US2337259A

US2337259A - Tube testing apparatus

Info

Publication number: US2337259A
Application number: US405899A
Authority: US
Inventors: Mason Joseph
Original assignee: United Aircraft Products Inc
Current assignee: United Aircraft Products Inc
Priority date: 1941-08-08
Filing date: 1941-08-08
Publication date: 1943-12-21
Anticipated expiration: 1960-12-21

Description

J M A s o N 2 3 3 7 2 59 TUBE TESTING APP AAAA US Dec. 21, 1943. J MASON TUBE TESTING APPARATUS Filed Aug. 8, 1941 4 Sheets-Sheet 2 Dec. 21,- 1943. J. MASON TUBE TESTING APPARATUS Filed Aug. 8., 1941 4 Sheets-Sheet 3 l l I ll y! H!!! mm g Y Q 3 g a NW hm QQ RN D A W .IN"ENTOR.

4055 11 MASON BY 4 v M Pic 6 Dec. 21, 1943. J; MASON 2,337,259

TUBE TESTING APPARATUS Filed Aug. 8, 1941 4 Sheets-Sheet 4 s n g PM V Q gg Z n STOCK v 80 151M070)? For? Y as Q N N v ENTOR.

JOSf MASON Patented Dec. 21, 1943 TUBE TESTING APPARATUS Joseph Mason, Providence, R. 1., assignor, by

mesne assignments, to United Aircraft Products, Ina, Dayton, Ohio, a. corporation of Ohio Application August 8, 1941, Serial No. 405,899

4 Claims.

This invention relates to improvements in tube testing apparatus and especially to automatic apparatus for subjecting a series of tubular articles to reduced internal pressure to test such articles for leakage, and for automatically discharging the leaky articles and the perfect articles at separate stations. It is primarily applicable to testing machines of the rotary type in which open-ended tubular articles are fed successively to an annular series of receiving stations extending around the periphery of a rotating unit, arranged to subject each article to reduced internal pressure and to release leaky articles for discharge prior to the discharge of perfect articles at a receiving station.

A general purpose of the invention is to improve the construction and arrangement of the mechanism which engages the ends of the articles at each station, reduces the internal pressure of each article and then releases the mechanical pressure on the article-engaging elements, whereby the latter are held in place solely by the reduced pressure in the article, and are released prematurely when leakage through the article raises the internal pressure to that of the external atmosphere.

Mechanism of this type heretofore employed on rotary testing apparatus has been complicated and has generally included objectionable projecting parts and external framework. The present invention provides a compact, simplified structure free from such projections or framework. It also includes a novel arrangement for adjusting the apparatus to accommodate articles of different sizes, as well a an improved construction for ejecting tubes that tend to remain on the rotary structure beyond the proper point of discharge.

Other objects and advantages will appear from the following description considered in connection with the accompanying drawings in which Fig. 1 is a front elevation of a machine embodying the invention, with parts broken away;

Fig. 2 is a vertical central section on line 22 of Fig. 1 with parts broken away and the central shaft portion shown in elevation;

Fig. 3 is a fragmentary rear view of the rotary unit with parts broken away;

Fig. 4 is a enlarged fragmentary radial section on line 4-4 of Fig. 3, showing the tube clamping mechanism;

Fig. 5 is a fragmentary view on line 5-5 of Fig. 4 showing a tube knock-out device for defective tubes in operative position;

Fig. 6 is a similar view with the device in inoperative position; and

Fig. '7 is a side elevation of the knock-out device.

The invention is illustrated in its application to a rotary testing apparatus suitable for testing metal tubes such as those employed in the manufacture of automobile radiators and the like. In this specific embodiment the apparatus includes a base ID on which the front standard H and rear standard [-2 are mounted. Horizontal shaft I3 revolves in bearings l4 and [5 on standards l2 and II respectively, and is provided at its rear end with a drive sprocket l6 and chain ,ll driven from any suitable source (not shown).

The rotary testing unit is mounted on shaft. l3 between bearings l4 and [5. It comprises two aligned heads, the front head l8 bein fixed to shaft l3 adjacent bearing [5, by key is, while the rear head 20 is mounted on shaft l3 adjacent rear bearing l4 and is suitably held in place on the shaft adjacent said bearin as by means hereafter described in detail.

Heads l8 and 20 are provided with registering annular peripheral portions carrying means for initially receiving and positioning successive tubes at a series of stations and means at each station for testing and selectively releasing the tubes. The specific construction for receiving and holding the tubes, shown best in Figs. 3 and 4, includes an inwardly xtending flange 2| on front head 18 provided with a series of radial recesses 22 and an inwardly extending flange 23 on rear head 20 provided with radial recesses 24.

Each recess 22 is arranged in axial alignment with a recess 24 to provide a cradle 25 for a tube or other elongated hollow article to be tested, recesses 22 and 24 being preferably shaped to fit loosely around the lower face of each article and to extend along the sides of the article for a sufficient distance to hold the article in place in the cradle until it is engaged by the clamping means, or descends approximately to the level of shaft I3. I

The peripheries of heads I8 and 20 are provided with registering pairs of clamp members in alignment with cradles 25, each pair of clamp members including a fixed seat for one end of a tube and a movable seat shiftable into engagement with the other end of such tube located in a cradle 25. In the construction illustrated the periphery of front head I 8 is provided with a series of stationary yieldable seats 26 mounted in suitable sockets 21 and each. provided with a.

central opening 28 communicating with a bore 29 extending through head I8. Each bore 29 is provided with an air-tight connection to a registering radial bore 38 in a pIOjecting boss 3| formed in head l8. In the form shown each pair of bores 29 and 3!) is connected through a metal tube 32 extending radially along the outer face of head l8 with its ends seated in bores 29 and 30. a ,The inner end'of each bore .30 is connected with an aperture in the face of a rotary valve member carried by the central portion of head [8. In the form shown the valve member is formed by an annular projection or hub 33 on head it provided with a conical outer face 34. Each radial bore 38 is connected through an axial bore 35 with an opening 36 in face 34, the openings 35 forming an annular series.

A suitable cooperating fixed valve member is provided, the form illustrated including an outer valve member 3? slidably mounted on the outer face of bearing 85 and having a conical face 38 fitting tightly against face 34. Valve member 31 is provided with an exhaust aperture 39 in face 38 registering with openings 36 and connected through exhaust passage 40 in member 31 to a suction line 4| extending to a suitable exhaust pump or the like (not shown), and an air relief inlet passage 42 extending through outer valve tl to the outer air from an aperture 43 in face 38 in register with openings 36. Annular sealing grooves 44, normally filled with oil, may be provided on

valve faces

34 and 38 at either side of openings 35 and 39 to minimize the leakage of air.

Means is provided for holding outer. valve member 31 in non-rotating position with face 38 held under pressure against face 34 of the inner valve member 33. The construction illustrated for this purpose comprises an expansion spiral spring 45 attached at one end to the valve member 3! and at the other end to a sleeve 48- slidably mounted on the outer face of bearing l5, said spring being interposed between said valve member and said sleeve so as to react from the latter to urge the former against the hub 33. Sleeve .46 is held against rotation and adjustably inposition to compress springs 45, as by a plu rality of circumferentially arranged screws 41 threaded through flange 48 on bearing l and fitting into suitable sockets in sleeve 46, screws 41 being held inadjusted position by lock nuts 49. Shaft I3 is held against the thrust of the springs 45 by a suitable thrust roller bearing 50 engaging the outer face of bearing I5 and connected to shaft l3 by screws 5|.

An annular series of axially movable seat members 52 is carried by the periphery of rear head 20 in register with fixed seats 26. Each seat member 52 includes a head 55 provided with a yieldable seat 54 in a suitable socket 55 in the front of the head, and a stem 56 slidable in a bore'5l in rear head 29. A cam bead 58 is mounted'on the end of stem 56 and is slidable in an enlarged bore 59, coil spring 58 being arranged in bore 59 and bearing against the inner end of the bore and the inner face of cam head 58 to urge the seat member 52 into retracted position.

Each cam head 58 is provided with a diagonal cam face 5|; and suitable radially reciprocating means engaging cam face El is provided for shifting the seat member 52 axially into tubeengaging position. The illustrated construction comprises a plurality of radial push rods 64, one for each cam member 58, slidably mounted on games the outer face of rear head 20 and actuated by suitable cam means. As shown, each rod 64 is provided with a bevelled end face 65 flush with and slidable along cam face 5! of head 58, and is slidably mounted in a radial guideway 66 in an annular guide flange 6? extending along the outer portion of the rear head 28, the bores 59 being formed through flange 61. The push rods 64 are held in guideways 66 by a removable annular retainer plate 68 which may be sectional and held in place by screws 69, plate 68 being advantageously provided with openings registering with bores 59. Each push rod 54 is also slidable in a guideway 18 in annular guide flange H on the outer face of rear head 28 and is held in said guideway by an annular retainer plate 72 which may be sectional and held detachably in place by screws 13.

The inner ends of push rods 64 are maintained in yielding engagement with a stationary disk cam T5 carried by rear bearing H4. The peripheral face 16 of cam 15 is formed with a depressed section ll positioned to maintain push rods 54 in retracted inactive position and a raised section 18 arranged to shift push rods 64 radially outward against cam heads 58, thereby moving seat members 52 into engagement with tubes seated in

recesses

22 and 24.

Suitable means is provided for holding each push rod 64 in engagement with cam 15 and advantageously for providing a yielding connection between cam 15 and seat members 52 to prevent excessive pressure on the tubes 88 through the action of cam 75. In the arrangement illustrated each push rod 64 is provided with a coil spring 8! bearing against the inner face of guide flange H and a collar 82 adjustably fixed on the rod, thereby urging such rod inwardly against cam face 16.

Yielding engagement with said cam face is provided by threading each push rod 84 into a cylindrical tip 83 provided with a bore 84 in which a hollow plunger 85 is slidably mounted, the outer end of the plunger being suitably rounded and adapted for sliding engagement with cam face 16.

Plunger 85 is retained in bore 84 as by tongue 86 projecting into longitudinal slot 81 in tip 83, and is urged outwardly by coil spring 88 in bore 84. Spring 88 is sufficiently strong to maintain plunger 85 in its outer position against the pressure of springs 60 and 8| during outward radial movement of push rod 64, being yieldable only under resistance offered by a tube 80 after seat 54 has engaged the end of the tube, thereby limiting the pressure on the tube to that exerted by spring 88. Tips 83 are slidably mounted in guide channels 89 in annular guide flange 90 projecting from rear head 28, and are held in place by annular retainer plate 9| which may be sectional and held detachably in place by screws 92.

Suitable means is provided for feeding tubes 80 successively to successive cradles 25 during rotation of heads 18 and 28, the form illustrated being provided with a hopper having a discharge spout 95 located directly above and in alignment with

recesses

22 and 24, the advance face of spout 96 terminating just above the path of the outer surface of a tube properly positioned in said recesses to permit the tube to pass beneath said face, but to retain the succeeding tube during passage of the concentric portions of flanges 2| and 23 intermediate the recesses until the next pair of

recesses

22 and 24 come into register with spout 96 and permit the succeeding tube to drop into place in said recesses.

' An arrangement is provided for adjusting the distance between seats 26 and seats 54 to adapt the apparatus to handle tubes of different lengths. This is in general accomplished by axially shifting rear standard I2 and head 20. For this purpose standard I2 is slidably mounted on base I0, as by bolts 94 passing through suitable slots in the base I into threaded engagement with clamping blocks 91. Adjusting screw 98 is threaded through standard I2 and is rotatably mounted at its inner end in pillow block 99 attached to base I0, collars I00 fixed on screw 98 engaging opposite faces of block 99 and preventing longitudinal movement of screw 98. The projecting outer end of said screw is detachably engaged by a suitable crank It" for adjusting standard I2 and head 20 when required, bolts 94 being loosened during such adjustment.

A suitable arrangement is provided for maintaining heads I8 and 20 in axial alignment throughout the entire range of axial adjustment,

and for holding rear head 29 in position on shaft I3. For this purpose front head I8 is provided with a plurality of tongues I02 extending around shaft I3 and having a close axial sliding fit with tongues I03 extending from rear head 20. Tongues I02 and I03 are of suitable length to overlap when head 20 is at itsmaximum distance from head I8, and are conveniently formed with registering cylindrical inner and outer faces and with abutting radial side faces.

In order to permit head 20 to be moved close to head I8 in handling very short tubes, the central portion of head I8 may be provided with recesses I04 accommodating the ends of tongues I03 and the central portion of the head 20 may be provided with recesses I05 adapted to receive the ends of tongues I02. Head 20 is suitably held in juxtaposition to bearing I4, during operation as by set screw I06 threaded through a tongue I03 into engagement with shaft I3. Set screw I06 will of course be released during adjustment of the position of head 20.

A feature of the invention is the construction and arrangement of heads I8 and 20 and of the various supports and guides associated with them so that each head and its associated parts may be formed integrally from a single casting. Specifically the casting for head I8 may include flange 2I. boss 3!, hub 33 and tongues I02, and the casting for head 20 may include flanges 23, 61, II and 90- and tongues I03.

Suitable means is provided for receiving separately the perfect tubes discharged at a predetermined station and the imperfect tubes which are discharged prior to reaching said station. In the form illustrated a hopper H0 extends along the descending side of the rotary unit from a point slightly above the level of the axis of shaft I3 to a point adjacent the lowermost portion of heads I0 and 20, in position to receive tubes released by the retraction of seat members 50 due to leakage through the tubes. A hopper III for perfect tubes is located adjacent heads I8 and 20 toward the bottom of the rising portion of the unit in position to receive perfect tubes intentionally released by the clamping mechanism.

Under certain conditions a tube 80 may stick in place despitethe retraction of the corresponding seat member 52; and knock-out means may be provided for positively discharging such tube from the apparatus, An arrangement of this type may be provided which is suitable both for the discharge of perfect tubes which are intentionally released at th discharge station, and

for the discharge of leaky tubes which are pre maturely released in advance of said station, or for either purpose alone.

A device of this type is illustrated in its application to the discharge of defective tubes and is shown in Figs. 5 to '7. It comprises a standard II5 mounted on base I0 and carrying a trip arm II-6 pivoted on pin II! to swing at right angles to shaft I3 in a path adjacent the inner face of the peripheral portion of rear head 20, which carries movable seat members 52. A trip extension N8 of arm IIB extends inwardly into the path of heads 53 of the seat members 52 when the heads are in inactive retracted position shown in Figs. 2 and 6; but passes between said heads and the inner face of rotating head 20 when heads 52 are in extended tube engaging position as shown in Fig. 4.

Trip arm H6 is provided with a tailpiece II9 carrying a pin I20 working in a slot I2I in rocking lever H2 fixed to rod I 23 and having a tailpiece I 24 urged toward head-engaging position shown in Fig. 6 by pring I25 attached to stand.- ard I I5. Rod I23 is pivotally mounted in standard H5 and instandard I25 on base I0, located adjacent the periphery of rotary head I8. Rod I23 carries a knock-out finger I21 in alignment with the approximate longitudinal center of tubes positioned between seats 26 and 54, finger I21 including an end portion I28 normally lying just outside of the path of tubes but constructed and arranged to extend inwardly between tubes 80, when actuated by trip arm II 6, to engage the inner face of the succeeding tube and force said tube outwardly to discharge. For this purpose end portion I28 may be suitably curved inwardly at its lower part to clear the subjacent tube, and recurveol adjacent its outer end to provide an outer tube-engaging face I29 which may be inclined downwardly and outwardly across the path of the tubes, thereby serving to impose a gradual outward pressure on descending tubes coming in contact with said face.

A suitable receiver i advantageously located in register with knock-out finger 521 in position to receive tubes forced outwardly by said finger. A modified form of hopper 30 is illustrated, and may be mounted on standards H5 and I26. It is provided with a top I3! to confine tubes that may be thrown outwardly at an angle by finger I21, and may include narrow guide plates I32 on either side of finger I27, detachably mounted on the lower lip of hopper I30 as by bolts BSI.

The knock-out mechanism may be located. at av point sufiiciently below the level of the axis of shaft I3 to permit tubes 80 to be discharged normally by gravity, the knock-out mechanism being eifective in that case only on defective tubes that are improperly retained; but the illustrated type of knock-out mechanism may also be positioned at or about the poin where defective tubes released by the retraction of seat members will be discharged by gravity, this arrangement permitting a much greater restriction of the zone in which defective tubes are discharged.

In operation, after adjustment of the spacing of heads I0 and 20 as already described, tubes 80 are fed from hopper to successive cradles 25 during the rotation of shaft I 3 in the direction indicated by arrows. Seat members 52 are then shifted into engagement with the ends of tubes 80 by the action of section 18 of cam 15 on push rods 64, clamping each tube between seats 26 and 54 which seal the tube end from the outer air. Immediately after a tube is clamped in place by a seat member 52, air is exhausted through the corresponding valve opening 36 and the connections between said opening and the openin 28 in seat 26 communicating with the interior of the tube. The seat member 52 is positively held in clamping engagement with the tube by cam section 18 acting on the corresponding push rod 64 until the air in the tube is exhausted to a point where said member will be held in engagement with the tube by the reduced internal pressure. Thereafter the push rod 64 is retracted by spring 8| when the plunger 85 rides down over the end of the raised cam section 18.

Exhaust aperture 39 extends along the path of openings 35 for a sufficient distance to maintain suction on each tube until the air pressure in the tube is reduced to the desired point.

Thereafter each opening 36 travels past the end of aperture 39 and the suction connection is broken. If the tube is perfect the reduced pressure will hold seat member 511 against the tube and will retain the tube in place until the aperture 36 comes into register with relief aperture 43, through which air will pass from the outer air into the tube, permitting spring 60 to withdraw head 53 and release the tube.

Upon release the tube will be discharged into a suitable receiver such as hopper II I by gravity or through the action of a knock-out mechanism, the point of discharge being normally located in the lower half of the rotating unit so that the tube will not be held by cradle 25; but this disclosure is not intended to be restrictive, since the means disclosed may be arranged so that the tube, when released by restoring the internal pressure to normal, may remain in cradle 25 until positively ejected by the knock-out mechanism if preferred, by locating the point of release above the level of shaft iii.

The reduced pressure in each tube 86 will tend to draw in air through any leak, thereby gradually raising the internal pressure until spring Bil is able to withdraw head 52, releasing the defective tube. The period during which perfect tubes are held in engagement with head 52 is sufficient to permit the release of defective tubes through leakage prior to reaching the point of intentional discharge of perfect tubes. The receiver H for prematurely releasing imperfect tubes extends from about the level of the axis of shaft it downwardly along the periphery of heads i8 and 20 in position to receive tubes released at any point prior to the point of discharge of perfect tubes. If a tube is released through leakage in the upper part of the path of rotation it will be held in a cradle until it approaches the level of said axis and is discharged by gravity.

Where an automatic knock-out mechanism is employed the receiver for defective tubes may be restricted in extent as already indicated. In the operation of the knock-out mechanism the clamping heads fiiiwhich are in engagement with tubes as they pass the extension I 18 of trip arm H6 normally clear said extension, and knockout finger l2'l remains outside of the path of the tube. When a head 53 has been released by a defective tube and is retracted by spring 60, it engages the extension US, which is shaped to ride outwardly on the head, rocking pin 20 inwardly and swinging knock-out finger 527 inwardly against the pressure of spring E25 into position between tubes 89 at a point where face I29 of the finger lies within the path of the succeeding tube, where it is held by engagement of extension H8 with head 53 until the tube in register with said head overlies face I29. Ex tension H8 is shaped to ride inwardly along the further face of head 53 as the latter continues downwardly, moving finger I21 outwardly; and if the tube has been inadvertently retained in place it will be forced out by finger I21 into hop per I30. I

I have described what I believe to be the best embodiments of my invention. I do not wish; however, to be confined to the embodiments shown, but what I desire to cover by Letters Patent is set forth in the appended claims.

I claim:

1. An open ended tube testing apparatus com-- prising a rotary frame, a series of tube testing units on the frame, each including a stationary and a movable tube-end engaging and sealing member; means for shifting said movable member into tube end engaging position so that the ends of the tube are hermetically sealed between the stationary and movable members, means for testing a. tube so positioned in each unit including means for reducing the internal pressure in the tube while the movable tube end engaging member is held in tube end engaging position by said shifting means, spring means operable thereafter for withdrawing said movable tube end engaging member from tube engaging and sealing position only when the internal pressure within the tube is not sufficiently reduced to retain said member in tube end sealing position thereby permitting the tube if faulty to fall from the unit, a faulty tube receiver, means beyond said receiver for increasing the pressure within the tube if the same is not faulty thereby to release said movable tube end engaging and sealing member, and a second receiver for receiving the tube if released by the last said means.

2. An open ended tube testing apparatus comprising a rotary frame, a series of tube testing units on the frame, each including a stationary and a movable tube-end engaging and sealing member; means for shifting said movable member into tube end engaging position so that the ends of the tubes are hermetically sealed between respective stationary and movable members, means for testing tubes so positioned in said units including means fo reducing the internal pressure in the tubes successivel while the tube end engaging members are held in tube end engaging positions by said shifting means, spring means operable thereafter for withdrawing said movable tube end engaging members from their tube end engaging and sealing positions only when the internal pressure within the tubes is not sufficiently reduced to retain said members in tube end sealing positions thereby permitting the tubes if faulty to fall from their units, a faulty tube receiver, means beyond said receiver for increasing the pressure within the tubes if the same are not faulty thereby to release said movable tube end engaging and sealing members, a second receiver for receiving the tubes released by the last said means, and a mechanical tube ejector operable to discharge from their units tubes which adhere to one of the end engaging members after the movable members have been retracted from their tube end engaging and sealing positions, said ejector including a rockable element disposed to be engaged and rocked by said movable tube end engaging members only when the latter are retracted, and a tube ejector element normally out of the path of travel of the tubes in the units and movable into said path in response to rocking movement of said rockable element by any movable tube and engagingmem'ber which may be retracted, thus positively to effect ejection of tubes from units in which the movable tube end engaging members are retracted.

3. In a machine for testing hollow articles each having at least one open end, a rotary carrier for the articles, a testing unit carried by said carrier and including a pair of article end engaging members at least one of which is shiftable into engagement with an open end of the article to urge the article toward the other member and thus close the open end or ends of the article, means operable in response to rotation of said carrier to shift said shiftable member to confine the article between said members and thereafter to release said shiftable member for retraction to release the article, means also operable in response to rotation of said carrier and prior to release of said shiftable members to exhaust air from the article to reduce its internal pressure below atmospheric pressure and then to cease its air exhausting operation, means operable upon release of said shiftable member to retract the latter if and onl if the pressure of the air in the article rises to atmospheric pressure, and normally inactive article ejecting means movable to article ejecting position by rotation of said shif"- able member with said carrier when and only when said shiftable member is in its retracted position.

4. In a machine for testing hollow articles each having at least one open end, a rotary carrier for the articles, a testing unit carried by said carrier and including a pair of article end engaging members at least one of which is shiftable into engagement with an open end of the article to urge the article toward the other member and thus close the open end or ends of the article, means operable in response to rotation of said carrier to shift said shiftable member to confine the article between said members and thereafter to release said shiftable member for retraction to release the article, means also operable in response to rotation of said carrier and prior to release of said shiftable members to exhaust air from the article to reduce its internal pressure below atmospheric pressure and then to close its air exhausting operation, means operable upon release of said shiftable member to retract the latter if and only if the pressure of the air in the article rises to atmospheric pressure, an actuatine member disposed to be engaged and moved by said shiftable member as the latter rotates with said carrier when and only when said shiftable member is in its retracted position, and an article ejecting element normally disposed out of the path of movement of the article and operatively connected to said actuating member for movement into said path to effect ejection of the article in response to movement of said actuating member by said shiftable member.

' JOSEPH MASON.