US2565492A - Flash lamp ejector socket - Google Patents

Description

Aug.'28, 1951 H. w. FRENCH, JR

FLASH LAMP EJECTOR SOCKET Filed Nov. 15, 1946 f. 5 .J WY

R h M mm m Wm in Patented Aug. 28, 1951 Hubert W. French, Jr., Howell, Mich, assignor to Argus Cameras, Inc., a corporation of Michigan Application November 15, 1946, Serial No. 710,015

BClaims.

This invention relates to flash bulb supporting and actuating apparatus for attachment to a camera and is particularly concerned with an ejector socket for the flash bulbs.

Flash-light photography has become common in newspaper and indoor work where it is necessary to provide artificial light on the subject, and is particularly useful for speed work where it is desired to take a number of pictures in quick succession. It is time-wasting to unscrew bulbs by hand and even though some sockets are spring thrust sockets, it is dangerous and often painful.

to handle the hot newly fired bulb. Hence ejector V sockets have been proposedv in a large number of designs. Many of these, however, employ a spring action for the purpose of propelling the bulb out of the socket, as this has been considered necessary. Some of these spring powered ejector sockets however have proven obj ectionable in that they are so powerful as to actually propel the bulb a substantial distance across the room so that there is danger of hitting persons in the room with the ejected bulb.

I have found that with a properly designed socket and with special arrangements of parts in combination, it is possible to provide a satisfactory ejector socket for flash bulbs wherein the bulb may be thrust into thesocket .and held there resiliently while the picture is being taken and the bulb exploded, and then ejected manually by a positive thrust withoutany recourse to aux-iliaryspring ejector action, for quickly removing the bulb entirely from the socket, so that the operator may be instantly ready for taking a new picture as fast as he can push. a new bulb into the socket and set the camera for the succeeding. exposure.

It is therefore a major object of myinvention to provide a flash bulb ejector device which is positive in operation and does not depend on auxiliary spring or other means for expelling the bulb from the socket.

It is a further object of my invention to provide a novel flash bulb ejector socket having a non-conductive plunger slidably mounted therein for positively pushing the bulb out of the socket after it has been used.

It is a further object of my invention to provide a novel conductor and plunger arrangement in a flash lamp ejector socket.

A further object .of my invention is to provide a. novel adapter for a flash lamp ejector socket.

Further objects of my invention will presently appear as the description proceeds in connection with the annexed claims and the appended drawings, wherein. i

vention wherein the full line position of the partsillustrates their relative arrangement just when the bulb is being axially thrust into the socket and. just as its center contact touche the plunger, and the dotted lines represent the position of the parts when the lamp has been thrust fully into its operative position in the socket so that the ejection plunger becomes projected from the back of the unit so as to be available for operation by the operator after the flash bulb has been used; and

Figure 2 is an exploded view of the elements of the socket of Figure 1 illustrating the structure in detail.

In its preferred embodiment my invention comprises a self-contained attachment unit for a camera comprising a Bakelite, hard rubber or other insulated housing II having integral back, bottom, top and side walls and being formed with an opening in the upper part of the front wall for mounting a reflector 13 on the unit. Housing H has a removable lower front wall M which fits below the reflector. Reflector I3 is firmly but removably mounted on the housing I! as by means of a split resilient collar 15 which is thrust into opening 12 and frictionally retains the reflector in position on the housing coaxially with the socket to be described.

Cover 14 is removably mountedon the housing by means of spring clips I6 and I! cooperatingv with recesses in the interior of the housing, and the purpose' of making Wall I' l removable is to enable the batteries I8 to be replaced when desired.

The lower wall of housing .H is provided with a depending metal slide clip assembly I9 which is adapted to fit with a corresponding part on the camerav and. which is rigidly secured to the exterior of housing H. as by a rivet and vulcanized plate construction, the details of which are notconcerned with this part of the invention. Clip assembly I9 is centrally apertured for the free passageof an electrical terminal member 2| which issecured at its upper end within housing II to a spring 22 on which rests the bottom metallic surface of the battery [8; Metal spring 22 is riveted or otherwise secured to housing II and provides a lead between the outer battery terminal and. terminal 2|. When the unit is mounted inposition on the cameraby clip 1.9, terminal ll engages a suitable insulated terminal on the camera leading to one of the-shutter operated contactsas in the usual flash bulb arrangement.

tu'bular metal rivet or thimble 23 is fixedly mounted in a small bore 24 at the bottom of opening l2 and in the rear wall of the housing H in axial alignment with reflector l3. outwardly of bore 24, housing II is formed concentrically with an enlarged circular recess 25 providing a flat shoulder 26 at its bottom. Rivet 23 is flanged at its inner end at 21, and the purpose of rivet 23 is to rigidly mount the socket assembly on housing II.

The inner surface 20 of the rear wall of housing adjacent and surrounding bore 24 isflat its larger end secured to a flat metal washer 51 and normal to the axis of bore 24 and formed with a small shouldered recess 28 at the innerend of bore 24 for receiving the apertured tip 29 of a flexible conductor strip 3|. The lower end of strip 3| is attached to tip 32 to thecentral terminal of battery 8.

A second conductor strip 33 formed with an enlarged circular aperture 34 much larger than the diameter of rivet 23 is axially spaced and electrically isolated from strip 3| by a fiat insulating washer disc 35 which has a central aperture 35 of the same size as aperture 34. The purpose of conductor strip 33 is to connect the outer terminal of battery IS with the outer shell terminal of the socket to be described.

This outer socket shell terminal preferably comprises a generally cylindrical metal shell member 3? closed at its bottom except for a central circular aperture 38 of the same size as apertures 34 and 38 and open at its front end. Shell 3'! is formed along its cylindrical side with diametrically opposed longitudinally extending slots 39 and 4| for receiving guiding and locating spring arms 42 and 43 of a generally U-shaped conductor strip having a flat base 44 apertured at 45 in alignment with aperture 33 of shell 31.

Adjacent its bottom wall and midway between slots 39 and 4|, shell 3'! is formed with a pair of diametrically opposite slots 46 adapted to interflt with corresponding projecting integral ribs or keys 4! formed on the interior of housing [I as illustrated in Figure 2. The purpose of this key and slot arrangement is to orient the shell within the housing and to prevent its rotation when the bulb is thrust thereinto. If desired spring contact member 44 may have any number of spring arms,

but in this embodiment only two are shown located above and below the lamp base as this number has been found to be usually enough for holding a lamp bulb for the purpose required.

Spring arms 42 and 43 diverge inwardly from flat base 44 which in the assembly is held flat against the rear wall of shell 31 as will appear, so that when a bulb is thrust axially into the socket, these spring arms 42 and 43 are sprung outwardly through the slot 39 and 4| as the give in response to axial pressure on the bulb. As illustrated in Figure l, at least one spring contact arm may be formed with an integral projecting bend 40 for keying into a suitable recess 40' in the housing II for aiding assembly and orientation of the socket.

An insulated washer 48 which has a smaller cylindrical boss 49 projecting in turn through apertures 45, 33, 34 and 36 abuts against tip 29' thickness of the two bottom walls of the shell, members 31 and 44, the strip conductor'33 and the washer 35.

A plunger rod 5|, which is preferably a hollow internally threaded rod of hard rubber, Bakelite slidably surrounding rivet 23, surrounds the inner end of rod 5| within the socket.

The function of rivet 23 is to hold all the parts of the socket in position, as well as to establish conductive relation between battery connected conductor 3| and spring 56. In assembly after insulating member 48 has socket members 31 and 44, conductor 33 and washer 35 threaded over boss 49 thereof, the rivet is thrust through washer 51, insulating washer 48 and conductor tip 29 in succession, and its outer end is peened over where it enters housing recess 25. Rivet 23 is thus rigidly secured to the housing and tightly clamps the socket parts and conductors between flange 21 and flat surface 25] at the bottom of recess l2. Since conducting washer 5'! is tightly clamped against flange 21 and since metal rivet .23 has a tight fit with terminal 29 of conductor strip 3|, the circuit comprising conductor strip 3|, rivet 23, washer 51 and spring 56 provides a live socket center'terminal at 53 for engaging the center contact of the lamp bulb. This center .contact circuit is insulated from the circuit of movement of the plunger from its inward position.

It is however immaterial to operation whether the plunger 5| is disposed in this inner position or in any intermediate position between the full line and dotted line positions of Figure 1 when there is no bulb in the socket. When a screw thread based bulb is thrust into the socket, its screw threads engage spring contact fingers 42 and 43 and its bottom contact comes into engagement with the head of screw 53, and the full line showing in Figure 1 illustrates the condition of the parts substantially at the moment of such contact.

As the bulb B is thrust into its innermost position, shown in dotted lines in Figure 1,

plunger 5! is pushed rearwardly to assume its dotted line position of Figure 1, spring 55 in the meantime offering little or no resistance to such movement and collapsing and the conical shape of spring 56 enabling the spirals thereof to nest until the fully collapsed spring approximates a substantially flat annulus. Spring 56 maintains contact between washer 51 and head 53. lunger 5| and head 55 assume the dotted line position of Figure 1 projecting from housing ll. When the bulb has been thrust into its dotted line position in Figure 1, it is firmly held and maintained there by the spring fingers 42 and 43, and the flash bulb actuating unit is read for actuation.

" After the camera shutter is operated to make an exposure, the operator immediately pushes inwardly on head 55 to positively project plunger 5| to the left in Figure 1v as far as permitted by engagement of head 55 with shoulder 25, and this positive movement pushes the bulb outwardly to a position where it will readily drop out of the socket by substantially its own weight.

There is absolutely no spring action in the election of the bulb so that there is no danger of the bulb being thrown across the room or striking the party being photographed. Ordinarily, after the plunger has been pushed in to eject the bulb, it remains in substantially the full line position of Figure 1 with head 55 seated within recess 25.

Shell 37 is provided with a pair of diametrically opposed bayonet slots 58 for accommodation of an insulated adapter base 59 having a metal shell GI and diametrically disposed bayonet pins 62 adapted to enter slots 53. The adapter has a pair of spring fingers 63 bent out of shell GI and adapted to engage the corrugated base of a small size bulb when the adapter is used. A metal plunger 64 having opposite heads 65 and 66 is slidably and centrally mounted within adapter base 59. The location of the bayonet slots 58 and the length of plunger 64 are chosen such that when the adapter is mounted in position in shell 31 b bayonets G2, the adapter plunger 64 will engage head 53 of the main plunger, and insertion of :a bulb axially into the adapter will push plunger 64 rearwardly and in turn displace plunger 5| rearwardly into the dotted line position of Figure 1. Then when the bulb in the adapter has been used, it is removed merely by pushing on button 55 to thereby advance both plungers 5i and 64 to the left and positively eject the bulb from the adapter.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. In a flash lamp apparatus, a non-conductive support, a socket shell assembly on said support adapted to receive and hold a bulb thrust axially thereinto, a metal sleeve on said support substantially concentric with and electrically insulated from said socket shell, a nonmetallic non-conductive plunger slid'able in said sleeve and having an operating head projecting externally of the support, a conductive center contact for the socket on the inner end of said plunger, and a flexible conductor extending between said head and said sleeve in all positions of said plunger.

2. In :a flash lamp apparatus, a housing having a forwardly facing opening, a bulb receiving socket in said opening secured to said housing, a spring backed light weight non-metallic bulb ejector plunger slidably mounted in a base on said housing at the bottom of said socket and projecting at opposite ends into said socket and exteriorly of said housing, an enlarged head on said plunger and a pocket in the exterior surface of said housing at the outer end of said bore, said head being held in projected position out of said pocket when a bulb is in said socket, and said pocket being adapted to receive said head when the plunger is pushed inwardly to eject a bulb from said socket.

3. In a flash lamp ejector socket, an insulated support, an outer socket member on said support having resilient means to grip and hold the base of a bulb thrust axially thereinto, a slidable non-conductive plunger carrying the center contact of said socket at its inner end and having an enlarged head externally of said support, a battery connected relatively stationary conductor sleeve fixed on said support and insulated from said outer socket member and slidably supporting said plunger, and a flexible current carrying member extending between said center contact and said conductor sleeve.

4. In the flash lamp ejector socket defined in claim 3, said current carrying member comprising a substantially conical coil spring at its smaller end on said center contact.

5. In a flash lamp apparatus, a housing of electrically insulating material, a conductive thimble secured in an aperture in a rear wall of said housing, a non-conductive lamp ejector plunger slidably mounted in said thimble, a socket shell secured to the rear wall of said housing by said thimble and insulat d from said thimble, means on said socket for resiliently gripping and holding the base of a bulb thrust axially into said socket, a center contact for said socket mounted on said plunger, and a flexible conductor between said contact and said thimble.

6. In a flash lamp ejector socket assembly, a support of electrically insulating material, a socket shell, resilient means on said shell for gripping and holding the base of a bulb thrust axiall into said socket, a tubular conductive member rigid with said support clamping said shell on said support, said member being in.- sulated from said shell, a plunger of insulating material slidably mounted in said member and carryin the center contact of said socket at its inner end, means providing electrical connection between said contact and said member in all positions of said plunger, and an operating head on said plunger outside said support.

HOBERT W. FRENCH, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,020,741 Rush Nov. 12, 1935 2,317,465 Kende et al Apr. 27, 1943 2,343,552 Hollister et a1 Mar. 7, 1944 2,384,327 Mendelsohn Sept. 4, 1945 2,424,446 Fulton et al. July 22, 1947 Certificate of Correction Patent No. 2,565,492 August 28, 1951 HOBERT W. FRENCH, JR.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 6, line 1, for base read bore; line 27, after spring insert bearing;

and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Oflice. Signed and sealed this 13th day of November, A. D. 1951.

THOMAS F. MURPHY,

Assistant Oommissioner of Patents.

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