Abstract:
A pivotable window sash assembly includes a pivot bar which engages a balance shoe for holding the sash to a master frame. The shoe has a recess in which a locking member is rotatably mounted. The locking member includes an exposed keyway which is selectively aligned with at least one slot in the shoe located at the recess. The pivot bar has an arm which functions as a key for fitting in the keyway and has at least one projection extending outwardly from the arm for fitting in each slot when the slot and keyway are aligned.

Description:
BACKGROUND OF INVENTION 
     Various types of window assemblies exist including a pivotable window sash assembly which includes a tilt window sash mounted to a channeled window frame. In use, the window sash would move up and down and would also be capable of pivoting outwardly with respect to the window frame for access, for example, in cleaning the window. A conventional mechanism for accomplishing these movements is to include a balance shoe which is mounted for slidable movement in a channel in the window frame. A pivot bar is secured to the window sash and is engaged with the balance shoe. In this manner the balance shoe moves in the channel which acts as a track during the up and down movement of the window sash. In one form of balance shoe a freely mounted sleeve is included in the balance shoe with a slot in the sleeve engaged by an arm on the pivot bar. As a result, it is possible to rotate the window sash because of the pivotal connection effected by the sleeve being able to freely pivot within its balance shoe. 
     U.S. Pat. Nos. 4,930,254, 5,069,001 and 5,237,775 reflect various prior art approaches for mounting a pivot bar to a balance shoe and various details of pivotable window sash assemblies. 
     SUMMARY OF INVENTION 
     An object of this invention is to provide a pivotable window bar assembly which includes a pivot bar for holding the sash to a master frame. 
     A further object of this invention is to provide such a pivot bar which may be effectively mounted to a balance shoe to keep the sash tight and to keep the master frame plumb. 
     In accordance with this invention the balance shoe which is slidably mounted in the channel of a window frame includes a recess in which is rotatably mounted a locking member. The locking member has an exposed keyway. At least one slot is provided at the recess for selective alignment with the keyway. The pivot bar has an arm which functions as a key for fitting in the keyway. The arm also includes a projection extending outwardly from the arm to fit in the slot only when the slot and keyway are aligned. 
     In a preferred practice of this invention two slots are provided at the recess and two projections, each in the form of a pin, is provided on the arm. The keyway further includes an extension which fits in a channel form in the arm. 
    
    
     THE DRAWINGS 
     FIG. 1 is a fragmental front elevational view showing a portion of a pivotable window sash assembly in accordance with this invention; 
     FIG. 2 is a cross-sectional view taken through FIG. 1 along the line 2--2; 
     FIG. 3 is a view similar to FIG. 1 showing the position of the window sash assembly structure rotated 90°; 
     FIG. 4 is a cross-sectional view taken through FIG. 3 along the line 4--4; 
     FIG. 5 is a side elevational view showing the pivot bar mounted in the balance shoe; 
     FIG. 6 is a cross-sectional view taken through FIG. 1 along the line 6--6; 
     FIG. 7 is a left end elevational view of a portion of the assembly shown in FIGS. 1-6; 
     FIG. 8 is a side elevational view of the pivot bar shown in FIGS. 1-7; 
     FIG. 9 is an end elevational view of the pivot bar shown in FIG. 8; 
     FIG. 10 is a top plan view of the pivot bar shown in FIGS. 8-9; 
     FIG. 11 is a bottom plan view of the pivot bar shown in FIGS. 8-10; 
     FIG. 12 is a front elevational view of the balance shoe shown in FIGS. 1-7 when the keyway and slots are out of alignment; 
     FIG. 13 is a bottom plan view of the balance shoe shown in FIG. 12; 
     FIG. 14 is a front elevational view of the balance shoe shown in FIGS. 12-13 when the keyway and slots are in alignment; and 
     FIG. 15 is a bottom plan view of the balance shoe shown in FIG. 14. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 illustrates a portion of a pivotable window sash assembly in accordance with this invention. Most of the components of the assembly 10 may be of known construction wherein, for example, a main frame 12 is provided made of extruded PVC. Frame 12 is, for example, a master frame. The window sash 14 may also be an extruded PVC lift rail. Main frame 12 includes a plurality of channels. One of the channels is channel 16 formed by a pair of flanges 18 which extend over and are parallel to the base wall 20. This channel serves as a track for a modification of a known balance shoe 21. Balance shoe 21 would slide in track 16 under the urging or against the force of, for example, springs 24. Felt strips 26 are mounted to a wall of window sash 12. See FIG. 5 
     Lift rail window sash 14 contains a modification of a known pivot bar 22 which is inserted into the hollow window sash 14 into opening 32. Pivot bar 22 includes an extension 30 peripherally along three sides thereof to act as a stop member and prevent pivot bar 22 from being completely inserted into the hollow opening 32 of sash 14. Extension 30 is clearly shown in FIGS. 8 and 1011. 
     Exemplary construction of known pivotable window sash assemblies are found in U.S. Pat. Nos. 4,930,254, 5,069,001 and 5,237,775, the details of which are incorporated herein by reference thereto. 
     As shown in FIGS. 8-11 pivot bar 22 includes a pair of projections 36,36 in the form of pins which extend inwardly from the outer edge 38 of arm 34. Arm 34 has a channel 40 in its upper surface as shown in FIG. 10 and as also shown in FIG. 7. The opposite end of pivot bar 22 has a downwardly sloping surface 42. The bottom wall of pivot bar 22 includes a locking projection 44 which extends into an opening 46 as shown in FIG. 1 and as described in greater detail in co-pending application Ser. No. 08/641,433 filed May 1, 1996, in the names of Colin L. Slocomb and Edward J. Subliskey, the details of which are incorporated herein by reference thereto. 
     FIGS. 12-15 show the details of the balance shoe 21. As shown therein balance shoe 21 includes a U-shaped housing 48 having a wall 50 disposed toward pivot bar 22. Wall 50 includes an opening or recess 52 in which is mounted a locking member 54. Locking member 54 is in the form of a disk body having a boss 56 which extends through opening 52 so that the locking member or disk 54 may freely rotate in the housing 48. Boss 56 includes a recess forming a keyway 58 having generally the same shape but slightly larger than pivot bar arm 34. Keyway 58 includes pairs of end shoulders 60 with a single projection 62 formed along one side of and extending into the keyway. A pair of slots 64 are formed in housing wall 50 aligned with each other and communicate with the recess 52. Thus, the keyway 58 may be selectively aligned with the slots 64,64 as shown in FIG. 14 or selectively rotated out of alignment with the slots as shown in FIG. 12. 
     A plate 66 is mounted in the open end of U-shaped housing 48 opposite wall 50. Plate 66 is shown in FIG. 3 to be fixedly mounted or anchored at its end 68. The opposite end 70 of plate 66, however, may move outwardly from housing 48 under the influence of rotating disk 54 as also shown in FIG. 3. End 70 includes a pair of peripheral flanges 72 along each side thereof which fit within the U-shaped housing 48. See FIGS. 13 and 15. A tapered tongue 74 extends from the central portion of plate 66. Tongue 74 may be selectively engaged in a correspondingly shaped notch 76 in locking member or disk 54. 
     FIGS. 12-13 show the relative position of plate 66 and disk 54 when the keyway 58 is completely out of alignment with slots 64. As shown therein, tongue 72 is engaged in notch 74 to maintain the disk 54 in its non-aligned position. Because of the resilient nature of plate 66 tongue 70 is urged to remain in engagement in notch 74 thus helping to hold the components against any further movement unless a positive force is applied. This condition shown in FIGS. 12 and 13 represents the sash 14 being moved to its closed position for closing the window and thus helping to maintain the window closed. 
     In order to assemble the various components pivot bar 22 is installed into opening 32 of sash 14 at, for example, the manufacturing site. Extension 30 limits the degree to which the pivot bar can be inserted into the sash 14. If desired, the utilization of the locking projection 44 may help securely mount the pivot bar to the sash, although such locking projection is not necessary for the practice of the invention. Balance shoe 21 is also installed in main frame 12 during initial assembly. Sash 14 is positioned so that the pins 36,36 extending from arm 34 of pivot bar 22 are aligned with slots 64,64 and boss 56 is rotated to align keyway 58 with slots 64,64. Pivot bar 22 is then pushed toward balance shoe 21 to engage arm 34 into the balance shoe 21 and thus lock the pivot bar 22 to the balance shoe 21. This is the condition of balance shoe 21 shown in FIGS. 14-15 as well as, for example, FIGS. 3-4. This would also represent sash 14 being in a window-open condition with respect to main frame 12. 
     After the window assembly has been mounted in place pivot bar 22 remains engaged with balance shoe 21 thereby permitting sash 14 to be rotated or pivoted from a completely closed condition where the locking components are shown in FIGS. 12 and 13 with tongue 74 engaged in notch 76 to an open position such as shown in FIGS. 3-4 and 14-15. During the rotation of sash 14 from the completely closed position the inclined walls of notch 76 function as a cam with respect to the inclined walls of tongue 74 to overcome the resilient engagement of the tongue in the notch and thus permit the boss 56 to be rotated to a condition where the tongue 74 rests on the upper edge of the boss as shown in FIG. 14 rather than in the notch. During this open condition of sash 14, pins 36,36 are rotated away from slots 64,64 and are disposed under portions of wall 50 to effectively maintain engagement between pivot bar 22 and balance shoe 21. 
     It is to be understood that the above description and the drawings relate to the preferred practice of the invention. The invention, however, may be practiced in other manners. For example, instead of having pins 36,36 integral with arm 34, arm 34 could have a hole completely therethrough with a shaft or other structural member in the hole and extending outwardly of the hole to perform the function of the pins. 
     In addition, although in the preferred practice a pair of aligned slots are provided for selective alignment with the keyway, other arrangements may be used. Thus the invention may be practiced with only one slot or with more complicated aligning structure, such as a keyway having an additional diverging recess for alignment for yet still another slot. Similarly, while the invention is preferably practiced by utilizing pins for engagement in the slots, other types of projections or structure may be used. The intent is to provide complementary projections which fit in complementary openings with respect to the pivot bar and balance shoe.