CA1071598A - Vacuum pump - Google Patents
Vacuum pumpInfo
- Publication number
- CA1071598A CA1071598A CA264,070A CA264070A CA1071598A CA 1071598 A CA1071598 A CA 1071598A CA 264070 A CA264070 A CA 264070A CA 1071598 A CA1071598 A CA 1071598A
- Authority
- CA
- Canada
- Prior art keywords
- pump
- vacuum
- housing
- venturi tube
- plunger
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
- Jet Pumps And Other Pumps (AREA)
Abstract
ABSTRACT
A vacuum pump having a mechanically operated plunger or piston which is so arranged as to either fully open or fully close a supply of compressed gas.
The compressed gas flows through a venturi tube to create a vacuum. This vacuum in turn causes the atmospheric pressure to urge the plunger against a spring force to close the connection between the compressed gas and the venturi tube. This will maintain the vacuum pressure between two predetermined limits. As soon as the pressure in the vacuum chamber rises above a predetermined value the compressed gas supply is opened again to reduce the gas pressure in the vacuum chamber. There are also disclosed a new desoldering tool, a power cylinder, clamping fixtures and suction cups operable with the vacuum pump of the invention.
A vacuum pump having a mechanically operated plunger or piston which is so arranged as to either fully open or fully close a supply of compressed gas.
The compressed gas flows through a venturi tube to create a vacuum. This vacuum in turn causes the atmospheric pressure to urge the plunger against a spring force to close the connection between the compressed gas and the venturi tube. This will maintain the vacuum pressure between two predetermined limits. As soon as the pressure in the vacuum chamber rises above a predetermined value the compressed gas supply is opened again to reduce the gas pressure in the vacuum chamber. There are also disclosed a new desoldering tool, a power cylinder, clamping fixtures and suction cups operable with the vacuum pump of the invention.
Description
~L~73~
This invention relates generally to vacuum systems and par-ticularly relates to a vacuum pump of the type having a venturi tube and associated equipment such as a desoldering instrument, vacuum clamping ~ixtures, a power cylinder and vacuum operated suction cups.
Many types of vacuum pumps are known in the art.
A very e~ficient type of vacuum pump is operated by a supply of compressed gas such as air. The compressed air is caused to flow through a venturi tube which creates a -reduced pressure at its throat to provide the desired YaCuUm. Such a pump has been disclose~j in the patent to Thurman et al. 1,0149729. The pump includes a valve which is designed to create a steady state according to a var~ing vacuum load. Thus the valve will control the amount of compressed air ~ed into the pump. Accordingly, the valve is either completely turned off or remains partially open during opera-tion to control the flc)w of compressed air.
mis is effected by utilizing two preset limit valves.
The disadvantage of such a system is that it requires a continuou~ supply of compressed gas, thus wasting the compressed air. As a result, this type o~ pump is not suited to provide a compact, portable system including a compressed air supply and a vacuum pump. A
somewhat similar vacuum pump nas been disclosed in the patent to Des Rocher 1,187~719. In other words, in this pump the valve is never completely on or completely off.
me pump disclosed in the patent to Lung 2,457,388 is never completely closed.
It is accordingly an object of ~he present invention to provide a vacuum system including a vacuum ~L~7~5~
pump where the vacuum is generated by a venturi tube a~d which is characterized by an on-o~f operation.
The present invention is a demand operated vacuum pump comprising a venturi tube, means including a passage-way for supplying co~pressed gas to said venturi tube, a ~ vacuum chamber, conduit means for exhausting the air from ; said vacuum chamber and connected to the throat of said venturi tube, piston means disposed in said vacuum rhamber and capable of moving from one end position to the other9 said piston means having a portion capable of opening and closing said passageway to permit or prevent the compressed gas from entering said venturi tube, spring means associated with said piston means and disposed in said housing for urging said piston into one end position, while an existing vacuum tends to urge said piston in the other i end position, thereby to close off the supply of compressed I gas, and means coupled to said piston means for causing I said piston means to rapidly snap from one end position to the other.
Additional attachments which may be used with the vacuum pump of the invention will be subsequently discussed.
Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:-Fig. 1 is a cross-sectional view of a preferred embodiment of a vacuum pump embodying the present invention;
Fig. 2 is a cross-sectional view of another vacuum pump in accordance with the present invention;
Fig~ 3 is an ele~ational view of a desoldering tool which may be used with the vacuum pump of the present ~ 5 invention;
Fig~ 4 is an elevational view of a vacuum desoldering tip which may be used with a temperature-controlled desoldering instrument;
Fig. 5 is an elevational view of a power cylinder having forward and backward action without embodying springs and without requiring more than a single connection to a source of compressed air and another source of vacuum;
Fig. 6 is a view in perspective o~ a pair of clamping blocks or fixtures for securely gripping a component and which may be secured to a bench top by he action of a vacuum;
Fig. 7 is a cross-sectional view taken on line 7_7 of Fig. 6 to illustrate particularly the seal provided for each of the clamping fixtures;
Fig. 8 is a view in perspective of two clamping blocks similar to those of Fig. 6 for gripping a component such as a circuit board and which are secured to a bench top by a vacuum connection provided in the bench top;
Fig. 9 i~ a cros~-sectional view taken on line 9-9 o~ Fig. 8 to illustrate the clamping block, its seal and the ~acuum connection to the bench top; and Fig. 10 is a view in perspective of a worker carrying the vacuum system of the present invention and with suction cups o~ his boots to provide a secure ~oothold for the worker on a slippery surface.
Referring now to the drawings wherein like elements are designated by the same reference numbers and particularly to Fig. 1, there is illustrated a preferred embodiment of a vacuum pump embodying the present invention and forming ~ 7 ~ 5~ ~
part of the vacuum system o~ the present invention. me vacuum pump of Figo 1 includes a housing generally designated at 10 within which moves a control element or plunger 11 and further including a venturi tube 12. The housing 10 may, as illustrated, be made in three parts and may include a plunger cap 14, a plunger housing 15 and a muffler portion 16~ The purpose of the vacu~ pump ol Fig. 1 is to utilize compressed air to generate a vacuum. In addition, the compressed air having passed the venturi tube 12 is converted into a gas or air at a relatively low pressure so that both a vacuum and a low pressure gas are avaliable.
me pump is so arranged that it will automatically block the supply of high pressure air when a vacuum o~
predetermined pressure has been obtained. The pump is provided with an automatic control to apply compressed air again when the pressure in the vacuum reservoir has risen to ~nother predetermined value. Therefore, the vacuum is maintained between two limits by a demand action. The operation may be described as a variable pulse width modulation system, that is a system where the -time duration of the on and off operation varies in accordance with demand.
Before further explaining the operation of the pump o~ the invention the structure of the pump of Fig. 1 will now be described in some detail.
me plunger housing 15 consists of a generally cylindrical outer body having, for example, four outlets 17~
189 20 and 21 connected to the interior which forms a plenum 22. The outlets 17, 18, 20 and 21 are each provided wi-th an outer serrated nipple for connection to a suitable hose such as a hose 23 to provide a vacuum at a desired work place.
~ 3 The hose 23 may consist of a sui-table plastic material which is ~lexible. It need not necessarily be able to withstand atmospheric pressure and may be allowed to collapse due to the ambient air pressure. It will, o~
course, be obvious that more or less than the four nipples 17, 18, 20 and 21 may be providedA The plunger housing 15 is also provided with an apertured conical inlet 24 by means o~ which the high pressure air or gas may be supplied through a ~lexible hose 25. me hose 25 should be able to withstand the high pressure which may amount to 80 - 100 psi (lbs. per square inch). The conlcal end 24 may be threaded for receiving a coupler element 26 which in turn is connected to the high pressure hose 25 and which may have a serrated nipple 27 to which the hose is secured.
The radially extending inlet 24 has a bore 30 which is connected to an axial bore ~1 in the plunger housing 15. The bore 30 is connected to the axial bore 31 through a reduced por-tion 32 which interconnects the high pressure hose 25 to the bore 31 and which can be opened and closed by the forward portion ~3 o~ the plunger 11 which is sealed on either end by two 0-rings 34. The bore 31 connects to a conical opening 35 which has a much reduced ~entral cylindrical opening 36 connected in turn to the venturi 12.
me plunger housing 15 may be provided at its rear end with suitable internal holes not sho~n in Fig. 1, for receiving self-tapping screws to secure the plunger cap 14 to the plunger housing 15. Finally, the plunger housing 15 is provided with recesses 38 which cooperate with corresponding projections 4~ in the venturi 16 to provide a bayonet lock to lock the ven1;uri or muffler housing 16 to the plunger 5~3 housing 15.
Turning now to the description of the muffler and venturi housing 12, it will be se~n that this housing portion consists of a ~o~ardly open cylindrical portion or manifold 42 provided with a slot or hole 43 in its side wall.
The open end o~ the cylinder 42 is closed by a muffler material 44 to d~mpen noise created by the intermittent operation o~ the pumpO ~he slot 43 serves the purpose to receive a portion o~ the muf~ler material 44 so as to prevent its being blown out of the open cylinder 42. me manifold 42 may be connected to the outside o~ a room to ventilate the ~umes and the like which may be sucked up by the vacuum.
This will keep the room clean and ~ree of obnoxious gases.
The rear end of the muffler housing 16 is closed by a disk-like structure 45 which in turn carries the venturi tube 12. The rearward end 46 of the venturi tube 12 is spaced ~rom the front end 47 of the plunger housing ~5 and from its ~ore 36 to provide an opening 48 through ~hich air can escape from a bore 50 to the venturi tube 12, thus creatin~ a vacuum in a manner well understood. In other words, the venturi tube 12 has a reduced portion or throat through which the compressed gas or air must flow at ~n inc~eased speed and reduced pressure. This reduced pressure in turn will cause air to flow through the opening 48 into the venturi tube 12 thus creating a vacuum in the bore 50.
me bore 50 in turn has an enlarged cylindrical portion 51 in which is provided a check valve 52 which is capable of sealing the bore 50 against a connector element 53 by means o~ the 0-ring 54. The connector element 5~
snaps over the outwardly bulging ring 55 at the end o~ the ~ 37~5~8 housing portion 16 and again has a serrated nipple 56 for connecticn to a hose 57. The hose 57 should also consist of a material capable of withstanding the air pressure.
Hence the hose 57 whould be relatively rigid to resist j collapse due to the air pressure and to provide a ~ast response time. It serves the purpose to interconnect the plenum 22 with the bore 50 so as to create a vacuum in the plenum 22. It will be understood that the projections 40 at the rearward end of the muffler housing 16 which create a bayonet lock, extend on both sides through a predetermined angle so that the two parts can be con~,ected and locked by rotating one against the other.
After the high pressure air has passed the venturi tube 12 it has a relatively low pressure such as say 2 - 6 psi. This air may be obtained through an aperture 60 in the cylinder 42 which connects to a connector 61 ~lhich may be identical to the connector 53 and which is snapped over an outwardly bulging portion 62 of the housing 42. me connector 61 is provided with a hole 63 ~.a~ing an eccen-tric portion 64 which can be connected to the bore 60 by rota-ting it. mis will permit to control the size of the opening between the interior of the cylinder 42 and a flexible hose 65 from which the low pressure air can be obtained. This can be stored in a reservoir 66 shown schematically. This regulated output air can be utilized for many purposes.
Having now described the three housing portions 14 15, and 16, the control piston or plunger and its function will now be described. As explained before, the plu~ger 11 has a forward or control portion 33 for either opening or closing the opening 32 which connects to the compressed air ~L(;97~L5~3 supply. The plun~er 11 is provided with a cylindrical central sha~t 68 which is integral with the control portion 33. me rearward portion 70 is provided with a small metal pin 71 which cooperates with a trip cam 72. Finally the plunger 11 has a disk-like portion 73 which slides within the cylindrical opening 74 of the plunger housing 15 and is sealed by an 0 ring 75. A main spring 76 bears against one surface of the disk 73 and against the ~ront wall 77 o~ the plunger housing 15.
The trip cam 72 is of fork-like construction and has a generally U-shaped opening 78 in both of its end portions in which the plunger shaft 71 can move. I-t is provided on its forward side with a semicircular detent 80 which helps the snap action provided by the trip cam 72 and its spring load 81. The spring 81 is loaded in compression and disposed between the cylindrical wall 74 of the plunger cap 14 and the top portion o~ trip cam 72. The spring 81 is pressed against a shoulder 82 in the plunger cap by a proJection or retaining leg 83 ~orming part o~ the plu~ger cap 14 and which is secured to a semicircular disk ~4. The disk 84 additionally has two rearwardly proJecting retaining legs 85 spaçed from retaining leg 83 and through which extend outwardly projecting pins 86 about which the trip cam 72 is capable of pi~oting. The pins 86 preferably form part of the trip cam 72 and are molded integral therewith.
A foam-like filter 88 of annular shape may be provided in the plenum 22 for retaining particles such as solder which may have been sucked in by one of the hoses such as 23.
By wa~J o~ example, the muffler housing 16 may consist o~ a clear plastic such as a polycarbonate which is sold in _ g the trade under the name Lexan (trade mark). The connector 53 may consist of polyethylene. The plunger h~using 15 need not be transparent and may consist of a self-lubricating plastic such as Delrin (trade mark) which is an acetal. The plunger cap 14 may again consist of Lexan. The trip cam 72 may also consist of Delrin.
If desired, a vacuum tank 90 may be connected to one of the vacuum hoses 23 as shown schematically and this in turn may be connected to various work areas, for example by a hose 89.
Hexagonal bore holes 91 may be provided in the housings 15 and 16 for securing the pump to a fixed support.
The operation of the pump of Fig. 1 will now be described. Initially the plunger 73 is in the position shown in ~ig. 1. In other words, the pressure of spring 76 pushes the plunger disk 73 rearwardly thus keeping the opening 32 free. Accordingly, air pressure applied through hose.2~ flows through bore 30, opening 32, conical portion 35, reduced openi.ng 36 into venturi 12. This will cause a redueed pressure at the point 48 thus opening check valve 52. The air is now capable of flowing from plenum 22 through ' hose 57 into the bore 50 and out of the venturi tube 12. The air at reduced pressure is available from hose 65 and may be stored in the low gas pressure reservoir 66 which may also be provided with a suitable check valve such as shown at 52.
As the vacuum in the plenum 22 reaches a predetermined low pressure, the differential air pressure will be able to push the disk 73 of the plunger 11 forwardly, that is toward the right of ~ig. 1 and the control portion 33 will block opening 32 thus shutting off the air supply.
3L07~L59,B
This motion of -the plunger 11 is accelerated by the ; snap action created by spring 81 and trip cam 72. In other words, the initial mo-tion o~ the plunger 68 will eventually cause the spring to reach near dead center so that subsequent fo~ward motion, toward the right of Fig. 1 is accelerated by the toggle action of the spring and cam.
The ~orce o~ control spring 7~ and the size of the disk 73 are so dimensioned that the plunger moves -toward the right when a predetermined low air pressure has been reached in the plenum 22.
As the vacuum is used up by ope~ation of the tools connected $hereto or simply by leakage, the pressure in the plenum 22 increases again. When it has reached a predetermined upper value again determined by the force o~
spring 76 and the si~e o~ the disk 739 the reverse action takes place, that is the plunger 11 moves rearwardly, that is to~ard the leXt oX Fig. 1 because the air pressure diXferential has been reduced. Again the motion is accelerated by the snap action or toggle action o~ spring 81 and trip cam 72. The o~f action, that is the movement of the plunger 68 into the position o~ Fig. 1, is helped by the provision of the semicircular recess 80 in the two legs of the cam 72. This is so because the recess 80 tends to retain the pin 71 on the plunger 11.
It will now be seen that the pump of Fig. 1 operates on demand and hence the compressed air is only used when it is needed. This helps to conser~e the supply oX compressed air and makes it possible for a person to carry a self-contained system including a compressed air supply and a pump.
~0 The pump will last ~or years. The system provides not only ~al7~5~1~
a vacuum but also a low gas pressure supply which may be used for other purposes. Since the system operates on ; demand the on and off times are variable; therefore the system becomes essentially a variable pulse width modulation control O
i The snap action caused by spring 81 and trip cam 72 - serves the purpose to prevent that the plunger 68 with its control portion ~3 keeps the opening 32 partially open and partially closed. This would mean that the compressed air is wasted and that no positive control is obtained. There-fore, in order to obtain the on-off action of the vacuum pump of the invention the snap action is essential.
Having now described the construction and operation of the preferred vacuum pump of the invention, reference is now made to Fig. 2 which shows a modified vacuum pump. This vacuum pump has a different arrangement for providing the required snap action of the demand control plunger. The pump of Fig. 2 again may have a three-pa~t housing including plunger housing cap 100, a plunger housing 101 and a muffler and ~enturi housing 102. mus the plunger cap 100 has a ~-ylindrical portion 103 and may be open to atmosphere at a reduced rearward portion 104. The plunger cap has cylindrical radial extensi4n 105 ~or housing a ~pring 106 which urges a conical tip 107 against the plunger 110. Its ~ operation will be subsequently described.
The plunger housing 101 has an outer cylindrical portion 111 for receiving the plunger ilO. It has a disk-like forward portion 112 against which bears a main spring 114. It also has a central cylindrical portion 115 for the plunger 110 and which has a reduced open~ng 116 for connection - ~2 -~7~59~
to a venturi. A bore 116 connec-ts to the venturiO
The muffler portion 102 has a forward end 118 with external openings 120 and which serves as a muffler. It may be provided with sound deadening material not shown. Its main body 121 ~orms a venturi 119 in the manner previously e~plained and connects to the bore 116 of the plunger i housing. It has a first outlet 122 from which the vacuum is available. A check valv8 123 may be provided in a connector 124 similar to those previously described. The connector in 10 ~urn connects to a hose 125 which interconnects the outlet 122 with the outlet 117 ~orming a serrated nipple so as to create a vacuum in the plenum 126 formed in the oylindrical portion i11. A filter 129 may be provided in the plenum 126. The compressed air is applied to the inlet 127.
i m e air at reduced pressure is available from an air ¦ outlet 128 which may be closed by a check ~alve 130.
¦ l~e plunger 110 may be somewhat similar to that of ¦ Fig. 1 and again has a forward portion 131 sealed by two 0-rings 132 for opening or closing the air inlet opening 133.
20 The ~orward portion 131 of the plunger 110 is made integral with a ciroular disk 134 sealed by a~ 0-ring 135 against the cylindrical portion 111 of the plunger housing. Its rearward portion 136 has a disk-like termination 137 which cooperates with the spring biased detent 107.
me pump of Fig. ~ differs primarily from that of Fig. 1 ~y its different snap action provided by the detent 107 and the spring 106. I-ts operation may be described as followsO Due to the force of spring 114 acting against the plunger disk 134 the plunger is initially in its rearward position, that is in the left-hand position as viewed in ~71S9~3 Fig. 2. ~en compressed air having a pressure of say 80 - 100 psi is applied to the inlet 127 a vacuum is created at the outlet bore 122 in the manner previously described. This reduced pressure is applied by the hose 125 to the plenum 126. At the same time air at reduced pressure is available from the outle~ 128 as long as the check valve 1~0 is open.
Eventually the pressure in the plenum 126 decreases to a predetermined value. mis will now permit the disk 134 to move toward the right against the pressure of the main spring 114. The snap action is obtained by the enlarged disk-like portion 137 of the plunger being ~orced past the detent 107. This will now permit the control po~tion 131 to seal off the bore 133 thus cutting off the air supply. At that time the check valve 130 closes so as to preserve the low pressure air which may be maintained in the reservoir similar to the one shown in 66 in FigA 1- At the same time the check valve 12~ closes. The regulated vacuum output lir.e 140 may also be con~ected to a vacuum tank such as shown at 90 in Fig. 1. As the vacuum is used up the pressure in the plenum 126 will slowly rise until it reaches a predetermined value. This is again determined by the force of main spring ~14, the size of the plunger disk 134 and the force of the spring biased detent 107. Eventually, however, the plunger 110 will be able to snap rearwardly, that is to the left of Fig. 2 thus opening the bore 1~3 and the previously described action repeats again~
It should be noted that the embodiment of Fig. 1 has certain advantages over that of Fig. 2. In other words, the plunger 110 of the embodiment of Fig. 2 must overcome the ~0 relatively strong force of the spring biased detent 107 to ~ 7~ ~9 ~
move le~t or right. This additional :force is wasted, that ; is it requires an additional supply of compressed air.
Otherwise, however7 the operation of the vacuum pump of Figo
This invention relates generally to vacuum systems and par-ticularly relates to a vacuum pump of the type having a venturi tube and associated equipment such as a desoldering instrument, vacuum clamping ~ixtures, a power cylinder and vacuum operated suction cups.
Many types of vacuum pumps are known in the art.
A very e~ficient type of vacuum pump is operated by a supply of compressed gas such as air. The compressed air is caused to flow through a venturi tube which creates a -reduced pressure at its throat to provide the desired YaCuUm. Such a pump has been disclose~j in the patent to Thurman et al. 1,0149729. The pump includes a valve which is designed to create a steady state according to a var~ing vacuum load. Thus the valve will control the amount of compressed air ~ed into the pump. Accordingly, the valve is either completely turned off or remains partially open during opera-tion to control the flc)w of compressed air.
mis is effected by utilizing two preset limit valves.
The disadvantage of such a system is that it requires a continuou~ supply of compressed gas, thus wasting the compressed air. As a result, this type o~ pump is not suited to provide a compact, portable system including a compressed air supply and a vacuum pump. A
somewhat similar vacuum pump nas been disclosed in the patent to Des Rocher 1,187~719. In other words, in this pump the valve is never completely on or completely off.
me pump disclosed in the patent to Lung 2,457,388 is never completely closed.
It is accordingly an object of ~he present invention to provide a vacuum system including a vacuum ~L~7~5~
pump where the vacuum is generated by a venturi tube a~d which is characterized by an on-o~f operation.
The present invention is a demand operated vacuum pump comprising a venturi tube, means including a passage-way for supplying co~pressed gas to said venturi tube, a ~ vacuum chamber, conduit means for exhausting the air from ; said vacuum chamber and connected to the throat of said venturi tube, piston means disposed in said vacuum rhamber and capable of moving from one end position to the other9 said piston means having a portion capable of opening and closing said passageway to permit or prevent the compressed gas from entering said venturi tube, spring means associated with said piston means and disposed in said housing for urging said piston into one end position, while an existing vacuum tends to urge said piston in the other i end position, thereby to close off the supply of compressed I gas, and means coupled to said piston means for causing I said piston means to rapidly snap from one end position to the other.
Additional attachments which may be used with the vacuum pump of the invention will be subsequently discussed.
Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:-Fig. 1 is a cross-sectional view of a preferred embodiment of a vacuum pump embodying the present invention;
Fig. 2 is a cross-sectional view of another vacuum pump in accordance with the present invention;
Fig~ 3 is an ele~ational view of a desoldering tool which may be used with the vacuum pump of the present ~ 5 invention;
Fig~ 4 is an elevational view of a vacuum desoldering tip which may be used with a temperature-controlled desoldering instrument;
Fig. 5 is an elevational view of a power cylinder having forward and backward action without embodying springs and without requiring more than a single connection to a source of compressed air and another source of vacuum;
Fig. 6 is a view in perspective o~ a pair of clamping blocks or fixtures for securely gripping a component and which may be secured to a bench top by he action of a vacuum;
Fig. 7 is a cross-sectional view taken on line 7_7 of Fig. 6 to illustrate particularly the seal provided for each of the clamping fixtures;
Fig. 8 is a view in perspective of two clamping blocks similar to those of Fig. 6 for gripping a component such as a circuit board and which are secured to a bench top by a vacuum connection provided in the bench top;
Fig. 9 i~ a cros~-sectional view taken on line 9-9 o~ Fig. 8 to illustrate the clamping block, its seal and the ~acuum connection to the bench top; and Fig. 10 is a view in perspective of a worker carrying the vacuum system of the present invention and with suction cups o~ his boots to provide a secure ~oothold for the worker on a slippery surface.
Referring now to the drawings wherein like elements are designated by the same reference numbers and particularly to Fig. 1, there is illustrated a preferred embodiment of a vacuum pump embodying the present invention and forming ~ 7 ~ 5~ ~
part of the vacuum system o~ the present invention. me vacuum pump of Figo 1 includes a housing generally designated at 10 within which moves a control element or plunger 11 and further including a venturi tube 12. The housing 10 may, as illustrated, be made in three parts and may include a plunger cap 14, a plunger housing 15 and a muffler portion 16~ The purpose of the vacu~ pump ol Fig. 1 is to utilize compressed air to generate a vacuum. In addition, the compressed air having passed the venturi tube 12 is converted into a gas or air at a relatively low pressure so that both a vacuum and a low pressure gas are avaliable.
me pump is so arranged that it will automatically block the supply of high pressure air when a vacuum o~
predetermined pressure has been obtained. The pump is provided with an automatic control to apply compressed air again when the pressure in the vacuum reservoir has risen to ~nother predetermined value. Therefore, the vacuum is maintained between two limits by a demand action. The operation may be described as a variable pulse width modulation system, that is a system where the -time duration of the on and off operation varies in accordance with demand.
Before further explaining the operation of the pump o~ the invention the structure of the pump of Fig. 1 will now be described in some detail.
me plunger housing 15 consists of a generally cylindrical outer body having, for example, four outlets 17~
189 20 and 21 connected to the interior which forms a plenum 22. The outlets 17, 18, 20 and 21 are each provided wi-th an outer serrated nipple for connection to a suitable hose such as a hose 23 to provide a vacuum at a desired work place.
~ 3 The hose 23 may consist of a sui-table plastic material which is ~lexible. It need not necessarily be able to withstand atmospheric pressure and may be allowed to collapse due to the ambient air pressure. It will, o~
course, be obvious that more or less than the four nipples 17, 18, 20 and 21 may be providedA The plunger housing 15 is also provided with an apertured conical inlet 24 by means o~ which the high pressure air or gas may be supplied through a ~lexible hose 25. me hose 25 should be able to withstand the high pressure which may amount to 80 - 100 psi (lbs. per square inch). The conlcal end 24 may be threaded for receiving a coupler element 26 which in turn is connected to the high pressure hose 25 and which may have a serrated nipple 27 to which the hose is secured.
The radially extending inlet 24 has a bore 30 which is connected to an axial bore ~1 in the plunger housing 15. The bore 30 is connected to the axial bore 31 through a reduced por-tion 32 which interconnects the high pressure hose 25 to the bore 31 and which can be opened and closed by the forward portion ~3 o~ the plunger 11 which is sealed on either end by two 0-rings 34. The bore 31 connects to a conical opening 35 which has a much reduced ~entral cylindrical opening 36 connected in turn to the venturi 12.
me plunger housing 15 may be provided at its rear end with suitable internal holes not sho~n in Fig. 1, for receiving self-tapping screws to secure the plunger cap 14 to the plunger housing 15. Finally, the plunger housing 15 is provided with recesses 38 which cooperate with corresponding projections 4~ in the venturi 16 to provide a bayonet lock to lock the ven1;uri or muffler housing 16 to the plunger 5~3 housing 15.
Turning now to the description of the muffler and venturi housing 12, it will be se~n that this housing portion consists of a ~o~ardly open cylindrical portion or manifold 42 provided with a slot or hole 43 in its side wall.
The open end o~ the cylinder 42 is closed by a muffler material 44 to d~mpen noise created by the intermittent operation o~ the pumpO ~he slot 43 serves the purpose to receive a portion o~ the muf~ler material 44 so as to prevent its being blown out of the open cylinder 42. me manifold 42 may be connected to the outside o~ a room to ventilate the ~umes and the like which may be sucked up by the vacuum.
This will keep the room clean and ~ree of obnoxious gases.
The rear end of the muffler housing 16 is closed by a disk-like structure 45 which in turn carries the venturi tube 12. The rearward end 46 of the venturi tube 12 is spaced ~rom the front end 47 of the plunger housing ~5 and from its ~ore 36 to provide an opening 48 through ~hich air can escape from a bore 50 to the venturi tube 12, thus creatin~ a vacuum in a manner well understood. In other words, the venturi tube 12 has a reduced portion or throat through which the compressed gas or air must flow at ~n inc~eased speed and reduced pressure. This reduced pressure in turn will cause air to flow through the opening 48 into the venturi tube 12 thus creating a vacuum in the bore 50.
me bore 50 in turn has an enlarged cylindrical portion 51 in which is provided a check valve 52 which is capable of sealing the bore 50 against a connector element 53 by means o~ the 0-ring 54. The connector element 5~
snaps over the outwardly bulging ring 55 at the end o~ the ~ 37~5~8 housing portion 16 and again has a serrated nipple 56 for connecticn to a hose 57. The hose 57 should also consist of a material capable of withstanding the air pressure.
Hence the hose 57 whould be relatively rigid to resist j collapse due to the air pressure and to provide a ~ast response time. It serves the purpose to interconnect the plenum 22 with the bore 50 so as to create a vacuum in the plenum 22. It will be understood that the projections 40 at the rearward end of the muffler housing 16 which create a bayonet lock, extend on both sides through a predetermined angle so that the two parts can be con~,ected and locked by rotating one against the other.
After the high pressure air has passed the venturi tube 12 it has a relatively low pressure such as say 2 - 6 psi. This air may be obtained through an aperture 60 in the cylinder 42 which connects to a connector 61 ~lhich may be identical to the connector 53 and which is snapped over an outwardly bulging portion 62 of the housing 42. me connector 61 is provided with a hole 63 ~.a~ing an eccen-tric portion 64 which can be connected to the bore 60 by rota-ting it. mis will permit to control the size of the opening between the interior of the cylinder 42 and a flexible hose 65 from which the low pressure air can be obtained. This can be stored in a reservoir 66 shown schematically. This regulated output air can be utilized for many purposes.
Having now described the three housing portions 14 15, and 16, the control piston or plunger and its function will now be described. As explained before, the plu~ger 11 has a forward or control portion 33 for either opening or closing the opening 32 which connects to the compressed air ~L(;97~L5~3 supply. The plun~er 11 is provided with a cylindrical central sha~t 68 which is integral with the control portion 33. me rearward portion 70 is provided with a small metal pin 71 which cooperates with a trip cam 72. Finally the plunger 11 has a disk-like portion 73 which slides within the cylindrical opening 74 of the plunger housing 15 and is sealed by an 0 ring 75. A main spring 76 bears against one surface of the disk 73 and against the ~ront wall 77 o~ the plunger housing 15.
The trip cam 72 is of fork-like construction and has a generally U-shaped opening 78 in both of its end portions in which the plunger shaft 71 can move. I-t is provided on its forward side with a semicircular detent 80 which helps the snap action provided by the trip cam 72 and its spring load 81. The spring 81 is loaded in compression and disposed between the cylindrical wall 74 of the plunger cap 14 and the top portion o~ trip cam 72. The spring 81 is pressed against a shoulder 82 in the plunger cap by a proJection or retaining leg 83 ~orming part o~ the plu~ger cap 14 and which is secured to a semicircular disk ~4. The disk 84 additionally has two rearwardly proJecting retaining legs 85 spaçed from retaining leg 83 and through which extend outwardly projecting pins 86 about which the trip cam 72 is capable of pi~oting. The pins 86 preferably form part of the trip cam 72 and are molded integral therewith.
A foam-like filter 88 of annular shape may be provided in the plenum 22 for retaining particles such as solder which may have been sucked in by one of the hoses such as 23.
By wa~J o~ example, the muffler housing 16 may consist o~ a clear plastic such as a polycarbonate which is sold in _ g the trade under the name Lexan (trade mark). The connector 53 may consist of polyethylene. The plunger h~using 15 need not be transparent and may consist of a self-lubricating plastic such as Delrin (trade mark) which is an acetal. The plunger cap 14 may again consist of Lexan. The trip cam 72 may also consist of Delrin.
If desired, a vacuum tank 90 may be connected to one of the vacuum hoses 23 as shown schematically and this in turn may be connected to various work areas, for example by a hose 89.
Hexagonal bore holes 91 may be provided in the housings 15 and 16 for securing the pump to a fixed support.
The operation of the pump of Fig. 1 will now be described. Initially the plunger 73 is in the position shown in ~ig. 1. In other words, the pressure of spring 76 pushes the plunger disk 73 rearwardly thus keeping the opening 32 free. Accordingly, air pressure applied through hose.2~ flows through bore 30, opening 32, conical portion 35, reduced openi.ng 36 into venturi 12. This will cause a redueed pressure at the point 48 thus opening check valve 52. The air is now capable of flowing from plenum 22 through ' hose 57 into the bore 50 and out of the venturi tube 12. The air at reduced pressure is available from hose 65 and may be stored in the low gas pressure reservoir 66 which may also be provided with a suitable check valve such as shown at 52.
As the vacuum in the plenum 22 reaches a predetermined low pressure, the differential air pressure will be able to push the disk 73 of the plunger 11 forwardly, that is toward the right of ~ig. 1 and the control portion 33 will block opening 32 thus shutting off the air supply.
3L07~L59,B
This motion of -the plunger 11 is accelerated by the ; snap action created by spring 81 and trip cam 72. In other words, the initial mo-tion o~ the plunger 68 will eventually cause the spring to reach near dead center so that subsequent fo~ward motion, toward the right of Fig. 1 is accelerated by the toggle action of the spring and cam.
The ~orce o~ control spring 7~ and the size of the disk 73 are so dimensioned that the plunger moves -toward the right when a predetermined low air pressure has been reached in the plenum 22.
As the vacuum is used up by ope~ation of the tools connected $hereto or simply by leakage, the pressure in the plenum 22 increases again. When it has reached a predetermined upper value again determined by the force o~
spring 76 and the si~e o~ the disk 739 the reverse action takes place, that is the plunger 11 moves rearwardly, that is to~ard the leXt oX Fig. 1 because the air pressure diXferential has been reduced. Again the motion is accelerated by the snap action or toggle action o~ spring 81 and trip cam 72. The o~f action, that is the movement of the plunger 68 into the position o~ Fig. 1, is helped by the provision of the semicircular recess 80 in the two legs of the cam 72. This is so because the recess 80 tends to retain the pin 71 on the plunger 11.
It will now be seen that the pump of Fig. 1 operates on demand and hence the compressed air is only used when it is needed. This helps to conser~e the supply oX compressed air and makes it possible for a person to carry a self-contained system including a compressed air supply and a pump.
~0 The pump will last ~or years. The system provides not only ~al7~5~1~
a vacuum but also a low gas pressure supply which may be used for other purposes. Since the system operates on ; demand the on and off times are variable; therefore the system becomes essentially a variable pulse width modulation control O
i The snap action caused by spring 81 and trip cam 72 - serves the purpose to prevent that the plunger 68 with its control portion ~3 keeps the opening 32 partially open and partially closed. This would mean that the compressed air is wasted and that no positive control is obtained. There-fore, in order to obtain the on-off action of the vacuum pump of the invention the snap action is essential.
Having now described the construction and operation of the preferred vacuum pump of the invention, reference is now made to Fig. 2 which shows a modified vacuum pump. This vacuum pump has a different arrangement for providing the required snap action of the demand control plunger. The pump of Fig. 2 again may have a three-pa~t housing including plunger housing cap 100, a plunger housing 101 and a muffler and ~enturi housing 102. mus the plunger cap 100 has a ~-ylindrical portion 103 and may be open to atmosphere at a reduced rearward portion 104. The plunger cap has cylindrical radial extensi4n 105 ~or housing a ~pring 106 which urges a conical tip 107 against the plunger 110. Its ~ operation will be subsequently described.
The plunger housing 101 has an outer cylindrical portion 111 for receiving the plunger ilO. It has a disk-like forward portion 112 against which bears a main spring 114. It also has a central cylindrical portion 115 for the plunger 110 and which has a reduced open~ng 116 for connection - ~2 -~7~59~
to a venturi. A bore 116 connec-ts to the venturiO
The muffler portion 102 has a forward end 118 with external openings 120 and which serves as a muffler. It may be provided with sound deadening material not shown. Its main body 121 ~orms a venturi 119 in the manner previously e~plained and connects to the bore 116 of the plunger i housing. It has a first outlet 122 from which the vacuum is available. A check valv8 123 may be provided in a connector 124 similar to those previously described. The connector in 10 ~urn connects to a hose 125 which interconnects the outlet 122 with the outlet 117 ~orming a serrated nipple so as to create a vacuum in the plenum 126 formed in the oylindrical portion i11. A filter 129 may be provided in the plenum 126. The compressed air is applied to the inlet 127.
i m e air at reduced pressure is available from an air ¦ outlet 128 which may be closed by a check ~alve 130.
¦ l~e plunger 110 may be somewhat similar to that of ¦ Fig. 1 and again has a forward portion 131 sealed by two 0-rings 132 for opening or closing the air inlet opening 133.
20 The ~orward portion 131 of the plunger 110 is made integral with a ciroular disk 134 sealed by a~ 0-ring 135 against the cylindrical portion 111 of the plunger housing. Its rearward portion 136 has a disk-like termination 137 which cooperates with the spring biased detent 107.
me pump of Fig. ~ differs primarily from that of Fig. 1 ~y its different snap action provided by the detent 107 and the spring 106. I-ts operation may be described as followsO Due to the force of spring 114 acting against the plunger disk 134 the plunger is initially in its rearward position, that is in the left-hand position as viewed in ~71S9~3 Fig. 2. ~en compressed air having a pressure of say 80 - 100 psi is applied to the inlet 127 a vacuum is created at the outlet bore 122 in the manner previously described. This reduced pressure is applied by the hose 125 to the plenum 126. At the same time air at reduced pressure is available from the outle~ 128 as long as the check valve 1~0 is open.
Eventually the pressure in the plenum 126 decreases to a predetermined value. mis will now permit the disk 134 to move toward the right against the pressure of the main spring 114. The snap action is obtained by the enlarged disk-like portion 137 of the plunger being ~orced past the detent 107. This will now permit the control po~tion 131 to seal off the bore 133 thus cutting off the air supply. At that time the check valve 130 closes so as to preserve the low pressure air which may be maintained in the reservoir similar to the one shown in 66 in FigA 1- At the same time the check valve 12~ closes. The regulated vacuum output lir.e 140 may also be con~ected to a vacuum tank such as shown at 90 in Fig. 1. As the vacuum is used up the pressure in the plenum 126 will slowly rise until it reaches a predetermined value. This is again determined by the force of main spring ~14, the size of the plunger disk 134 and the force of the spring biased detent 107. Eventually, however, the plunger 110 will be able to snap rearwardly, that is to the left of Fig. 2 thus opening the bore 1~3 and the previously described action repeats again~
It should be noted that the embodiment of Fig. 1 has certain advantages over that of Fig. 2. In other words, the plunger 110 of the embodiment of Fig. 2 must overcome the ~0 relatively strong force of the spring biased detent 107 to ~ 7~ ~9 ~
move le~t or right. This additional :force is wasted, that ; is it requires an additional supply of compressed air.
Otherwise, however7 the operation of the vacuum pump of Figo
2 is basically identical with that of Fig~ 1. It is again controlled by demand and provides variable on and o~f periods analogous to a variable pulse width modulation system.
The parts of the p~p of Fig. 2 may consist o~ the same materials as corresponding parts o~ the pump of Fig. 1.
Referring generally to the remaining Figs. 3 - 10, there are described various embodiments of the present invention making use of the vacuum pump of Figs. 1 or 2. In other words, the embodiments of Figs. 3 - 10 complete the vacuum system of the present invention.
Turning now specifically to Fig~ 3, there is illustrated a desoldering tube made possible by the vacuum pump o~ the invention. The desoldering tube of Fig. ~ is characterized by its extremely fast reaction. It includes a cylinder 145 which pre~erably is transparent and consists of a plastic matcrial capable o~ withstanding high impact~
Dlsposed within or connected to the cylinder 145 is an operating tip 146 having a central opening ~or applying the vacuum. The tip 146 is co~nected to a connector member 147 having an on-off valve therein of conventional construction which is operated by depressing a button 148 which preferably is spring loaded. Hense when the button 148 is depressed, the valve is open to permit a vacuum to be applied to the tip 146 through an inner cylinder 150 ~onnected thereto.
The vacuum may be applied by a hose 151 connected to a cap 152 which ~its over the cylinder 145 and is sealed theretoO The hose 151 in turn is connected by a flexible - 15 ~
,,, . ", ,,,, ,. ,.,,,,,, . . .. ,~,,,,, .,.. . ~.. ,,. ,, ,.. ,.,, ,,, .. , .~... ....... ... ... .. ..
5gl~
cylinder 15~ to a nipple 154 forming part of the cap 152.
The cylinder 145 provides a storage space for the vacuum and a filter material 155 may be disposed at its rear end ~or filtering, for example, solder drops that may be sucked in by the tool. Some o~ the solder may additionally be trapped inside the cylinder 150.
The operation of the desoldering 'cube o~ Fig. 3 will now be evident. The solder to be removed is first heated by a soldering instrument. After the solder has become liquid it is sucked in by the desoldering tube which can readily be held in one hand with the index ~inger operating the push button 148 by depressing it. Since the vacuum or the low pressure is stored in the cylinder 145 the action is extremely fast because as soon as the button 148 is depressed the liquid solder is sucked in in the usual manner. It should be noted that the desoldering tube of Fig. 3 is a strap-I down system which is mainly suited for production work.
¦ mus while the tool is very efficient and ~eatures a snap ¦ action switch it needs a permanent connection to a vacuum pump o~ the type previously disclosed.
Turning now to Fig. 4, this illustrates again a desoldering tip controlled by one hand and which may be attached to a soldering instrument such as a temperature controlled soldering instrument disclosed and claimed in Patent No. 3,~83,716 to the Applicant which issues on May 13, Thus referring again to Fig. 4, the soldering tool is generally shown at 158 and may be provided with a special desoldering tip 160 having a suction orifice at 161. The portion 160 may consist of stainless steel and a filter for S9~3 retaining the sucked in solder. The hose 162 connec-ts to i the vacuum pump previously described and may be secured to the soldering tool 158 by a band or tape 163.
The attachment 164 through which the hose 162 extends includes an on-o~f valve which may again be operated by a spring biased button 165. It will again be evident that the soldering tube 168 may be held with one hand with the index finger operating the spring biased button 165. This instrument operates basically in the same manner as does that described in Fig. 3~ It will be evident that the vacuum desoldering tip 160 may be removed when not needed. Alsog it will be evident that the on-o~ valve and push button 165 may be detachably secured to the soldering instrument 158 by a snap action connector 166. The vacuum available from the hose 162 may also be used to exhaust the fumes due to the soldering or desoldering operation. This is one reason why it may be desirable to exhaust the manifold 42 to the outside.
Fig. 5 to whlch reference is now made illustrates a power cylinder with forward and backward action. The power cylinder o~ Fig. 5 is characterized by a single piston which requires no spring and only a single connection.
The power cylinder o~ Fig. 5 includes a cylinder 168 which is open at its forward end 170 and closed at the other end by a disk 171. It ~eatures a plunger 172 having a seal 173, for example, in the form of an O ring. Its forward portion 174 cooperates with a series of forward stops 175 in the forward portion of the cylinder 168. Its rearward portion abuts the disk 171 during rearward motion~
A central sha~t 176 may be molded to or provided on the plunger 172 to operate a power tool or the like. The 7 ~ 5~ ~
power cylinder is controlled by a single hose connection 177 which may either be connected to a vacuum supply 180 or to a compressed air supply 181 by the respective valves 182 or 183. me valves 182 and 183 may be hand operated or may be automatically controlled in accordance with the desired motion of the sha~t 176.
The power cylinder of Fig. 5 provides double action by means of a single plunger having a single seal. ~nly a single connection to a source of vacuum or compressed air is required. Conventional power cylinders o~ this type require either two inlets or a spring. The spring in turn requires more power to overcome the spring pressure. Hence the power cylinder o~ Fig. 5 features a longer life, requires less power and is not subject to the metal fatigue of a spring.
The vacuum system of the present in~ention also I permits the use of clamping fixtures which may be moved at will over any bench top or other ~lat surface and then secured to a desired spot by the use of a vacuum. Such a system has been illustrated i~ Figs 6 and 7. As shown here, there are two clamping fixtures or clamping blocks 185 and 186 which operate in the manner of a ~ise. The blocks 185 and 186 may, for example, consist of a plastic, transparent material having a flat bottom 187 provided around its edges with a resilient seal 188 such as a resilient gasket material permanently fixed to the bottom surface 187. The clamping fixtures may have a substantially triangular side view as shown in Fig. 6. rme long vertical sides 190 may be provided with a substantially triangular depression 191 ~0 for securely gripping or grasping a component illustrated ~ 7~59~
by way of example at 192.
Each of the blocks 185 and 186 is provided with a hose 19~ which connects to a vacuum pumpO The hose 193 in turn is connected by a cylinder 194 extending through the block to a hose or tube 195 which extends through the bottom surface 187. An on-of~ valve not sho~ and disposed in the cylinder 194 is controlled by the push button 196 for connecting the tube 195 to the vacu~ or disconnecting it therefromO
In order to secure one o~ the blocks such as 185 to a bench top 19~ the push button 196 is pushed to connect the tube 195 to the source o~ ~acuum. The vacuum will then evacuate the air space between the bottom 187 o~ the block and the bench top 197 to press the block 185 against the bench top 197 due to the atmospheric pressure.
The advantage o~ the clamping fixtures 185 and 187 are several. The clamping blocks may be put anywhere at convenience on the bench top. Furthermore, they can be conveniently moved closer together cr further apart to accommodate components of dif~erent sizes.
It will be realized that the clamping fixtures of Figs. 6 and 7, tQke the place o~ a conventional vise.
HoweYer, a vise must be secured to the bench top and cannot readily be moved about. Also it t~es some time to open and close the vise jaws to receive components o~ different sizes.
Therefore, it will be realized that the use o~ the blocks 185 and 186 will considerably speed up the work and make it more convenient. It will also be realized that components or parts may be clamped between the lateral sur~ace 198 of the blocks rather -than against the vertical end surface ~90.
: ' ~7~59~
Referring now to Figs. 8 and 9, there are again shown the same two clamping blocks 185 and 186 previously discussed~ However, the clamping blocks 185 and 186 may now be used in a different manner. Here vacuum hoses 200 and 201 extend through an opening or bore 202 in the bench top 197. Therefore by disposing one of the blocks such as ' 185 over the opening 202 a vacuum will be created under the ; bottom surface 187 so as to press the block 185 against the bench top and against the seal 188 me other block 186 may be similarly positioned over the opening o~ the hose 201.
In this case a component such as a circuit board 204 may be pressed against the lateral surfaces 198 of the two blocks 185 and 186.
This system has a certain disadvantage in that the position of the two blocks 185 and 186 is determined to some extent by the position of the holes or openings such as 202 in the bench top. It is still possible to move the blocks somewhat as long as the opening 202 is below the bottom surface 187 o~ each block.
It is also ~easible to apply the vacuum created by the vacuum pump of the invention to a suitable suction cup.
Such suction cups may be applied to smooth surfaces for lifting, for example, a plate glass sheet or a metal app,iance. Such vacuum cups may also be used at the boots or shoes of a worker to permit him to walk on a slippery surface9 for example, on the wet wings of an airplane or to permit a diver to walk on a ship's hull or to hold him against such a hull under water~
Such a system is illustrated in Fig. 10. Here a worker carries ,~n air tank 205 on his back which is connected ~7~5~8 by a hose 206 to a vacuum pump 207 which may take the form o~ that illustrated in Fig. 1. By means of vacuum hoses 208 and 209 the vacuum pump 207 may ~e connected to two sets of suction CUp5 210 and 211 which may be secured each to one of the shoes or boots 212 of the worker.
Pressure sensors may be provided at 214 on the boot 212 to control the vacuum applied to the suction cups 211 by a hose 215. In other words, as the worker or diver ; straightens his boot to put it down on the sur~ace the pressure sensor 214 will connect the vacuum to the suction cups 210 and 211 to provide a secure hold to any slippery sur~ace.
Similarly the pressure sensors 214 will release the vacuum upon appropriate motion o~ the foot so -tha-t the worker can lift one ~oot of~ the surface and put it down at I some other location.
¦ The vacuum system of Fig. 10 is made possible by the vacuum pump 0~ Figo 1~ In other words~ because the vacuum p~mp only operates on demand it requires a relati~ely small air supply which can be readily carried by a person with air tank 205~ Hence since both the re~uired aîr tank 205 and the vacuu~ pump 207 are small and light weight they can readily be carried about by a worker going about his tasks.
There has thus been disclosed a vacuum pu~p having a mechanical feedback so that the pump operates only upon demand. It will maintain a vacuum between two predetermined limits. It has variable on and of~ times depending on the demand and is analogous to a pulse width modulation system~
There have also been disclosed various vacuum systems cooperating with the vacuum pump of the invention .... .. . . . .
:
~7151'~
and featuring, for example, desoldering tools, a double action power cylinder, movable vacuum clamps and suction cups for various purposesO These are made possible by the vacuum pump of simplified construction and light weight and by the fact that less compressed air is needed. The ; vacuum pump will not only supply a vacuum, that is it will reduce -the air pressure but it will also provide a supply of air at relatively low pressure. mis is made possible because the high pressure air is converted into low pressure air.
,
The parts of the p~p of Fig. 2 may consist o~ the same materials as corresponding parts o~ the pump of Fig. 1.
Referring generally to the remaining Figs. 3 - 10, there are described various embodiments of the present invention making use of the vacuum pump of Figs. 1 or 2. In other words, the embodiments of Figs. 3 - 10 complete the vacuum system of the present invention.
Turning now specifically to Fig~ 3, there is illustrated a desoldering tube made possible by the vacuum pump o~ the invention. The desoldering tube of Fig. ~ is characterized by its extremely fast reaction. It includes a cylinder 145 which pre~erably is transparent and consists of a plastic matcrial capable o~ withstanding high impact~
Dlsposed within or connected to the cylinder 145 is an operating tip 146 having a central opening ~or applying the vacuum. The tip 146 is co~nected to a connector member 147 having an on-off valve therein of conventional construction which is operated by depressing a button 148 which preferably is spring loaded. Hense when the button 148 is depressed, the valve is open to permit a vacuum to be applied to the tip 146 through an inner cylinder 150 ~onnected thereto.
The vacuum may be applied by a hose 151 connected to a cap 152 which ~its over the cylinder 145 and is sealed theretoO The hose 151 in turn is connected by a flexible - 15 ~
,,, . ", ,,,, ,. ,.,,,,,, . . .. ,~,,,,, .,.. . ~.. ,,. ,, ,.. ,.,, ,,, .. , .~... ....... ... ... .. ..
5gl~
cylinder 15~ to a nipple 154 forming part of the cap 152.
The cylinder 145 provides a storage space for the vacuum and a filter material 155 may be disposed at its rear end ~or filtering, for example, solder drops that may be sucked in by the tool. Some o~ the solder may additionally be trapped inside the cylinder 150.
The operation of the desoldering 'cube o~ Fig. 3 will now be evident. The solder to be removed is first heated by a soldering instrument. After the solder has become liquid it is sucked in by the desoldering tube which can readily be held in one hand with the index ~inger operating the push button 148 by depressing it. Since the vacuum or the low pressure is stored in the cylinder 145 the action is extremely fast because as soon as the button 148 is depressed the liquid solder is sucked in in the usual manner. It should be noted that the desoldering tube of Fig. 3 is a strap-I down system which is mainly suited for production work.
¦ mus while the tool is very efficient and ~eatures a snap ¦ action switch it needs a permanent connection to a vacuum pump o~ the type previously disclosed.
Turning now to Fig. 4, this illustrates again a desoldering tip controlled by one hand and which may be attached to a soldering instrument such as a temperature controlled soldering instrument disclosed and claimed in Patent No. 3,~83,716 to the Applicant which issues on May 13, Thus referring again to Fig. 4, the soldering tool is generally shown at 158 and may be provided with a special desoldering tip 160 having a suction orifice at 161. The portion 160 may consist of stainless steel and a filter for S9~3 retaining the sucked in solder. The hose 162 connec-ts to i the vacuum pump previously described and may be secured to the soldering tool 158 by a band or tape 163.
The attachment 164 through which the hose 162 extends includes an on-o~f valve which may again be operated by a spring biased button 165. It will again be evident that the soldering tube 168 may be held with one hand with the index finger operating the spring biased button 165. This instrument operates basically in the same manner as does that described in Fig. 3~ It will be evident that the vacuum desoldering tip 160 may be removed when not needed. Alsog it will be evident that the on-o~ valve and push button 165 may be detachably secured to the soldering instrument 158 by a snap action connector 166. The vacuum available from the hose 162 may also be used to exhaust the fumes due to the soldering or desoldering operation. This is one reason why it may be desirable to exhaust the manifold 42 to the outside.
Fig. 5 to whlch reference is now made illustrates a power cylinder with forward and backward action. The power cylinder o~ Fig. 5 is characterized by a single piston which requires no spring and only a single connection.
The power cylinder o~ Fig. 5 includes a cylinder 168 which is open at its forward end 170 and closed at the other end by a disk 171. It ~eatures a plunger 172 having a seal 173, for example, in the form of an O ring. Its forward portion 174 cooperates with a series of forward stops 175 in the forward portion of the cylinder 168. Its rearward portion abuts the disk 171 during rearward motion~
A central sha~t 176 may be molded to or provided on the plunger 172 to operate a power tool or the like. The 7 ~ 5~ ~
power cylinder is controlled by a single hose connection 177 which may either be connected to a vacuum supply 180 or to a compressed air supply 181 by the respective valves 182 or 183. me valves 182 and 183 may be hand operated or may be automatically controlled in accordance with the desired motion of the sha~t 176.
The power cylinder of Fig. 5 provides double action by means of a single plunger having a single seal. ~nly a single connection to a source of vacuum or compressed air is required. Conventional power cylinders o~ this type require either two inlets or a spring. The spring in turn requires more power to overcome the spring pressure. Hence the power cylinder o~ Fig. 5 features a longer life, requires less power and is not subject to the metal fatigue of a spring.
The vacuum system of the present in~ention also I permits the use of clamping fixtures which may be moved at will over any bench top or other ~lat surface and then secured to a desired spot by the use of a vacuum. Such a system has been illustrated i~ Figs 6 and 7. As shown here, there are two clamping fixtures or clamping blocks 185 and 186 which operate in the manner of a ~ise. The blocks 185 and 186 may, for example, consist of a plastic, transparent material having a flat bottom 187 provided around its edges with a resilient seal 188 such as a resilient gasket material permanently fixed to the bottom surface 187. The clamping fixtures may have a substantially triangular side view as shown in Fig. 6. rme long vertical sides 190 may be provided with a substantially triangular depression 191 ~0 for securely gripping or grasping a component illustrated ~ 7~59~
by way of example at 192.
Each of the blocks 185 and 186 is provided with a hose 19~ which connects to a vacuum pumpO The hose 193 in turn is connected by a cylinder 194 extending through the block to a hose or tube 195 which extends through the bottom surface 187. An on-of~ valve not sho~ and disposed in the cylinder 194 is controlled by the push button 196 for connecting the tube 195 to the vacu~ or disconnecting it therefromO
In order to secure one o~ the blocks such as 185 to a bench top 19~ the push button 196 is pushed to connect the tube 195 to the source o~ ~acuum. The vacuum will then evacuate the air space between the bottom 187 o~ the block and the bench top 197 to press the block 185 against the bench top 197 due to the atmospheric pressure.
The advantage o~ the clamping fixtures 185 and 187 are several. The clamping blocks may be put anywhere at convenience on the bench top. Furthermore, they can be conveniently moved closer together cr further apart to accommodate components of dif~erent sizes.
It will be realized that the clamping fixtures of Figs. 6 and 7, tQke the place o~ a conventional vise.
HoweYer, a vise must be secured to the bench top and cannot readily be moved about. Also it t~es some time to open and close the vise jaws to receive components o~ different sizes.
Therefore, it will be realized that the use o~ the blocks 185 and 186 will considerably speed up the work and make it more convenient. It will also be realized that components or parts may be clamped between the lateral sur~ace 198 of the blocks rather -than against the vertical end surface ~90.
: ' ~7~59~
Referring now to Figs. 8 and 9, there are again shown the same two clamping blocks 185 and 186 previously discussed~ However, the clamping blocks 185 and 186 may now be used in a different manner. Here vacuum hoses 200 and 201 extend through an opening or bore 202 in the bench top 197. Therefore by disposing one of the blocks such as ' 185 over the opening 202 a vacuum will be created under the ; bottom surface 187 so as to press the block 185 against the bench top and against the seal 188 me other block 186 may be similarly positioned over the opening o~ the hose 201.
In this case a component such as a circuit board 204 may be pressed against the lateral surfaces 198 of the two blocks 185 and 186.
This system has a certain disadvantage in that the position of the two blocks 185 and 186 is determined to some extent by the position of the holes or openings such as 202 in the bench top. It is still possible to move the blocks somewhat as long as the opening 202 is below the bottom surface 187 o~ each block.
It is also ~easible to apply the vacuum created by the vacuum pump of the invention to a suitable suction cup.
Such suction cups may be applied to smooth surfaces for lifting, for example, a plate glass sheet or a metal app,iance. Such vacuum cups may also be used at the boots or shoes of a worker to permit him to walk on a slippery surface9 for example, on the wet wings of an airplane or to permit a diver to walk on a ship's hull or to hold him against such a hull under water~
Such a system is illustrated in Fig. 10. Here a worker carries ,~n air tank 205 on his back which is connected ~7~5~8 by a hose 206 to a vacuum pump 207 which may take the form o~ that illustrated in Fig. 1. By means of vacuum hoses 208 and 209 the vacuum pump 207 may ~e connected to two sets of suction CUp5 210 and 211 which may be secured each to one of the shoes or boots 212 of the worker.
Pressure sensors may be provided at 214 on the boot 212 to control the vacuum applied to the suction cups 211 by a hose 215. In other words, as the worker or diver ; straightens his boot to put it down on the sur~ace the pressure sensor 214 will connect the vacuum to the suction cups 210 and 211 to provide a secure hold to any slippery sur~ace.
Similarly the pressure sensors 214 will release the vacuum upon appropriate motion o~ the foot so -tha-t the worker can lift one ~oot of~ the surface and put it down at I some other location.
¦ The vacuum system of Fig. 10 is made possible by the vacuum pump 0~ Figo 1~ In other words~ because the vacuum p~mp only operates on demand it requires a relati~ely small air supply which can be readily carried by a person with air tank 205~ Hence since both the re~uired aîr tank 205 and the vacuu~ pump 207 are small and light weight they can readily be carried about by a worker going about his tasks.
There has thus been disclosed a vacuum pu~p having a mechanical feedback so that the pump operates only upon demand. It will maintain a vacuum between two predetermined limits. It has variable on and of~ times depending on the demand and is analogous to a pulse width modulation system~
There have also been disclosed various vacuum systems cooperating with the vacuum pump of the invention .... .. . . . .
:
~7151'~
and featuring, for example, desoldering tools, a double action power cylinder, movable vacuum clamps and suction cups for various purposesO These are made possible by the vacuum pump of simplified construction and light weight and by the fact that less compressed air is needed. The ; vacuum pump will not only supply a vacuum, that is it will reduce -the air pressure but it will also provide a supply of air at relatively low pressure. mis is made possible because the high pressure air is converted into low pressure air.
,
Claims (15)
1. A demand operated vacuum pump comprising a venturi tube, means including a passageway for supplying compressed gas to said venturi tube, a vacuum chamber, conduit means for exhausting the air from said vacuum chamber and connected to the throat of said venturi tube a piston means disposed in said vacuum chamber and capable of moving from one end position to the other, said piston means having a portion capable of opening and closing said passageway to permit or prevent the compressed gas from entering said venturi tube, spring means associated with said piston means and disposed in said housing for urging said piston into one end position, while an existing vacuum tends to urge said piston in the other end position, thereby to close off the supply of compressed gas, and means coupled to said piston means for causing said piston means to rapidly snap from one end position to the other.
2. A pump as claimed in claim 1, wherein said means coupled to said piston means for snapping said piston means consists of a cam having one end coupled to said piston means, pivot means for fixedly pivoting said cam, and a spring urging said cam into one or the other of its end positions by a toggle action.
3. A pump as claimed in claim 1, wherein said means coupled to said piston means for snapping said piston means consists of a spring urged detent slideably positioned in the path of a portion of said piston means, said portion having a protrusion whereby motion of said piston means from one of its end positions to the other will force said protrusion to move past said detent.
4. A pump as claimed in claim 1, wherein said snap action means includes a trip cam having a pivot fixed to said housing, said trip cam having a portion in engagement with a portion of said piston means for moving said trip cam about its pivot to and fro, and spring means disposed between a housing for the pump and said trip cam for providing a toggle action.
5. A pump as claimed in claim 4, wherein said trip cam has a semicircular detent engageable with a pin provided on said plunger for loosely interconnecting said trip cam to said plunger.
6. A pump as claimed in claim 1, wherein a vacuum tank is provided, and means for correcting said vacuum tank to said vacuum chamber.
7. A pump as claimed in claim 4, wherein a check valve is provided in said conduit means for discollecting said venturi tube from said vacuum chamber.
8. A pump as claimed in claim 1, wherein means is provided for interconnecting the outlet of said venturi tube to a low gas-pressure reservoir.
9. A pump as claimed in claim 19 wherein a housing is provided having a cylindrical portion surrounding said venturi tube, and a sound deadening material in said cylindrical portion.
10. A pump as claimed in claim 9, wherein said cylindrical portion is provided with a slot for retaining said sound deadening material.
11. A pump as claimed in claim 1, wherein a plurality of vacuum connections are provided to said vacuum chamber.
12. A pump as claimed in claim 7, wherein a connection having a variable opening is provided between said venturi tube and said low gas-pressure reservoir.
13. A pump as claimed in claim 4, wherein said housing consists of a cap for housing said trip cam, a plunger housing for housing said piston means, and a muffler housing for housing said venturi tube.
14. A pump as claimed in claim 1, wherein said means for providing a snap action includes a detent slideable in a housing for said pump, a spring for biasing said detent and a portion on said piston means having a projection to depress said spring loaded detent upon motion to and fro to uncover or cover said passageway to provide said snap action.
15. A pump as claimed in claim 8, wherein a check valve is provided between said venturi tube and said low gas-pressure reservoir.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA264,070A CA1071598A (en) | 1976-10-25 | 1976-10-25 | Vacuum pump |
| CA330,473A CA1072990A (en) | 1976-10-25 | 1979-06-25 | Vacuum clamping fixture |
| CA330,472A CA1098381A (en) | 1976-10-25 | 1979-06-25 | Desoldering tool |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA264,070A CA1071598A (en) | 1976-10-25 | 1976-10-25 | Vacuum pump |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1071598A true CA1071598A (en) | 1980-02-12 |
Family
ID=4107112
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA264,070A Expired CA1071598A (en) | 1976-10-25 | 1976-10-25 | Vacuum pump |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1071598A (en) |
-
1976
- 1976-10-25 CA CA264,070A patent/CA1071598A/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4056334A (en) | Vacuum system | |
| US20060248861A1 (en) | Portable vacuum device | |
| US6729331B2 (en) | Pressure regulator | |
| CA2261266A1 (en) | Pressure-responsive lockout valve and method of use | |
| US7093624B2 (en) | Liquid pumping device | |
| EP0751301A3 (en) | Fluid control apparatus | |
| EP0833239A3 (en) | Pneumatic pressure relay | |
| TW200400869A (en) | Nail gun provided with duster function | |
| AU6800196A (en) | Pilot operated fluid valve | |
| KR20050053339A (en) | Vacuum-generating unit | |
| US4089622A (en) | Vacuum generator | |
| CA1071598A (en) | Vacuum pump | |
| EP0208247A1 (en) | Air brushing apparatus | |
| GB2067717A (en) | Flow control valves | |
| EP1158226A3 (en) | Gas charging device | |
| US4532670A (en) | Vacuum booster and filter | |
| CN219013021U (en) | Vacuum generator integrating automatic release and manual release functions | |
| JP3260092B2 (en) | Exhaust valve | |
| SE8804227D0 (en) | PRESSURE CONTROL DEVICE FOR A VACUUM CLEANER | |
| CA1072990A (en) | Vacuum clamping fixture | |
| CA1098381A (en) | Desoldering tool | |
| SU1496800A2 (en) | Medicinal suction device | |
| JPS60885Y2 (en) | Drip prevention device for dental air turbine handpiece | |
| JPS6014200B2 (en) | Vacuum pump | |
| EP0872205A3 (en) | Suction device attachment for wet cleaning surfaces for example |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |