Vacuum distribution controller apparatus

Information

  • Patent Grant
  • 6499506
  • Patent Number
    6,499,506
  • Date Filed
    Tuesday, March 27, 2001
    23 years ago
  • Date Issued
    Tuesday, December 31, 2002
    21 years ago
Abstract
A vacuum suction force control apparatus is disclosed by way of a duct, having an entrance port and at least one exit port. Flow of suction force is controlled by moving a piston-like plunger inside the duct, connecting the entrance port to one, or simultaneously, multiple, adjacent exit ports. The present invention achieves known vacuum distribution without utilizing prior art electromechanical vacuum valves and associated electrical control cabling and power supply equipment. Therefore, the present invention is inherently capable of maintaining a particular, temporary distribution configuration without requiring electrical nor mechanical energy.
Description




FIELD OF THE INVENTION




The present invention relates to devices for temporarily affixing objects utilizing vacuum and in particular to a vacuum distribution manifold apparatus for vacuum tables.




BACKGROUND OF THE INVENTION




Surfaces capable of affixing an object by vacuum are commonly known as vacuum tables. Prior art vacuum tables commonly have a predetermined perforated region through which maximum vacuum suction force typically is applied to an object that covers at least the predetermined perforated region. The suction force is usually generated by a vacuum pump system. The object becomes thus affixed to the surface while the suction force or vacuum is enabled. Suction force is lost through holes not covered by the object, and thus many techniques have been employed in the prior art to overcome this problem.




One possible solution is to utilize a suction force controlling device such as a Coanda-Effect operated diaphragm device, or a differential pressure valve. This is an inherently costly solution, since one such device is needed for each of the numerous holes of a vacuum table.




Another simple and effective solution is to cover any uncovered region with masks of various shapes. In mass manufacturing processes the objects usually has a constant size, and a custom made mask is therefore commonly utilized.




Another solution is to divide the perforated region into a number of smaller areas so that suction-force can be occluded from those areas not in contact with or covered by the object. Vacuum valves operated by electrically controlled solenoids are widely utilized in industrial vacuum table applications.




It should be noted here that, for ease of understanding the prior art predicaments, the following discussion relates to

FIGS. 1A and 1B

, illustrations of a 5-area addressable vacuum table. Persons versed in the art will readily appreciated that, for each addressable area, substantially identical subsystems need to be employed.





FIG. 1A

is a schematic view of a prior art vacuum table system configuration for directing suction-force to multiple addressable areas


100


of a vacuum table


102


. A vacuum pump


104


is coupled to a manifold


106


comprising a predetermined number (2, 3, or more) of ports


108


. Each port


108


is coupled to a respective area suction inlet port


110


via a suitable tubing


112


. To independently control suction-force to each area


100


, each tubing


112


is equipped with an individual shut-off tap


114


.




All shut-off taps


114


, except a shut-off tap


128


, are activated or, deactivated by a vacuum distribution control system


124


, thus inhibiting flow of suction force to all undesired areas


100


and enabling all available suction force to a predetermined area


126


.





FIG. 1B

shows a more detailed schematic view of individual shut-off tap


114


, comprising two main components, a vacuum valve


118


and a solenoid


120


. Suction force is either allowed to or inhibited from traversing vacuum valve


118


by activating or by deactivating solenoid


120


. Solenoid


120


, receives an activate/deactivate signal


122


from vacuum distribution control


124


(best seen in

FIG. 1A

) or any other suitable subsystem.




To achieve a highly precise dimensioning of an active suction area, a substantial number of addressable, small areas need to be controlled by an equal number of manifold ports, tubing, shut-off taps with accompanying devices, electrical control cabling, etc.




Thus, a substantial number of mechanical, electromechanical, power supply, and electrical control devices are needed in order to perform the task of directing suction force to a few areas of the vacuum table. Those versed in the art will readily appreciate that this can result in a multitude of potential sources of malfunctioning.




There is, accordingly, a need in the art for a novel technique for improved suction force directing means, directable in a variable way to a multitude of areas.











BRIEF DESCRIPTION OF THE DRAWINGS




In order to understand the invention and to see how it may be carried out in practice, a detailed description follows, by way of non-limiting examples only, with reference to the accompanying drawings, in which:





FIG. 1A

is a schematic representation of a prior art vacuum table system configuration;





FIG. 1B

is a schematic representation of a prior art single shut-off tap;





FIG. 2

is a schematic representation of the vacuum distribution controller in accordance with an embodiment of the present invention;





FIG. 3

is a schematic representation of the vacuum distribution controller, constructed and operated in accordance with another embodiment of the present invention;





FIG. 4

is a perspective, more detailed schematic representation of the vacuum distribution controller;





FIG. 5

is a frontal schematic representation of the vacuum distribution controller;





FIGS. 6A

,


6


B, and


6


C are frontal schematic representations of the vacuum distribution controller having different configurations;





FIG. 7

is a schematic representation of the vacuum distribution controller in accordance with another embodiment of the present invention, utilizing a prior art vacuum table system; and





FIG. 8

is a schematic representation of the vacuum distribution controller in accordance with another embodiment of the present invention, utilizing a second vacuum distribution controller in accordance with the present invention.











DETAILED DESCRIPTION




The present invention provides flow control by way of a duct, having an entrance port and at least one exit port. The flow of a fluid or gaseous substance is controlled by moving a piston-like plunger inside the duct, connecting the entrance port to one, or simultaneously, multiple, adjacent exit ports. The present invention achieves known vacuum distribution without utilizing prior art electromechanical vacuum valves and associated electrical control cabling and power supply equipment. Therefore, the present invention is inherently capable of maintaining a particular, temporary distribution configuration, without requiring neither electrical nor mechanical energy. Further advantages will become evident in the description and embodiments described below.




Those versed in the art will readily appreciate that the invention is by no means limited to the herein discussed particular examples and furthermore, a multitude of applications in other fields such as, inter alia, fluid and gaseous flow control, may equally and advantageously utilize the present invention and embodiments as discussed in the description.




Reference is now made to

FIG. 2

, a schematic illustration of a vacuum table


212


and a vacuum distribution controller apparatus


200


, constructed and operated in accordance with an embodiment of the present invention: a duct


201


, preferably, cylindrical, is coupled to a vacuum suction force source or pump


202


via a suitable tubing


203


. Duct


201


is closed at both peripheral ends and comprises an entrance port


205


and a multitude of exit ports P


1


, P


2


, P


3


, . . . P


n


. Each exit port P


1


, P


2


, P


3


, . . . P


n


is coupled via an associated suitable tubing


214


respectively, to a multitude of vacuum suction inlet ports


204


of a multitude of suction areas


206


.




Duct


201


may be part of a housing of any applicable shape, as to be discussed in more detail below. Duct


201


is effectively a close-fitting sleeve for a plunger


216


. Plunger


216


may be a disc or a piston, but it is noted here that, plunger


216


may have any shape that is configured to closely fit inside duct


201


.




A worm gear


218


may be positioned in the center of duct


201


. A motor


220


rotates worm gear


218


in either clockwise- or counterclockwise directions. In one embodiment of the present invention, motor


220


may be a stepper motor, which rotation movement is responsive to an electrical signal


221


, comprising a predefined number of electrical pulses outputted by a stepper motor controller (not shown).




Optionally, other devices, such as inter alia, a linear motor, may be utilized for moving plunger


216


, whereby worm gear


218


is replaced by a shaft, which is moved by the linear motor, forwards or backwards, in the longitudinal direction of duct


201


. Plunger


216


may be affixed to one end of the shaft and the linear motor may be positioned at the other end of the shaft.




Worm gear


218


may extend over the total length of duct


201


or, optionally, worm gear


218


may be part of a shaft extending over the entire length of duct


201


. In the latter case, worm gear


218


covers at least the segment over which plunger


216


may be able to move within duct


201


.




Plunger


216


may comprise a thread inside a concentrically positioned cylindrical tube, which meshes with worm gear


218


. Plunger


216


may be inhibited from rotating, (due to frictional and inertial forces) by a stationary rod or cable


222


, which is affixed inside duct


201


, over its entire length, and may be positioned in a non-concentric, parallel to above mentioned worm gear


218


. If, optionally, worm gear


218


is positioned in a non-concentric position inside duct


201


, rod


222


may be redundant. Furthermore, if duct


201


is of non-cylindrical shape and thus, plunger


216


is of non-cylindrical shape, rod


222


is also redundant. It is noted here that in the above mentioned configuration, wherein plunger


216


is moved by means of a linear motor, rod


222


may also be redundant.




Plunger


216


moves in a longitudinal direction, forwards or backwards, in accordance with the spin direction of worm gear


218


. Suitable leakage prevention sealing, such as gaskets, rings, and grease, are situated in the area of the thread and worm gear


218


. For a more detailed illustration of stationary rod


222


and worm gear


218


and their respective accompanying parts, attention is directed further below to

FIGS. 4

,


5


,


6


A, and


6


B.




Thus, a variable sized compartment


224


is formed by and enclosed by, duct


201


, a stationary peripheral end


226


at one side and plunger


216


at the other side. Accordingly, suction force from vacuum suction force pump


202


enters compartment


224


through entrance port


205


, and exits by any exit port that is at that time part of compartment


224


.




As an example, in the temporary configuration or situation depicted in

FIG. 2

, plunger


216


is positioned between exit ports P


2


and P


3


. Thus, any exit port located at the other side of plunger


216


, such as P


3


, P


4


, or any other port until P


n


, is effectively occluded. Accordingly, suction force is enabled for exit ports P


1


and P


2


, by virtue of their being part of compartment


224


in this temporary configuration.




Those versed in the art will now readily appreciate the inherent simplicity of a vacuum distribution controller apparatus


200


directing suction force from one entrance port to one or more adjacent exit ports. As will be discussed further below, if suction force needs to be directed to more than areas of a vacuum table, these areas are commonly adjacent to each other.




Another embodiment of the present invention is shown in

FIG. 3

to whom reference is now made. Exit ports P


2


, P


3


, P


4


, . . . are directly coupled to associated suction inlet ports


204


, substantially obviating the need for tubing


214


. Design considerations may determine an altogether different spatial position or configuration.





FIG. 4

shows a perspective and more detailed schematic representation of the vacuum distribution controller apparatus


200


in accordance with one embodiment of the present invention.




Duct


201


, part of a rectangular shaped housing, is shown in an elevated, sideways position. Thus, entrance port


205


, a multitude of exit ports P


1


, P


2


, P


3


. . . P


n


, plunger


216


, stationary rod


222


and worm gear


218


are shown in their three-dimensional relative positions. As mentioned above, motor


220


may be positioned at a predetermined distance or/and angle from duct


201


, depending on design considerations.




Plunger


216


is shown positioned in between exit ports P


2


and P


3


, similar as the position shown in

FIGS. 2 and 3

. It should be mentioned here that plunger


216


in one maximal lateral position, directs suction force to all exit ports and consequently, to all respective coupled areas. The opposite, maximal lateral position prevents suction force to be directed to any exit port and thus inhibits suction force in all respective coupled areas.




In order to achieve a substantially entire fitting of plunger


216


inside duct


201


, and alleviate above-mentioned lost of suction force, a spring-loaded ring


400


may be affixed to plunger


216


. One or more peripheral trenches on plunger


216


may accommodate spring-loaded ring


400


and provide fixation in a manner substantially similar to the workings of piston rings in a motor combustion cylinder. It is noted that numerous other means of leakage prevention sealing, such as gaskets, rings, or grease, may be equally advantageously utilized for contributing to suction force confinement to compartment


224


.





FIG. 5

shows a schematic cross-section from a frontal, longitudinal perspective of the area, as indicated in

FIG. 4

by plane


402


.




Entrance port


205


and an exit port


500


(PI in

FIGS. 2

,


3


and


4


) are shown on the bottom and top of duct


201


, respectively. Spring-loaded ring


400


seals the space between plunger


216


and duct


201


. In a similar manner, one or more spring-loaded rings


504


are positioned inside hole


502


, and seal the space between stationary rod


222


and hole


502


in plunger


216


. As mentioned above, numerous sealing techniques may be utilized. Plunger


216


, fitted on worm gear


218


, inhibited from rotating by means of rod


222


, moves forwards or backwards while worm gear


218


rotates by virtue of stationary rod


222


, protruding through a hole


502


in plunger


216


.




Yet another embodiment enables a multitude of exit port arrangements, as shown schematically in FIG.


6


A. Entrance port


205


, exit port


500


, an exit port


602


, an exit port


604


, and any additional exit ports (not shown), may be positioned at predetermined positions in relation to each other. This may alleviate potential design restrictions or/and may offer other benefits, such as, inter alia, enabling shorter tubing, eliminating tubing, or facilitating other direct/indirect connections between exit ports and suction inlet ports.




In another embodiment of the present invention, shown in

FIG. 6B

, duct


201


may have a cylindrical shape


610


, enabling a multitude of predetermined angular positions for entrance port


205


, exit port


500


,


602


,


604


, and any additional exit ports (not shown) in relation to each other. Thus, benefits may be obtained, such as mentioned above with reference to

FIG. 6A.

, addressing additional design restrictions.




In yet another embodiment of the present invention shown in

FIG. 6C

, a rectangular plunger


612


is utilized, wherein a rectangular, duct


614


is the close-fitting sleeve. By virtue of its rectangular properties, plunger


612


is not able to rotate, therefore, no stationary rod (


222


in

FIG. 2

) is necessary.




Those versed in the art will readily appreciate that in principle, no functional restrictions exist to the geometrical shapes of the plunger and the associated duct functioning as close-fitting sleeve. Therefore,

FIG. 6C

is only one possible example of a non-cylindrical configuration that may offer further benefits in design considerations and space confinement requirements.




It should be noted here that, for ease of understanding, only three out of a possible multitude of exit ports are depicted in

FIGS. 4

,


5


,


6


A,


6


B and


6


C.





FIG. 7

shows schematically a similar configuration to the prior art configuration described with reference to FIG.


1


and with reference to

FIG. 3

, one embodiment of the present invention.




It should be noted here that, in vacuum table applications, generally, a number of adjacent suction inlet ports, adjacent to each other, require vacuum suction. The present invention inherently addresses adjacency by virtue of above-mentioned compartment


224


, discussed above with reference to FIG.


2


.




Vacuum table


212


is divided into a predetermined number of horizontal areas


702


,


704


,


706


,


708


, and


710


, to which suction force may be directed in an accumulative manner by positioning plunger


216


at positions


722


,


724


,


726


,


728


, or


730


respectively. As mentioned before, for ease of understanding, an illustrative configuration of 5 areas is discussed hereinafter. Those versed in the art will readily appreciate that any desired number of areas may be controlled in a similar manner.




Vacuum suction force pump


202


is coupled to vacuum distribution controller apparatus


200


of the present invention by means of suitable tubing


203


. Plunger


216


is moved by motor


220


, which receives positional electrical control signals


221


from a controller or a dedicated subsystem.




In the temporary configuration shown in

FIG. 7

, plunger


216


is in position


722


, enabling suction force to horizontal area


702


only. Should a greater area than horizontal area


702


be needed to induce suction force to an object placed on vacuum table


212


, a predetermined number of pulses with predetermined polarity are sent as control signal


221


to motor


220


, causing worm gear


218


(

FIG. 2

) to rotate a predetermined number of rotations in the direction that will move plunger


216


into temporary position


724


. Therefore, suction force is then applied to horizontal area


704


as well as to horizontal area


702


.




In a similar manner, other temporary positions of plunger


216


, such as, position


726


, position


728


, and position


730


will result in enlargement of the vacuum suction region to include, respectively, horizontal area


706


,


708


and


710


.




It should be noted that one of the many important advantages of the present invention is that as long as no change in vacuum suction regions is required, all mechanical and electrical systems are substantially in a state of rest. No energy, electrical or mechanical, is required to maintain a given, temporary configuration by virtue of absence of vacuum valves and their associated devices.




Those versed in the art will readily appreciate that the temporary configuration may be maintained for substantially long periods, emulating an invariable configuration, if so desired.




With reference to

FIG. 8

, another embodiment is schematically shown, wherein vacuum table


212


is divided into vertical areas as well as into horizontal areas.




Vacuum table


212


comprises multiple horizontal areas


702


-


710


and multiple vertical areas


802


-


814


. An additional vacuum distribution controller apparatus


800


of the present invention is positioned along a perpendicular side of vacuum table


212


. Vacuum suction force pump


202


may be equipped with double suction force outlets to which suitable tubing


203


and


816


may be coupled. Optionally, a separate vacuum suction pump may be used. Tubing


816


may be coupled to an entrance port


818


of a second vacuum distribution controller apparatus


800


. The second vacuum distribution controller apparatus


800


functions substantially identically to vacuum distribution controller apparatus


200


. A control signal


820


may control movement and temporary position of a plunger


822


of second vacuum distribution controller apparatus


800


by means of a motor


824


or, optionally, motors


220


and


824


may both be responsive to the same control signals.




Thus, conform the area that is desired, suction force is directed to one or more adjacent horizontal areas, or to one or more adjacent vertical areas.




The present invention has been described with certain degree of particularity. Those versed in the art will readily appreciate that various modifications and alterations may be carried out without departing from the scope of the following claims:



Claims
  • 1. A distribution controlling apparatus comprising:a duct having an entrance port and one or more exit ports; a plunger longitudinally movable within said duct such that said duct and said plunger form a variable sized compartment, said compartment comprising said entrance port and a variable number of said exit ports; means for coupling said entrance port to a vacuum suction force pump; and means for coupling said at least one exit port to at least one suction inlet port of a vacuum table.
  • 2. The apparatus in accordance with claim 1, wherein said means for coupling said at least one exit port comprises suitable tubing.
  • 3. The apparatus in accordance with claim 1, wherein said at least one exit port is coupled directly to said at least one suction inlet port of said vacuum table.
  • 4. The apparatus in accordance with claim 1 further comprising:a worm gear coupled to a rotation device, said worm gear concentrically positioned within said duct.
  • 5. The apparatus in accordance with claim 4, wherein said rotation device is a motor responsive to an electrical signal.
  • 6. The apparatus in accordance with claim 4, wherein said rotation device is a stepper motor, responsive to electrical pulses.
  • 7. The apparatus in accordance with claim 1, further comprising leakage prevention sealing means positioned between said plunger and said duct.
  • 8. The apparatus in accordance with claim 1, wherein said duct is part of a cylindrical housing.
  • 9. The apparatus in accordance with claim 1, wherein said duct is part of a rectangular housing.
  • 10. The apparatus in accordance with claim 1, wherein said duct is cylindrical and said plunger is of cylindrical shape.
  • 11. The apparatus in accordance with claim 4, further comprising:a rod non-concentrically affixed inside said duct, said rod positioned parallel to said worm gear and said rod protruding through a non-concentric hole in said plunger.
  • 12. The apparatus in accordance with claim 11, further comprising leakage prevention sealing means positioned between said plunger and said rod.
  • 13. The apparatus in accordance with claim 1, wherein said duct is non-cylindrical and said plunger is of non-cylindrical shape.
  • 14. An apparatus comprising:a vacuum table having one or more inlet ports; and a vacuum distribution controller comprising: a duct having an entrance port coupled to a vacuum pump and at least one exit port coupled to said one or more inlet ports of said vacuum table; and a plunger longitudinally movable within said duct such that said duct and said plunger form a variable sized compartment, said compartment comprising said entrance port and a variable number of said exit ports.
US Referenced Citations (16)
Number Name Date Kind
677085 Johnson Jun 1901 A
871320 Bollee Nov 1907 A
1293840 McLeod et al. Feb 1919 A
1354580 Schumacher Oct 1920 A
2318964 Parker May 1943 A
2572640 Lovegrove Oct 1951 A
3115159 Yasui Dec 1963 A
3162210 Bemis Dec 1964 A
3408031 Muir, Jr. Oct 1968 A
4392915 Zajac Jul 1983 A
4468017 Pavone Aug 1984 A
4768763 Gerber Sep 1988 A
4934670 Witte Jun 1990 A
RE33782 Fujita et al. Dec 1991 E
5226451 Brumfield Jul 1993 A
6336492 Nagaoka Jan 2002 B1