US 3440683 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
April 29, E. H- WOOD SASH CONTROL MECHANISM Filed July 17J 1967 INVENTQR @W4/E@ H W00@ HIIl wwwm- April 29, 1969 E. LL W OOD 3,440,683
SASH CONTROL MECHANISM Filed July 17, 1967 Sheet 3 of 2 INVENTOR 50W/12.0 Af. /4/00@ @B5/MQ@ 6%@ Arrow/5v5 United States Patent O U.S. Cl. 16--197 11 Claims ABSTRACT OF THE DISCLOSURE This disclosure relates to a window sash balance mechanism which is generally secured to the window frame or jamb, with the side members of the sash having a groove or channel formed therein to receive the sash balance mechanism. The mechanism contains a double block floating anchor that has a pair of pulleys which are supported by a pair of longitudinally offset shafts forming acute angles with the frame of the double block oating anchor. By forming the double block floating anchor in this manner, it is possible to construct it so that it will twist or rotate with the balance cord as it is lengthened or shortened through use, and the cords will not be in frictional engagement with each other. The channel, and floating and xed double blocks are constructed to permit the balance spring to be confined in close proximity to the interior of the channel.
This invention relates to the eld of window construction and more particularly to the eld of sash control mechanisms.
In constructing window sash balances in the past, one of the problems has been to nd a way to make the channel of a small cross-sectional area while permitting a double block to be used within the channel. Heretofore, where a metal tape or strap has been used, it has been possible to offset one pulley shaft longitudinally from the other such as shown in Patent 2,279,600. However, it will be found that when using a mechanism of this type, the tape frictionally engages itself due to the overlapping arrangement and this is even more pronounced where the pulleys of the block arrangements are of the same size. Because such an arrangement has a tendency to stick and bind and not provide a uniform frictional resistance, the structure has been found to present certain problems n the operation of the structure. For instance, the steel tapes or metal ribbons are more susceptible to breaking should there be any sharp bending of the ribbon such as at the point of attachment and thus an additional problem is created.
The present invention contemplates using a nylon cable with the xed and floating anchor block assemblies being formed from material such as nylon and by offsetting the pulleys in the oating block longitudinally and angularly, it is possible to make the block to be fitted within the confines of the channel which closely engages the spring mechanism. In other words, the channel member is constructed in such a manner that it is formed to restrain the movement of the spring in such a manner that it will slide out through the channel only at the ends.
It is, therefore, a general object of the present invention to provide an improved window sash balance assembly having the mechanism contained in a channel constructed 3,440,683 Patented Apr. 29, 1969 ice to constrain the movement of a sash balance spring in one axis only.
It is another object to provide a window sash balance assembly having a double block floating anchor assembly in which the shafts are longitudinally offset from each other to provide a block of improved construction.
It is still another object to provide a window sash balance assembly having a double -block floating anchor constructed with shafts forming equal acute angles with the frame yof the floating double block.
It is still another object of the present invention to provide a window sash balance assembly in which the double block floating anchor is formed of symmetrical members having pulleys exposed therethrough providing unobstructed travel for the cable used therewith.
It is yet another object to provide a window sash balance assembly having a channel member forming at least seven areas in close proximity to the spring used therewith to confine its lateral movement while permitting the spring to expand and contract.
These and other objects and advantages of the invention will more fully appear from the following description, made in connection with the accompanying drawings, wherein like reference characters refer to the same or similar parts throughout the several views, and in which:
FIG. 1 is a side elevational view showing the construction of the window sash balance from the channel open side;
FIG. 2 is a partial elevational section view of a window sash with the sash balance control secured to the window jamb and connected to the sash;
FIG. 3 is a partial plan section view of an upper and lower window sash taken along a plane immediately above the end of the balance;
FIG. 4 is an exploded perspective view of the xed anchor double block and securing tab member;
FIG. 5 is an exploded perspective view of the floating double block showing the symmetrical parts;
FIG. 6 is an elevational view of the restraining bracket for securing the symmetrical parts of the double block floating anchor;
FIG. 7 is a perspective view of a foot member used to secure the balance cable to the window sash;
FIG. 8 is an end elevational view of the assembled double block floating anchor showing the relative angle between the pulleys; and
FIG. 9 is a plan view of the channel member with the end plug removed to expose the coil spring enclosed thereby showing the spring confining portions of the channel.
Turning now primarily to FIG. l, there is found a .vindow sash balance assembly 10 which has an outer elongated channel member 11 confining the other working elements of the sash balance assembly. Situated at the upper end of channel 11, is an end plug 12 which is formed from suitable material such as nylon and has a reduced end portion 13- which conforms to the inner dimensions of the channel member 11 to produce a snug fit. A hole 14 is formed in end plug 12. A spring hanger 15 is secured in end plug 12 by a suitable means such as forming a head portion on the spring hanger which is larger than the body when securing it in a slot in end plug 12 or through some other suitable means, the spring hanger also having a hole formed therein to coincide with hole 14 and end plug 12. Spring hanger l5 has three holes 16, 17, and 18 formed therein to receive a hook portion 20 of a coil spring 21. In other words, spring 21 may have its tension adjusted by changing the position of hook member 20 in holes 16, 17, or 18. The other end of spring 21 is constructed in a hook form 22 and is connected to a wire bracket element 23 which is secured about a double block floating anchor 24. At the other end of channel 11, is a double block fixed anchor 25 which is also snugly fitted within the internal dimensions of channel 11 and extends into channel 11 towards floating block 24. Floating block 24 contains a pair of pulleys 26 and 27. A pair of pulleys 30 and 31 (see FIG. 4) are secured on a shaft 32. A cable 33 is secured to one end of bracket element 23 and is alternately passed over pulleys 31, 26, 30, 27, and emerges through the end of double block fixed anchor 2S where it passes through a slot 34 formed in a foot member 35 (see FIG. 7) and the cord is secured in place -by tying a knot 36 in the end thereof.
As seen in the exploded view of FIG. and end view of FIG. 8, the double block floating anchor 24 is comprised of a pair of symmetrical frame members 40 and 41, each of which have a shaft 42 and 43 respectively which when mated together have their shafts engage a pair of bores 44 and 45 respectively. That is, when members 40 and 41 are held in place by bracket element 23, the two portions form a complete assembly. It will be noted that shafts 42 and 43 are inclined in opposite directions from the outer edge of symmetrical members 40 and 41 at an 'angle of approximately 17 degrees each so that the angle between the inner flanges of pulleys 26 and 27 is approximately 34 degrees. It will, of course, be recognized that the inner confines of members 40 and 41 are arranged so that cable 33 will not be permitted to jump the flanges of pulleys 26 and 27. Therefore when joined with bracket element 23, the double block floating -anchor 24 forms a secure and rigid member. Situated along the edges of members 40 and 41, are a pair of grooves 46 and 47 respectively which engage bracket element 23 and thus prevent it from becoming disengaged after being snapped in place. One end of bracket element 23 contains a slight dimple 50 which is formed therein to allow cord 33 to be secured thereto by tying a knot in the end of the cord. The other end of bracket element 23 has a pair of loops 51 and 52 formed therein to engage hook portion 22 of spring 21.
Double block fixed anchor 25 is substantially of a hollow square or rectangular cross section having an elongated side or -wall 53 and having a pair of sidewalls 54 and 55 communicating therewith which have scalloped edges that terminate at approximately the mid-distance of wall 53 which cooperate with the flanges of pulleys 31 and 30 to aid in restraining cable 33 from becoming disengaged with the pulleys. Another side or wall 56 opposite side 53 joins sides 54 and 55 to complete the hollow rectangular or square structure, the end of wall 56 terminating at approximately the same point as sides 54 and 55 and forming a clearance so that pulleys 31 and 30 may be slipped over shaft 32 which is formed integrally with wall 53. The end of shaft 32 contains a notched portion 57 which engages an axle hanger bracket 58 which is generally formed of a spring-steel wire construction and is shown formed in an inverted U-shape, with a pair of extending leg portions 59 and 60 engaging a pair of notched portions (only one of which is shown and is designated 61) formed in double block fixed anchor 25. A hole 62 is formed in shaft 57 an-d extends partially through the inner surface of wall 53 of fixed anchor member 25 to `allow cord 33 to be passed therethrough and extend outwardly through the bottom thereof. In other words, hole 62 is formed along the longitudinal dimension of wall 53, passing through shaft 32. Also shown in FIG. 4, is the end portion of a retaining tab 63 which is secured to a window jamb to engage the lower portion of the double block fixed anchor and hold it in place.
Because of the Offset and angular relationship of shafts 42 and `43 in double block floating anchor 24, it is possible to construct channel member 11 in such a manner that it closely confines the movement of spring 21 but allows sufficient room for the floating block to work within the channel. FIG. 9 shows the construction of channel 11 where the channel is formed of a somewhat square U- shaped construction where the outside dimensions are substantially equal, and in the present construction are approximately 0.550 inch on a side. Formed along a pair of lines which extend through what would be the closed corners of the channel and intersecting at the center thereof, are a pair of depressed ridges 64 and 65 which have a radius of approximately 0.032 inch, having their centers extending inwardly approximately 0.082 inch from the right-angle corners where the sides intersect. Another pair of depressed ridges 66 and 67 are formed at the rearward or open portion of channel 11 and have a radius of approximately 0.32 inch. The material preferably has a thickness of approximately 0.25 inch and thus a spring of approximately 1%2 of an inch may be confined within the channel member. It will thus be seen that the spring is restrained from lateral movement in each direction since the ends of channel member 11 which are open, are secured to the window jamb as will be presently described. There are, therefore, some seven areas of channel member 11 which form a close and intimate relationship with spring 21 to allow it to be expanded and contracted within the guide member while restraining its lateral movement.
As shown in FIG. 2, an upper sash 70 is shown in which the right-edge portion is shown sectioned and in which a channel or groove 71 is formed. A window jamb stop member 72 is shown situated behind channel 11 which is also shown in partial cross section to expose the internal construction. Channel member 11 is secured to a jamb frame member 73 by a suitable means such as wood screws 74 passing through hole 14 of end plug 12, and at the bottom thereof, tab 63 is secured to jamb member 73 by a suitable means such as a wood screw 75. Foot member 35 is secured in groove or channel 71 and is shaped generally to t the width of the channel so that there is a snug fit. Therefore, as window sash 70 is moved downwardly, cable 33 is drawn downwardly with foot member 35 and double block floating anchor 24 is drawn towards fixed anchor 25 with double block 24 rotating or twisting to follow the cable since the pulleys of double block members 24 and 25 are substantially at right angles to each other when window sash 70 is in its upward position where spring 21 is contracted.
In FIG. 3, a double-hung window partial section is shown in which window sash 70 is shown in one position and another window sash 76 is shjown having another groove or channel 77 formed therein to 1permit another channel member 11 to be secured to window jamb member 73. While in the one instance, when sash member 70 is in the lower position of a lower sash member, spring 71 will be extended to its furthest position and sash member 76 will be extended to the upper sash position where another spring 21 will be contracted to its shortest position.
Thus it will be seen that by offsetting the shafts of the double block floating anchor and orienting them at acute angles with respect to the frames carrying the shafts supporting them, it is possible to thread the cable through the pulleys in such a manner that the cables do not frictionally bind each other and in so doing, it is possible to construct the entire mechanism in such a manner that only a small groove or channel is necessary in the sash members. Using an arrangement such as this, a rather constant force will be required to move the spring from its contracted to extended position providing a smooth operation for the window unit.
It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the parts without departing from the scope of the invention which consists of the matter shown and described herein and set forth in the appended claims.
What is claimed is:
1. In a window balance assembly having an elongated channel unit with a coil spring positioned therein and anchored at one extremity to one end of the channel unit, the improvement comprising:
(a) a double block floating anchor connected to the other extremity of the coil spring and positioned within the channel unit, said double block having an enclosed rectangularly-shaped frame and a pair of transversely-oriented shafts extending across said frame near each"`end thereof, said shafts forming equal acute angles with said frame, each of said shafts supporting a pulley rotatable thereon;
(b) a double block fixed anchor secured to the other end of the channel unit, said double block fixed anchor having a frame formed in a substantially hollow rectangular cross section with atleast two opposing sidewalls cut away adjacent one end thereof to expose the other two walls, one of said other two walls having a tkansversely-oriented shaft extending inwardly therefrom to engage the opposite wall, said shaft supportinga pair of pulleys thereon and being oriented at substantially right angles to said shafts of said floating anchor;
(c) a balance cord connected at one end to said double block floating anchor and wound alternately around the pulleys of said double block fixed, and floating anchors,'with the free end of said cord extending through vsaid substantially hollow rectangular cross section, said shafts of said double block floating anchor rotating towards and away from align- .ment with saidshaft of said fixed anchor as said cord is drawn away from and returned towards said anchors;
(d) and a foot member secured to said free end of said balance cord, said foot member adapted to be connected to the edge of a window sash.
2. The invention as set forth in claim 1 wherein said rectangularly-shaped frame of said double block floating anchor includes:
(e) a pair of symmetrical members communicating with each other, one end of each of said symmetrical members having said shafts formed thereon and the other end of each of said symmetrical members having a cooperating bore formed therein to receive said shafts;
(f) and a bracket element securing said symmetrical members together.
3. The invention asset forth in claim 1 wherein:
(g) said shafts off' said double block floating anchor are oriented so that the portions of said pulleys exposed beyond the edges of said frame are offset and the travel of said cable passing over said pulleys is unobstructed.
4. The invention as set forth in claim 1 wherein:
(h) said frame of said double block fixed anchor has three sidewalls cut away, two of said sidewalls having depending edges with a scallopsed border, the points of which cooperate with the outer edges of said pulleys to restrain said balance cord from disengaging said pulleys, :and a support bracket extending into said hollow portion of said frame to support the end of said shaft.
5. The invention as set forth in claim 1 wherein:
(i) said shaft of said fixed anchor has a hole formed diametrically therein adjacent one end thereof exltending towards the coil spring of the assembly, said hole formed in said shaft also extending partially into one of said other two walls to provide alignment for said cord connected to said `foot member.
6. The invention as set forth in claim S wherein:
(j) said frame of said fixed anchor having said substantially hollow rectangular cross section constructed and arranged to receive a tab extending thereinto engaging said wall opposite said wall having said hole partially formed therein.
7. A window balance assembly comprising:
(a) an elongated coil spring;
(b) an elongated U-shaped channel member having an open side, said spring fitting snugly within said channel member and having one end thereof anchored to one end of said channel member, said channel member being constructed and arranged to be secured to the side of a window jamb;
(c) a double block floating anchor connected to the other extremity of said coil spring, said double block having an enclosed rectangularly-shaped frame formed of a pair of symmetrical members communicating with each other Iand constructed and arranged to be rotatable in said channel member, a pair of transversely-oriented shafts extending across said rectangularly-shaped frame near each end thereof, said shafts forming equal acute angles with said frame and each supporting a pulley for rotation so that said pulleys are oriented in an offset alignment from each other;
(d) a double block fixed anchor secured within the other end of said channel member, said double block fixed anchor having a frame formed in a substantially hollow rectangular cross section with three sidewalls cut away adjacent t-he portion extending into said channel member to expose the other wall, said other wall having a transversely-oriented shaft extending inwardly therefrom, said shaft supporting a pair of pulleys having an outside diameter substantially equal to the width of said frame, said shaft having the end thereof supported against movement with respect to said frame and being oriented at substantially right angles to said shafts of said floating anchor;
(e) a balance cord connected at one end to said double block floating anchor and wound alternately around the pulleys of said double block fixed and floating anchors, with the free end of said cord extending through said substantially hollow rectangular cross section, said double `block floating anchor rotating about a longitudinal axis extending through said channel member as said cord is drawn away from and returned towards said anchors;
(f) 1and a foot member secured to said free end of said balance cord, said foot member adapted to be connected to the edge of la window sash.
8. The invention as set forth in claim 7 including:
(g) a bracket element constructed and arranged to encompass said rectangularly-shaped frame longitudinally, one end of said bracket element engaging said coil spring 'and the other end thereof engaging said cable, said pair of symmetrical members forming said frame having grooves formed longitudinally on the outside thereof engaging said bracket element against movement.
9. The invention as set forth in claim 7 wherein said elongated U-shaped channel member has a cross section in which the three walls thereof are substantially of equal width with a pair of depressions formed therein at the corners where said walls join, said depressions being formed inwardly along lines intersecting said corners and the center of said cross section, the two walls forming the legs of said channel member having another pair of deto form at least seven areas in close proximity to said elonall of said depressions being of substantially equal radius to form at least seven areas in close proximity to said elongated coil spring and confine its lateral movement in all directions while permitting said spring to expand and contract in said channel member.
10. The invention as set forth in claim 7 wherein said equal :acute angles formed by said shafts with respect to said frame of said double block oating anchor is substantially 17 degrees.
11. The invention as set forth in claim 7 wherein said equal acute angles formed by said shafts with respect to said frame of said double block oating anchor is sufficient to cause the innermost flanges of said pulleys sup- References Cited UNITED STATES PATENTS Kreuscher 16-197 Teggelaar 16-197 XR Dinsmore 16-197 Prosser 16-197 Fanello et a1 16-197 XR Dinsmore 16-197 XR ported on said shafts to be no closer in longitudinal align- 10 BOBBY R. GAY, Primary Examiner.
J. L. KOHNEN, Assistant Examiner.
ment than having the same longitudinal axis.
U.S. DEPARTMENT OF COMMERCE PATENT OFFICE Washington,D.C. 20231 UNITED STATES 'PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,440,683 April 29, 1969 Edward H Wood lt is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:
In the heading to the printed specification, lines 3 and 4, "The D. J, Densmore Company" should read The D'. J. Dinsmore Company Column 5, line 60, ca1lopsed" should read scalloped Column 6, line 69, cancel "to form at least seven areas in close proximity to said elon" and insert pressions adjacent the open side of said channel member,
Si'gned and sealed this 14th day of April 1970.
WILLIANI E. SCHUYLER, IR.
Commissioner of Patents Edward M. Fletcher, Jr.