motor shaft  34  and completely removed from the operator O before the aforementioned cap is repositioned onto the cover  58 . Once power has been reinstated, the window W can be operated normally, that is by way of the motorized operator O since, upon withdrawal of the manual actuator  66 , the spring  54  forced the first gear upwardly  32  against the circlip  56  and thus into engagement with the second gear  36 . 
   It is noted that arm  40  includes various components which can be adjusted (see, for instance, threaded rod  74  which threadably engages both yokes  76 ). The arm  40  is further adapted to be disconnected from the window W, for instance at either of the pinned ends of the two yokes  76 , to allow for a more pronounced manual opening of the window W, i.e. up to 90 degrees, to facilitate the cleaning of both the inner and outer surfaces of the window W. 
   It is also possible to use a humidity sensor on the outside of the window W to automatically cause the actuation of the motorized operator O in the event that it starts raining such as to automatically close the window W. 
   The above motorized operator O and its associated hardware, namely the limit switch  10  and the switch assembly  18  can all be generally retro-fitted onto an existing casement window C in replacement of its conventional crank arm and associated mechanism linking it to the window W. It is noted that both the main limit switch  10  and the switch assembly  18  are substantially small and can be installed without altering significantly the appearance of the casement window C. It is also proposed to incorporate the switch assembly  18  to the cover  58  which itself blends very well with the molding of the frame F of the casement window C. 
   It is noted that the adjustment for the end travel of the window W when using the motorized operator O is provided by the aforementioned threaded rod  74  of the arm  40 . Alternatively, there could be a means to make that adjustment at the level of the positions of the first and second switches  46  and  48  on the base plate  30 . Furthermore, the third gear  36  may preferably be provided with stops (not shown) to prevent excess manual operation which could bend or break the first and second switches  46  and  48 . 
   As mentioned hereinabove, although the switch assembly  18  is shown in  FIG. 1  on one of the vertical moldings of the frame F, it is preferably incorporated to the cover  58  located on the lower horizontal molding of the frame F.

Summary:
A motorized operator for opening and closing a window sash relative to a window frame via an arm mechanism connected to the window frame and being adapted to be installed in a cavity defined in the window frame. The operator comprises a motor, a drive axle rotated by the motor, and first and second gears in meshed engagement. The first gear is mounted on the drive axle, while the second gear is mounted to the arm mechanism such that motorized rotation of the first gear rotatably drives the second gear thereby causing the arm mechanism to pivot for opening and closing the window sash. A manual operator is adapted to disengage the first and second gears from one another while becoming engaged to the second gear for manually rotating the second gear and so manually operate the arm mechanism. The manual operator comprises a handle and a manual actuator which includes a sprocket. The manual actuator is engageable on the drive axle for selectively displacing the first gear along the drive axle and cause the latter to disengage from the second gear while the sprocket of the manual actuator becomes engaged to the second gear, whereby a rotation of the manual actuator by way of the handle causes rotation of the sprocket and of the second gear and thus also a pivot of the arm mechanism.