Mechanically heated/cooled air system for welding helmet

Abstract

A mechanical refrigeration and heating unit supplies filtered air that is heated or chilled as needed for one or more welding helmets. A portable or transportable cabinet or housing has an air inlet on which a cartridge air filter is mounted. The air passes through an evaporator coil into an evaporator plenum where an evaporator fan moves the air to an outlet that connects with a heater plenum that contains an electric heater module. An outlet of the heater if fitted with an outlet port to which an air hose may be connected. A compressor, condenser coil, receiver, and condenser fan are located in an equipment compartment in the housing. A control board in the unit allows the user to select heated or chilled air. A clogged-filter alarm provides visual and audio alarm signals when pressure in the evaporator plenum falls below a threshold.

Claims

1. Mechanical heated/cooled air system for a welding helmet comprising: a housing having exterior walls and interior walls defining, in top-to-bottom order, at least an air inlet opening, an evaporator plenum and an equipment compartment within said housing, the evaporator plenum communicating with said air inlet opening, the latter being disposed in an exterior wall of the housing, and an evaporator pan within said housing and spaced from said air inlet opening such that the evaporator plenum is defined between said air inlet opening and said evaporator pan; an air filter mounted on said air inlet opening; an evaporator coil positioned within said evaporator plenum; an evaporator fan positioned on said evaporator pan and having an inlet port open to said evaporator plenum and a generally cylindrical outlet port; a heater plenum having an inlet positioned on and fitted to the outlet port of said evaporator fan, a heater chamber, and an outlet port positioned on an opening in an exterior wall of said housing; a heater module positioned within the heater chamber of said heater plenum; a mechanical refrigeration system positioned within the equipment compartment in said housing, including a condenser coil mounted at a condenser air intake opening in an exterior wall of said housing; a compressor having a suction port connected to an outlet port of the evaporator coil and a pressure port connected to an inlet port of said condenser coil; a receiver member connected to an outlet of said condenser coil; and a condenser fan within said equipment compartment having an inlet open to said equipment compartment and an outlet positioned an a condenser air exhaust opening in an exterior wall of said housing; wherein a thermally controlled expansion valve is positioned between an outlet of said receiver member and an inlet of said evaporator coil; a control portion that controls power output conductors connected with said compressor and to said heater module for selectively energizing one or the other of said compressor and said heater module such that the system provides filtered and heated or cooled air at the outlet port of said heater plenum; and a plug-in air hose connector interchangeably positioned at the outlet port of said heater plenum and protruding out of said housing.

2. Mechanical heated/cooled air system for a welding helmet according to claim 1, wherein said air filter mounted on said air inlet opening includes a cylindrical cartridge filter and a self-centering mount affixed atop the housing at said air inlet opening.

3. Mechanical heated/cooled air system for a welding helmet according to claim 2, wherein mount is pyramidical in shape, formed of a plurality of triangular vertical plates and having an apex at its upward end.

4. Mechanical heated/cooled air system for a welding helmet according to claim 1, wherein said air filter includes a protective cover.

5. Mechanical heated/cooled air system for a welding helmet according to claim 1, wherein a pressure switch located in said evaporator plenum is coupled to an alarm circuit, such that a predetermined low pressure in said plenum causes said alarm circuit to generate a clogged-filter alarm signal.

6. Mechanical heated/cooled air system for a welding helmet according to claim 5, wherein said alarm circuit provides both a visual alarm and an audible alarm.

7. Mechanical heated/cooled air system for a welding helmet according to claim 1, wherein said housing is arranged vertically, with said evaporator plenum situated below said inlet port and above said equipment compartment.

8. Mechanical heated/cooled air system for a welding helmet according to claim 1, wherein said housing includes a handle member affixed onto an upper end of said housing and having a transverse grip thereon; and further includes at least a pair of rollers mounted at a lower rear of the housing and a pair of caster wheels at a lower front thereof.

9. Mechanical heated/cooled air system for a welding helmet according to claim 1, wherein said heater plenum inlet and said heater plenum outlet port are each of tubular shape, and said heater plenum is in the form of a box containing said heater module with tapered ends that narrow to said heater plenum inlet and said heater plenum outlet port.

10. Mechanical heated/cooled air system for a welding helmet according to claim 1, wherein said plug-in air hose connector has a plug-in single-hose fitting adapted for attaching a flexible air hose.

11. Mechanical heated/cooled air system for a welding helmet according to claim 1, wherein said plug-in air hose connector has a pair of hose fittings each adapted for connecting to a respective flexible air hose to supply air to two welding helmets.

12. Mechanical heated/cooled air system for a welding helmet according to claim 1, further comprising a control circuit controlling power supplied to said heater module and to said compressor, and configured such that only a selected one of said heater module and said compressor is energized at a given time.

13. Mechanical heated/cooled air system for a welding helmet according to claim 1 wherein said evaporator fan includes a centrifugal blower having a housing situated between said inlet port said generally cylindrical outlet port and said generally cylindrical outlet port is fitted into or onto the inlet of said heater plenum.

14. Mechanical heated/cooled air system for a welding helmet according to claim 1, wherein said housing comprises a removable front panel that can be removed to access all of said evaporator plenum and said equipment compartment.

15. Mechanical heated/cooled air system for a welding helmet according to claim 1, wherein said heater module is electrically powered and has electrical connectors that protrude through said heater plenum.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) FIG. 1 is a perspective view of a mechanical cooled or heated filtered air supply unit for a welding helmet according to an embodiment of this invention.

(2) FIG. 2 is a rear elevation thereof.

(3) FIG. 3 is a top plan view thereof.

(4) FIG. 4 is a side elevation thereof.

(5) FIG. 5 is an elevation of this embodiment, with a front panel removed and showing component parts within the housing.

(6) FIG. 6 is an exploded perspective of a top of this embodiment showing the air filter and filter mount.

(7) FIG. 7 is an exploded assembly view of the evaporator fan, heater plenum and heater module in this embodiment.

(8) FIG. 8 is a perspective view of an assembled heater plenum and module, with a dual connector.

(9) FIG. 9 is a partly exploded assembly view thereof.

(10) FIG. 10 is a perspective view of an assembled heater plenum and module, with a single hose connector.

(11) FIG. 11 is a partly exploded assembly view thereof.

(12) FIG. 12 is a perspective view of the condenser air fan as employed in this embodiment.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

(13) With reference to the Figures of Drawing, and initially to FIGS. 1 to 4 thereof, a helmet air filtering and conditioning unit 10 has a generally rectangular housing 12 formed of several external walls including a side wall 14 and a rear wall 16 as well as a top wall 18. A filter unit 20 is seated on the top wall 18 and includes a generally cylindrical filter guard or cover 22 within which is a HEPA cartridge filter 24 (see FIG. 6). A handle 26 for pulling or pushing the unit 10 has a pair of arms that project out from the two sides of the housing 12, and a tubular handle bar is situated between the outer ends of the two arms. Wheels or rollers 28 are here mounted at the bottom or base of the housing 12, at the rear, and there are a pair of caster wheels 29 at the front. The caster wheels 29 are capable of pivoting 360 degrees about the vertical axis.

(14) A condenser air inlet grille 30 is shown formed in one side wall 14, and a condenser air discharge grille 32 is situated in the back wall 16. A helmet air outlet port 34 is shown projecting out through an opening is the rear wall 16. As shown in FIGS. 5 and 6, a filter cartridge holder 36 is situated at an evaporator air inlet port 38, here a round opening with the evaporator coil 40 visible in this view through the inlet port 38. In this case, the filter holder 36 has a generally pyramidical or Christmas tree shape, here formed of four triangular plates with the apex at the top. There is a threaded rod or similar fastener at the top or apex of the filter holder 36. This extends vertically through a small bolt hole at the center of the top disk of the cover 20 to secure the cover and filter cartridge 24 in place.

(15) FIG. 5 shows the unit 10 with a front cover removed, such that the mechanical refrigeration system inside the housing 12 can be seen. An evaporator pan 42 is spaced a predetermined distance below the top wall 18 of the housing, where the evaporator coil 40 and evaporator air inlet port 38 are located. The top wall 18 and the evaporator pan 42 define an evaporator plenum 44. An equipment chamber or equipment compartment 46 is defined between this evaporator pan 42 and the base of the housing 12. An evaporator blower 58 is mounted on the evaporator pan 42, here at the underside thereof, with an intake port 38 (FIG. 6) at the top side, opening to the evaporator plenum 44. Air is chilled when the mechanical refrigeration system is operating and is drawn from the plenum 44 and is discharged (through the wall 16) to the helmet air outlet port 34, as will be described. Any condensation is drained through a condensation tube 59 and can be discharged out of the unit in known fashion.

(16) Within the equipment compartment 46 is located a compressor 48 with a suction port S and pressure port P, where low pressure warm vapor refrigerant is drawn into the port S and high pressure hot vapor is discharged from the port P to a high pressure vapor line 49 that leads to a condenser coil 50 that is mounted onto the inside of the wall 14 at the location of the condenser air intake grille 30. From the condenser a high pressure liquid line 51 leads to a receiver or receiver/dryer tank 52 which serves as a reservoir for pressurized liquid refrigerant. A high pressure liquid line 53 then leads from the receiver 52 to a thermally controlled expansion valve 54 which provides low pressure liquid through a low-pressure liquid line 55 to the evaporator. A low-pressure vapor line 57 then brings the low pressure refrigerant gas back to the suction port S of the compressor 48.

(17) A condenser air blower 60 is mounted at the inside of the wall 16 with its outlet port at the location of the condenser air discharge grille 32 (as shown in FIG. 1)

(18) A control board 56 is positioned inside the equipment compartment 46 to control power that is applied to the compressor 48, blowers 58, 60, and other equipment inside the housing 12.

(19) The evaporator fan 58 or blower, and associated heating mechanism for alternatively supplying chilled air or heated air to the welding helmet, are shown in FIG. 7 as an assembly view. The blower 58 is here shown as a centrifugal blower with a housing 62 and associated motor 64. The housing 62 has a cylindrically shaped exhaust port 66. A heater assembly is comprised of a heater plenum 68 formed of a generally rectangular box 70 with a inlet portion that tapers down to a fitting ring 72 that mates with the exhaust port 66 of the fan 58. A heater block 80 is dimensioned to fit within the box 70 of the plenum 68. The heater block has a pair of electrodes that fit through slots in one wall of the plenum 68 and these connect to electrical conductors for powering the heater block 80. An end cover 74 for the heater plenum has a rectangular flange 76 that seats onto the distal end of the heater plenum 68 to enclose the heater block 80. The end cover 74 tapers down and leads to a tubular member 78 to which a plug-in hose connector (34 or 82) can be inserted. As shown in FIGS. 8 and 9 a plug-in connector module 82 can be fitted into the member 78, a dual arrangement for connecting to two welding helmets via a pair of air hoses. This can interlock to remain in place, or it can be permanently installed. A similar arrangement is shown in FIGS. 10 and 11 but with a plug-in module 32 that has a single outlet tube, and which is used when the unit 10 is to adapted to supply air to a single welding helmet.

(20) Air for the welding helmet(s) first passes through the HEPA filter 24 and through the inlet port 38 and evaporator coil 40 into the evaporator plenum 44. The evaporator blower 58 forces the air from the evaporator plenum through the heater plenum 68 and heater block 80 and this air exits out through the exit port or connector 34 or 82. Where heated air is needed the compressor is turned off and the heater block 80 is energized, but when chilled air is needed the compressor is energized and the heater block 80 is turned off.

(21) An example of the condenser fan 60 is shown in FIG. 12 as a centrifugal fan or blower having a housing 84 and motor 86, and other controls. An exit port 88 on the housing 84, is in this embodiment shown as having an exhaust of rectangular shape and dimensioned to fit on the wall 14 at the generally rectangular condenser air discharge grille 32.

(22) A low pressure sensor 90 can be present within an intake to the evaporator blower, and connected electrically with the control board 56. When the pressure is below a predetermined threshold that indicates the filter 24 may be clogged, the circuit board 56 can energize an alarm such as an audible alarm or klaxon, as well as a visible alarm such as a flashing light, to let the worker know to pay attention to the condition of the filter. If the alarm rings, this condition shuts off the power to the heater and/or the air conditioning compressor, for safety purposes. The circuit board 56 is also configure to energize the mechanical air conditioning system, e.g., the compressor 48, or to provide electric current to the heater block 80, depending on the temperature as selected by the user. Preferably, the circuit board 56 keeps the evaporator blower 48 at constant speed, and the same conditions also apply for the speed of the condenser fan 60.

(23) While a favorable arrangement of this invention has been described in reference to a preferred embodiment, it should be understood that the invention is not limited to that precise embodiment. Rather, many modifications and variations will present themselves to those skilled in the art without departing from the scope and spirit of the invention, as defined in the appended claims.