US3548513A

US3548513A - Dryer with ejectors

Info

Publication number: US3548513A
Application number: US726980A
Authority: US
Inventors: Frederick T Taylor
Original assignee: FREDERICK T TAYLOR
Current assignee: FREDERICK T TAYLOR
Priority date: 1968-05-06
Filing date: 1968-05-06
Publication date: 1970-12-22
Anticipated expiration: 1987-12-22

Description

F. T. TAYLOR DRYER WITH EJECTORS Dec. 22,1970

3 Sheets-Sheet 1 Filed May 6. 1968 Frederick T. Ta gl or BY INVENTOF? dag /W F. T. TAYLOR DRYER WITH EJECTORS Dec. 22, 1970 3 Sheets-Sheet 3 Filed MayG 1968 Frederi ckT. To 3101 BY INVENTOR fli fgs.

Dec. 22,, 1970 TAYLOR 3543,13

' DRYER WITH EJECTORS Filed May 6. 1968 3 Sheets-Sheet T6 Frederick T. Tcryl or INVENTOR United States Patent 3,548,513 DRYER WITH EJECTORS Frederick T. Taylor, 3274 NE. Everett St., Portland, Oreg. 97232 Filed May 6, 1968, Ser. No. 726,980 Int. Cl. F26!) 19/00 US. Cl. 34-205 7 Claims ABSTRACT OF THE DISCLOSURE A dryer is disclosed herein including an elongated drying chamber through which articles to be dried travel, an elongated plenum chamber extending alongside the drying chamber, a blower section for producing a current of gas along and through the plenum chamber, and conduit means for conveying gas from the plenum chamber to the drying chamber, including plural ducts distributed along opposite sides of the dryer and ejectors communicating with the ducts for ejecting gas into the drying chamber with such ejected gas impinging on articles traveling through the chamber.

This invention relates to drying apparatus, and more particularly, to such apparatus which is employed to dry articles such as sheets of wood veneer.

Among the more common forms of conventional veneer dryers are so-called forced circulation-type and jet-type dryers. Each of these types normally includes multiple sections set end-to-encl forming an elongated drying chamber for the dryer, and power-driven conveyer means extending along and through the drying chamber for conveying sheets of veneer through the chamber.

A forced circulation-type dryer normally includes a single blower section for producing a current of air, and a single heating section for heating the air. In such a dryer, air flow typically takes place generally longitudinally of the dryer, with air flowing from the blower section in a path extending alongside the drying chamber from the infeed toward the discharge end of the dryer, then into the drying chamber adjacent the discharge end of the dryer, and then back along the dryer through the drying chamber countercurrent to the flow of veneer.

The usual jet-type dryer, in contrast, includes a blower and heater for each dryer section, with means provided for directing air at localized points in jets impinging on opposite faces of veneer traveling through a section. Substantially no longitudinal flow of air takes place from section to section through such a dryer.

A forced circulation dryer of the type described has the advantage of requiring only a single blower and heater section for the whole dryer, and thus is relatively inexpensive to construct, operate and maintain. However, drying action in such a dryer depends almost entirely on air wiping along the faces of veneer sheets, and is relatively slow. A jet dryer, on the other hand, may be operated to dry veneer much more quickly, since it produces direct impingement of air jets on veneer faces. However, such a dryer is substantially more expensive to construct and maintain than a forced circulation dryer, because of the fact that a jet dryer requires a blower and heater for each of its dryer sections. A further disadvantage with known jet dryers is that the air impingement action which they produce sometimes tends to cause casehardening of veneer, which impairs proper drying.

Thus, a general object of the present invention is to provide an improved form of dryer for drying articles, which has many of the advantages of known dryers as described without the attendant disadvantages.

More particularly, an object of the invention is to provide a novel dryer having an elongated drying chamber Patented Dec. 22, 1970 through which articles to be dried travel, wherein an impingement drying action for such articles is produced at points spaced along the length of the chamber without the need for multiple blower sections in the dryer.

A related object is to provide such a dryer which includes a blower section producing a current of gas, a heating section for heating gas, and novel conduit means for receiving heated gas and directing such gas into the drying chamber in plural streams spaced along the length of the chamber with such streams impinging on articles traveling through the chamber.

Another object is to provide such a dryer wherein the conduit means enables a major portion of the gas returning through the drying chamber to be recirculated to the chamber. With such recirculation possible, waste of heated gas is held to a minimum, and circulation of gas in the dryer is readily performed by a single blower sec tion.

According to the invention, the dryer includes a conveyer deck extending along and through the drying chamher for conveying articles from one end to the other of the dryer, and the conduit means includes novel air ejectors that extend across, and are distributed along the length of the drying chamber on opposite sides of the deck. The conduit means further includes novel ducts through which gas coming from the blower section is supplied to the ejectors. The ejectors have elongated slots positioned closely adjacent the deck, and through these slots gas which is supplied the ejectors is directed onto opposite faces of articles traveling on the deck. The ejectors are constructed and mounted in a manner enabling gas, once ejected, easily to return along and through the drying chamber back to the intake of the blower section.

The invention also features a novel flow control for each of the ducts for controlling the flow of gas through the ducts to the ejectors.

Yet another object of the invention is to provide a dryer of the type so far described which further includes deflectors spaced along the length of the drying chamber located toward the infeed end of the dryer from the ejectors, adapted to deflect gas returning through the chamber against articles traveling on the conveyer deck.

Various other objects and advantages which are attained by the invention will become more fully apparent as the description which follows is read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a somewhat simplified perspective view illustrating a veneer dryer constructed according to the invention;

FIG. 2 is an enlarged, fragmentary, perspective view illustrating a section of the dryer of FIG. 1 which employs gas ejectors as contemplated herein;

FIG. 3 is a fragmentary perspective view, on a larger scale than FIG. 2, illustrating portions of ejectors employed in the dryer section of FIG. 2, with such ejectors removed from the dryer;

FIG. 4 illustrates, on approximately the same scale as FIG. 3, a portion of a flow control means employed in the dryer section of FIG. 2;

FIG. 5 is a simplified, longitudinal, cross-sectional view, on a larger scale than FIG. 3, illustrating how gas is ejected onto faces of veneer sheets traveling adjacent the ejectors of FIG. 3;

FIG. 6 is a simplified longitudinal view, partly in cross section, on approximately the same scale as FIG. 3, illustrating a section of the dryer of FIG. 1 which employs deflector assemblies as contemplated herein;

FIG. 7 is a fragmentary perspective view, on a larger scale than FIG. 6, illustrating one form of air deflector assembly with the same removed from the dryer; and

FIG. 8 is a fragmentary perspective view, on the same scale as FIG. 7, illustrating another form of deflector assembly removed from the dryer.

It should be understood that while the present invention has particular utility in the drying of wood veneer, and is described in connection with such veneer for the purpose of illustration, the invention is not limited to such application, but may be used as well in the drying of other kinds of articles. Further, air is ordinarily the gas employed in such drying, but the use of this specific gas is not required.

Turning now to the drawings, and referring first to FIG. 1, illustrated generally at is a veneer dryer constructed according to the invention. The dryer includes an infeed end 10a at which it receives sheets of veneer to be dried, and a discharge end 10b from which dried sheets are discharged. Adjacent the base of the dryer, and indicated generally at 11, is housing structure defining an elongated drying chamber for the dryer. The drying chamber extends along and through multiple dryer sections, designated by even numbers 12 through 34, which follow one another along the dryer. Positioned adjacent dryer section 34 is what is called a dead air section 36, and adjacent section 36 is a cooling section 38.

Extending along and through sections 12 through 38 of the dryer are multiple conveyor decks for transporting sheets of veneer through the dryer from end 10a to end 10b. The dryer illustrated includes four of such decks indicated generally at 40, 42, 44, 46. Each deck comprises multiple pairs of vertically spaced rolls, such as rolls 42a, 42b, for deck 42, that extend across the dryer and that are distributed along the length thereof. The rolls forming each deck are driven by a suitable power drive means 48 which is appropriately connected to the rolls by means of chains, such as chain 50, connected to the rolls of deck 42.

Extending over the tops of dryer sections 14 through 34 (but not over section 12) is an elongated, substantially horizontal roof illustrated in dashed outline including an expanse 52a which covers sections 14 through 22 and which extends substantially completely across the width of the dryer, and an expanse 52b which extends over sections 24 through 34 and which is somewhat narrower than expanse 52a. As can be seen clearly in FIG. 1, the opposite side edges of expanse 52b are located laterally inwardly from the opposite sides of dryer sections 24 through 34.

Dryer 10 further includes along its opposite sides above sections 12 through 34 side walls, such as wall 54, end walls, such as wall 56, extending transversely between and joining with the side walls, and top structure 58 spanning and joined to the side and end walls. The side and end walls, top structure, and previously-described roof together comprise casing structure herein defining an elongated plenum chamber extending along the length of the dryer over dryer sections 12 through 34.

Suitably mounted inside the plenum chamber adjacent end 10a of the dryer are a pair of laterally spaced fans, or blowers, indicated generally in dashed outline at 60, 62. The blowers together comprise a blower section for the dryer. Blowers 60, 62 are driven by electric motors 64, 66, respectively, mounted on top structures 58, and such motors are connected to the blowers by means of belts 68, 70 which extend through suitable belt wells, such as well 72 for belt 68, provided adjacent the top structure. An appropriate vent 74 is provided for venting the belt wells.

Also mounted inside the plenum chamber, and located toward the discharge end of the dryer from fans 60, 62, is a heating section 76 (shown in dashed outline) for heating air in the dryer. The heating section includes conventional burner units (not shown) which on operation heat air flowing through the section. A feed manifold 78 is provided for feeding fuel to the burner units of the heating section. A mixing pipe 80 connects both to manifold 78 and to a blower 82 which is driven by a motor 84. Pipe 80 is further connected to a suitable source of fuel, such as a fuel gas, by means of a conduit 86, and the intake of blower 82 is connected to a conduit 88 through which the blower receives air. With blower 82 driven by motor 84, air is drawn in through conduit 88 and forced into pipe where it is mixed with fuel gas supplied through conduit 86. The mixture is then supplied through manifold 78 to the burner units where it is burned to heat air in the dryer.

Located in-between the blower and heating sections is a main vent 90 for the dryer which connects with the interior of the plenum chamber. This provides for the venting of part of the air returned on circulation of air within the dryer.

Previously-mentioned dead air section 36, where it joins with

sections

34, 38 of the dryer, is provided with the usual baflles (not shown) which inhibit any substantial air flow through the section. The dead air section functions as an insulator between

sections

34, 38. A vent for the section is shown at 92.

Suitably mounted on top of cooling section 38 is a blower 94 which is driven by a motor 96. Section 38 is provided with a vent 98. Fan 94 functions to circulate cool air over sheets of veneer immediately prior to when they emerge from end 10b.

Illustrated in simplified dashed outline inside the dryer, adjacent laterally opposite sides of section 24 through 34, are a series of vertically-disposed ducts a, 1001:. The upper ends of the ducts communicate with the interior of the plenum chamber adjacent the opposite side margins of roof expanse 52b. In general terms, these ducts form part of conduit means according to the invention interposed between the plenum and drying chambers for conveying air from the former to the latter.

Considering briefly the general nature of air heating and fiow that takes place inside the dryer with blowers 60, 62 and the heating section operating, the blowers produce a current of air which flows along and through the plenum chamber in a direction toward end 10b of the dryer. As the air passes through heating section 76 it is heated to the desired temperature. From the plenum chamber air flows downwardly in paths along opposite sides of the dryer defined by the ducts adjacent dryer section 24 through 34, and from there, is ejected as will be later described in more detail, into the drying chamber.

In the drying chamber, the air circulates adjacent opposite sides of veneer sheets traveling through the chamber producing drying of such sheets, The air returns by flowing longitudinally through and along the drying chamber toward end 10a of the dryer. The air then flows upwardly out of section 12 back into the plenum chamber, such upward flow being possible by reason of the fact that roof expanse 52a does not extend over section 12. Upon retuming to the plenum chamber, the air is drawn through blowers 60, 62, and a major portion of it is recirculated through the heating section down along the plenum chamber and back into the drying chamber. The small portion which is not recirculated is vented to the atmosphere through vent 90. Fresh air is constantly drawn into the dryer through conduit 88 to replace air which is vented.

Turning now to FIG. 2 which illustrates portions of dryer section 26 in more detail, and describing the construction of the frame for the section, extending transversely of the dryer are rectangular frame assemblies such as the one illustrated comprising upper and lower

trans verse members

102, 104, and upright members, 106, 108 at opposite sides of the dryer, extending between and joining the transverse members. Extending longitudinally of the dryer and joining adjacent frame assemblies on each side of the dryer are spaced

upper members

110, 112 and spaced

lower members

114, 116. Mounted on and extending vertically between these longitudinally extending members, and spaced along the length of the dryer section, are posts, such as inner posts 118 between

members

110, 114 and outer posts 119 between

members

112, 116.

Ducts 100a, 100b were earlier described as functioning to convey air between the plenum and drying chambers. A duct may be constructed as best illustrated for the duct 100a shown in FIG. 2, and may comprise a side panel 120 closing off the outer side of the duct, a floor plate 121 closing off the ducts base, and partitions such as the one shown partially at 122 bounding the duct adjacent forward and rear ends of a dryer section,

A flow control is provided for controlling air flow through a duct. Exemplifying such a control is the one shown at 126 for duct 100a in FIGS. 2 and 4. Considering the construction of control 126, it comprises an elongated, substantially rectangular frame including side bars 130, 132, and end bars, such as end bar 134, joining the side bars adjacent opposite sets of ends thereof. The frame is mounted adjacent the top of the duct, with side bars 130, 132 mounted on

longitudinal members

110, 112, respectively, and the end bars mounted on the transverse members, such as member 102, adjacent the ends of section 26.

Extending transversely between and pivotally mounted on side bars 130, 132, at points spaced along the lengths of the bars, are elongated rectangular vanes 136. The vanes are connected together for simultaneous operation by an overhead bar 140 which is connected to the vanes through depending elements 142 which elements include journals 142a received within cylindrical collars 146 on the vanes. A shaft 150 (FIG. 2) connected to one of the vanes in a flow control extends laterally to the outside of the dryer. With turning of the shaft the inclination of the vanes may be adjusted to change the flow of air into a duct.

Within a dryer section, rolls such as rolls 42a, 42b making up a dryer deck extend between and are jo'urnaled on opposing inner posts for the section. In FIG. 2, only portions of such rolls are shown.

Suitably mounted on the inner posts of the dryer section frame, and extending transvesely of the dryer, are vertically extending stacks of air ejectors, such as the stack shown in FIG. 2 including

ejectors

152, 154, 156, 158 and 160. These ejectors are mounted with ejector 154 located between

decks

40, 42, ejector 156 between

decks

42, 44, and ejector 158 between

decks

44, 46. Ejector 152 is located below deck 40, and ejector 160 is located above deck 46. The ejectors are spaced apart to accommodate the travel of veneer along the various decks between the ejectors. In each of the

dryer sections

24, 26, 28, 30, 32, and 34, multiple stacks of ejectors follow one another in the section, all communicating with the ducts supplying the dryer section.

Referring now to FIG. 3 which illustrates portions of

decks

40, 42 and

ejectors

152, 154, 156 removed from the dryer, and considering first the construction of ejector 154 (which ejectors 156 and 158 resemble), it comprises an elongated hollow unit having opposite ends, as illustrated by end 154a, which are open. The unit includes a pair of elongated, vertically spaced,

hollow sections

154b, 1540 which define separate paths for the flow of air along and through the unit. The sections communicate with one another adjacent the opposite ends of the unit, as can be seen with reference to end 1154a, The sections, progressing inwardly from opposite ends of the unit, diminish in crosssectional area, and thus, an elongated, somewhat diamondshaped opening or passage 154d exists between the channel sections. Suitable braces such as

braces

162, 164, are provided between the sections.

The unit has upper and lower, horizontally disposed faces 154e, 1541, respectively, facing

dryer decks

42, 40, respectively. Formed in

faces

1546, 154 are elongated slots, or orifices, 154g, 1541:. These communicate with the interiors of

sections

154b, 1540, respectively.

Considering now the construction of ejector 152, this ejector resembles in construction a single section of

ejectors

154, 156, 158. Thus, it comprises an elongated section 152a which is open adjacent its opposite ends and which, progressing inwardly from such ends, diminishes in cross-sectional area. The ejector includes an elongated,

horizontally disposed face 1521; facing dryer deck 40, and an elongated slot 152a formed in this face. Air ejector 160 is substantially the same in construction as ejector 152, but i positioned with its slotted face facing downwardly toward dryer deck 46. The ejectors of other stacks in the dryer resemble the ejectors in the stack just specifically described.

Explaining how the air ejectors in the stack function to introduce air into the drying chamber, and referring to FIGS. 2, 3, and 5, it will be recalled that air flows from the plenum chamber downwardly along the sides of the dryer in ducts 100a, 1001:. Ducts 100a, 10Gb communicate with opposite ends of the various ejectors, and hence, introduce air into the ejectors from opposite sides of the dryer. Air within the hollow sections of the ejectors flows out through the slots, and is directed against opposite faces of veneer sheets traveling on the conveyor decks.

Referring particularly to FIG. 5 where

veneer sheets

165, 167 are shown on

decks

40, 42, respectively, and portions of previously-described

ejectors

152, 154, 156 are illustrated, arrows indicate how air flow takes place adjacent the ejectors. Air flowing out of the ejectors slots impinges on opposite faces of the sheets, and after such impingement, flows along the sheets countercurrent to the direction in which they are moving on the decks. In the regions between the confronting faces of the ejectors, such flow produces a wiping drying action. The air in returning to the feed end of the dryer, flows between the decks in the drying chamber through the passages provided by the spaced-apart sections of the ejectors.

Dryer sections

24, 28, 30, 32 and 34 of the dryer have a construction similar to section 26, and include ducts 100a, 100b, flow controls for these ducts, and air ejectors disposed in stacks substantially as described for section 26.

Considering now sections 14 through 22 of the dryer, these sections are provided with appropriate frame structure which is similar in construction to the frame structure described for section 26. Posts in such frame structure journal rolls of the conveyer decks in the dryer as described in connection with dryer section 26. Ejectors, however, may be omitted from sections 14 to 22.

According to the invention, air deflector assemblies are provided in sections 14 through 22 whereby air returning through the drying chamber toward infeed end 10a of the dryer is directed against opposite faces of veneer traveling on the decks. Referring to FIG. 6, which illustrates portions of dryer section 14 (typifying sections 14 to 22), such deflector assemblies are disposed in vertically extending stacks, with the deflector assemblies in a stack illustrated generally at 168, 170, 172, 174 and 176. The deflector assemblies are mounted on the inner posts of the dryer section which support the deck rolls, and extend transversely of the dryer. Assembly 170 is located between

decks

40, 42; assembly 172 is between

decks

42, 44; and assembly 174 is between

decks

44, 46. Assembly 168 is located below deck 40, and assembly 176 is positioned above deck 46.

Considering in more detail the construction of a deflector assembly provided between conveyer decks, as exemplified by assembly 174, and referring to FIG. 7, it comprises, adjacent opposite ends, a pair of substantially rectangular mounting brackets, such as bracket 174a. Suitably joined to and extending between the brackets are elongated deflector elements 174b, 1740, each of which has a somewhat S-shaped cross-sectional configuration.

Considering the construction of assembly 176, and referring now to FIG. 8, this assembly includes, adjacent its opposite ends, a pair of brackets, such as bracket 17 6a. Extending between and joining with the brackets is a single deflector element 176b, which is similar in construction to previously-described elements 174b, 174c. Deflector assembly 168 has a similar construction.

As can be seen in FIG. 6, the deflector assemblies in successive stacks are mounted in such a manner as to accommodate air flow generally longitudinally through the drying chamber between the various decks, with streams of such air repeatedly being directed against faces of the veneer traveling on the decks thus to produce wiping of the faces with air to promote drying of the faces.

With the dryer described herein, removal of moisture from veneer takes place quite rapidly, by reason of the impingement action produced in the drying chamber by the air ejectors provided adjacent the off-bearing end of the dryer, and the wiping action produced by the deflector assemblies provided adjacent the infeed end of the dryer. Additionally, there is a wiping action occurring between ejectors, because of the confronting faces of opposed air ejectors which operate to channel air in a narrow path extending directly adjacent veneer faces.

Drying of veneer is facilitated by virtue of the fact that air flowing into the ejectors, and hence out of the slots onto the veneer, may readily be regulated by the controls which are adjustable to increase or decrease flow of air permitted through the various ducts provided along the sides of the drying chamber. With proper setting of the controls, any tendencies for casehardening to occur may be minimized.

The dryer contemplated operates efliciently, since its construction enables air to be recirculated with air flowing in paths which extend longitudinally of the dryer. Waste of heated air is held to a minimum. Moreover, only a single blower and heating section is required to produce air flow in the dryer, and thus, the dryer may be constructed, operated, and maintained relatively inexpensively.

While a particular dryer has been illustrated herein, it is appreciated that variations may readily be made without departing from the spirit of the invention. For example, a dryer may be constructed having a diflerent number of dryer sections than the dryer shown. Additionally, the number of such sections having ejectors and deflector assemblies may vary depending upon the circumstances.

Other variations and modifications will become apparent to those skilled in the art, and it is desired to cover all such variations and modifications which come within the scope of the appended claims.

It is claimed and desired to secure by Letters Patent:

1. In a dryer, housing structure defining an elongated drying chamber which articles to be dried travel through,

a conveyer deck extending longitudinally through said chamber for conveying such articles,

casing structure defining an elongated plenum chamber,

said plenum chamber having an inlet and communicating with the drying chamber adjacent the one end of the drying chamber and having an outlet end, conduit means interconnecting the outlet end of said plenum chamber and said drying chamber accommodating the flow of gas from the former to the latter, said conduit means including plural ejectors spaced at intervals along the length of said drying chamber and located toward the opposite end of said drying chamber from where the inlet end of the plenum chamber communicates with the drying chamber, each ejector having orifice means through which gas is ejected from the ejector at an angle upon articles carried by said conveyer deck, and

a blower for producing a current of gas along said plenum chamber from its inlet toward its outlet end and into said drying chamber through said conduit means, said drying chamber constituting a channel extending to the inlet end of the plenum chamber and channeling gas ejected thereinto through said ejectors back to the inlet end of said plenum chamber for recirculation.

2. The dryer of claim 1, which further includes a duct 8 for each of multiple ejectors connecting the ejector with the plenum chamber, and an adjustable flow control for each duct, adjustable to' control the flow of gas through the duct.

3. The dryer of claim 1 which further includes a second conveyer deck spaced from and substantially paralleling the first-mentioned deck, and wherein said ejectors are located between said decks, each ejector comprising an elongated hollow unit extending across the drying chamber with opposite sides facing the two decks on either side of the unit, and the orifice means of an ejector unit includes an elongated slot extending longitudinally of the unit in each of the units said opposite sides.

4. The dryer of claim 3, wherein an ejector unit includes a pair of hollow sections extending along opposite sides of the unit defining separate paths therein for the flow of gas, and the interior of each section communicates with one of the slots in the unit.

5. The dryer of claim 4, wherein the sections of a unit are spaced laterally of each other to form a passage for the return flow of gas between the decks.

6. The dryer of claim 3 which further includes deflectors spaced at intervals along the length of said drying chamber, located between said decks and toward said one end of said dryer from said ejectors, adapted to deflect air flowing through the drying chamber against articles carried by said conveyer decks.

7. In a dryer, housing structure defining an elongated drying chamber with which articles to be dried travel through,

casing structure defining an elongated plenum chamber extending along the top of said drying chamber, said plenum chamber having an inlet end communicating with the drying chamber adjacent one end of the drying chamber and an outlet end spaced toward the opposite end of the drying chamber,

conduit means interposed between said outlet end of the plenum chamber and said drying chamber accommodating the flow of gas from the former to the latter, said conduit means including plural gas ejectors spaced at intervals along the length of said drying chamber and located toward the opposite end of said drying chamber from where the inlet end of the plenum chamber communicates with the drying chamber, and multiple ducts on either side of the drying chamber connecting such ejectors with said plenum chamber, each ejector having orifice means through which gas is ejected from the ejector into the drying chamber, and

a blower for producing a current of gas along and through said plenum chamber and then into said drying chamber through said ducts and said ejectors, said drying chamber channeling gas ejected thereinto through said ejectors back to the inlet end of said plenum chamber for recirculation.

References Cited UNITED STATES PATENTS 1,138,751 5/1915 Grosvenor 34-231X 2,308,767 1/1943 Mayes 34231X 3,371,427 3/1968 Thygeson 34l55 3,372,630 3/1968 Schmidt 34-156X 3,417,484 12/1968 McCarthy 34160X 1,563,963 12/1925 Byrd 342l9 1,668,314 5/1928 Harvey 34224X FOREIGN PATENTS 1,104,437 4/1961 Germany 34-160 MARTIN P. SCHWADRON, Primary Examiner H. B. RAMEY, Assistant Examiner