DE1502744A1 - Valve screw for vacuum chuck - Google Patents

Description

DIPl -.- INQ. M.SC. DIPL-PHYS- DR

HÖGER - LEGAL RIGHT - GRIESSBACH 1 502744

PATENT LAWYERS IN STUTTGART

A 34 350 h h - th April 8, 1965

The Dunham Tool Company, Inc., Hew ^ airfield, Connecticut, ü. 3, A,

Vent ¹ ! ! screw for vacuum chuck

The present invention relates to simple, small-sized valves and, more particularly, to a new and improved valve screw which can be used, in particular, in vacuum chucks and the like.

When clamping workpieces on iTwiversal vacuum plates of vacuum chucks, such as those in

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U.S. Patent Application Serial No. 254 085 are described and shown, it is often desirable to selectively open and close the holding openings of a vacuum grid in order to create different holding shapes or clamping surfaces according to the special profiles of the objects being held were accordingly closed or opened with sealing plugs or the like, whereby the necessity of inserting these plugs resulted every time the clamping surface was changed or removed.

According to an important feature of the present invention is a new and different

^w better valve screw arranged, which represents a miriature valve in cooperation with this breakthrough. The valve screw seibat can optionally be rotated by a predetermined, minimum angle to open or close the holding passage, or it can also be left permanently in the holding openings. In the valve device according to the invention, a single turn of the screw is sufficient to fully open the valve in a typical application, which is particularly advantageous in the case of a universal vacuum chuck, several hundred or even

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has several thousand separate valves,

Next «» ir.erkf..ale and advantages eier Krfindan ,; 'ii'ceV'n aioh miss the nacnful {- (hden description in addition :."ii:han.-. :: iv of the drawing, the execution examples -λΊχ' Ti:. ·· τ "j r.-iunc or: holds. In the drawing zsi.'on:

Pig.1 an echau'ildliohe view eiue.i Yakuumspa · :).] ' Μ ^ tcra using the new and vernecsc-rten vent j I-sohruben e & u: .ßs of the invention,

Flg.2 a 'cross section according to line'? 2-2 ilar JMg,], Pig.3 a partial cut dui'ch swei Venti laughing / jc-iuäsf. ' Fig. 2 in a larger Hasatab ale (Hese for the representation of a valve head in οΓΓ «ηο ^ · position, and another valve head in ge.-chlooeener position _s

A typical application of the new type of valve tube occurs in connection with a Va-lruumspanniutt-e * DC, as it is for example in the UOA-PatentanxtMtui / uer.Uo. 254 ΟΘ5 described and illustrated irt. The ijpanr.futter essentially has a rectangular housing 11 which has an inner vacuum chamber 9 (FIG. 2), the rait Hill'o a pipe connection 12 connected to a vacuum pump can be, with a pressure gauge 13 to display θπε in the pump is used to develop a vacuum; a ventilation system is also

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valve 14 is provided to let atmospheric air into the chamber and so set or cancel the vacuum therein. Further, mounted in the chuck 10 on the housing 11 above the vacuum chamber nor a vacuum plate 15, which is formed in a lattice-like manner by a plurality of said shouldered openings 16 erfindungegemäasen _c Gemäas the invention (s.insbesondere 2 and 3) are the new and Valve screws 17 in operative connection with the individual openings 16 provided with shoulders, the walls 8 of these openings being provided with internal threads 18 on their lower, smaller-diameter sections. The individual valve screws 17 have a one-piece sealing head 21 and a shaft 19 with an external thread 20, which can be screwed into the internal thread 18 of the openings 16 _{or the like}

As shown in Pig.3, an O-ring 24 is in a circumference groove on the underside 22 of the Abdichtkopfes 21 next to the Shank 19 arranged. The O-ring can now be pressed together between the sealing head 21 and the shoulder surface 23 when the valve screw is screwed to the closed position.

A further feature of the invention is in the shaft 19

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continuous L-shaped channel 25 provided, which with an axial section axially in a first direction from the free end of the shaft to a point immediately next to the sealing head 21 and from there au3 with, one Radial section extends radially outwards to the surface of the thread 20. This allows the valve screw in the screwed in the lower threaded part of the Halteäurchgäiige ao den, daos the radial / section of the & anala 25 through the wall parts the openings 16 and is sealed by the U-ring 24. In this position (see left side of Pig. 3) there is communication between the external atmosphere above the vacuum plate 15 and the vacuum atmosphere inside the chamber 9 effectively interrupted below the plate 15.

The closed position is particularly advantageous the valve screw reaches against the passage surface immediately after the channel 25 through the thread 18 of the passage 16 is closed. When all valve screws 17 are in a sealed position, the Vacuum plate 15 effectively separates the two Atmospheres. A partial unscrewing of the valve screw 17 from the threads 18 of the passages 16 into the open position (see right side of? ig..3) can thereby be effected,

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that the shaft is given a predetermined rotation, preferably less than one full revolution, whereby communication between the atmospheres on both sides of the vacuum plate 15 is established by exposing the channel 25 will.

When used as a chuck is according to the invention the order in relation to a bagged Breakthroughs 16, the Kan ?! 25 that screwed together Thread 18,20 and the sealing head 21 taken so that the sealing head 21 is safely below the Sxjannflache Vacuum plate 15 is both in the open and in the closed position.

In order to clamp a work piece B au, the valve screw 17 is opened below the work piece to create a corresponding one To form clamping surface, while the other valve screws remain closed. This means that the vacuum holding forces are in the chamber 9 is effectively concentrated on these clamping surfaces, and the workpiece is firmly against the holding plate 15 drawn.

Ea should be noted that the valves are wet according to the present Invention with the help of a screwdriver or

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the like easily and eiηΓ; cn can be opened and closed, usi ao the ^ ew-nschto fcjpannfl before the vacuum plate can be reached. In addition, the new and ver beseerten Yontilschrauben wirtach.-iftlich can be prepared and installed in existing Vakuumupannfutter, so as to improve their impact and applicatio ;; ufuhi, l ^ ince.

- 8th

909885/0382

Claims (1)

A 34 350 h h - ta April 8, 1965 - 8 - Patent claims: 1 * Jlatte, especially the clamping plate of a vacuum chuck. ters, with a large number of openings which can be closed individually by locking devices, characterized in that the locking device ^{w is} a valve screw (17) which with its sealing head (21) fits into an extension of the opening (16), preferably with play, and whose thread schoft (19) can be screwed into a threaded part (20) of the opening (16), and that the threaded shaft (19) has a channel (25) with an axial partial channel and a radial partial channel exiting below the sealing head (21) which, when the valve plug (17) is screwed in, with the sealing head (21) resting in a sealed manner against the Wall of the opening (16) dioht closed let. 2, plate according to claim 1, characterized in that flase through the expansion of the breakthrough a cross shoulder (23) is formed, against which the sealing head (21) can be pressed is" 9098 8 5/0382 A 34 350 h h - ta April 8, 1965 - 9 - 3. Plate according to one of the preceding claims, characterized in that on the underside (22) of the sealing head (-21) a seal (24) is arranged. 4. Plate according to claim 3> characterized in that
the seal is a sealing ring (24) arranged on the underside (22) of the head (21) and a groove. 5. Plate according to one of the preceding address, characterized in that the radial sub-channel directly
exits under the sealing head (21). 6. Plate according to one of the preceding claims, characterized characterized in that the channel (25) is L-shaped. 7. Plate according to one of the preceding claims, characterized in " characterized in that the depth of the expansion in relation to the abutting head (21) is so perpendicular that the ab- v.ichtkopf (21) in the open and closed position below the outer surface of the plate (I5) is _s 8. Plifcte after one of the previous speeches, thereby / ^ e ^! r. innzeioaruj i ;, da ;;;; cli · .. Anor-inmi / j ίί ο tvi. ■■ "!" ■ ■. -t, da.Mtj 'iu ^r ' oh eint ririninuil «UrGhun; clt-r Vf.m. i Innhrüulir (l /), / v>ri; n,. ·: - viiitjo duroh ni.oh .: vnhe hU.! '? i. ia full lh: iti '.- ii-iu ^ l. ->' - tdial teilku.al Γι-ΙΙ ,, ^: - l, l :, ³ ° ^{9 8} 8 ^l > / Π Ί B 2 BATH ORIGINAL 40 . Blank page