US 3900729 A
Description (OCR text may contain errors)
United States Patent 1191 Smith et al.
1 1 LAMP SHADE CENTER  Inventors: Peter S. Smith, Nabnasset; Richard B. Theurer, Burlington, both of Mass.
(73] Assignee: Massachusetts Machine Shop Inc.,
22 Filed: Mar. 11, 1974 21 Appl. No.; 449,779
 US. Cl 240/136; 29/417; 240/108 R  Int. Cl. F21v 17/00  Field of Search 240/136, 144, 108 R, 108 A  References Cited UNITED STATES PATENTS McGann 240/136 Wager 240/144 14 1 Aug. 19, 1975 1,732,416 10/1929 Pauchek 240/136 X 2,048,988 7/1936 Atkinson 240/148 2,458,136 1/1949 Berger 1 .1 240/148 2,668,906 2/1954 Miller 240/148 Primary Examiuer.loseph F. Peters, Jr.
 ABSTRACT A lamp shade center is formed of flat metal stock with adjacent sections lanced in opposite directions, defining tunnel-like openings for receiving radial lamp shade support wires. The center is adapted to be secured to the wires by deformation of the lanced sections back toward the original plane of the stock, preferably the lanced portions of all the retainers constructed to be deformed to grip the respective wires in one motion.
3 Claims, 7 Drawing Figures LAMP SHADE CENTER This invention relates to the center element of a lampshade which holds the radial support wires near the top of the shade and which attaches to the lamp.
A principal object of the present invention is to provide a lampshade center which is easily manufactured from inexpensive material using simple manufacturing processes, and which connects to lampshade support wires in a simple. positive fashion.
Other objects and advantages of the invention will be apparent from the following description and drawings wherein:
FIG. 1 is a plan view of a strip of metal showing the action against it of a progressive die set in producing a lampshade center:
FIG. 2 is a top view of a lampshade center for use with four support wires while FIG. 3 is a side view of that center;
FIG. 4 is a perspective view of that center;
FIG. 5 is a view of a press joining the center of FIGS. 1 and 2 to respective support wires;
FIG. 6 is a perspective view of a lampshade employing the center of FIGS. 1 and 2;
and FIG. 7 is a view similar to FIG. 2 of a lampshade center for use with three support wires.
Referring to FIGS. 1-4, lampshade center I. made of flat metal stock has a hole 2 in its middle for attaching the lampshade to the lamp. Referring to FIGS. 2-4, the center has four retainers 3 each to receive a lampshade support wire. Each retainer consists of a region of stock in which there are three lanced portions of metal separated from each other and deformed in alternate directions from the flat plane of the lampshade center while remaining attached at both ends. Two of the resulting protrusions 4. 4' are lowered and one 5 raised relative to the plane of the original metal stock. The protrusions together form a radial tunnel-like passage. ending in a positive inner stop 6 consisting of the edge of undeformed material inwardly beyond the innermost deformed portion 4'.
Referring to FIG. 1, center I is produced from a flat strip of metal 10 moving through a progressive die. the steps of which are designated A through H. In step A a punch ll of the die moves down against the metal strip, punching out a circular hole. Punch 11 is withdrawn. the metal strip is indexed and the operation is repeated on the following portion of the strip simultaneously with operations at stations B through H on more advanced portions of the strip. In stations B and C pilot pins 12 move through the previously punched holes to positively position the metal strip 10. Between the pilot pins is an H-shaped punch 13 which punches out metal betweeen stations B and C. defining the outer edges of tab-like formations I4 on the eventual lampshade center. The die is withdrawn and the metal strip again indexed one station. At station D a pilot pin 12 positions the metal strip and is followed by two U- shaped punches 15 which define the outer edges of two more tab-like formations 14. The die is withdrawn and the metal strip indexes one station. At station E a pilot pin 12 positions the strip, but no metal is removed. At station F the die lances the metal strip providing alternately downward and upward protrusions 4, 5, 4' on each tablike formation. The die is withdrawn and the metal strip is indexed one station. At station G a pilot pin 12 positions the strip. but no metal is removed. Be-
tween stations F and G and between stations G and H are pairs of spring-loaded stock lifters which raise the metal strip slightly while it is indexing to prevent the lanced protrusions 4, 5, 4' from interfering with the travel of the strip 10. At station H a circular punch l8 blanks out the major area of the lampshade center. and since the metal around the tab-like portions has already been removed, this blanking operation produces a complete lampshade center ready for assembly with lampshade support wires. All of the above punch. lance, blank. and pilot pin devices are carried on a single die platen with the workpiece material automatically fed through the successive operations; therefore. every stroke of the die platen produces one completed part.
Referring to FIG. 3 in the preferred embodiment all of the raised sections 5 of the various retainers are raised a like distance d from the flat stock and similarly all of the lowered sections 4, 4' of the various retainers are lowered a like distance d from the flat stock. Refe rring to FIG. 2, in the preferred embodiment each lanced section 4, S, 4' in plan view. is straight and of uniform width w throughout its length and lies with its edges E parallel to the other sections of the respective retainer.
Referring to FIGS. 4 and 5, the lampshade support wires 20 are permanently connected with the lampshade center 1 in a press consisting of top and bottom platens 21. 22. One support wire is inserted into each lanced retainer 3 of the lampshade center until it contacts inner positive stop 6. The design and size of the lancing is such that each support wire 20 is held in its proper radial position during the press operation. and the positive inner stop 6 insures that the support wire is inserted into the lanced retainer the correct distance. This combination of alignments eliminates the use of jigs to position the support wires. A single stroke of the press squeezes all lancings 4, 5. 4' into permanent contact with their respective support wires 20 simultaneously. Because of the lancing design the press which does this squeezing can comprise flat platens 21., 22 or dies with minimal tooling. eliminating the need for expensive dies and multiple operations.
What is claimed is:
I. A lamp shade center formed of a flat metal stock stamping having a hole in its middle and a plurality of retainers spaced radially from the center of said hole for receiving radial lamp shade support wires, each said retainer comprising at least three wire supporting lanced sections spaced readially along an axis in the plane of said stock. the first and third of which are deformed in one direction normal to said plane of said stock, and the intervening section deformed in the opposite direction from said plane of said stock. said lanced sections being connected to one another at their ends and severed from one another at their middle portions. said lanced sections defining together a radially extending tunnel-like opening terminating at a positive inner stop defined by the edge of said metal stock from which the innermost said section was separated during lancing. said retainers adapted for securing said wires by being simultaneously deformed by a press. thereby to grip and retain said wires.
2. The lamp shade center of claim 1 wherein the said lanced sections of each said retainer are deformed the same respective distance from the plane of said stock. said retainers adapted for circumferentially and radially positioning said support wires on insertion.
3. The lamp shade center of claim I wherein said lanced sections of each said retainer, in plan view. are straight. of uniform width throughout their length. and
lie with edges parallel to each other.
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