Information
-
Patent Grant
-
6499506
-
Patent Number
6,499,506
-
Date Filed
Tuesday, March 27, 200123 years ago
-
Date Issued
Tuesday, December 31, 200221 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Eitan, Pearl, Latzer & Cohen-Zedek
-
CPC
-
US Classifications
Field of Search
US
- 137 62511
- 137 62512
- 269 21
- 251 270
-
International Classifications
-
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)