US3308635A - Refrigerating apparatus - Google Patents

Description

H. J. TENNISWOOD ETAL 3,308,635

March 14, 1967 REFRI GERATING APPARATUS Filed May 5, 1965 3 Sheets-Sheet 1 INVENTORSY HOWARD J. TENNISWOOD LEO PETERS B -flmgm OLWm March 1967 H. J. TENNISWOOD QETAYL 3,308,635

REFRIGERATING APPARATUS Filed May 1965 3 Sheets-Sheet 2 Fl 4 I Q |O-r 37 I 50 1 5 so 22 INVENTORS: I HOWARD J. TENNISWOOD LEO PETERS ATT'YS March 1967 H. J. TENNISWOOD \ETAL\ 3,308,635

REFRIGERAT ING APPARATUS Filed May 5, 1965 3 Shets-Sheet 3 FIGIZ INVENTORSI HOWARD J. TENNISWOOD LEO PETERS ATTYS L i I U I J 58 United States Patent 3,308,635 REFREGERATIN G APPARATUS Howard J. Tenniswood, 212 Richards St., Adrian, Mich. 49221, and Leo Peters, 750 Plymouth Road, SE, Grand Rapids, Mich. 495% Filed May 3, 1965, Ser. No. 452,629 8 (Iiainrs. (Cl. 62-277) This invention relates to a refrigerating apparatus, and, more particularly, to an electrically energized, mechanically operated, portable refrigerated plate for holding butter patties in restaurants and cafeterias in cold, easyto-dispense condition.

This invention is useful in connection with the refrigeration of all butter patties, but is particularly advantageous for decorative-surfaced patties, such as those having imprinted or embossed designs. Decorative-surfaced butter makes up about 70% of all butter patties served in eating establishments in the United States. It is this segment of the industry that this invention can serve especially advantageously.

All butter requires refrigeration to prevent the damaging effects caused by softening and melting at normal room temperatures, but decorative-surfaced butter is particularly subject to damage if allowed to touch anything while in a warm condition. All restaurants desire to hold and dispense their surface decorated patties in a manner that eliminates surface damage. But under past methods for holding and dispensing butter patties, this has not been generally possible. Butter patties with designs on their to surfaces, especially embossed (upraised) surfaces, must be kept cold, upright, out of contact with, and away from pressures exerted by another surface. This invention enables these basic requirements to be met in a highly practical, commercially-acceptable manner. In particular, the invention fulfills the need providing refrigcrating apparatus for butter patties adapted for use on service islands.

Restaurants and dining rooms that have table service also have service islands near diners tables. In these islands, waitresses can give rapid service for frequently served staple foods. Such foods always include coffee and butter. Coffee is kept hot by and is dispensed from modern, electrically operated, portable hotplates. Butter by contrast is normally kept cold by and dispensed out of manually-maintained beds of crushed ice or ice water held in bowls or old-fashioned crocks, a method which damages butter. There has been no commercially-practical means for refrigerating surface-decorated butter patties in an efficient, low cost, easy to use and easy to move manner. No modern efficient equipment comparable to that used for hot foods and cold beverages is available for butter. That 70% segment of the butter patties served in restaurants, referred to above, still is held in crushed ice or ice water and is dispensed by jabbing with a fork. This practice is highly unsatisfactory: butter becomes crushed and mutilated, bleached by direct ice contact, speckled with drops of water, and involves waste of butter and time involved in daily preparation, maintenance and cleanup. Further, when butter is held in ice, it becomes too cold and hard for spreading. Such butter breaks bread and at best can only be lumped on-it leaves some areas of bread or rolls heavily covered with butter and other areas completely devoid of it.

It is an object of this invention to provide a solution for the above-mentioned problem. More specifically, it is an object of this invention to provide a means for holding butter patties on restaurant service islands in a cold, quality-preserving, firm-bodied but spreadable condition, without damaging weights or pressures on them, without the need for daily preparation and cleanup and in a quickly accessible, easy to dispense condition.

Another object is to provide a means for maintaining a steady, concentrated, relatively invariable temperature slightly above freezing for refrigerating butter patties which are held on and are readily accessible for serving from an open area located in a room characterized by a substantially higher ambient temperature.

Still another object of the invention is to provide a refrigerating apparatus, especially suited for the maintenance and reduced temperatures of butter patties in which the deteriorating and unsanitary presence of water condensation is avoided.

Other objects and advantages of the invention may be seen in the details of operation and construction set down in this specification.

The invention is explained in conjunction with an illustrative embodiment in the accompanying drawings, in which- FIG. 1 is a perspective view of an embodiment of the invention equipped with a sanitary cover and also arranged to support serving plates;

FIG. 2 is a perspective exploded view of the apparatus seen in FIG. 1;

FIG. 3 is an enlarged fragmentary perspective view of the refrigeration plate portion of the apparatus seen in F168. 1 and 2;

FIG. 4 is a longitudinal sectional view such as would be seen along the sight line 4-4 applied to FIG. 3;

FIG. 5 is a transverse sectonal view such as would be seen along the sight line 5-5 applied to FIG. 3;

FIG. 6 is a schematic piping diagram of the refrigeration circuit utilized in connection with the apparatus seen in the preceding view;

FIG. 7 is a top plan view of the apparatus of FIG. 1, but without the sanitary cover and serving plates;

FIG. 8 is a bottom view of the structure of FIG. 7;

FIG. 9 is a rear elevational view of the apparatus of FIG. 7;

FIG. 10 is a side elevational view of the apparatus of FIG. 7;

FIG. 11 is a front elevational view of the apparatus of FIG. 7; and

FIG. 12 is an enlarged fragmentary sectional view of the lower righthand portion of FIG. 4 showing the details of construction of the condensate evaporating tray and compressor support.

In the illustration given and with particular reference to FIG. 1, the numeral 10 designates generally the refrigerating apparatus constructed according to the teachings of this invention. The apparatus 10 includes a generally rectangular enclosure 11 providing an upper cooling surface as at 12 (see, particularly, FIGS. 2 and 3). At the rear of the apparatus a higher enclosure generally designated 13 provides a housing for the means for refrigerating the surface 12.

In FIG. 1, a side portion of the upper cooled surface is used as a storage facility for a stack of serving plates 14 with individual plates being designated 15 and carrying thereon decorative-surface butter patties 16. At the left in FIGS. 1 and 2, a protective or sanitary sub-assembly generally designated 17 is provided to confine and protect butter patties between periods of peak usage. The details of the sub-assembly 17 will be described in greater detail hereinafter and it will be appreciated that the use of this sub-assembly is optional.

The refrigerating portion of the apparatus 10 can be more readily appreciated from a consideration of FIGS. 4 and 5 which are longitudinal and transverse sections, respectively, of the apparatus as seen in FIG. 3. Referring now to FIG. 4, it will be seen that the surface 12 is provided by a relatively thin metal plate supported atop a generally rectangular frame generally designated 18. The frame 18 is defined by a bottom plate or pan 19 which is slightly longer than the plate 12 and which provides an upstanding rear wall as at 20- integral with the bottom plate or wall 19. Further, the rear wall 20 is inwardly turned at its top edge in order to provide a supporting flange 21. The remainder of the generally rectangular frame 18 is provided by a C-shaped wrapper or channel portion 22. The wrapper portion 22 can also be seen in FIG. 3 and is seen to provide the two side walls of the bottom portion of the apparatus 10 as well as the front wall (see also FIG. 11). The channel shape of the wrapper 22 permits a weldable connection between it and the bottom wall 19 so as to develop the rectangular frame 18.

The refrigerating surface 12 is provided as part of an evaporator unit generally designated 23 (see FIGS. 4 and 5). The unit 23 includes a bottom wall or panshaped element 24. Along its four sides, the pan 24 is equipped with L-shaped flanges as at 25 over which the plate 12 is crimped. The flanges 25 are supported on the inwardly extending, flanges 26 of the wrapper 22 and the upper flange 21 of the bottom wall 19. Serving to thermally insulate the unit 23 from the rectangular frame 18 is flexible urethane tape as at 27 (see FIG. 5) and a silicone sealing compound 28. The sealing compound 28 extends perimetrically around the flange 25 to reduce conductive thermal transmission. Additionally, the flange 26 along one side and along one end as at 29 and 30 (see FIG. 3) are equipped with a ridge element for the purpose of confining and positioning the sub-assembly 17 and for limiting the possible outflow of condensate developed on the cooling surf-ace 12.

The condensate developed on the cooling surface 12 is advantageously removed through a depression or drain trough 31 (see particularly FIGS. 3 and 5). The trough 31 is integrally formed in the surface 12 and is coupled to a condensate tray 32 (see FIGS. 3 and 4) by means of a drainage tube 33.

The evaporator unit 23 further includes a serpentine arrangement of evaporator coils 34 (see FIGS. 4 and 6) which are embedded in a thermally conducting mastic material 35 filling the space between the plate 12 and the pan 24. Additionally, mounted within the evaporator unit 23 is a tube into which is placed a thermostatic bulb as at 36 (see FIGS. 3 and 6). The thermostatic bulb is coupled to the usual compressor switch 37a interposed in the voltage supply line to the compressor 37 (see FIG. 4) for the purpose of energizing and de-energizing the same as cooling requirements are changed.

The evaporator unit 23 is advantageously thermally insulated along the lower side and further optimally supported by means of a rigid urethane foam as at 38 (see FIGS. 4 and 5). For the purpose of filling the space between the bottom wall 19 of the frame 18 and the evaporator unit 23, the bottom wall 19 is equipped with an access opening as at 39 (FIG. 8) which is closed by a formed plastic cap. In the course of manufacture, liquidfoamed urethane plastic is caused to flow through the opening 39 into the space between the pans 24 and 19, and after the same has solidified, remains in place and is further preserved against contamination by means of the cap closing the opening 39.

Referring now to FIGS. 4 and 6, it will be seen that the compressor 37 is equipped with a hot. gas outlet line as at 40 which has a first portion arranged in serpentine fashion as at 41 under the condensate tray 32. Thus, the hottest refrigerant is lit thermally conducting relation with the condensate tray 32. Thus, the hottest refrigerant is in thermally conducting relation with the condensate liquid emanating from the cold surface 12. In FIG. 12, it will be seen that the serpentine tubes 4141 are bonded to the underside of the bottom 42 of the tray 32 as at 4112.

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Referring again to FIG. 6, it will be seen that the hot line includes as a second and continuing portion 43, a tube which extends perimetrically around the frame 18 as at 43a (see FIG. 4), 4312 (see FIGS), 43c (see FIG. 4) and 43d (see FIG. 5). The portions 43a43d are bonded to the bottom wall 19 and the wrapper 22 in thermallyconducting relation by means of thermomastic material such as that employed at 35 relative to the evaporator unit 23. This warms the wrapper 22 and wall 20, which is in close contact at a point with plate 12, and prevents condensation from forming on wrapper 22 and wall 20 by virtue of the transfer of heat from the hot line portions 43a-43d to the wrapper 22.

Ultimately, the hot line 43d (see FIG. 6) is coupled to the upper portion of a condenser generally designated 44 and which is seen in FIGS. 6 and 9.

Further tracing the refrigerant line in FIG. 6, it will be seen that the outlet of the condenser leads to a dryer and strainer unit 45 and then leads to the evaporator tubes 34 through a restrictor tube or capillary line 46. The evaporator tubes 34 at their outlet are coupled to a return cold line 47 which is arranged in thermally conductive relation to the restriction tube 46 (as by bonding at 46:: in FIG. 6), and ultimately the return line 47 leads to the suction inlet 48 of the compressor.

The compressor 37 is housed within an enclosure generally designated 49 (see FIG. 4) and the enclosure 49 is developed by an upstanding front wall 50 of general channel shape and which is seeen to be secured as at 51 to the flange 21. The enclosure is completed by side walls 52 and a top wall 53 (see FIGS. 10 and 7), respectively. Each of the walls is suitably insulated as at 54 (see FIG. 4) and the top wall 53 adjacent the open back 55 is equipped with a vent 56 permitting the advantageous outflow of air heated by contact with the compressor and which also carries out the evaporated moisture from the condensate tray 32. i

As seen in FIGS .4 and 9, theconde-nser 44 is positioned in the open back 49 for contact with the air. We find it advantageous to provide bumpers as at 57 (FIGS. 7 and 9) to insure spacing the condenser 44 from any vertical wall. Feet 58 (see FIGS. 4 and 8) are provided on the wrapper 22 to space the apparatus above any supporting surface, and in this connection it will be noted that the serpentine coil arrangement 41 under the condensate tray 32 is also open to the atmosphere. Reference to FIG. 12 reveals that the condensate tray is upset as at 59 so as to provide supports forthe compressor 37. The compressor base flanges 44a are positioned within a rubber grommet 6%) which in turn is secured to the raised portion 59 by means of a stud 61 riveted at its lower portion as at 61a. A hairpin clip 62 in combination with a metal washer 63 insures stable positioning of the compressor base 44a. Thus, the condensate tray 32 is immobilized as part of the compressor, yet the support of the compressor (through openings as at 64 in the tray 32) does not permit gravity outflow of any liquid condensate-this being prevented by the grommet 60. The condensate tray 32 is additionally integrated with the frame 18 by means of transversely extending angles as at 65 extending between the sides of the wrap per 22.

As a specific example of the invention, the apparatus 10 has a width of 18" as viewed from the frontsee FIG. ll-a height of the surface 12 of 2 /2", a length of 24" as viewed in FIG. 10. and a height of the compressor enclosure of 8 /2". The evaporator unit 23 is constructed with 20 gauge stainless steel providing the upper plate 12 and 24 gauge Zinc-coated steel providing the pan 24. The zinc-coated steel is slightly rough in its surface configuration to provide a good anchorage for the urethane foam. The urethane foam has a thickness of about 1%", while the evaporator unit 23 has a thickness of about inside dimension between the plate 12 and the pan 24. The filling of mastic material has a specific gravity of approximately 1.5, and this is found advantag'eous in working as a heat sink surrounding the evaporator coils 34. The refrigerant is No. 12, a dichlorodifiuoromethane operating at approximately 135 psi. head and approximately p.s.i. evaporating pressure. The overall weight of the exemplary unit is lbs., which makes for advantageous portability.

The additional parts indicated to make up the subassembly 17 include a perimetric frame portion 66 which supports transparent removable covers as at 67.

In the operation of the invention, a horizontally positioned refrigerator plate is utilized on which the butter rests in pressure-d contact due to the weight of the butter itself. Refrigeration is provided for the butter through conduction of heat-as contrasted to convection, and cooling is maintained by the cooperating pressure from the butter itself, not by air stratification or convection. Heat is transferred out of the butter and into the refrigeration system without movement of either the butter or any refrigerated air.

The construction described is particularly advantageous in operation through utilization of the heat sink principle. The evaporator unit 23, upon being initially subjected to refrigeration, develops a cooling pattern corre sponding to the serpentine pattern of the coils 3-4 therein. However, within minutes the surface temperature on the plate becomes uniform and the serpentine pattern of cooling is erased. Thus, a uniform cooling surface is provide-d and this stems from the relatively thin sandwich construction of the evaporator unit 23. The mastic material, coupled with the metal plate and pan and the insulating support provided thereto by the urethane material 38, makes possible the elimination of the usual type of air sensing temperature control. This further eliminates the undesirable rapid cycling of the refrigeration unit. With the heat sink principle provided in the invention, the un desirable cycling is avoided.

The coaction of the urethane 27 and silicone cement 23 material with the evaporator unit 23 is advantageous in preventing the flow of heat inward from the perimetric walls of the frame 10. In this respect, it differs from the conventional thermal break used in refrigerators. The urethane material constituting the thermal break also seals off the unit from undesirable condensation.

Further in the operation, the air circulating in and about the rear end of the unit follows a chimney pattern in exhausting through the vent 56. This air creates a slight indraft in and around the condenser 44 and does not impair the operation of the condenser by having to flow out of the rear of the condenser enclosure 13. Further, the location of the enclosure 13 essentially above the evaporator unit 23 and by providing discharge of air in an upward pattern, prevents unfavorable heat transfer from the mechanical side of the system to the refrigeration side.

The inventive construction provides a continuous and automatic operation without failure over a long life. In

achieving this, the operation is fast and uniform in absorbing the heat extracted from the butter when required, but at the same time uniformly releases the heat to the evaporator. Further, the unit is adapted to serve the temperature requirements of the butter alone. Butter in restauranhcafeteria use requires a refrigerating temperature which ideally is peculiar to it alone. The temperature is about 40 F. or more broadly in the 3545 F. range. At this temperature, butter is sufficiently cold to maintain fresh quality, sufiiciently hard to maintain shape and make dispensing easy, yet sufficiently warm to enable it to come to the ideal soft-spreading temperature of F. when exposed to 70 F. room temperature during the four to eight minute interval between the time of dispensing and the time of spreading by a restaurant patron.

The unit is further advantageous in holding the butter in an open, easily accessible, removable-without-damage,

quickly dispensable and sanitary condition. In particular, the butter can be readily removed by utilizing the available restaurant implements, such as forks and knives, to slip the same under a patty to lift and dispense it. It is not necessary to jab, spear or engage in a multilating action in order to grasp and hold a butter patty. Besides providing the advantageous accessibility, the instant invention provides a refrigeration apparatus which is economical to operate, involving a minimum of waste. The butter is provided on a flat exposed surface which can be easily shielded from air currents if desired, but even in the absence of such shielding, the film of colder air surrounding the unit effectively minimizes heat transfer. This is further implemented through the enclosure configuration 13 utilized for the heat generating portions of the apparatus, as pointed out previously.

Further, in operation the unit automatically controls the amount and disposal of water condensate on the outside (topside) of the plate 12. The inside (underside) is sealed, therefore, and this is advantageous in preventing mold growth, rust and corrosion, maintaining good sanitation in unseen areas, and eliminating the unwanted increase in heat absorption by exposure of both sides of the refrigerator evaporating coil.

While in the foregoing specification, a detailed description of an embodiment of the invention has been set down for the purpose of illustration, many variations in the details herein given may be made by those skilled in the art without departing from the spirit and scope of the invention.

We claim:

1. Refrigerating apparatus comprising a generally rectangular frame, a metal evaporator plate mounted on said frame and providing a generally horizontal exposed upper surface, an evaporator coil mounted in said frame below said plate, a heat conductive material surrounding said coil and contacting the under surface of said plate, a heat insulating material below said heat conductive material and providing a support for said plate within said frame, a compressor compartment in said frame adjacent one edge of said plate and equipped with a compressor operatively coupled to said coil, and drain means in said plate connected to said compartment, said compartment including an enclosure provided as part of said frame, said enclosure projecting vertically above said plate, said enclosure having a pair of vertically extending sides arranged generally parallel to said edge and the enclosure side remote from said plate edge being open and having a condenser coil positioned therein, said condenser coil projecting above said plate.

2. The structure of claim 1 in which said enclosure is equipped with a pan arranged to receive condensate from said drain means, said compressor being equipped with an outlet line arranged below said pan and in heat transfer relation therewith.

3. The structure of claim 1 in which said compressor is equipped wit-h an outlet line disposed perimetrically relative to said frame and separated from said plate by said heat insulating material.

4. The structure of claim 1 in which said enclosure is equipped with a topwall, and an exhaust aperture in said topwall adjacent said remote side.

5. Refrigerating apparatus comprising a generally rectangular open top frame defining side, bottom and end walls, said sidewalls being extended at one end to provide a base for a compressor enclosure, an evaporator unit supported in said frame closing the open top thereof, said unit including a generally horizontal metal top plate of relatively high thermal conductivity, a pan perimetrically secured to said plate and spaced therebelow, refrigerant evaporator coils arranged in serpentine fashion between said plate and pan, and a thermally conductive mastic material filling the space between said pan and plate and surrounding said coils, a relatively rigid thermal insulation material filling said frame in supporting relation with said unit, a thermally insulating seal between said plate and adjacent portions of said frame, said plate adjacent one side being equipped with a trough-like depression extending substantially between the frame ends, said enclosure including a vertical wall extending the said frame one end wall and said extended side walls, said enclosure further including a top wall and defining thereby an open back, an aperture in said top wall adjacent said open back, a condensate pan in said enclosure adjacent the bottom thereof, a drain connection connecting said depression and condensate pan, a compressor mounted in said enclosure and equipped with inlet and outlet connections, a hot refrigerant line coupled to said outlet and having a first portion disposed in serpentine fashion below said condensate pan and secured thereto, said line having a second portion extending generally perimetrically interiorly of said frame and bonded with thermally conductive material to said frame adjacent the bottom wall thereof, a condenser coil in said enclosure open back, said line second portion being connected to said condenser coil, a cold line connected to said compressor inlet and coupled to one end of said evaporator coil, the other end of said evaporator coil being coupled to said condenser coil, a thermostat embedded in said mastic material, and a switch-equipped source of operably associated with said compressor thermostat.

6. The structure of claim 5 in which said thermal insulating material is a urethane, said pan being constructed of metal and surface bonded to said urethane material.

7. Refrigerating apparatus comprising a generally rectangular frame, a metal evaporator plate mounted on said frame and providing a generally horizontal exposed upper surface, an evaporator coil mounted in said frame below said plate, a heat conductive material surrounding said coil and contacting the under surface of said plate, a heat insulating material below said heat conductive material and providing a support for said plate within said frame, a compressor compartment in said frame adjacent one edge of said plate and equipped with a compressor operatively coupled to said coil, and drain means in said plate connected to said compartment, said drain means including an elongated trough extending generally perpendicularly to said one edge and adjacent to another edge of said plate, two other edges of said plate being equipped with upstanding walls, and a subframe removably positioned within said walls for hygienically confirning butter patties on said plate.

8. Refrigerating apparatus comprising a generally rectangular frame, a metal evaporator plate mounted on said frame and providing a generally horizontal exposed upper surface, an evaporator coil mounted in said frame below said plate, a heat conductive material surrounding said coil and contacting the under surface of said plate, said conductive material being confined within a generally rectangular pan, said plate constituting a cover for said pan, and insulating cement and tape between said plate and adjacent portions of said frame, a heat insulating material below said heat conductive material and-providing a support for said plate within said frame, a compressor compartment in said frame adjacent one edge of said plate and equipped with a compressor operatively coupled to said coil, and drain means in said plate connected to said compartment.

References (Iited by the Examiner UNITED STATES PATENTS 1,955,186 4/1934 Hill 62-458 1,993,328 3/1935 Ingvardsen 62458 2,124,110 7/1938 Hall 62-458 2,175,946 10/1939 Smith 62-279 2,640,329 6/1953 Ingvardsen 62458 2,759,339 8/1956 Kundert 62-458 WILLIAM J. WYE, Primary Examiner.

Claims (1)

1. REFRIGERATING APPARATUS COMPRISING A GENERALLY RECTANGULAR FRAME, A METAL EVAPORATOR PLATE MOUNTED ON SAID FRAME AND PROVIDING A GENERALLY HORIZONTAL EXPOSED UPPER SURFACE, AN EVAPORATOR COIL MOUNTED IN SAID FRAME BELOW SAID PLATE, A HEAT CONDUCTIVE MATERIAL SURROUNDING SAID COIL AND CONTACTING THE UNDER SURFACE OF SAID PLATE, A HEAT INSULATING MATERIAL BELOW SAID HEAT CONDUCTIVE MATERIAL AND PROVIDING A SUPPORT FOR SAID PLATE WITHIN SAID FRAME, A COMPRESSOR COMPARTMENT IN SAID FRAME ADJACENT ONE EDGE OF SAID PLATE AND EQUIPPED WITH A COMPRESSOR OPERATIVELY COUPLED TO SAID COIL, AND DRAIN MEANS IN SAID PLATE CONNECTED TO SAID COMPARTMENT IN SAID FRAME ADPARTMENT INCLUDING AN ENCLOSURE PROVIDED AS PART OF SAID FRAME, SAID ENCLOSURE PROJECTING VERTICALLY ABOVE SAID PLATE, SAID ENCLOSURE HAVING A PAIR OF VERTICALLY EXTENDING SIDES ARRANGED GENERALLY PARALLEL TO SAID EDGE AND THE ENCLOSURE SIDE REMOTE FROM SAID PLATE EDGE BEING OPEN AND HAVING A CONDENSER COIL POSITIONED THEREIN, SAID CONDENSER COIL PROJECTING ABOVE SAID PLATE.

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