CA1043247A - Window shade support roller and method of assembling - Google Patents

Abstract

ABSTRACT
A window shade support roller having an improved spring motor construction and method of manufacture includes a spring retaining structure which holds a driving spring and a spear structure having an integral spear. The spear structure and the spring retaining structure cooperate together, and with a ball, to form a ball clutch mechanism.
The spring retaining structure has ball-receiving recesses with canting floors which simplify assembly. Assembly steps include inserting balls into the spring retaining structure, inserting the spear structure into the spring retaining structure, inserting a dowel into the spear structure, po-sitioning a spring around the dowel, and inserting one end of such spring between portions of the spring retaining structure, which uniquely capture and retain the end without ether securement, for torsional winding of the spring.

Description

~43~2~7 BACKGROUND OF THE INVENTION
I. Field of the Invention.
This invention relates to window shade support apparatus and a method for manufacturing the apparatus.
More particularly, the in~ention relates to an improved and simplified shade roller spring motor assembly, in which the drive spring is connected through a ball clutch to a spear by means of a greatly simplified apparatus and method of fabricating ~he assembly.
II. Background. --Window shade support apparatus including a motor -drive spring connected to a spear through a ball clutch is known in the prior art. Typically, the end of the drive spring remote from the spear is non-rotationally fixed in ;
lS the far end o a dowel o~er which the spring is telescoped.
The dowel ls usually attached to a spear which in use is non-rotationally received by a mounting bracket. The end o the drive spring nearest the spear is connected to a TO~
tating portion of the shade roller apparatus. Typically, -numerous components have been required to asse~ble the spring motor and implement its connection of the drive spring to the rotating portion, as well as to form the clutching -:
a~rangement between the rotating portion and the non-rotating spear, to enclose the spear and the clutching apparatus, and to attach a dowel to the spear. Each of these components must be separately fabricated and handled, and then labor-iously assembled into the completed product.
Por example, U. S. Patent No. 659,584 issued to ;~
. C. Cordes on October 9, 1900 teaches a spring shade roller having a shat, a collar with pockets, a disc with a recess, ;~
a cap and securing means for the cap. The disc has lugs

-2- ~ ;
: ... - ~
,`` ;''.'' :' ~4~247 1 which are attached to the end of the spring drive nearest the spear. It can be appreciated that a reduction in the number of pieces required to fabricate a shade support and a corresponding simplification of fabrication would be de-sirable. Further, improving the securing means for the spear end of the driving coil to simplify fabrication is desirable.
U. S. Patent No. 375,986 issued to G. T. Briggs on January 3, 1888 teaches a spindle with a tapering ferrule and with an annular groove or channel for receiving the end nearest the spear of a coiled driving spring~ Similarly, U. S. Patent No. 1,329,992 issued to A. R. Nelson et al on Pebruary 3, 1920 and U. S. Patent No. 1,803,042 issued to T. B, Thurman on April 28, 1931 teach a drive spring coil slipped over a spindle with no inward radial compressive re-taining force on the spring. It would be desirable to have a positi~e compressive force on the drive spring to better secure the spring rom turning on the spindle or from slipping of the spindle. Additionally, the aforementioned patcnts teach abricating the shade support roller using a multitude of parts such as sleeves, tubes, shaftsJ supporting brackets, nail like protrusions, washerx and caps. Again, it would be desirable ~o reduce ~he cost of manufacture by reducing the number of parts and simplifying the assembly process.
U. S. Patent 3,763,916 issued to R. C. Gossling on October 9, 1973 teaches a window shade motor which includes an allegedly improved connection of the spear end of the drive spring to a rotating portion of the shade roller. As before, the spring is slipped over a spindle. However, in addition, the drive spring includes a bent portion near its end which engages a recess in a bodiy element of the window shade motor.
The end of the drive spring, just beyond the bent portion,

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1 extends into and engages the inside o~ the roller wall.
Accordingly, the inside of the roller wall applies a loading force to the end of the bent portion to keep the ~ent portion in the recess. It would be desirable to more evenly distri- ~ ~
bute any compressive force over the secured end portion of -the driving spring to better retain the driving spring.
Further, it would be desirable to simpli~y the apparatus and fabrication of the window shade support.
It is an objeet of this invention to simplify the apparatus o a shade support assembly and to reduce the num-ber o~ parts in such an assembly.
It is a further object of this invention to simplify the manufacturing process used in window shade support roller assembly, thereby reducing the time r0quired to assemble the support assembly and reducing the labor and expense required by manufacture.
It is thus a major objective of this invention to provide a new ty~ o~ shade roller construction having greatly improved simplicity o~ structure, durability, and economy o manufacture, together with a new method o~ manu-facturing such an assembly.
SU~ RY OF THE INVENTION
To these and other ends, apparatus and fabrica-tion of a shade roller assembly in accordance with an embodi-ment o~ this invention includes a spring-retaining structure having ball-retaining recesses with canted ~loors, a spear structure, balls ~or a ball clutch, a spring support dowel, a drive spring and an outer tube. The spring-retaining ;
structure has a central barrel with resilient circumferen-tially spaced spring-gripping lugs projecting parallel to the ;~ ;~
axis of the central barrel and radially spaced outwardly from

-4-1~43Z47 l the barrel. The spear structure has an integral spear and a central barrel smaller in diameter than the barrel of the spring retaining structure and insertable therethrough to join such two parts together. In so doing, the ball clutch is also assembled, since each of these parts defines a mu-tually cooperating portion of the clutch, as explained more ~ -fully hereinafter.
In the assembly process made possible by the invention9 the balls are placed in the ball retaining re-cesses of the spring retaining structure. This can be done efficiently and positively because the canted floor allows each ball to rest partially against a side wall of the recess, thus preventing the balls from rolling out of their ball retaining recesses.
In another operation (which may optionally pre-ceed ball placement), the barrel of the spear structure is inserted lnto the barrel of the spring retaining structure and snapped into place. Slots in the barrel of the spear structure together with its structural flexibility permit compression, or circumferential contraction, of the spear structure barrel when being inserted in~o the spring-retaining structure. Flanges at the end of the spear structure barrel pass through the sprinK-retaining structure and snap out to positively engage the end of the spring retaining structure barrel, to thereby couple the two structures securely to-gether.
In a third operation, the spring support dowel is inserted into and secured within the central opening of ,~ the spear structure barrel. As a result, the dowel is secured against rotation and is able to torsionally wind the spring, and the dowel also prevents the spear structure from being '~
,, . ''" ' ~ 3Z47 1 compressed OT con~racted to permit withdrawal of the spring retaining structure. Accordingly, with the end flanges of ~ ~-the spear structure firmly indexed behind the spring-retain-ing structure, the two pieces are securely joined.
In a fourth operation, the coil-type drive spring is telescoped over the spring support dowel and its leading end is inserted between the barrel and spring-compression lugs of the spring retaining structure. As a result, this end of the spring is securely retained from rotation and from axial withdrawal.
In a fifth operation, a window shade support tube is telescoped over the spring and over the compression lugs of the spring-retaining structure. Typically, the window shade is attached to the tube. The tube further com-presses or annularly contracts the compression lugs, thereby ~ ~ -even further securing the spring. The end of the tube is abutted against an edge of the spring-retaining structure to prevent relative lateral movement o the tube.
An assembly in accordance with a preferred embodiment of this invention is particularly advan~ageous because of the relativel~ few parts required to fabricate the assembly. The abrication of the assembly is advantageous because of the relatively few operations required and of the simplicity and rapidity with which the operations can be ~5 correctly accomplished. ~
DRAWINGS - ;
Fig. 1 is a side elevational view of a spear structure in accordance with an embodiment of this invention~
Pig. 2 is a side elevational view of spring-re~aining structure and a frag~entary portion of a spring support dowel in accordance with an embodiment of this " " ;''-~ ': ' ~ ~43Z47 ~ :
1 invention, showing the relative alignment therebetween;
Fig. 3 is an elevational view of an assembled -~ -spear structure, spring retaining structure and spring -~
support dowel, in accordance with an embodiment of this invention;
Fig. 4 is an elevational view of the assembly of Fig. 3, together with the addition of a drive spring in- 1 serted in secured position;
Figs. 5a and Sb are cross-sectional views along ~ -section Va-b--Va-b of Fig. 4 showing a ball clutch in a locked and an unlocked position; and Fig. 6 is a longitudinal cross-sectional view of the assembly shown in Fig. 4, along the plane VI-VI.
DETAILED DESCRIPTION
lS Reerring to Flg. 1, the spear structure 10 has certain portions which engage an external window shade support bracket, while others act to form part of a ball clutch arrangement. In the embodiment illustratedJ such portions include a solid, substantially rectangular spear 11, preferably as an integral part of spear structure 10. Typi-cally, spear 11 is received in a slotted external bracket ~
used for supportin~ the shade and preventing rotation of - ;
the spear. Spear structure 10 fur~her integrally includes an end cap 15, a barrel 12 and a flange 13 at the end of barrel 12. End cap portion 15 is a thin disc-like cylindri-cal solid. Barrel 12 is a tubular section having a blind central cylindrical opening with a pair of internal ribs 17.
~lange 13 sllrrounds an end portion of barrel 12 to provide -a truncated cone-shaped ridge near such end portion, as illustrated. Spear 11 projects from end cap 15 in a first 1: . ., . ~
direction along the central axis of end cap 15 and barrel 12 ~: ;
.'' '' ' '' '.': , ~1)43Z47 1 projects in the opposite direction. To provide for com-pression, or annular contraction, of the flanged end o~
barrel 12 there are two (or more) diametrically opposed slots 16, parallel to the central axis o structure 10, extending through flange 13 and a portion of barrel 12.
It can be appreciated that the number of slots can vary.
A Tatchet arrangement 14 is part of spear structure 10 and is used as part of a ball clutching arrangement for a spring drive of the shade. Ratchet arrangement 14 surrounds a portion of barrel 12 adjacent end cap 15 and includes cir-cumferentially-spaced protrusions extending radially outward ~rom barrel 12. A cross-sectional view of ratchet arrangement 14 is shown in Figs. 5a and 5b. Typically, spear structure 10 is made as one piece, preferably from nylon, by an injec-tion molding process.
Fig. 2 shows a spring retaining structure 20 which includes a spring-retaining barrel 21 and spring-compression lugs 22. Also shown is the relative alignment ~-o a spring support dowel 25 having a slotted end 30, dis-posed coaxially with barrel 21. An end disc 23 provides a support or base ~rom which project barrel 21 and lugs 22.
End disc 23 is a disc-like cylindrical solid having an align-ed central cylindrical opening (not seen in Fig, 2). Barrel 21 is a tubular projection having an aligned central cylin-drical opening. The central openings of disc 23 and barrel 21 are aligned and communicate with one another. The diame- ~ ;
ter of the opening of disc 23 is at least as great as the diameter of the opening in barrel 21.
The lugs 22 are circumferentially spaced, axially ~;
aligned portions forming in essence a slotted cylindrical shell. One end of each lug can be tapered toward the central "" . ...
'. ~''' ' ,.,., . . .. ..... . .. 1.. ,. . . . .- - . . , . . - -..... , , . - . ... ,. . ,- .. - . . .

~3;Z 47 1 axis of barrel 21~ Lugs 22 are longitudinally aligned with the central axis of barrel 21, ~ircumferentially spaced - .
from each o~her around the barrel, and radially spaced there-from so that the end of a coil spring can be fitted into the annular space between lugs 22 and barrel 21.
Fig. 6 shows a cross-sectional view of spring-retaining structure 20, where it can be oberved that end disc 23 has recesses 24 in its lateral side 26, opposite from barrel 21, for receiving balls 61. In accordance with an embodiment of this invention, the recesses have canted floors 62 (Fig. 6), i.e., the floors of the recesses angu-larly deepen as the radial distance from the central axis increases. During manufacture, canted floors 62 are particu-larly advantageous for retaining balls 61 against side walls lS 63 of the recesses. Such positive placement of balls 61 facilitates ~he manu~acturing process. The cross sectional view in Fig. 5b shows how a ball placed on canted floor 62 ~ ;~
would automatically (i.e., by gravity) roll into position against sidewall 63. Preferably, as with spear structure ~
10, spring-retaining structure 20 is made from nylon by an ` `
injection molding process. O~ course, structure 10 and 20 ;
could be made from various other materials, including, for example, various other plastics.
Fig. 3 shows an assembly of spring support dowel ;
25, spring-retaining structure 20 and spear structure 10.
In particular, barrel 12 and flange 13 of spear structure 10 have been inserted through the central opening in barrel 21 of spring-retaining structure 20. During insertion, the slots 16 permit portions of barrel 12, including the flange 13, to squeeze toward each other, and then to snap outward once through barrel 21. The lengths of barrels 12 and 21 '. . . .

~3;~7 1 are adapted so that when ridge flange 13 snaps outward it butts against the end of barrel 21, at which time end cap 15 is flush against (or narrowly clears) end disc 23.
Accordingly, structures 10 and 20 are simply and positively connected, being self-retaining. The insertion of spear structure 10 into structure 20, or at least the insertion ~ -of the balls 61 into their recesses 24, is preferably done with the ball-retaining recesses of structure 20 opening upward. That is, after initial insertion of spear structure 10 but prior to the time when ridge 13 snaps out into place behind the end of barrel 21, the balls 61 are placed into their recesses 24, where they rest on canted floors 62, whereupon spear assembly 10 is inserted the rest of the ~ -way into structure 20. The one-way clutching action required in a shade roller is complete after the simple operations of inserting the balls into the ball-retaining recesses and inserting structure lO fully into structure 20.
After the complete insertion of spear structure 10, dowel 25 is inserted in the central opening of its barrel 12. The diametral fi~ between dowel 25 and barrel 12 is such that the presence of the dowel prevents barrel 12 from being compressed sufficiently to allow flange 13 to l pass back through barrel 21 of structure 20. This further j insures the proper cooperation of structures 10 and 20 both in support of the final shade assembly and in the clutching action to control shade winding. While it is possible to merely secure dowel 25 within the opening of barrel 12 by gluing or other such measures, it is preferred to use a self-retaining, snap-fit construction as illustra~ed. This i-includes a straight-sided groove 32 ~Figs. 2 and 6) around the circumference of dowel 25 immediately inward of the - 1 0 ~ ,,, , ", ,.,, -',~

.

1 diametral slot 31 which forms the aforementioned divided end 30 of the dowel. Also, barrel 12 of spear structure 10 has a conical internal ridge 18 (Figs. 1 and 6) similar to its outer such ridge 13 already described. When dowel 25 is inserted into spear strueture 10, the interaction between ridge 18 and dowel 25 at first causes diametral enlargement of the spear structure barrel, but when the groove 32 comes into alignment with ~idge 18 the latter snaps into place within the groove locking the dowel in -place. In this operation the end slot 31 of dowel 25 (which preferably has the same such shape at each end) must first be rotated into alignment with the internal ribs 17 of the spear structure barrel, which thus slide into such end slot and there act to preclude relative rotation be- ~ ~
tween the dowel and the spear structure.
Referring to Figs. 4 and 6, a spring 41 is `
shown, which is to be understood as being attached to dowel 25 at the end thereof opposite spring retainer 20 (not shown) in a conventional way, as by an offset diametrally disposed end o the spring which engages the slot in the end of the dowel. At the opposite end, shown in the draw-ings, the spring i~ compressed ~i.e., radially contracted) and inserted between lugs 22 and barrel 21. The securing of spring 41 between lugs 22 and barrel 21 is particularly advantageous because this securely retains one end of the spring without the need for any mechanical fasteners such as pins, clips, staples or tacks, which are often used for such purpose. Further, eliminating such attachment devices simplifies and reduces the labor and time required by the manufacturing process. Spring ~1 is secured by a simple axial thrusting insertion, preferably including at least -, ~q~3Z4~ ~:
1 some rotation of the spring end at the same time.
In this connection, it should be observed that the inside diameter of spring 41 preferably fits comple- ;
mentarily over the ou~side of barrel 21, with the annula~
clearance between the inside sur~aces of the lugs 22 and - the outside of barrel 21 being preferably on the order of, or slightly less than, the diameter o~ the wire from which spring 41 is wound, so as to provide an interference fit therebetween. Further, the lugs are preferably at least slightly flexible. Accordingly, in such a preferred embodi-ment, when the spring is inserted into place, the lugs are forced outwardly at least slightly, whereupon their natural resilience or "plastic memory" causes them to grip the out-side of the spring, contracting it annularly, radially about the barrel 21. The end of spring 41 inserted between lugs 22 and barrel 21 may if desired have a lateral, radially bent end portion. Such an end portion is inserted between lugs 22 and can butt up against the side of a lug to ensure that no rota~ion of drive spring 41 can occur with respect to spring retaining structure 20. Because the entire spring ~ ~ ~
motor assembly, including lugs 22, is subsequently inserted ~ -into a tube, any such bent end portion of the spring should havc a radial extension less than the maximum radial exten~
sion of any portion o lugs 22, so as not to engage the inside wall of such tube. It is to be pointed out, however, that such an offset or bent end of the drive spring is not essen-tial to the satisfactory practice of the invention, since the engagement of the spring between the barrel 21 and lugs 22 will hold the spring very satisfactorily agains~ rota-tional slippage of the spring, allowing the latter to be torsionally wound upon the dowel for driving operation '.'.:''~.

~ 4 3Z ~
1 between the spear structure 10 and its receiving and cooper-ating structure, upon rotation therebetween through the ball clutch.
Figs. 5a and 5b illustrate the operation of the ball clutch. In the locked position, shown in Fig. 5a, one ~or, at times, two) side of the ratchet surface arrange-ment 14 is engaged by one (or both) of the balls 61. In the unlocked position, shown in Fig. 5b, the sides of ratchet arrangement 14 are free to turn, clear of balls 61.
As will be understood, the basic na~ure of such a clutch is known in the art and no detailed description is therefore required here.
Fig. 6 shows a cross-sectional view of a com- .
pletely assembled shade support roller and spring motor.
In this view, an outer shade support tube 64 is shown in place over drive spring 41, the spring motor assembly having been inserted fully therein, During such insertion, lugs 22 frictionally engage, and preferably embed into, the inside wall o tube 64, and this serves to radially compress or contract the lugs tightly about spring 41, forcibly trap-ping the same against barrel 21. Tube 64 provides an attach-ment means, and a support for, the window shade panel.
Various modifications and variations will no doubt occur to those skilled in the various arts to which this invention pertains. For example, the support dowel may be provided wi~h side protrusions to positively engage the slots in the barrel o the spear assembly. Also, spring retaining surfaces may be grooved to improve retention.
These and all other variations which are based upon the teachings through which this clisclosure has advanced the art are properly considered within the scope of this invention.

, .. . - .

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows.

An end support assembly for a window shade roller characterized by:
a spear structure having a portion for engaging an external support bracket and another portion forming a first part of a window shade clutch;
a spring-retaining structure having a portion for cooperatively engaging the spear structure, a portion forming a second part of a window shade clutch, and a portion for positively retaining a drive spring;
a clutch element acting in cooperation with said first clutch part of the spear structure and the second clutch part of the spring-retaining structure for providing a window shade roller clutch mechanism; and radially-projecting portions extending laterally from at least one of said spear structure or said spring-retaining structure and interfitting with the other such structure to maintain the two structures assembled together.

An end support assembly for a window shade roller as recited in claim 1 further characterized by the spear structure comprising:
a substantially rectangular, integral spear portion for engaging a slotted shade support bracket;
a generally cylindrical barrel portion extending away from the spear portion the barrel portion having radially-projecting elements for engaging said spring-retaining structure and fitting around portions thereof to thereby help to maintain such structure assembled to said spear structure.

An end support assembly for a window shade roller as recited in claim 1 further characterized by:
spring-retaining structure comprising an end surface having at least one clutch dog-receiving recess, a barrel portion projecting laterally away from the end surface in a direction opposite said recess, and spring-retaining lugs extending in the same direction as the barrel circumferentially spaced from each other to form an annular locus and radially spaced from the barrel sufficiently to receive and frictionally engage a spring therebetween.

An end support assembly for a window shade roller as recited in claim 1 further characterized by the spear structure comprising:
an integral spear element and barrel element projecting in opposite directions along a central axis of the spear structure, the barrel element having a compressible end portion and an interlock element; and said spring-retaining structure characterized by having a barrel with a central opening for receiving the barrel of the spear assembly and a portion for engaging and interlocking with said interlock structure of the spear assembly.

An assembly as recited in claim 4, further characterized by:

a ball-receiving recess defined in an end portion of the spring-retaining structure, the opening of the recess being on the opposite side of the structure from the barrel, and the floor of the recess having an angular surface to form a deeper recess as the radial distance from the axis of the spring-retaining structure increases.

An assembly as recited in claim 4, further characterized by:
a clutch dog-receiving recess defined in an end portion of the spring-retaining structure, the opening of the recess being on the opposite side of the structure from the barrel, and a ratchet arrangement around the barrel of the spear structure adapted for use as a part of a clutch arrangement in cooperation with the spring-retaining structure; and a clutch dog in the dog-receiving recess, acting in cooperation with said ratchet arrangement and portions of the spring-retaining structure to provide a clutch.

An assembly as recited in claim 4, further characterized by:
said spring-retaining structure having an end wall part having at least one ball-receiving recess with a floor having an angled surface to form a deeper recess as the radial distance from the central axis of the spring-retaining structure increases;
a barrel portion projecting in at least a first direction from said end wall and centrally oriented with respect to said axis;

resilient compression lugs extending from the wall in the same direction as the barrel and generally parallel to said axis, said lugs being circumferentially spaced from each other around the periphery of the barrel with a radial spacing between the barrel and the lugs for receiving and retaining a spring.

An end support assembly for a window shade roller as recited in claim 1 further characterized by:
a barrel portion integral with said spear structure portion which engages an external support bracket, and extending away from the latter portion, symmetric about the central axis of the spear portion;
wall portions around the barrel at the end thereof closest to the spear, such wall portions comprising part of a ratchet mechanism for use as part of a clutch;
and an end cap portion having a generally disc-like shape and separating the spear portion from the barrel and ratchet arrangement.

An end support assembly for a window shade roller as recited in claim 1 further characterized by:
a ball-receiving recess having side walls located at a distance radially outward from the axis of the shade roller and having a sloping floor which forms a deepening recess as the radial distance from the axis of the shade roller increases and approaches said side walls.

An end support assembly for a window shade roller as recited in claim 1 further characterized by:

said spring-retaining structure having at least one ball-receiving recess and a cylindrical interior wall defining an opening in communication with said recess;
a ball member within the recess of the spring-retaining structure;
an integral, one-piece spear structure having a spear portion, a barrel portion extending away from the spear portion and received within said opening of the spring-retaining structure, having a ratchet portion positioned adjacent said ball-receiving recess and adapted to operate in cooperation with said spring-retaining structure and with said ball to form a ball-clutch arrange-ment, and having a barrier wall disposed generally between the spear portion and the ratchet portion for helping to retain said ball within said recess;
a rod member inserted into the barrel of the spear structure;
a drive spring positioned around the rod member, anchored at one end to the rod member and anchored at the other end by the spring-retaining structure; and a tube positioned about the spring-retaining structure and the drive spring.

An end support assembly for a window shade roller as recited in claim 1 further characterized by:
said spear structure including an integral spear portion and a barrel portion which portions project in opposite directions along a central axis of the spear structure;
a spring-retaining structure including a barrel for engaging with the barrel of the spear structure, and means for holding the barrels together when so engaged;
an elongated rod member extending generally axially of said spear structure in a direction away from said spear portion thereof; and interlock portions on said rod member and on said barrel portion of said spear structure, said interlock portions disposed generally transversely of the spear structure axis at least in part and engaging one another in a manner inhibiting axial separation of the rod member and the spear structure.

An assembly as recited in claim 11 wherein at least certain of said interlock portions comprise resiliently flexible formations which flex to engage other interlock portions.

The assembly as defined in claim 12 wherein at least some of said flexible formations are carried on said spear structure barrel.

The assembly as defined in claim 13 wherein said spear structure barrel also carries resiliently-biased formations disposed to index behind said spring-retaining structure to hold the spear structure and spring-retaining structure against axial separation.