US2340893A

US2340893A - Instrument for firing pin inspection

Info

Publication number: US2340893A
Application number: US467544A
Authority: US
Inventors: Meister Leo
Original assignee: Individual
Current assignee: Individual
Priority date: 1942-12-01
Filing date: 1942-12-01
Publication date: 1944-02-08
Anticipated expiration: 1961-02-08

Description

Feb, 8, 1944. L. MEISTER INSTRUMENT FOR FIRING PIN INSPECTION Filed Dec. 1, 1942 .M ii.li-L

Elma/14m i-sier Lem ME Patented Feb. 8, 1944 UNITED STATES PATENT OFFICE (Granted under the act of March 3, 1883, as I amended April 30, 1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to apparatus for inspecting and testing firing pins in the course of their production preparatory to being placed in the explosive shell or projectile, and more particularly, to the type of firing pin provided with a collar. The object of this invention is to devise apparatus for inspecting firing pins of the type described, more particularly, to inspect such pins with reference to the dimension between the conical point of the pin and the underside surface of its collar. It is of prime importance to the satisfactory performance of the firing pin that this dimension be maintained within close tolerance of standard. A further object of this invention is to provide an inspection apparatus of the character described which will be capable of high accuracy, simple to manipulate, of large productive capacity, and adapted to be readily adjusted to accommodate different kinds and sizes of firing pins.

For the attainment of these and such other objects of inventions as may herein appear or be pointed out, I have shown one embodiment of my invention in the accompanying drawing, wherein:

Fig. 1 is a side, sectional elevation of the machine.

Fig. 2 is a plan view thereof.

Fig. 3 is a partial sectional view taken on the line 3-3 of Fig. 2, and

Fig. 4 is an isometric View of the finger block of the rejecting manual.

The top surface In of the apparatus is provided with a long grooved passage H extending along the length thereof of sufficient width to accommodate the collar 2 of firing pins I and provided along its bottom with a long slotted passage l2; both the groove l l and slot [2 are open at both ends of apparatus table I 0, so that the firing pins may be inserted at one end (the end lowermost on the sheet, Fig. 2) and removed, at least, the ones passing inspection, at the other end (the end uppermost on the sheet, Fig. 2). Fresh pins, inserted as described, are moved along the grooved (H) slot l2 to be singly received in a rejecting manual 20, more particularly, in the finger 2i thereof. Rejecting finger or block 2| is secured to one end of a rod 22, the other end of which extends through the front wall I3 of the machine where it terminates in a knob 23. A collar 24 is fastened on rod 22; compression spring 25 interposed between collar 24 and machine wall l3 normally maintains finger block 2i in its rightmost position (as viewed in Figs. 1 and 2).

Finger block 2| is provided with a ledge 26 which is fiush with the top surface of the slotted (12) bottom of groove H. In the rightmost, normal position of finger block 2!, its ledge 26 is spaced from the opposite side of slot 12 a distance equal to the width of the slotted passage I2. Hence in the normal, right most position of rejector manual 20, particularly, its finger ledge 26, the ledge will provide a surface to support the collar 2 of firing pins l as they are moved up (as viewed in Fig. 2) to the rejector manual. For the purpose of aligning the single pins precisely on the center line of the rejector manual (rod 23) and for holding the pin thereat, the finger ledge 26 is provided with a V-shaped notch 21, see Fig, 4. The compression spring 25 together with notch 27 cooperate as a detent to accurately position the individual pin as it is moved to the rejector manual 2t.

A firing pin, properly positioned at, and held by, the rejector manual 2% as shown in Fig. 1, has its conical (lower) point substantially in the center line AA of an optical system now to be described. An incandescent lamp 3! and condenser lenses 32 are contained in a collimating tube at, the centers of the lamp, condenser and tube being substantially on the said optical center line A-A. Collimating tube 30 is supported, preferably by the adjustable pivot connection I 4, at the upper end of a standard I5 resting on the floor is of the machine for an extent of sliding movement. Rod I'l, screwed into standard l5, may be turned, as by its knob It at the front of the machine, to adjust the position of the collimating tube relative to the suspended pin I, Fig. 1.

Light from the collimating tube 36 is directed to flood the suspended pin (i) held in position at the rejector manual, and to pass through a. lens tube 33 containing one or more enlarging lenses. As clearly shown in Fig. 1, lens tube 33 is suspended as by means of a pivot connection Hi from the top surface ill of the apparatus. The enlarged image or shadow of the firing pin under inspection, emerging from lens tube 33, is directed to mirror or reflecting surface 34, from which it is reflected onto ground glass screen 35 set in the front panel of the apparatus. Reflector 34 is mounted, as by a pivot connection, Fig. 1, for adjustment to reflect the enlarged pin shadow upon the ground glass 35.

The enlarged shadow of a firing pin held at (and by) rejector manual 20, is observed in ground glass 38, to determine whether the aforementioned dimension between its conical point and its collar 2 is accurate within the prescribed tolerances. To make this determination precisely, a gauge 40 (see especially Fig. 2) is pivotally mounted, as by wing screw 4|, on ground glass 35. Gauge 40 is made adjustable to accommodate different lengths or types of firing pins.

If the enlarged pin shadow on the ground glass screen is of the proper height (as determined by gauge 40) the pin under observation is continued along the slotted passage [2 to emerge from the uppermost end (as viewed in the sheet, Fig. 2) of the slotted passage for deposit in a box or container 5 reserved for pins which had passed the inspection test. If the pin shadow is above or below the gauge 40, rejector manual 20 is pulled outwardly, to withdraw ledge 26 from underlying relation to pin collar 2, thus causing the rejected pin to fall through slot II for deposit in discard or reject box 8.

In the operation of the apparatus, the operator uses both hands, one hand for pushing the fresh firing pins to the rejector manual 20 and for pushing the good pins beyond the rejector manual and into the collecting box 5; the other hand is held on the knob 23 of the rejector manual ready to pull out the manual whenever an unsatisfactory pin is encountered, to drop the pin into discard box 6. The firing pins may be conveniently and rapidly assembled in the grooved passage III by being placed on the sloped top surface ill, see Fig. 1, and permitted to roll down to seat themselves in the grooved passage.

I claim:

1. In apparatus for inspecting firing pins of the type provided with a collar with reference to the dimension between its point and the uni derside of its collar, a table surface provided with a passage sufilciently wide for the pins to clear and grooved to accommodate their collars, the said grooved passage being open at both ends of the said table for receiving fresh pins at one end and for removing approved pins at the other end, a recess in one side of the said grooved passage and enlarged at one point sufiiciently wide for the firing pin collar to drop through, a block disposed in the said recess and rabbetted to conform to the said groove and to present a ledge spaced from the opposite edge of the said passage a suflicient distance for pin clearance, a rod extending from the said block to an accessible point at the front of the: apparatus and terminating in a knob, spring means urging the said block rearwardly to position its ledge in supporting relation to the pin collars, whereby in the normal position of the said block the firing pins in being moved along the said grooved passage will pass the enlarged point, a V-notch provided in the said block ledge for centering the pins, an optical system including a light source, an enlarging objective, a condenser for collimating light beams past the suspended point of a firing pin held at the said enlarged point of the grooved passage into the said objective, a reflecting surface positioned in said light beam and a ground glass screen to receive an enlarged image of the said block according to the inspected dimension as shown by the said gauge.

2. In apparatus for inspecting firing pins of the typ provided with a collar with reference to the dimension between its point and the underside of its collar, a table surface provided with a passage sufiiciently wide for the pins to clear and grooved to accommodate their collars, the said grooved passage being open at both ends of the said table for receiving fresh pins at one end and for removing approved pins at the other end, a recess in one side of the said grooved passage and enlarged at one point sumciently wide for the firing pin collar to drop through, a block disposed in the said recess and rabbetted to conform to the said groove and to present a ledge spaced from the opposite edge of the said passage a sufficient distance for pin clearance, a rod extending from the said block to an accessible point at the front of the apparatus and terminating in a knob, spring means urging the said block rearwardly to position its ledge in supporting relation to the pin collars, whereby in the normal position of the said block the firing pins in being moved along the said grooved passage will pass the enlarged point, an optical system including a light source, an enlarging objective, a condenser for collimating light beams past the suspended point of a firing pin held at the said enlarged point of the passage into the said objective, a reflecting surface positioned in said light beam and a ground glass screen to receive an enlarged image of the pin, and a gauge associated with the said screen for measuring the said inspected dimension on the enlarged image.

3. In apparatus for inspecting firing pins of the type provided with a collar with reference to the dimension between its point and the underside of its collar, a table surface provided with a passage sufficiently wide for the pins to clear but not for their collars, the said passage being open at both ends of the said table for receiving fresh pins at one end and for removing approved pins at the other end, a recess in one side of the said passage and enlarged at one point sufiiciently wide for the firing pin collar to drop through, a block disposed in the said recess and normally spaced from the opposite edge of the said passage a sufllcient distance for pin clearance, a rod extending from the said block to an accessible point at the front of the apparatus and terminating in a knob, spring means urging the said block rearwardly tu position its ledge in supporting relation to the pin collars, whereby in the normal position of the said block the firing pins in being moved along the said passage will pass the enlarged point, an optical system including a light source, an enlarging objective, a condenser for collimating light beams past the suspended point of a firing P held at the said enlarged point of the passage into the said objective, 9, reflecting surface positioned in said light beam and a ground glass screen to receive an enlarged image of the pin. a gauge associated with the said screen for measuring the said inspected dimension on the enlarged image, and a box underlying the said passage at its said enlarged point for receiving disapproved pins falling through the said enlargement upon pulling the knob of the said block according to the inspected dimension as shown by the said gauge.

4. In apparatus for inspecting firing pins of the type provided with a collar with reference to the dimension between its point and the underside oi its collar, a table surface provided with a passage sufllciently wide for the pins to clear but not for their collars, the said passage being open at both ends of the said table for receiving tresh pins at one end and for removing approved pins at the other end, a recess in one side 01 the said passage and enlarged at one point sufliciently wide for the firing pin collar to drop through, a slidable block disposed in the said recess and normally spaced from the opposite edge of the said passage a sufilcient distance for pin clearance, whereby in the normal position or the said block the firing pins in being moved along the said passage will pass the enlarged polnt means for retracting said block, on optical system including a light'source, an enlarging obiective, a condenser for collimating light beams past the suspended point ota firing pin held at the said enlarged point or the passage into the said objective, and a ground glas screen to receive an enlarged image of the pin, a gauge associated with the said screen for measuring the said inspected dimension on the enlarged image, a, box underlying the said grooved passage at its said enlarged point for receiving disapproved pins, and manual means for withdrawing the said block to the type provided with a collar with reference to the dimension between its point and the underside of its collar, a table surface provided with a passage sufilciently wide for the pins to clear, the said passage being open at both ends of the said table for receiving fresh pins at one end and for removing approved pins at the other end, a recess in one side of the said passage and enlarged at one point sufficiently wide for the firing pin collar to drop through, a slidable block disposed in the said recess and normally spaced from the opposite edge or the said passage a sufiicient distance for pin clearance, whereby in the normal position or the said block the firing pins in being moved along the said passage willpass the enlarged point, means for retracting said block, an

optical system including a screen; tor-collimating light beams past the suspended point of a firing Din held at the said recessed point of t e" LEO MEIS'I'ER.