US2774861A

US2774861A - Repeating flashgun

Info

Publication number: US2774861A
Application number: US411452A
Authority: US
Inventors: Robert E Shaw; Frank H Walker
Original assignee: Sylvania Electric Products Inc
Current assignee: GTE Sylvania Inc
Priority date: 1954-02-19
Filing date: 1954-02-19
Publication date: 1956-12-18
Anticipated expiration: 1973-12-18

Description

Dec. 18, 1956 R. E. SHAW ETAL 2,774,861

REPEATING FLASHGUN mm MH MS a a m 4 E B m m F 4 5 9 1 9 1 b e F d e 1, i F m A V F FRANK WALKER United States PatentO 2,774,861 REPEATING FLASHGUN Application February 19, 1954, Serial No. 411,452 1 Claim. 01. 240-31 .This invention relates 'to' photoflash. lamps and to apparatus in which they are used. Such apparatus is generally called a flashgun.

Such flashguns have heretofore required expensive constructions and gearing to be effective, and were hence unsuitable for use with the simpler and cheaper types of camera. The object of the present invention is to provide a flashgun suitable for such types of camera, although it is not confined to such use.

In the embodiment of the invention described herein, a cylinder holding several flashbulbs is rotatable about a chamber into which the flashbulbs can be introduced through an opening therein and can be then moved longitudinally into position at the front of the chamber. At the rear of the chamber a rod is provided which can be pushed into the chamber to grasp the flashbulb and push it forward into place in a reflector, which is at the forward end of the chamber and in communication therewith.

Other objects, advantages and features of the invention will be apparent from the following specification, taken in connection with the accompanyingdrawings, in which:

Fig. 1 shows a plan view of the device, in section.

Fig. 2 shows a transverse section through the cylinder and chamber of Fig. 1.

Fig. 3 shows an elevation of the device, partly in section; and

Fig. 4 shows a rear view of the device.

In Fig. 1, the reflector 1 is attached to the chamber 2 at the latters open front end, the reflector 1 having a central hole in register therewith, so that a bulb can move from the chamber into the reflector. The rubber ring 3 is set into the inside surface 4 of chamber 2, a short distance inside the open end of said chamber 2. The flanged plastic annular disks 5, 6 are fixed to the chamber 2. The cylinder 7 having one open end and one annularly closed end 8, is rotatable around chamber 2 between the annular disks 5, 6. The cylinder 7, shown in transverse section in Fig. 2, has the longitudinal grooves 9 in its inner surface and roughly parallel to the axis of the chamber 2, the radial depth of the grooves 9 being about equal to half the outside diameter of the bulbs 10. The bulbs 10 will thus be held between the cylinder 7 and the outside of the chamber 2, where the latter passes through the cylinder 7. The bulbs 10 are shown as in contact with the grooves 9 and the outside 11 of the chamber 2, but actually there should be some clearance around the bulbs, to provide freer rotation and to allow for slight differences in bulb diameters.

The chamber 2, when it passes through cylinder 7, is open at its top, being somewhat U-shaped in cross section in that region, as shown in Fig. 2. Then when the bulbfilled cylinder 7 is rotated around chamber 2, a bulb will drop into the chamber 2 on coming into register with the opening 30 in the top thereof. Bulb 11 is shown dropping into place, in the two positions shown in phantom.

Fig. 3 shows a side view of the device, with the bulb 11 in its forward positionpreferably at about the focus of the reflector 1. The bulb is held by the holder 12, the forward motion of the holder being limited by the cap 19. The pin 14 projects out of the rod 13 being biased to do so by, the coiled spring 15. The pin 14 has a head 16 on its "end inside rod v13. The front portion of the rod 13 is drilled to a diameter suflicient to make a sliding fit with the body of pin 14 but not sufficient to allow the head 16 to'pass through. The rear portion of the rod 13 is drilled to a diameter large enough to takethe head 16 of pin 13. The'head 16 is kept biased in the forward direction by the coiled spring 15, acting betweenfhead 16 and the cap 19 which is screwed onto the rear end of rod'13 closing the same. A smaller diameter portion 20 of pin. 14 extends rearwardly from .the head 16, through the inside of the coiled spring 15 and through an opening in the cap 19. A closure member 21, pivoted on screw 22 extends across the opening 23 in the rear disc member 5, affording a hole through which the bulbs can be put into the cylinder. A bracket 24, attached to the members 6, for example by screws 25, is also attached to the battery case 26 of a type usual in the art. The battery case has the usual two

pins

27, 28, for electrical and mechanical connection to a camera in the ordinary manner, with the aid of the clamping screw 29.

The

'pins

27 and 28 are connected electrically to, respectively, the holder 12 and the-pin 13, the latter making contact with the center base contact 30 of the bulb, such contact sometimes being called the eyelet contact.

In operation, the flash bulbs 10 are loaded into the cylinder 7 one at a time, by pushing the closure member 21 aside to permit their entry into the cylinder. After each bulb is loaded in, the cylinder 7 is turned to the next position and another bulb inserted, until the entire cylinder is loaded. To put a bulb 10 into the chamber 2, the rod 13 is pulled back, and the cylinder 2 turned until a bulb is just above the opening 30 in chamber 2, thereby allowing the bulb to drop into the chamber.

The rod 13 is then pushed forward, without pushing on the smaller diameter portion 20, until it grasps the side 31 of base 32, the rubber ring 3 providing enough friction to hold the bulb tightly enough to cause the holder 12 to grasp it securely, but without preventing the bulb 10 from being pushed further forward after being grasped. The cap 19 limits the forward motion by bearing against the rear end of cylinder 2. When the forward motion is thus stopped, the bulb should be at about the focus of the reflector 1.

The bulb 10 is then ready for use, being in the proper position and in electrical contact with the holder 12 and the pin 13. It will be flashed when the camera shutter is operated, in the synchronizing manner well-known in the art.

After the bulb is flashed, the pin 20 is pushed forward, while cup 19 is held in place, thus ejecting the bulb from holder 12 and allowing it to fall out of the reflector 1. The cap 19 can then be pulled back and the cylinder 7 revolved until another bulb drops into chamber 2, and the cycle repeated. The empty positions can be reloaded with bulbs as desired.

In the above description we have, for convenience, referred to the front andback or forward and rear, of the device. The front or forward part is theend containing the reflector 1, and the back or rear is the other end. The device is intended to be held so that the battery chamber 26 is at the bottom.

The bulb 11 can also be ejected without ejection pin 20, by merely retracting the loading rod 13. The rubber ring 3 will prevent the bulb 11 from being retracted with the rod 13, thus disengaging the holder 12 from the bulb base 31 and allowing the bulb to drop out, especially if the gun is tilted downward. The device can thus be used with the pin 20 omitted. In that case, it is best to cause the part of the chamber in front of the rubber ring 3 to 11am u ard, o permi the re d b b. 1 t fell mo e r ad The ubbe v in 3 gen e made la er in finene s-s io of i s ub r 9 an be rs ass'd by s ri g y P ns ia d ntQ h sh m r by p Tjhs l 11 w l dr p out mo e e d l on e ecti n f re te le ranc s Pmv etw en h @12 nd he insert of the chamber 2. When the ejection pin 20 is used, the additional clearance is unnecessary.

For best ejection, the base 31 or the portion of the bulb nea e h b ss hou d ve a sma l d ameter a that of the front part of the bulb 11. i i

at we c m 1. s

v A r ating ph wfl sh gun fa l s ho o a h bulbs ha in a some b s com is a s es a h n a central opening, a hollow chamber fixed to said reflector, s id shamb in an ening in esis s? th th opening in the reflector to permit passage of a bulb from the chamber to the reflector, a rotatable annular cylinder extending around said chamber and being concentric therewith and having longitudinal bulb-receiving grooves in its inner surface, said chamber having a longitudinal opening through which a bulb can pass from said cylinder to said chamber when the cylinder is rotated to bring a bulb into register with said opening, means for grasping a bulb by said contact base and means for moving said aspin mean lon i udinally hro h aid ch mber into said reflector to hold said bulb in said reflector solely by the grasping of said contact base.

References Cited in the tile .01? this patent l a stars AT 2,006,171 Kalhaus June 25, 1935 2,343,552 Hollister Mar. 7, 1944 2 5 6 B ans a s May 3 1 2,672,032 Schwart; Mar. 16 1954