US 3795477 A
For a photoflash assembly comprising a plurality of percussively-ignitable flashlamps mounted on a support member and arranged in a planar array with respectively associated reflectors and preenergized striker springs, a selective actuating mechanism for sequentially releasing the striker springs to fire respective flashlamps in response to successive indexing. The selective actuating mechanism comprises a single slidable bar retained in a longitudinal channel in the support member and having a number of linearly spaced projecting ramps. The lamps and striker springs are mounted in two parallel rows on each side of the channel with the strikers in each row projecting in opposite directions over the bar to lie in the path of travel of the ramps. Linear indexing of the slidable bar along the channel causes one of the ramps to release a striker. A detent retains the position of the bar after each indexing cycle, and the sequence of releasing the strikers in response to successive indexing is programmed by the number and respective location of the ramps along the length of the bar and the respective location of the strikers.
Description (OCR text may contain errors)
[ Mar. 5, 1974 i 1 SELECTHVE ACTUATING MECHANISM FOR PERCUSSIVE PHOTOFLASH LAMP ARRAY I75] lnventor: David R. Broadt, Lewisburg, Pa.
 Assignee: GTE Sylvanialncorporated,
1221 Filed: Dec. 18, 1972 1211 Appl. No.: 315,812
 US. Cl. 431/93 240/1.3, 95/11 L Primary Examiner Carroll B. Dority, Jr. Attorney, Agent, or Firm-Edward J. Coleman [5 7] ABSTRACT For a photoflash assembly comprising a plurality of percussively-ignitable flashlamps mounted on a support member and arranged in a planar array with respectively associated reflectors and preenergized striker springs, a selective actuating meehunism for sequentially releasing the striker springs to tire respective flashlamps in response to successive indexing. The selective actuating mechanism comprises a single slidable bar retained in a longitudinal channel in the support member and having a number of linearly spaced projecting ramps. The lamps and striker springs are mounted in two parallel rows on each side of the channel with the strikers in each row projecting in opposite directions over the bar to lie in the path of travel of the ramps. Linear indexing of the slidable bar along the channel causes one of the ramps to release a striker. A detent retains the position of the bar after each indexing cycle, and the sequence of releasing the strikers in response to successive indexing is programmed by the number and respective location of the ramps along the length of the bar and the respective location of the strikers.
15 Claims, 6 Drawing Figures PATENTEI] MAR 51974 SHEET-1 0F 2 PATENTED MAR 74 SHEET 2 0f 2 2 I 4 O 6 5 7 mz/Q W vantages of greater SELECTIVE ACTUATING MECHANISM FOR PERCUSSIVE PHOTOFLASH LAMP ARRAY BACKGROUND OF THE INVENTION This invention relates to multilamp photoflash units and, more particularly, to an array of percussivelyignitable photoflash lamps with means for selectively controlling the firing thereof.
The trend of photoflash devices has been toward the use of subminiature flashlamps (an envelope volume of less than 1 cubic centimeter) in compact, disposable,
multilamp units to provide camera users .with the adconvenience, compactness and portability. A currently popular flashlamp unit of this type is known generally in the trade as a flashcube, a specific embodimentof which is shown in U.S. Pat. No. 3,327,105, for example. The unit comprises a set of four flashlamps,each with its own reflector, mounted socket on a camera. lnoperat'ion, the flashcube is sequentially rotated a quarter of a turn at a time, usually in response to each operation of the film advance mechanism of the camera, to successively place unused lamps in a firing position facing theobject being photographed. Eachof the flashlamps consists of an hermetically sealed, light transmitting glass envelope containing a filamentary combustible material, such as shredded zirconium foil, and a combustion supporting gas, such as oxygen. In thecase of flashcubes employing electrically ignited lamps, a pair of lead-in wires pass through the lamp envelope to support therein a filament in combination with globules of ignition paste. When the flashcube is in the firing position, segments of the lead-in wires disposed outside the lamp envelope are securely engaged with electrical-contacts in the camera socket, which in turn are connected by wires anda shutter actuated switch to the camera power source, usually a pair of dry cell batteries. When a photographer actuates the shutter release mechanism to Tsnap a picture, he also, by the same operation, closes the electrical circuit from the batteries to the ignition system in the lamp to thereby flash thelamp. The timing of the ignition of the combustible material in the lamp is synchronized-with the exposure of the film by actuation of the shutter release so that efficient utilization of the light from the flashlamp may be obtained.
A not infrequent problem. that has been faced by the average amateur photographer when using a battery operated flash system, however, has been failure of the lamp to fire due to weak batteries and/or dirt or corrosion on one or more of the electrical contacts in the system. To overcome this problem and provide improved flashlamp reliability, percussive-type flashlamps have been developed which may be mechanically fired without the need for batteries. As described in U.S. Pat. No. 3.535.063. for example. such flashlamps have a mechanical primer sealed in one end of the lamp in lieu of lead-in wires. This primer may comprise a metal tube extending from the lamp .envelope and a charge of fulminating material on a wire supported in the tube. Operation of the percussive flashlamp is initiated by an impact onto the tube to cause deflagration of the fulminating material up through the tube to ignite the combustible disposed in the lamp envelope. The percussivetype lamps are also produced in subminiature envelope sizes and are employed in percussive flashcube units having respective preenergized stroker springs associated with each lamp, as described in U.S. Pat. No.
3,597,604.'The percussive flashcube is indexed into firing position similarly to the electrical flashcube; however, the flashlamp to be used is fired by the action 'of a member, associated withthe camera shutter mechanism, moving up through the flashcube base to release the respective preenergiz ed striker spring, whereby it sharply impacts against the primer tube of the lamp.
Another development in the field of multilamp flash units for providing additional convenience and flexibility is the provision of a linear'or planar array of flashlamps. In such an arrangement, a plurality of lamps face in the direction of the object being photographed v whereby it is possible to rapidly switch from one lamp to another or to flash more than one lamp at a time if additional light is required. Examples of previously described flashlamp arrays are provided by the following U.S. Pat. Nos: 3,267,272, 3,430,545; 3,438,315;
3,454,756; 3,458,270; 3,473,880; 3,500,732; 3,544,251; 3,545,904; 3,443,875; 3,552,896; 3,562,508; 3,598,984; 3,596,985; 3,608,451 and All of these patents describe electrically energized flash systems with the sequence of lamp flashing being controlled by various electrical switching means including: manually controlled spring slide contacts; a rotary switch; thermally or chemically reactive switches placed in thermal proximity .to the flashlamps; a switch within each lamp envelope which closes in response to firing to prepare the next lamp in sequence; a voltage surge across the lamps causes ignition of only the lamp having the lowest voltage break down characteristics, bimetallic switches; a meltable junction within each lamp envelope; and solid state switching circuits. Although providing a number of advantages, the electrical arrays are still prone to the reliabilityproblems associated with an electrical flash system, namely, ignition failures due to weak batteries and/or dirty or corroded'electrical contacts.- 1
Another disadvantage of electrical arrays is the relative difflculty of maintaining the proper lamp firing sequence in the event the array is removed from a camera and subsequently replaced. To overcome this problem, the prior art, as indicated above, employs special type flashlamps or relatively complex momory circuits or switches in the camera. Such approaches are generally considered undesirable with respect to both cost and reliability. v
To overcome the "above-described disadvantages of electrical arrays, 21 copending application Ser. No. 261,587, filed June 12, 1972 and assigned to the present assignee, describes a linear photoflash lamp array including a plurality of percussively ignitable flashlamps mounted in a row on a horizontal base, an array of reflectors, and a plurality of preenergized strikers releasable to fire the flashlamps. Each reflector of the array. is radially disposed behind a respective lamp. The
and strikers. The slidable bar is provided with a number of linearly spaced projecting ramps, and the strikers are mounted to project beyond the periphery of the channel to-lie in the path of travel of the ramps. Linear indexing of the slidable bar along the channel cause one of the ramps to release a preenergized striker and fire a respective-lamp, and sequentially lamp firing is effected by successive indexing of the bar. The sequence of releasing the strikers in response to successive indexing is, programmed by the number and location of the rampsalongthe length of the bar.
In the specific embodiment described in the abovementioned copending application, the photoflash assembly comprises two rows of percussive flashlamps and reflectors facing in opposite-directions. A slidable bar is required for each row of lamps and strikers; hence, the two rows of lamps and strikers are mounted on the base between two parallel channels containing slidable bars which move in opposite directions with respect to each other. Each ramp on a slidable bar is adapted to release a respective striker, and each successive ramp after the first is spaced D (n l).r from its pre'ceeding ramp in the striker sequence, where D is the distance between strikers, n is the number of the .ramp in the striker release sequence, and .r is the distance the slidable bar translates during each indexing movement for release of a striker. Each bar travels from left to right as viewed from its side of the array, but the strikers are released from right to left. Accordingly, the two rows of lamps are staggered and the reflectors are nested back-to-back to provide a somewhat extended free end space in each channel into which the bar can move upon being indexed.
SUMMARY OF THE INVENTION The percussive array described in the aforementioned copending application is bidirectional and requires rotation after expending the first row of lamps so as to place the remaining row of unused lamps into the firing position. In many applications it is desirable to use a mOre compact, planar array of flashlamps to enable rapid flashing of all lamps without rotation of the array. v
' Accordingly, it is an object of the present invention to'provide an improved slide-bar actuating mechanism which is particularly suitable for use in compact planararrays.
A further object of the invention is to provide a percussive flashlamp array which is economically and compactly packaged to provide increased light output and which does not require movement of either the lamps or the array during the entire operating sequence.
1 mechanism comprising a slidable bar retained in a longitudinal channel in the support member which is located between and parallel to the two rows of strikers. .The slidable bar is provided with means for sequentially releasing the preenergized strikers to fire respective flashlarnps of the array in response to successive indexing of the bar'along the channel. In a specific embodi- BRIEF DESCRIPTION OF THE DRAWINGS This invention will be more fully described hereinafter in conjunction with the accompanying drawings in which:
FIG. 1 is a perspective view of'the exterior of a multilamp photoflash assembly including features of the invention;
FIG. 2 is a plan view on an enlarged scale of the rear wall of the flash assembly of FIG. 1 with a slidable bar actuating mechanism according to the invention and the several spring members shown in full and the several flash-lamps associated therewith shown in phantom;
FIG. 3 is an enlarged perspective of the flash assembly of FIG. 1 as viewed facing the base, with sections broken away to illustrate portions of the interiorthereof;
FIG. 4 is a sectional view on line 4-,4 of FIG. 2 which is. somewhat enlarged and simplified to'more clearly show one of the spring members and its position with respect to the slidable bar, and to show the aperture through the rear wall member;
FIG. 5 is an enlarged scale, somewhat schematic view of the slidable bar in its channel with respect to the striker spring positions; and, I
FIG. 6 is a fragmentary detail of a portion of the bottom of the slidable bar of FIG. 5, illustrating the ratchet drive teeth.
DESCRIPTION 'OF THE PREFERRED EMBODIMENT In the specificembodiment illustrated in FIGS. 1-3, the photoflash assembly comprises a group of eight axially disposed flashlamps 11-18 and associated coaxial reflectors 20 arranged in a compact planar array comprising two stacked rows of 4 lamps each. The array is housed in a box-like container 22 comprising a substantially planar base member 24, a substantially planar rear wall, or support, member 26 secured to the rear of base 24 and disposed substantially normal thereto, a pair of side walls 28 and 30, and a top wall 32. Members 24-32 maycomprise a unitary structure of molded plastic, or wall member 26 may be separately longitudinal axes of the lamp disposed normal thereto.
Also mounted on wall member 26 are eight preenergized striker springs 41-48 each positioned in operative relationship'with a respective one of the lamps. Accordingly, the striker springs are arranged in two rows, the row 41-44 being associated with the row of lamps 11-14, and-the row 45-48 being associated with the row of lamps -18. As will be described'in detail hereinafter, the striker springs are individually releasable to fire their respectively associated lamps.
Referring to FIGS 1 and 3, each concave reflector is disposed coaxially about its associated tubular shaped lamp 11-18, with all reflectors oriented to face in one direction away from the lamp mounting surface. Each reflector is essentially parabolic modified by the provision of 4 flats 39 along the sides thereof. Adjacent flats of adjacent reflectors abut one another to define a compact planar array of reflectors The hairpin torsional section of'each of the springs 41-48 are disposed in the clearance space between or about the reflectors.
The array of eight reflectors 20 may comprise a singlepreformed sheet 40 of plastic material having alight reflective coating; for example, the inwardly dished reflect r surfaces 20 may be provided by vacuum forming. Toward the vertex of each reflector is provided a coaxial aperture 51 of suitable shape for fitting about the tubular flashlamp (see lamp 13 of FIG. 3). If the radiation from a flashed lamp proves to be a problem by causing sympathic ignition of an unselected lamp, the parabolic reflector skirt 20 may be extended back to cover substantially the entire lamp envelope, rather than-leaving an exposed portion as illustrated in FIG. 3. The overall package configuration of the lamp reflector array may be similar to that described in the copending application Ser. No. 260,271, filed June 6., 1972 and assigned to the present assignee, except for the type of selective actuating mechanism employed and the arrangement of the pre-energized striker springs I Each of the lamps 11-18 is substantially identical and comprises (see lamp 14 of FIG. 3)v an hermetically sealed light-transmitting envelope 50 of tubular shape having a primer depending therefrom. A filling of combustible foil 52, such as zirconium, and a combustionsupporting gassuch as oxygen, are disposed in the envelope. The primer comprises a metal tube 54 coaxially projecting from the envelope and within which a wire anvil and a charge of fulminating material are disposed. Each lamp is supported on the wall member 26 to project normal therefrom, and thus axially parallel to the base 24, by means of a respective bore 56 (also see FIG. 2) into which the primer tube 54 is inserted. That is, there are two rows of four bores56 as shown in FIG.
Each of the preenergized striker springs 41-48 is substantially identical and comprises a folded torsion device typically formed from 0.021 inch music wire about 2.5 inches long. Referring to FIG. 4, and the numerically identified elements Qof spring 42, the wire is shaped to form a hairpin torsional section having segments 58 and 60 joined by a bight 62; The end portion Initially the striker 68 may be formed at an angle of about 90 to the stationary supporting foot 64, although the angle through which the striker is rotated to position it behind catch 66, as shown, may be of any value that does not cause over stressing of the wire. The wall member 26 is shaped to provide a suitable bearing surface 70 for the heel of the striker during cocking. This bearing surface also aids in preventing accidental displacement of the spring sufficiently to free the striker from the catch some time after cocking and before firing is intended.
Sequential displacement of each cocked striker 68, to release it from the catch 66 and thus permit it to strike the percussive primer. tube 54 and tire the associated lamp, is effected by a selective actuating mechanism in accordance with the invention. Referring to FIGS. 2-4, the actuating mechanism comprises a slidable bar 72 having five linearly spaced projecting ramps 81-85 disposed along one side thereof. The bar 72 is retained in a longitudinal channel 86 in wall member 26 which is located between and parallel to the two rows of strikers 41-44 and 45-48. Each of the cocked strikers 68 of the springs 41-48 projects beyond the peripheries of channel 86 to overlie a portion of the slidable bar 72. In particular the strikers of the row of springs 41-44 project in a direction opposite that toward which the strikers of row 45-48 project, with the free end of each striker 68 disposed to lie in the of segment 58 is shaped to define a' stationary supporting foot 64, the tip of which is shaped to define a catch 66. The end of segment 60 is shaped to define a striker 68, which when the spring is preenergized, or cocked, as shown, crosses over the supporting foot 64 and is retained by catch 66. The stationary supporting foot 64 is seated in an elongated slot formed in the wall member 26, the slot being sufficiently shallow so that the catch 66 formed in the free end of the foot 64 will project above the upper surface of the wall member 26.
path of travel of one ofthe ramps 81-85 on bar 72. Hence, upon translationally indexing the bar 72 along channel 86, the striker adjacent to an up-coming ramp (such as striker 68 of spring 45 is adjacent to ramp 8]) is pushed upwardly by the ramp a distance sufficient to clear the top of catch 66. The striker then swings clockwise, as viewed facing the mounting surface of wall member 26, and hits and indents the impact sensitive primer tube 54 at ahigh velocity to cause deflagration of the'fulminating materiallocated therein and thus ignite the combustible foil 52.
Bar 72 may be retained in channel 86 by means of tabs 88 which project from the top of channel 86 and overlie a portion of the bar 72. The ramps 81-85 do not dexed. Tabs 88 prevent the bar 72 from moving up out of channel 86 after some of the springs have been released and prevent inadvertent spring release and consequent lamp flashing due to movement of the bar 72 if the array is dropped on its face.
To enable indexing of the slidable bar 72 in equal increments, eight evenly spaced ratchet drive teeth 90 are provided on a side of the bar adjacent that on which the ramps are located. More specifically, referring to FIGS. 4-6, the ramps 81-85 aredisposed along the top of the bar 72, while the ratchet drive teeth 90 are located in the lower half of the adjacent side of bar 72, as illustrated. The teeth 90 are rendered accessible to external actuating means through an aperture 92 which extends through wall member 26 from its edge at the base 24 to the side of channel 86 (FIGS. 3 and 4). For example, translational indexing of the bar from left to right may be effected by a suitable actuating member 94 (FIG. 2) moving up'through the aperture 92 to engage one of the teeth and then moving laterally to the right to translate the bar 72 along channel 86. More specifically, member 94 pushes bar 72 to the right a distance x determined by the length of aperture 92 and the spacing of drive teeth 90. This action causes one of the ramps on bar.72 to lift its associated spring striker 68 over retaining catch 66. The ramp ends at this point,
and the released spring drvies the striker into a lamp primer, which action flashes that lamp. Member 94 is 'then disengaged from the ratchet drive teeth by a downward movement and then moved laterally to the left to ready it for the next indexing cycle. The square pattern of arrows below actuating member 94in FIG. 2 illustrates this path of travel. In a typical application,
actuating member 94 may be part of a camera mechanism designed to enable the photographer to flash a lamp in synchronization with the tripping of a camera shutter to'take a picture.
The bottom of base 24 may be provided with suitable means for mounting the photoflash assembly 10 on apcessive indexing ofthe slidable bar by member 94.
Thus, for example, eight rapid'flash exposures may be taken with the camera without the need for moving the lamps or rotating the unit. The sequence of releasing the strikers in response to indexing is programmed by the number and respective locations of the ramps along the length of the slidable bar and the respective location of the spring strikers 68. In this case, five ramps on the bar 72 are arranged so that for a selected increment of translation along the channel 86, the bar travel will cause a first ramp on that bar to release a strikerand a second ramp on that bar to be moved to a position adjacent another preenergized striker; This pattern of ramp positioning then continues'for all successive x increments of translation until all, eight springs have been released.
For example, referring to FIGS. 25, according to one embodiment, there are an equal number of evenly spaced strikers in each of the two rows of springs 4144 and 48. Typically, the common distance D between strikers in each row is equal to the distance between the corresponding lamps in each row, which is determined by the lamp and reflector design. The length of the index increment'x is then based upon this'striker spac ing D and in the present case is equal to D/(n l), where n is the total number of strikers. Hence, it may be stated that the common distance D between strike-rs in each row is .t(n 1), where n is the total number of strikers in the two rows thereof (8) and x is the distance the slidable bar translates along the channel dur- 7 ing each indexing increment for release of a striker. ln
this instance, therefore, the spacing between strikers in each row is 9.\'. It will be noted that the number of ramps equals n/2 l, which in this instance is 5'. The
' first ramp 81' is adapted to release the first striker in wall member 26 comprises a slot parallel to the side of channel 86 and having a length of 2):.
Thus, in FIG. 5, ramp 8! is positioned adjacent the striker spring 45, which is the first to be released in the firing sequence. Ramp 82 is spaced 7x from ramp 8] and, thus, is spaced a distance x from striker spring 41 and a distance 2): from striker spring 46. Ramp 83 is spaced 3x from strikerspring 42 and 4x from-striker spring 47. Ramp 84 is spaced 5x from striker spring 43 and 6x from striker spring48. The last ramp 85 is spaced distance 7x from striker spring 44. Accordingly, the spring release sequence will be: (1) spring 45 by ramp 81; (2) spring 41 by ramp 82; (3) spring 46 by ramp 82', (4) spring 42 by ramp 83; (5) spring 47 by ramp 83; (6) spring 43 by ramp 84; (7)spring 48 by ramp 84; and (8) spring 44 by ramp 85. I
This ram'p arrangement requires no extension of the base to accommodate movement of the release bar since the flash sequence moves in the same direction as the movement of the bar itself, i.e., left to right as illustrated. The only travel space required is a minimum distance of 8x from the right end of the bar to the-right end of the channel. Hence, the minimum length imposed on channel 86 is x (n n 2)/2 and, thus, is dependent on the number of strikers (lamps) n and the striker spacing D, from which x is determined.
Referring to FIG. 5,-the new position of the slidable bar 72 is retained after eachindexing cycle by means of a detent mechanism, which may comprise a spring loaded ball 98 engaging one of nine notches 100 provided along the bottom of bar- 72. The spring loaded ball 98 is retained in a cylindrical cavity (not shown) provided in the wallmember 26 at the bottom of channel 86. I
Accordingly, by virtue of the mechanical firing system, the ramp programming, and the detent control,
the" present flash assembly'provides 'a self-contained memory function, whereby the next unused lamp in the flash sequence will always be ready for immediate triggering, even thoughtlte unit may have been removed from a'camera and subsequently replaced. This is a sig- I nificant advantage as compared to electrical arrays.
Although the invention has been described with respect toa specific embodiment, itwill be appreciated that modifications and changes may be made by those skilled in the art without departing from the true spirit and scope of the invention. For example, the number of springs and lamps in the array may be varied, and the sliding bar could move from right to left.
What I claim is:
l. A selective actuating mechanism for a photoflash lamp'array; said array including a support member, a
' plurality of percussively-ignitable flashlamps mounted .in two parallel rows 'on saidsupport member, and a plurality of preenergized strikers mounted in two parallel rows on said support member, each row of strikers being associated with a respective row of said flashlamps and each striker being individually releasable to fire a respective one of said flashlamps; the selective I actuating mechanism comprising, in combination:
a longitudinal channel in said support member located between and parallel to said two rows of strikers;
a slidable bar retained in said channel; and,
means provided on said slidable bar for sequentially releasing said preenergized strikers to tire respective flashlamps of said array in response to successive indexing of said slidable bar along said channel. I
2. The mechanism of claim 1 wherein the sequence of releasing said strikers is programmed by the spatial disposition of said releasing means on said slidable bar and the respective location of said strikers.
3. The mechanism of claim 1 wherein said strikers are mounted so that, in the preenergized conditions, said strikers project beyond the peripheries of said channel to overlie a portion of said slidable bar, the strikers associated with one of said rows of lamps projecting in a direction opposite that toward which the strikers associated with the other row of lamps project.
4. The mechanism of claim 3 wherein said releasing means comprises one or more ramps, and the sequence of releasing said strikers is programmed by the number and respective location of said ramps along the length of said slidable bar and the respective location of said strikers. Y
5. The mechanism of claim 4 in which there are an equal number of evenly spaced strikers in each of said rows of strikers, the distance between strikers in each row is .r(n l), where n is the total number of strikers in the two rows thereof and x is the distance said slidable b'ar translates along said channel during each indexing increment for release of a striker, the number of said ramps equals n/2 l, the first ramp on said bar is adapted to release the first striker in one of said rows of strikers, the last ramp on said bar is adapted to release the last striker in the other of said rows of strikers, each of the ramps intermediate said first and last ramps is, adapted to sequentially release twooppositely projecting strikers, each set of two oppositely projecting strikers to be released by one of said intermediate ramps is spaced apart by a distance x', and said ramps are evenly spaced apart by a distance of (n l)x.
6. The mechanism of claim 5 wherein the minimum length of said channel is x(n n 2)/2.
7. The mechanism of claim 1 further including a plurality of ratchet drive teeth on said slidable bar which are engagable for indexing said bar.
8. A photoflash assembly comprising, in combination a substantially planar .base member;
a substantially planar wall member secured to said base member and disposed substantially normal thereto, said wall member containing a longitudinal channel;
a plurality of percussively-ignitable flashlamps mounted in two parallel rows on the side of said wall member containing said channel with the longitudinal axes of said lamps projecting parallel to said base member;
a plurality of preenergized strikers mounted in two parallel rows on said wall member with said longitudinal channel located between and parallel to said rows of strikers, each row of strikers being associated with a respective-row of said flashlamps and each striker being individually releasable to fire a respective one of said flashlamps;
a slidable bar retained in said longitudinal channel;
means projecting from said slidable bar and adapted for selectively releasing said preenergized strikers;
to successive indexing to sequentially release said strikers by means of said projecting means to fire respective ones of said flashlamps.
10. The assembly of claim 9 wherein the preenergized strikers mounted on said wall member project beyond the peripheries of said channel to overlie a portion of said slidable bar, and said means projecting from said slidable bar comprises one or more ramps linearly disposed along one side of said bar, said sequence of releasing said strikers being programmed by the number and respective location of said ramps along the length of said slidable bar and the respective location of said strikers.
11. The assembly of claim 10 wherein said means accessible to be engaged for indexing said slidable bar comprises a plurality of evenly spaced ratchet drive teeth, said teeth being disposed on a side of said bar adjacent that on which said ramps are located, and said aperture being located on a side of said channel.
12. The assembly of claim 11 wherein there are an equal number of evenly spaced strikers in each of'said rows of strikers, the distance between strikers in each row is x(n l), where n is the total number of strikers in the two rows thereof and x is the distance said slidable bar translates along said channel during each indexing increment for release of a striker, the number of said ramps equals n/2 l, the first ramp on said'bar is adapted to release the first striker in one of said rows of strikers, the last ramp on said bar is adapted to release the last striker in the other of said rows of strikers, each of the ramps intermediate said first and last ramps is adapted to sequentially release two oppositely projecting strikers, each set of two oppositely projecting strikers to be released by one of said intermediate ramps is spaced apart by a distance x, and said ramps are evenly spaced apart by a distance of (n l)x.
13. The assembly of claim 12 wherein the minimum length of said channel is x(n n 2)/2.
14. The assembly of claim 10 wherein: each of said flashlamps has a primer tube depending therefrom; said wallmember contains a plurality of bores each for receiving the primer tube of a respective one of said flashlamps to provide support therefor; and, each of said preenergized strikers is a portion of a folded torsion spring comprising a substantially hairpin torsional section having two segments joined by a bight, said striker portion projection from one of said segments, a supporting foot projecting from the other of said segments and fixedly mounted on said wall member, and a catch formed at the tip of said foot, said striker portion crossing said foot with said catch restraining said striker portion in a cocked condition.
15. The assembly of claim 14 further including an array of substantially concave reflectors each disposed coaxially about a respective one of said flashlamps, the optical axes of said reflectors being substantially perpendicular to said wall member and said reflectors all facing in one direction away from the side of said wall member upon which said flashlamps are mounted.