US2973632A

US2973632A - Portable refrigerated cooler

Info

Publication number: US2973632A
Application number: US695435A
Authority: US
Inventors: Cecil L Moore
Original assignee: ENGINEERING AND RES LAB SERVIC
Current assignee: ENGINEERING AND RES LAB SERVIC; ENGINEERING AND RESEARCH LAB SERVICE Co
Priority date: 1957-11-08
Filing date: 1957-11-08
Publication date: 1961-03-07
Anticipated expiration: 1978-03-07

Description

March 7, 1961 c, MOORE 2,973,632

I PQRTABLE REFRIGERATED COOLER Filed Nov. 8, 1957 '3 Sheets-Sheet 1 INVENT OR. (5504 L. Homer.

Mmh 7, 1961 Filed NOV. 8, 1957 c. L. MOORE PORTABLE REFRIGERATED COOLER 3 Sheets-Sheet 2 (Zr/4 L. Moo/QE- www March 7, 1961 c. L. MOORE 2,973,632

PORTABLE REFRIGERATED COOLER Filed Nov. 8, 1957 3 Sheets-Sheet 3 PIE. 5 FIE'r 73 Fla. 8

I Z Z l H l IO. w m n a 0 0 9688 $6 8689 QQQQ spring, which subsequently operates air PORTABLE REFRIGERATED coornn Cecil L. Moore, St. Louis Park, Minn., assignor: to Engineering and Research Lab Service Co., Indianapolis, Ind., a company Fi Ied Nom-S, 1957, Ser. N0. 695,435

4 Claims, c1. 62-498) This invention relates generally to portable cooling boxes and in particular to a refrigerated box in which the refrigeration system operates by the slow release of energy originally provided by a manual operation.

In providing portable cooling boxes for perishable food it has been customary to perform the cooling function by means of ice packed in the insulated boxes, with the melting of the ice providing the lowered temperature necessary to preserve the foods in an edible state. When such cooling boxes are required to cool the'bo'x contents for prolonged periods such as on picnics or boating trips, the cooling capacity of the box is often insufficient to hold the contents of the box at the required low temperature.

The present invention provides a cooling box maintained at a desired low temperature by means of a meadapted to be integrated into the system chanical refrigeration .system in which the energy for I operating the system is provided by a manual operation, and 'the slow release of this energy maintains the functioning of the system for prolonged periods after the manual charging operation. In general, the refrigeration system herein disclosed for providing this type of operation is similar toa' conventional mechanical refrigeration system, however, the refrigerant compressor or pump has connected thereto, a vacuum reservoir and a pressure reservoir which serve to maintain the circulation of refrigerant through the system for a prolonged period after the pump has ceased operation. A mechanical means is provided for manually operating the pump for a short period to chargethe system, and mechanism is provided which permits this manual operation to also wind a moving means for cooling the condenser.

The principal object of the present invention is to provide a mechanical refrigeration system in which a vacuum reservoir and a pressure reservoir are provided for maintaining the circulation of refrigerant through the system for a period subsequent to shut-down of the'pump or compressor. I p

A further object of the present invention is to provide a sytern of the type referred to above in which the refrigerant pump ismanually operated and in which the fans for drawing cooling air over the condenser are operated by a mechanism which is. charged or wound by the manual operation of the pump. J

A further object of the present invention is to provide a portable cooling .box in which the temperature of the cooledkompartment' is maintained at a relatively low system. 9 I

j -A further object of the present invention is to provide a refrigeration system of the type referred to above into which it an electrically operated pump may be conveniently integrated for use whenever electrical service is available.

value by means of amanually actuated refrigeration Afurther object of the present invention is to provide 2,973,632 Patented Mar. 7, 1961 tieularly adapted for integration into'the system referred to above.

These and other objects will become apparent as the descriptionproceeds with reference to the accompanying drawings in which: V

Fig. 1 is a perspective view of the exterior of a cooling box embodying the present invention.

Fig. 2 is a schematic illustration of the mechanica refrigeration system incorporated into the' cooling box, with an alternately usable electric pump shown in broken lines.

Fig. 3 is a top, sectional View of some of the system components showing their placement within the box.

Fig. 4 is a side sectional view of the cooling box further illustrating the placement ofthe components therein.

Fig. 5 is a sectional view taken generally along the line 5--5 of Fig. 3. V

Fig. 6 is'an enlarged, fragmentary view of a portion of the mechanism shown in Fig. 4.

Fig. 7 is a fragmentary, enlarged view of a portionof the mechanism shownin Fig. 3.

Fig. 8 is an enlarged view, partially'in section, illustrating the construction of the refrigerant pump.

'Fig. 9 is a fragmentary, sectional view taken generally along the line 9-9 of Fig. 4.

Fig. 10 is a sectional view of an electrical pump of the present invention. 4

Fig. 11 is a side, sectional view of an alternative form of pump for use when electrical service is available.

Referring initially to Figs. 1, 2 and 3, the cooling box embodying the present invention is composed of

side walls

10 and 11,

end walls

12 and 13 and a removable cover or lid 14. The box is provided with carrying handles 16 on its end walls and has a transverse partition 17 (Fig. 3) which divides the box into a cooling chamber 18, and a chamber 19 housing the components of the refrigera tion system. It will be understood that the side walls of the box, particularly the portion adjacent the cooling chamber, and the cover are provided with suitable thermal insulation to resist the transfer of heat therethrougn.

The refrigeration system is schematically shown in Fig. 2 in which a manually operated pump, or compressor is indicated at 21. The high pressure, or discharge line 22 from the pump, communicates with a pressure reservoir which takes the form of a tank 23.

The discharge line 24 from the tank communicates with a condenser 26, cooling air being circulated between passes of the condenser tubes by fans whose operation will be subsequently described. The outlet line 27 communicates with a receiver 28, and a line'29 connects the receiver to a restriction provided by a capillary tube, indicated schematically at 31, to an adjustable, temperature responsive valve having a capillary tube 33a and bulb 33 for causing the valve to respond to the temperature of the evaporator. An adjusting means 34 permits the valve tobe set so as to maintain a desired temperature within the evaporator or cooling compartment. The adjustable temperature responsive valve is of a conventional type and forms no part of the present invention.

A line 36 connects the valve to the evaporator 37, the evaporator discharge line 38 being connected to a vacuum reservoir taking the form of the tank 39. The intake line 41 to the pump or compressor is also connected to the vacuum reservoir. At 42 there is shown an electrically actuated pump which may be operated when electrical service is available, its connections beingl indicated in the system by broken lines in Fig. 2. The function and operation of this pump .will be subsequently described, and its function is omitted from the description of the operation of the basic system which is next described.

From the description of the refrigeration system shown in Fig. 2, it will be apparent that this system is similar to conventional mechanical refrigeration systems, but differs from them in two important'respects. These-differences comprise the integration of the vacuum reservoir and the pressure reservoir into the system, and the form of the pump or compressor which is hand-operated, as distinguished from the conventional electric motor operated pump in electrically powered refrigeration systerns.

When the pump is operated the expanded refrigerant entering the pump through the line 41 will be pressurized and delivered to the pressure reservoir. As operation of the pump continues, the portion of the system between the pump discharge and the restriction 31 will be raised in pressure and the pressurized refrigerant traversing the passes of the condenser tubes will be liquefied and delivered to the receiver where the refrigerant will be maintained in both a liquid and a vaporized state. Liquid refrigerant will circulate through the line 29, and because of the pressure drop provided'by the restriction 31, will be permitted to expand into the evaporator, with the latent heat of vaporization of the expanding refrigerant acquired by removing heat from the evaporator in conventional fashion.

The low pressure, expanded refrigerant flows to the vacuum reservoir by means of the line 38, and from the vacuum reservoir to the inlet side of the pump by means of the line 41. When the manual operation of the pump is halted, after a period of a few minutes, the system will, of course, be blocked at the pump. Circulation of refrigerant through the system will, however, continue for a prolonged period after stopping of the pump because of the presence of the vacuum and pressure reservoirs. In other words, upon halting of the pump the supply of pressurized refrigerant contained in the pressure reservoir will continue to expand from the restriction 31 into the evaporator, and the expanded refrigerant will continue to flow into the vacuum reservoir whose pressure, at the halting of the pump operation, is at a relatively low value. This circulation of refrigerant through the evaporator will continue until the pressure on both sides of the pump has been equalized. It will thus be seen that the salient feature of the system just described is that the hand-operated pump rapidly pressurizes the high pressure side of the system, with cooling in the evaporator or cooling chamber continuing after operation of the pump has ceased until the pressure in the high and low sides of the system are equalized.

The means for cooling the condenser tubes and operating the pump will now be described with reference principally to Figs. 3, 4, and 9. As may best be seen in Figs. 4 and 9, the condenser tubes 26 are disposed along the inner face of the rear side wall and extend across the box to form similar tube passes along the inner face of the opposite side wall 10, this latter pass of tubes, which does not appear in Fig. 4, also being omitted from Fig. 3 so as not to obstruct the view of the other components of the system shown in that view.

As indicated in Fig. 9 the side wall 11 (and also the side wall 12, not shown in Fig. 9) is provided with an opening 46, which is louvered at 4-7, adjacent the tubes 26. These openings provide for admission of air into the compartment 19.

The means for evacuating air drawn in through the openings 46 comprises fans 48 and 49 (Fig. 3) which discharge air through radially louvered openings 51 and 52'.

The means for driving the fans, and their mountings, includes a bracket of a squared, annular configuration having an outer wall 53' and an inner wall 54. Journaled Withinbearing members 56 and 57, carried by the bracket, is a housing provided by opposed cup-shaped

members

58 and 59. Extending through the housing and journaled for rotation therein is a hollow shaft 61 which is formed at its inner end to provide a ratchet wheel 62.

. 4 A central shaft 63 extends rotatably through the hollow shaft and at its inner end is provided with a cup-shaped head 66 which is toothed at 67 on its periphery to provide a pinion meshing with a toothed rack 68 which is slidably carried in an extension 69 of the inner bracket wall.

The rack 68 is shown in detail in Fig. 7 and includes a tooth surface 72 and a handle 73. An extending arm 74 is secured to the rack intermediate its ends for a purpose to be subsequently explained.

When the rack 68 is manually reciprocated by manually pulling and pushing on handle 73, the head 66 will be rotated alternately in opposite directions to correspond with movement of the rack. As may best be seen in Fig. 6, motion of the head 66 in one direction (clockwise as viewed in Fig. 6) will be transmitted to the ratchet wheel 62 by means of pawls 76 which extend from the inner surface of the head. A generally U-shaped member 77. pivoted on the wall 54 at 78 carries diametrically opposed teeth which engage the teeth of the ratchet wheel 62 to prevent counter clockwise rotation of the ratchet wheel and the hollow shaft during the upstroke of the rack.

From the foregoing it will be evident that as the rack is manually reciprocated the hollow shaft 61 will be intermittently rotated in one direction. Within the housing provided by the

members

58 and 59 there is accommodated a spring 81, formed of a coiled steel band, and having its inner end anchored to the hollow shaft 61 and its outer end secured to the member 58. Rotation of the hollow shaft thus serves to wind the spring 81 and the energy stored therein is subsequently released through rotation of the member 58.

A means for disconnecting the ratchet drive when the spring 81 is wound to sulficient tightness is provided by a wedge 82 (Fig. 4) which is slidably mounted upon the outer face of the housing member 59 and at its outer extremity is provided with an inwardly flanged portion 83 which overlies the outer coil of the spring. A tension spring 84 extending between the wedge and the inner face of the housing member 54, urges the flange into engagement with the outer coil of the spring 18. As the spring is wound its outside diameter gradually decreases and the sloping inner section of the wedge eventually engages a pin 86 which extends through the wall 54 and abuts the inner edge of the head 66. The resulting outward movement of the pin serves to slide the head 66 outwardly sufiicient to disengage the pawls, carried by the head, from the ratchet wheel. Upon subsequent unwinding of the spring 81, the wedge will be withdrawn from the pin, permitting the leaf spring 87 carried on the outer face of the wall 54 to again urge the pawls into engagement with the ratchet wheel.

As may best be seen in Fig. 5, the housing member is provided with teeth 88 around its outer periphery, these teeth engaging with a gear 89 keyed to a shaft 91 which is journaled in the upwardly extending

walls

53 and 54 of the spring mounting bracket.

Also keyed to the shaft 91 is a gear 92 which, in turn, meshes with a gear 93 keyed to a shaft 94. As may best be seen in Fig. 3, the shaft 94 is journaled in

bearings

95 and 97, carried by members and 99, respectively, which are extensions of the

walls

53 and 54. Also keyed to shaft 94 is a gear 96 which meshes with a gear 97b keyed to a shaft 98b journaled at 101 and 102 (Fig. 3) in the

members

100 and 99.

As may best be seen in Fig. 3, the inner end of the shaft 98b is provided with a taper gear 103 which meshes with a similar gear 104 carried by a shaft 106 which also carries the fan 48. The shaft 106 is journaled in a bearing 107 carried by the side wall 10 and in a bearing 108 mounted in a transversely extending plate 109 secured to the

members

98 and 99.

As may best be seen in Figs. 3 and 5, a set of gearing, identical to that just described, drives the fan 49, which is mounted for rotation similarly to the mounting arrangement for the fan 48., In this set of gearing, gears corresponding to those previously described are given the same reference numerals but with the suffix a.

,As will be evident from the foregoing description of the drive means for the fans 48and 49, rotation of the housing, which occurs upon unwinding of the spring 81, serves to rotate the'fans which are pitched so as to draw air out' through theopenings 51 and 52 in the housing sidewalls. The air drawn in through louvered openings 47 is thus circulated across the passes of the condenser coils and serves to remove heat fromithem.

-Referring to Figs. 3 and 8, it will be seen that the vacuum reservoir 39 and the pressure reservoir 23 are disposed within the chamber 19, together with the pump 21 previously referred to with reference to Fig. 2. t

The pump 21 comprises a flexible diaphragm element 111, the flexible sidewalls of the element being held in shape by internal and external wire rings 112. At their base the flexible sidewalls of the element are sealed to the header 113, provided with an inlet passage 114 and an outletpassage 116. The inlet passage has communication to the internal area of the flexible member by means of avalved opening 117 which is closed by a fiexiblereed 118 secured at one of its ends to the header. Theoutlet passage 116 has communication with the interior of the flexible element through a passage 119 which 'is closed by means of a flexible reed 121, secured at one of its ends to the header. A compression spring 122 extends through the interior of the flexible member and bottoms against a top plate 123 carried thereby. Extending from the upper face of the top plate is a headedmember 124 which extends through a slot 126 formed in the end of the arm 74 carried by the toothed rack 69. When the rack 68 is reciprocated to wind the coiled spring as previously described, the arm '74 carried by the rack serves to collapse and extend, the pump and, .by means of the one-way passage of fluid permitted by the flexible reeds 118 and 121, draws refrigerant through the inlet passage 114 and expels it through the outlet passage 116. This action of the pump serves to build up pressure within the pressure reservoir to which it is connected by means of the line 22, it being understood that the inlet opening 114 to the pump communicates with the vacuum reservoir by means of theline 41 shown in Figures 2 and 3. l

As may be seen in Figures 3 and 4 the evaporator coils 37 are disposed within the housing so as to enclose the chamber. 18 and receive refrigerant from the valve 32. The line 27 leading from the condenser to the receiver is coiled at 127 within the vacuum reservoir, and 'communicates with the receiver.

, .Although the cooling box so far described is primarily designed for use on picnics'and'the like where "electrical service is not available, a means may be additionally provided for operating the refrigerating system when such electrical service is available. For such alternate operdirection by means of the flexible reed 139, suitably secured at one of its margins to the housing. The outlet or discharge passage 145 from the pump is closed in one direction by means ofthe flexible reed 142, secured at one of its margins to the housing.

Adjacent the outlet passage from the pump a toroidal coil 140 surrounds the housing and is adapted to be suitably connected to a source of electrical power and in series with a switch operated by movement of the piston. This switch includes contact elements 141 and 141a which extend through the side wall of the housing in spaced relation to each other and are bridged by the body of the piston. The electrical circuit includes the wire 143 which is connected to one side of a source of electrical power, and a wire 144 whichextends from the coil to the contact element 141. A wire 146 extends from the contact element 141a and is adapted to be connected to the other side of the source of electrical power.

In operation, with the pump 42 connected into the system as shown in Fig. 2, the spring 137 will drive the piston; into its furthest right hand position. In this posi- 'As the piston moves into its position of Figure 10, the

contact elementswill be unbridged thereby de-energizing the toroidal coil. The spring 137 will thereupon drive the piston back to its furthest right-hand position. During this rightward movement of the piston the reed 139 will close off the inlet passage and the reed 136, carried ation of the system an electrically operated pump is provided which may be of the type shown in Figure 10. This pump may be mounted in any convenient location within the chamber 19 and connected into the refrigerating system as shown by broken lines in Figure 2, where the pump is designated by reference numeral 42.

Referring to Figure 10, the pump includes an elongated housing 131 formed of a magnetically impermeable material and having a central bore 132 therethrough. Slidably carried within the bore is a piston 133 formed of electrically conductive and magnetically permeable material and having a central passage 134 therethrough closed in one direction by a flexible reed 136 secured at one of its ends to the piston. A compression spring 137, seated within the bore urges the piston rightwardly, as viewed in Figure 10.

The inlet passage 138 to the pump is closed in one by the piston, will open the passage 134 through the piston. The rise in pressure on the left side of the piston Will'open the reed 142 permitting refrigerant to flow through the discharge passage 145. The toroidal coil willthus be alternately energized and de-energized to pump refrigeration through the inlet passage 138 and out of the discharge passage 145.

With the pump 42 connected into the system as shown in Figure 2, upon electrical energization of the pump, refrigerant will be caused to by-pass the vacuum reservoir and the manually operated pump. Operation of the system will then proceed in the fashion of a conventional mechanical refrigeration cycle. When the refrigeration system is to be operated manually, the

wires

143 and 146 aredisconnected from the source of electrical power, and since the one-direction valves provided by the

reeds

139 and 142 preclude passage of refrigerantthrough the pump 42, the manually actuated system may operate in the fashion previously described.

In a further modified form of the electrical alternative pumping arrangement, an electric motor may be mounted within the chamber 19 and connected in suitable fashion to the driveshafts for the

fans

48 and 49. This electrical alternative driving means may further include a multilobed cam shown fragmentarily in Figure 11 at 151. R0-

tation of this cam by the auxiliary electric motor may be caused to operate a diaphragm type pump, illustrated in Figure 11, which would, in this modified form of the invention replace the pump 42 described with reference to Figure 10. i

Referring to Figure 11, the pump there disclosed includes an upper housing member 152 and a lower house ing member 153, joined at their periphery to mount a flexible diaphragm 154. The diaphragm is suitably connected to a plunger 1S6 extending through the upper housing member, and provided at its outer end with a rotary cam follower 157. The cam follower is adapted to ride the peripheral edge of the multi-lobed cam 151.

The pressure chamber 158 existing below the flexible diaphragm has an inlet opening 161 extending through the lower housing member, which is closed by a flexible reed or flapper 162 secured at one of its margins to the lower housing member. An outlet passage 163 extends through the lower housing member and is closed by a flexible reed 164, secured at one of its margins to the outer face of the lower housing member.

In operation, as the multi-lobed cam rotates, the plunger, and consequently the flexible diaphragm, will be rapidly reciprocated to draw refrigerant through the inlet passage into the chamber 158 and, on the downward stroke, to discharge refrigerant from the outlet passage 163.

As was the case with the pump described with reference to Figure 10, when the electrical alternate driving means is not in use, the

reeds

162 and 164 will block the passage of refrigerant through the electrically operated pump, and the manually operated system may function as previously described.

The present invention thus provides a manual refrigeration system which is particularly adapted for use in portable cooling boxes because it can be manually charged and will then maintain cooling operation over a prolonged period subsequent to the manual charging operation. The system may further be'provided with a pump driven by an electrically energized power means so that, when electrical service is available, the system may be operated in conventional electrically powered fashion.

I claim:

1. A mechanical refrigeration system having an evaporator and a condenser, an intermittently operated hand pump connected between the evaporator and the condenser for pressurizing the refrigerant circulating through the system subsequent to its excursion throughthe evaporator, means cooperating with the condenser for removing heat from the refrigerant, a control for metering refrigerant into the evaporator, and kinetic energy storage means including a vacuum reservoir tank connected between the evaporator outlet and the low pressure side of said pump and a pressure reservoir tank connected between the high-pressure side of said pump and said condenser inlet, said energy storage means permitting continued functioning of the refrigeration system for a time interval subsequent to the shut-down of said pump.

2. A mechanical refrigeration system having an evaporator and a condenser, an intermittently operated hand pum connected between the evaporator and the condenser for pressurizing the refrigerant circulating through the system subsequent to its excursion through the evaporator, means cooperating with the condenser for removing heat from the refrigerant, a control for metering refrigerant into the evaporator, and kinetic energy storage means including a vacuum reservoir tank connected between the evaporator outlet and the low pressure side of said pump and a pressure reservoir tank connected between the high-pressure side of said-pump and said eondenser inlet, said energy storage means permitting continued functioning of the refrigeration system for a time interval subsequent to the shut-down of said pump, an auxiliary electric pump having its inlet connected to the evaporator outlet and its outlet connected to the outlet line from said intermittently operated pump, said auxiliary pump thereby by-passing said vacuum reservoir tank and said intermittently operated pump to permit functioning of the system when electrical service is available without operation of said hand pump.

3. A mechanical refrigeration system having an evaporator and a condenser, an intermittently operated hand pump connected between the evaporator and the condenser for pressurizing the refrigerant circulating through the system subsequent to its excursion through the evaporator, means cooperating with the condenser for removing heat from the refrigerant including a fan and a spring wound motor for driving said fan, a control for metering refrigerant into the evaporator, and kinetic energy storage means including a vacuum reservoir tank connected between the evaporator outlet and the low pressure side of said pump and a pressure reservoir tank connected between the high-pressure side of said pump and said condenser inlet, said energy storage means permitting continued functioning of the refrigeration system for a time interval subsequent to the shut-down of said pump.

4. In a mechanical refrigeration system including an intermittently operated hand pump for refrigerant, a vacuum reservoir connected to the low pressure side of the pump and a pressure reservoir connected to the highpressure side of the pump, said reservoirs serving to store kinetic energy within the system to permit the functioning of the refrigeration system for a period subsequent to termination of manual operation of the pump, an auxiliary pump of the diaphragm type having an inlet connected to the outlet line from said evaporator and a discharge line connected to the high pressure side of said hand pump, electrically operable pump-driving means for use when electric service is available including a multi-lobed cam operated by the driving means and adapted to operate said auxiliary pump.

References Cited in the file of this patent UNITED STATES PATENTS 930,989 Richards Aug. 10, 1909 1,185,944 Schley June 6, 1916 2,075,722 Zehnder Apr. 6, 1937 2,419,993 Green May 6, 1947 2,724,240 Sloan Nov. 22, 1955 2,734,351 Stewart Feb. 14, 1956 2,764,098 Dickey Sept. 25, 1956 2,832,291 Gorsko Apr. 29, 1958