Window jamb liner

A jamb liner for a window assembly permits tilt-takeout sashes to be assembled to form a standard window assembly without tilt or takeout capabilities. The liner has an extruded body with a pair of channels for engaging the sashes. The channels are interconnected by two webs. One of the webs forms adjacent portions of sash runs, and the other web forms a bow-shaped spring for urging the channels against the sashes.

BACKGROUND OF INVENTION 
Standard window assemblies with double sash runs are made with sashes that 
cannot be removed from the sash runs without disassembling the window. 
However, so-called tilt-takeout window assemblies that permit sash removal 
are also in widespread use. 
Generally, both the window sashes and jamb liners forming the sash runs are 
designed much differently for use with either standard or tilt-takeout 
window assemblies. Since both types of assemblies are widely used, window 
manufacturers are required to stock inventories of the different sashes 
and jamb liners. Of the two, the sashes are much more costly to stock in 
inventory than the jamb liners. 
Accordingly, a number of attempts have been made to make both standard and 
tilt-takeout sashes compatible with one or the other window assembly 
types. For example, U.S. Pat. No. 3,724,131 to Schnormeier discloses 
special jamb liners for adapting standard window sashes to tilt-takeout 
window assemblies. However, Schnormeier's attempt requires costly slots be 
formed along jambs to receive the special liners. 
Other jamb liners have been designed to adapt tilt-takeout sashes to 
standard window assemblies. These other liners have also not been very 
successful because they have not provided appropriate tracking for the 
tilt-takeout sashes. The liners are not well reinforced, and pairs of 
springs built into the liners for urging the liners against the sashes 
tend to warp the liners away from jambs along portions of sash runs not 
currently occupied by the sashes. Ordinarily, only one or the other of the 
springs is compressed by one of the sashes along most of the jamb liner 
length. The other spring is free to urge an adjacent portion of the liner 
away from the jamb. 
SUMMARY OF INVENTION 
Our invention is an improved jamb liner for mounting tilt-takeout window 
sashes between jambs to form standard window assemblies. The improved jamb 
liner is made with a single spring that reduces tendencies of the sashes 
to warp the liner, and the liner is configured to exhibit increased 
torsional rigidity to resist any residual warping that might otherwise 
occur. Together, the single spring and rigid configuration provide better 
tracking for the sashes. 
The liner can be made as an extruded body having two pairs of tracks for 
engaging respective sash plows of upper and lower sashes. The tracks of 
both pairs are joined by respective channels that can be used to house 
sash balances. The channels are joined by two webs. One of the webs forms 
separate portions of sash runs for the respective upper and lower sashes, 
and the other web forms a spring for urging the channels away from a jamb 
against the respective sashes. 
The spring is bow-shaped between two ends; and respective brackets, also 
formed in the other web, connect the two spring ends to the respective 
channels. The single bow-shaped spring is used to urge both channels 
against their respective sashes. Accordingly, to the extent the spring is 
compressed along a portion of its length through either channel by one of 
the sashes, less spring travel remains to urge the other channel away from 
the jamb along a corresponding portion of the spring length. The brackets 
connecting the spring to the channels also function as stops for limiting 
compression of the spring. 
The channels are also connected to marginal flanges by respective pairs of 
webs. One of the webs of each of these pairs of webs forms a remaining 
portion of each of the sash runs. The other of the webs connecting the 
marginal flanges to respective channels reinforces the connection and 
contributes to overall torsional rigidity of the liner.

DETAILED DESCRIPTION 
One example of our jamb liner for mounting tilt-takeout sashes in a 
standard window assembly is shown in the drawing figures. The window 
assembly 10 includes upper sash 12 and lower sash 14 that are particularly 
designed for use in tilt-takeout window assemblies. The two sashes 12 and 
14 are movable along respective upper and lower sash runs 16 and 18 that 
are formed in our jamb liner 20. Preferably, our jamb liner 20 is made as 
an extrusion of resin material that is cut to desired length. 
The upper and lower sashes 12 and 14, as shown in FIG. 2, are formed with 
respective shallow plows 22 and 24 that are engaged by respective pairs of 
tracks 26, 28 and 30, 32. The respective pairs of tracks are formed on 
ends of U-shaped channels 34 and 36 that provide housings for sash 
balances (not shown). The two channels 34 and 36 are interconnected by two 
webs 38 and 40. One web 38 of the two webs 38 and 40 forms adjacent 
portions of the sash runs 16 and 18. The other web 40 forms a bow-shaped 
spring 42 that urges the channels 34 and 36 apart from jamb 44 toward the 
respective sashes 12 and 14. The bow-shaped spring 42 exerts a 
substantially constant force on the sashes 12 and 14 throughout its length 
of compression against the jamb 44. 
Brackets 46 and 48 are also formed by the other web 40 and join respective 
ends 50 and 52 of the spring 42 to the channels 34 and 36. The brackets 46 
and 48 are shaped to function as respective stops for limiting compression 
of spring 42 and for establishing a minimum clearance between the channels 
34 and 36 and the jamb 44. 
The channels 34 and 36 are also connected to respective marginal flanges 54 
and 56 by pairs of webs 58, 60 and 62, 64. One of the webs 58 and 62 of 
each pair forms a remaining portion of one of the sash runs 16 and 18. The 
other of the webs 60 and 64 of each pair provides reinforcement for 
holding the sashes 12 and 14 within the respective sash runs 16 and 18. 
The marginal flanges 54 and 56 are supported within the window assembly 10 
by strips 66 and 68 that are attached to jamb 44. 
The webs 58, 60, 62, and 64 joining the marginal flanges 54 and 56 to the 
channels 34 and 36 cooperate together with the webs 38 and 40 to provide 
our jamb liner with considerable torsional rigidity. Both channels 34 and 
36 are urged into a tight sealing engagement with the respective sashes 12 
and 14 by a single spring 42 that also seals our liner 20 to the jamb 44. 
Compression of the spring 42 by engagement of either channel 34 or 36 with 
one of the respective sashes 12 and 14 reduces any remaining travel of the 
spring 42 for urging the other channel away from the jamb 44. The brackets 
48 and 50 are preferably right angled to further resist any warping of our 
liner when the spring 42 is fully compressed.