US2744671A - Port section for double turret sealex - Google Patents

Description

May 8, 1956 Filed Feb. 12, 1954 J. J. REGEC' Er AL PORT SECTION FOR DOUBLE TURRET SEALEX Z She'BtS-Sheet 1 ATTORNEY May 8, 1956 J. J. REGEC ErAL 2,744,671

PORT SECTION FOR DOUBLE TURRET SEALEX Filed Feb. I 12, 1954 2 Sheets-Sheet 2 [NV JOHN J. EEEE asnav w. ROEBER W ATTORNEY United States Patent O v 7 2,744,671 PORT SECTION FOR DOUBLE TURRET SEALEX John Regec and Henry W. Roeber, Emporium, Pa.,.assignors to Sylvania Electric Products Inc., a corporation of Massachusetts Application February 12, 1954, Serial No. 409,931 7 "4 Claims. (Cl. nit-20.4),

Thisinvention relates to vacuum tube'exhausting and sealing machines and particular'lyto valve mechanism thereime :In a certain type of exhausting machine there is provided a'turret which progressively indexes a container such as an electron tube envelope or incandescent bulb around the machine to have a number of operations performed on the container including exhausting thereof.

Usually the exhausting operation is performed at a number of indexed positions or stations of the turretand fre- 'quently a number of successive exhaust stations are connectedviaa common manifold to a single exhaust pump, there being a number of such groupings around the machine. Since the capacity of the exhaust pump is limited, should any leakage exist through the envelope or bulb into the container, due to some defect in manufacture or mishandling of the container, the pump would not properly exhaust the leaky container.

Furthermore due'to the'interconnectio'n of the ditferent exhaust stations affordedby-the manifold those containers immediately preceding and immediately following the leaky container would also be insufliciently exhausted. Thus a leaky envelope 'at' a first exhaust station where four stations are connected to a common manifold, would result in the loss or so called shrinkage, not only of the leaky envelope but of the three envelopes ahead of it, and, as the leaky envelope indexes to its fourth exhaust position, of the three envelopes behind it, a total loss of seven envelopes. This invention is directed to providing means to confine the loss solely to the leaky container.

-It is an object of this invention to provide a means to cut off communication of the pump with a leaky container to prevent undue loss of vacuum in an evacuating system.

-'It is a further object of the invention, in an exhausting system to prevent an increase in pressure in that system, due to leakage of a container, being communicated to other containers which are being exhausted in the system.

Further object of the invention will be apparent after reading the following specification in conjunction with the accompanying drawing in which Fig. 1 is a fragmentary top view of a turret carrying a number of exhaust port mechanisms.

- Fig. 2 is a vertical sectional view through one of the mechanisms, taken on the line 2-2 of Fig. 1, an electron 1 tube to be vexhausted being 'shownclamped in the'exh'aust port.

Fig. 3 'is a view of an exhaust port mechanism looking ice Referring to the drawings more in detail, see Figs. 1 and 2, at 10 there is shown the table of an indexable turret. Mounted on the table there is a number of exhaust port mechanisms or sections 12, each capable of supporting the exhaust stem of a container to be exhausted and connecting the same to an exhaust duct 14 carried by the table. Only the mechanisms at the container loading station at the left and the next three stations are shown. Actually a large number of these sections are equally spaced around the periphery of the table and various operations are performed on the electron tubes'as they are indexed around the machine. At the loadingstation 16 the exhaust stem of a container is inserted through the intake port; at the next or clamping station 18 the exhaust stem is clamped into air tight relationship with the port mechanism; at the next stations 20, 22, and several therebeyond, valve mechanism is operated to connect thecontainers to ducts which in turn communicate with a common manifold leading to an exhaust pump.

Within each port mechanism there isa valve whose position is under control of cam and detent mechanism, on the turret. Each valve, see Figs.,1 and 2, has a valve control rod 24 having a stepped down narrower valve control operation stem 26. Straddling the stem, see Fig. 5, are the tines 28 of the shifter 30, the stem of the shifter having a'cam follower roller 32 mounted thereon. The tines, see Fig. 2, lie between a shoulder portionof the rod 24 and a slidable collar 34 on stem 26, the collar being pressed against the tines by a spring 36 compressed between the slidable collar and a second collar 38 pinned on stem 26. The shifter is mounted in an arm 40 pivotally mounted on a stud 42 suitably mounted on the table. The free end of the arm is provided with 'a spring pressed detent 44 engageable with either one of a pair of recesses 46 in a detent block 48 mounted on the table. A number of cams are'fixedly mountedon stationary frame work supporting the turret table, a pair' of these being shown at 50. Although one .cam is sulficient to move the arm 40 to the position shown at station 20 in Fig. 1, out of an abundance of caution, a second cam 50 is provided at the next station 22 to insure the detent 44 being properly seated in a recess 46. At another'point or points in the path traversed'by the cam followers 32 a cam or cams will operate on the followers 32 to cause the detents to engage in the other of the recesses 46.

The valve control rod 24 is provided with oil grooves -52 along its length and, at the righthand end as shown in Figs; 1 and 4, it is provided with a reduced end 54 'to which is pinned'a thimble 56 having a flat crown 58,

see. Fig. 6, provided with an eccentrically positioned key hole'slot 60. Slidably engaged with the narrower-portion of the key hole slot is the neck portion 62 of'a poppet valve 64 normally spring pressed awayfroni its seat, when the arm 40 is in the position shown in Fig. 4, by a spring 66 reacting against the head 68 of the'valve and the bottom of a recessed portion in-a valve guide 70 within the valve block 72. In the initial motion of the thimble 56 to the right, Figs. 2 and 4, it will engage the stem of the poppet valve at the right hand end of reduced neck portion 62 and'force the valve to valve open positienshould there be pressure on the face of the valve. A packing ring 74 and a gland block76 serve to retain the guide 70 in place against a shoulder in the valve block 72. A valve seat 78 of any suitable material may be provided against which the head of the valve may be seated in the closed position of the valve. The thimble 56 is within a cavity of such size in the valve guide 70 to permit disassembly of the poppet valve parts for repair purposes when the gland block 76 is removed from valve block 72. The valve block is ported at 80 to provide for free passage of air into the duct 14 and the valve guide has a passageway 82 to permit air to flow from the valve inlet to the port 80.

With normal exhaust operation and when the amount of air being displaced through the port is not too great, the spring 66 serves to'maintain the poppet valve inpartially open position, as shown in Figs. 1 and 2, thepoppet valve moving to the position shown due to the pressure differential existing at the valve head. This differential arises because of differences in areas on the face of the valve and on the stem side of the valve and the drop in pressure of the fluid flowing past the valve head. Upon excessive flow of fluid past the valve, due, for example, to the non-presence of an exhaust stem in the inlet port of the mechanism or due to glassbreakage of the envelope or a blow hole in the envelope, the poppet valve will close, notwithstanding the position of the arm-'40, thuspreventing excessive rise of pressure in the duct 14, which itwill be remembered communicates with other port mechanisms through the common manifold. Shifting arm-40 to its other detentheld position or counter-clockwise in Fig. 4 will cause the crown 58 to pull back on the head portion of the valve to the left of .the neck and close the valve against the action of spring 66.

The exhaust stem clamping mechanism comprises an upstanding hollow cylinder 84 integral with the valve block 72, the cylinder communicating with a recess 86 in'the block which in turn, via the poppet valve, communicates with the passageway 82. Within the cylinder .and resting on the valve block proper is a resilient gasket ring88 on which is positioned a rigid cylinder 90 with bevelled ends, surmounted by a second resilient gasket ring92. Telescopically engaged with the hollow cylinder 84 and engaging the top gasket 92 is the flanged compressing member 94 and resting on the flange of the member is a ball bearing 96. Surrounding the cylinder 84 and fastened to the valve block is threaded stud 98 and threaded on this stud is the gasket compressor oper- =ator 100, said operator having an inturned flange resting on the ball bearing 96. Clamped to each operator 100 ,as bya screw 102 is the operator lever 104. As the turret'is indexed, the lever 104 is engaged by a fixed abutment pin 106 to cause the lever to compress the gaskets 92 and 88 in airtight engagement with the exhaust tubulation of an .envelope. Other suitable means are provided for reverselymoving the lever 104 before it approaches theloading position.

Within the recess 86 is a cylindrical air filter screen 108, .the screen being held in position on a seat 110 :at the top of a stud 112 pinned in a saddle 114 pivoted at 116 to the table and the saddle being spring-held to its operative position by a tension spring 118 fastened at one-end to a projection 120 extending downwardly .from thetable and at its other end around the reduced ,neck portion of a screw 122 threaded through the saddle.

Glass and other obstructions can be cleaned out of the port section by removing the spring 118, swinging the saddle 114, removing the filter and passing a cleaning tool straight down through the inlet port.

munication between its inlet and exhaust duct, said valve mechanism comprising a control rod portion and a poppet valve portion with a lostmotion connection between the portions, and means urging said poppet valve portion to valve open position; said valve portion, when in said valve open position, being moved to closed position, against the action of said urging means, on excessive flow of fluid past the valve portion.

2. In a container exhausting machine, a turret having a number of port sections each provided with an inlet and an exhaust duct, all said ducts being adapted to be connected simultaneously to an exhaust pump; a valve mechanism in each port section movable to cut ofi communication between its inlet and exhaust duct, said valve mechanism comprising a control rod portion and a poppet valve portion with a lost motion connection between the portions, and means urging said poppet valve portion to valve open position; and fixed cam means in the path of movement of the control rod portion to move the rod portion so as to release the poppet valve portion to the action of the valve opening urging means, whereby excessive flow of fluid past the valve will overcome said urging means to move the valve to closed position.

3. In a container exhausting machine, a turret having a number of port sections each provided with an inlet and an exhaust duct, all said ducts being adapted to be connected simultaneously to an exhaust pump; a valve mechanism in each port section movable to cut off cornmunication between its inlet and exhaust duct, said valve mechanism comprising a control rod portion and a poppet valve portion with a lost motion connection between the portions, and means urging said poppet valve portion to valve open position; fixed cam means in the path of movement of the control rod portion to move the rod portion so as to release the poppet valve portion to the action of the valve opening urging-means, and means to releasably hold the rod portion in said position, all whereby excessive flow of fluid past the open valve will move thevalve to closed position.

4. In an exhausting machine, a port section having a valve block, a valve guide in said block, and a retaining block fixed to the valve block holding the guide against displacement, a valve control rod passing through said retaining block, an eccentric key hole slot coupling means on the end of said control rod interiorly of the valve block, and a poppet valve in said port section having a concentric portion coupled into the eccentric portion of the control rod, said concentric portion comprising an elongated neck portion riding in the narrower portion of the key hole slot to provide for a lost motion connection between the control rod and the poppet valve, there being a free space in the guide and surrounding the coupling end of the control rod, to enable disassembly of parts after removal of the retaining block and guide from the valve block.

'ReferencesCited in the file of this patent UNITED STATES PATENTS 809,859 Stulp Jan. 9, 1906 984,994 Armstrong Feb. 21, 1911 1,933,322 Fagan Oct. 31, 1933 2,113,798 Mullan Apr. 12, 1938 2,467,408 Semon Apr. 19, 1949 2,606,628 Hasselwander Aug. 12, 1952

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