US3509741A

US3509741A - Labyrinth seal tub cover

Info

Publication number: US3509741A
Application number: US756111A
Authority: US
Inventors: Everett D Morey
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1968-08-29
Filing date: 1968-08-29
Publication date: 1970-05-05
Anticipated expiration: 1987-05-05

Description

y 5, 1970 E. D. MOREY 3,509,741

LABYRINTH SEAL TUB COVER Filed Aug. 29, 1968 2 Sheets-Sheet 1 45 46 4o 32 37 as as S a 4-2 35 72 ({j) 0 v 33 4| INVENTOR EVERETT D. MOREY H\S ATTORNEY y 5, 1970 E. D.MOREY 3,509,741

LABYRINTH SEAL TUB COVER Filed Aug. 29. 1968 2 Sheets-Sheet 8 INVENTOR.

EVERETT D. MORE! m S ATTORNEY United States Patent O 3,509,741 LABYRINTH SEAL TUB COVER Everett D. Morey, Louisville, Ky., assignor to General Electric Company, a corporation of New York Filed Aug. 29, 1968, Ser. No. 756,111 Int. Cl. D06f 39/08 US. Cl. 68--27 7 Claims ABSTRACT OF THE DISCLOSURE A washing machine, adapted to wash two loads of fabncs simultaneously in separate solutions without liquid interchange therebetween, includes a first tub to receive liquid and fabrics to be washed in that liquid, a general y vertically disposed agitator in the first tub for causing a washing action and a second tub mounted on the agitator for movement therewith. A liquid inlet is positioned to direct a stream of liquid into the machine in registry with the top of the second tub and a cover is provided for substantially closing the open top of the second tub. The cover includes an upper wall and a lower wall defining a passageway positioned within the upper portion of the second tub and communicating with the interior of the second tub. A number of radially spaced, circumferentially extending walls project from the upper wall toward the lower wall within the passageway and an annular float is provided in the passageway to rise and close off the openings in the upper wall communicating with the passageway as the level of liquid in the second tub rises to the level of the passageway. Thus, liquid interchange between the second and first tubs is prevented.

BACKGROUND OF THE INVENTION This invention relates to fabric washing machines which are adapted to wash two separate loads of fabrics concurrently, without intermingling the liquid used in the washing process.

More particularly, this invention relates to an improved cover arrangement for the inner tub of a dual tub machine such as those described in application Ser. No. 727,437 filed for Eugene E. Ziegler on May 8, l968, and application Ser. No. 727,570 filed for John Bochan on May 8, 1968, both of which are assigned to General Electric Company, assignee of the present invention.

The present invention provides an improved cover arrangement by which intermingling of the liquid used in such dual tub washing machines is positively prevented both during and after the filling operation.

SUMMARY OF THE INVENTION By one form of the present invention there is provided; for use in a vertical axis washing machine having an outer tub to receive liquid and fabrics to be washed in that liquid, an inner substantially imperforate, open top tub mounted in the outer tub to receive liquid and fabrics to be washed in that liquid, and liquid inlet means positioned to direct a stream of liquid into registry with the top of the inner tub; a cover structure adapted to substantially close the top of the inner tub. The cover includes a pair of vertically spaced walls defining a passageway positioned in the upper portion of the inner tub. The uppper of the walls defines an entrance to the passageway for liquid emitted by the liquid inlet means and the lower of the walls defines an exit for liquid to flow from the passageway to the inner tub. A circumferentially extending wall means projects from one of the upper and lower walls toward the other sothat liquid will flow through the passageway into the inner 3,509,741 Patented May 5, 1970 tub until liquid therein rises to the level of the passageway and thereafter will be directed into the outer tub.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a somewhat schematic, side elevational view of a clothes washing machine incorporating one embodiment of the present invention, the view being partly broken away and partly in section for purposes of illus tration;

FIG. 2 is an enlarged, fragmentary, side elevational view of the machine of FIG. 1, illustrating certain aspects of the present invention;

FIG. 3 is an enlarged plan view of the inner tub and inner tub cover of the machine of FIG. 1, in their assembled position, the view being partly broken away for purposes of illustration; and

FIG. 4 is a fragmentary perspective view of a portion of the upper part of the outer wall of the inner tub of the machine of FIG. 1, illustrating certain details in construction.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. 1, there is shown a clothes washing machine of the generally vertical agitator, spin tub type, incorporating one embodiment of the present invention. An outer appearance cabinet 1 is provided with a bottom bulkhead 2, welded or otherwise secured within the casing to provide a water collection chamber 3 and a machinery compartment 4. Disposed within the latter compartment is a frame 5, mounted for gyratory movement about a pivot point (not shown) located in a transverse structural member at the base of the cabinet. The frame carries a drive motor 6 disposed with its shaft projecting vertically downward. The shaft has a drive sheeve and its end is attached to the rotor of a pump 7, which receives liquid from the chamber 3 by way of a screened inlet 8 in the bulkhead 2, the inlet being attached to the pump by an inlet hose 10. A dis charge hose 11 leads from the pump 7 for discharge of liquid from the washer by some suitable means such as by the discharge hose hooking over the side of a laundry tub to discharge the spent washing and rinsing liquid thereinto.

The motor 6 is of the reversible, split phase, induction type commonly used in washing machines. As is well understood in the art, when the motor operates in one direction, it oscillates the agitator for washing and rinsing functions, and, when operated in the other direction, it rotates the clothes tub and agitator together for centrifugal extraction of liquid from the fabrics in the tub. The pump 7 may be of any of the well known types so that, when the motor is operating in the spin direction, the pump removes water from the chamber 3; and, when the motor is operating in the wash direction, the pump is generally substantially less effective as a pumping mechanism.

A transmission 14 is mounted within the frame 5 and has a casing 15 about the lower portion of which a circular, concentric skirt 16 provides a driven clutch element. Within the skirt 16 there is a uni-directional clutch 17 of a type well known in the art. The clutch is fixed to a sheave 18, from which a belt 20 connects to the motor shaft drive sheave. When the motor operates in the spin direction the clutch 17 engages the skirt 16 to rotate the housing 15 therewith. By means of a conventional slip clutch 21 of the coil spring type, the rotation of sheave 18 in the wash direction transmits torque to the transmission 14 while clutch 17 disengages the skirt 16 so that drive torque is not transmitted to the housing 15. It will be understood that any conventional braking or snubbing device (not shown) may be used to restrain rotation or oscillation of the casing during the washing operation. During the spin operation, the clutch 21 slips relative to the transmission 14 whereupon no torque is transmitted thereto. Details of construction of one suitable transmission of this general configuration are illustrated and described in US. Pat. No. 3,l45,553McMillan, assigned to the General Electric Company, assignee of the present invention.

A sleeve 23 extends from the transmission and is secured to a fixture 24 on which ismounted an outer liquid and fabric receiving receptacle or tub 25; so that, when the transmission housing is rotating as aforesaid, tub 25 rotates therewith. A flexible rubber boot 26 is fixed to the sleeve 23 and bulkhead 2 to prevent passage of liquid into the machinery compartment while permitting gyratory movement of the sleeve 23 relative to the bulkhead 2. A coil spring 27 is mounted between the frame 5 and a damping device (not shown) on the underside of bulkhead 2 which serves to damp excessive gyrations, as is well known in the art.

Within the tub 25 and coaxial therewith is an agitator 28. The agitator includes a relatively large center post 30, from which extend a plurality of vanes 31, the vanes being arranged in a spiral about the post 30. The agitator is secured to a splined upper end 32 of an agitor shaft 33, which extends downwardly through the agitator and through the sleeve 23 to the transmission 14. During wash and rinse steps, the transmission 14 isefiective to cause the shaft 33 to oscillate about its axis which, in turn, causes oscillation of the agitator. The shaft 33 is disposed within a sleeve 34 which is connected at its upper end to a depending flange 35 formed on the interior of the agitator center post 30. The lower end of sleeve 34 forms a portion of a pump structure 36, which is mounted on the agitator for movement therewith. A cap 37 is threaded on the upper portion of the splined end 32 and holds the agitator assembly together during operation.

During agitation operations the agitator and pump oscillate together with the agitator shaft 33 about a generally vertical axis. The vanes 31 cause relative motion of the fabrics and liquid in the tub 25 to effect Washing of the fabrics. Liquid is drawn inwardly through openings 38 in the lower portion of agitator 28 by the pump 36 and forced upwardly through an annular passage 39, formed between the sleeve 34 and the agitator center post 30. Appropriate openings 40 are formed adjacent the top of the agitator for the recirculated liquid to fiow outwardly from the agitator. Additional details of structure of the agitator shaft and pump arrangement and a more complete description of the manner of operation of a suitable pump of this type are found in the aforementioned McMillan Patent 3,145,553.

The tub 25 is generally frusto-conical in shape and substantially imperforate, having only a row of exit openings or apertures 41, formed adjacent the top of the outer wall of the tub through which liquid is ejected into the chamber 3 during spin or centrifugal extraction operations of the tub. A ring 42 of heavy material is carried at the top of the tub 25, above the openings 41, to contribute a stabilizing influence during spin.

The tub 25 has an open top 44, generally defined by the ring of material 42, through which fabrics may be loaded into and unloaded from the tub. To this end the top of the cabinet is provided with an aligned opening 45, which selectively may be closed by means of a lid 46 which is mounted over the opening 45.

A second or inner, substantially imperforate, open top tub 47 is mounted within the tub 25 on the agitator 28. The tub 47 includes an inner wall 48, a bottom wall 49 and an outer wall 50. A resilient grommet 51 is mounted to the inner side of the inner wall 48 and is'provided with serrations 52 which interfit with similar serrations 53 on the agitator post 30. These interfitting serrations insure that the inner tub 47 moves with the agitator both when the agitator oscillates for a Washing action and when it rotates with the outer tub 25 for centrifugal liquid extraction. The positioning of the serrations also is such that the top of the inner tub 47 is above the top of the outer tub 25.

Around the circumference of the inner wall 48 there are provided a number of channels such as that illustrated at 54. These channels serve a number of purposes, one of which is to help agitate the liquid and fabrics in the tub 47 to provide a washing action for such fabrics. The channels also provide recesses which fit about the vanes 31 in the agitator so that the tub 47 may fit closely around the agitator. Thus, while the channels are generally vertical, they may spiral or take on such other shape as is necessary to conform tothe vanes.

As explained above, the pump 36 draws liquid inwardly from the tub 25 at the lower portion of the agitator and pumps it upwardly through the agitator and then outwardly through holes 40. The channels 54 also define conduits 55 which are spaced around the agitator and communicates with the upper portion of the agitator adjacent the holes 40. The conduits 55 form return paths for the liquid emitted from the holes 40 so it may return to the tub 25 without going into the tub 47.

A perforated filter 56 is mounted inside the upper portion of the tub 47 so as to rest on the grommet 51 and to be in registry with both the openings 40 and the conduits 55. Thus the liquid exiting from the openings 40 fiows through the filter 56, which effectively filters out lint and other foreign matter from the liquid before it returns to the tub 25.

An L-shaped member 57 extends completely around the upper, inner edge of the outer Wall 50 of the tube 47 and is joined thereto in fluid tight relationship. The L-shaped member includes a first portion 58 which is juxtaposed to the Wall 50 and attached thereto and a portion 59 which extends inwardly, substantially perpendicular to the wall 50. A number of openings 60 are provided in both the

portions

58 and 59 of the member 57 and are distributed circumferentially around the member 57. In alignment with each of the openings 60 the upper edge of the wall 50 is provided with an upwardly extending tab 61 having a small slot 62 formed therein. The radially inner edge of the wall portion 59 is provided with a number of circumferentially spaced openings 63 which are used to help mount a cover in the upper portion of the tube 47.

A cover structure generally indicated by the numeral 63a is removably mounted in the top of the tub 47 and includes a first or upper cover member 64. The cover member 64 has a first section 65 which, in its mounted position, overlies the upper edge of the outer wall 50 and rests upon the tabs 61. This first section joins a second section 66 which extends downwardly adjacent the portion 58 of the L-shaped member 57, then inwardly above the portion 59 of member 57 and then downwardly again inside the inner edge of the portion 59. This second section 66 then joins a third section 67 which extends radially inwardly in a generally horizontal direction. The inner edge of section 67 joins an L-shaped section 68 which extends upwardly and then inwardly. The inner edge of section 68 joins a generally upwardly extending section 69, which has a number of generally vertical slots '70 spaced circumferentially around the section 69. A handle 71 extends upwardly and outwardly from the upper edge of section 69.

A second or lower cover member or wall 72 is formed with a first section 73 which extends downwardly in juxtaposition to that portion of the upper wall section 66 which is radially inward from the wall 59 and extends slightly beyond the lower end of wall section 66. Section 73 is joined to a second section 74 which extends radially inward in a generally horizontal manner, spaced slightly below the section 67 of the upper wall 64. At its inner edge, the section 74 joins an upwardly extending third section 75, which is joined to the generally vertical portion of the L-shaped section 68. A ring shaped member 76 of flexible material is trapped in fluid tight relationship between the

wall sections

75 and 68 and extends radially inward therefrom so as to come into firm, water tight engagement with the upper end of the inner wall 48 .of the inner tub when the cover structure 63 is mounted in the inner tub. A number of tabs 77 are formed extending radially outward from the wall section 73. These tabs are complementary in shape, number and position to the recesses 63 formed in the wall portion 59.

Thus, to mount the cover in the upper end of the inner tube 47, the user grasps the handle 71 and moves the cover so as to align the tabs 77 with the recesses 63 and then pushes the cover downwardly into the top of the inner tub 47. After the tabs 77 have passed through the recesses 63, which distance is sufticient to cause the ring like member 76 to firmly engage the upper edge of wall 48, the user rotates the cover slightly so that the tabs 77 are in interfering relationship with the wall 59 to firmly but releasably hold the cover within the open top of the inner tub.

The wall section 67 is provided with a number of slots or openings 78, circumferentially spaced around the radially inner periphery of section 67. A number of similar openings or slots 79 are spaced circumferentially around the outer periphery of the section 74 of the lower wall 72. The openings or

slots

78 and 79 are circumferentially oflset from each other. The openings 78 form an entrance to a passageway 80 formed between the wall sections 67 and 74 and the openings 79 form an exit from this passageway to the inner tub 47. Thus, liquid coming into registry with the cover may enter the tub 47 through the openings 78, passageway 80 and opening 79.

A circumferentially extending wall means comprising radially spaced walls or ribs 81 extend downwardly from the section 67 and terminate above the section 74. These walls are positioned between the inlet provided by the slots 78 and the outlet provided by the slots 79 so as to form a labyrinth therebetween. This labyrinth restricts the flow of liquid within the passageway 80 between the inlet and the outlet. This assures that, as the inner tub 47 is filled to the level of the passageway 80 and the passageway thus becomes full, additional liquid coming into registry with the cover, particularly the wall section 67, will no longer flow into the inner tub but will be directed for flow into the outer tub. Furthermore, the restriction provided by ribs 81 prevents any substantial reverse flow of the water out of the inner tub into the outer tub so that there will be no substantial intermingling of the liquid in the inner tub with the liquid going into the outer tub.

Assuming that colored items are placed in the inner tub, the liquid in the portion of passageway 80 adjacent outlet slots 79 will tend to be discolored while that adjacent inlet slots 78 will tend to be clear. Thus if there is any leakage through the

slots

78 and 79 it would have an effect on the character of the liquid in the tub it enters. The shape of the ribs 81 minimizes this situation. As the inner tub 47 oscillates with agitator 28, the ribs rotate about their axis and create little or no turbulence within the passageway while providing suitable restriction. If a means were employed to provide the restriction which also created turbulence, such turbulence could thoroughly mix the liquids in the passageway and cause the liquid, which might leak into the tube with White items, to be discolored.

It may be desirable to prevent any intermingling whatsoever of the liquid when, for instance, the load in the inner tub is such as to immediately badly discolor the water therein. To this end an annular or ring-shaped float 82 is positioned in alignment with the entrance formed by the slots 78. As the passageway 80 fills, the float 82 will rise and close oif the slot 78 to positively prevent any subsequent water interchange whatsoever.

An inlet mechanism, generally indicated at 83, is provided to cooperate with the cover to fill the

tubs

47 and 25 with suitable liquid for washing and rinsing fabrics in the machine. As is well known in the art the water inlet mechanism may include a suitable solenoid operated valve assembly 74, which is adapted to be connected to sources of hot and cold water (not shown) so that hot, cold or warm water selectively may be provided to the machine by suitable actuation of the valve mechanism. An inlet tube 85 is connected to the outlet of the valve mechanism and extends inwardly so as to project a stream of inlet water into registry with the cover.

In order to prevent excessive splashing of the inlet water, the inlet tube 85 is positioned so that the stream of liquid emitter therefrom will not flow into the machine in a manner so as to be substantially perpendicular to the center post 28, but rather will flow in generally tangential to the center post. As this stream of water comes into registry with the wall portion 67 it will tend to cause a circumferential flow of water around the recess 86 formed by the wall portions 66, 67 and 68. Such circumferential flow would tend to cause water to enter some of the slots 78, flow circumferentially within the passageway and then flow back out through other of the slots 78. This could have a very deleterious effect as the inner tub approaches a full condition and some water from the inner tub, which is perhaps discolored due to fabrics in the tub, has been transferred to the passageway 80. Such a circumferential flow within the passageway might cause this water to be mixed with water being emitted outwardly through the slots 78, so that some contaminants might get into the outer tub 25. In order to prevent any appreciable amount of such circumferential flow of the inlet water a number of dams or ribs 87 are circumferentially spaced around the recess 86 and extend outwardly across the upper surface of the wall portion 67 and thus across the recess 86. Each of these dams 87 is positioned so as to pass just outside the downstream edge of each of the inlet slots 78, with respect to the circumferential flow. These dams prevent any appreciable circumferential movement of the inlet liquid Within the recess 86. The walls or ribs 81 also serve the added function of limiting any circumferential liquid flow Within the passageway 80 to the area immediately adjacent the inlet openings 78. This further restricts any possibility of such a circumferential flow causing a mixing of the water within the inner tub 47 with that going into the outer tub 25.

It will be noted that the

holes

78 and 79 and the passageway 80 in the cover are positioned so as to be above the opening 41 in the outer tub, and below the exit openings for the inner tub 47, provided by the openings 60 and this spacing between the upper edge of wall 50 and the portion 65 of the upper cover member. When the stream of inlet Water is projected from the tube onto the cover, it initially will flow through the openings 78, the passageway 80 and the openings 79 into the inner tub 47 until the level of liquid in that tub rises to a sufficient height to be even with and fill the passageway 80. At this time no more liquid can enter the tub 47. The stream of liquid then builds up within the upper cover member 64 until it rises to a level sufiicient to flow through the slots 70 and over the inner edge of the flexible member 76. Then it flows through the filter 56 and the conduit 55 to fill the outer tub 25.

It will be recognized that, as thus far described, the machine will fill both the inner and the outer tubs with washing and rinsing liquid, without any interchange of these liquids. It will also circulate and filter the liquid in the outer tub, without any interchange with the liquid in the inner tub.

Normally the water emitted through holes 40 will flow through the filter 56 and conduit 55 back into the inner tub 25. In the unlikely event that the filter 56 has become so clogged with lint and other foreign matter that this water is forced over the top of the filter, the engagement of member 76 with wall 48 prevents its entry into tub 47 and it flows onto the cover 63a. The filled passageway 80 prevents any interchange therethrough.

In order to prevent any interchange of the liquid between the inner and outer tubs during centrifugal extraction a protective member 88 is mounted to extend completely around the upper edge of the outer tub 25. This protective member is formed with a first wall 89 extending inwardly from the upper edge of the outer tub and inclining slightly upwardly to form a flange extending around the upper edge of the outer tub 25. The outer edge of the protective member 88 is bent outwardly to form a similar flange 90 which extends outwardly and downwardly from the outer bottom edge of the balance ring 42. The protective member 88 also includes a plurality of vanes 91 spaced circumferentially around the upper surface of the member 88. These vanes extend generally radially outwardly across the top of the tub 25 and project upwardly therefrom. A wall 92. extends outwardly from the upper edge of the walls t of the inner tube 47 below the openings for the inner tub provided by the spacing between the Wall 50 and cover section 65 and overlies the walls 89.

During centrifugal extraction both the outer tub and inner tub 47 are rotated at high speed. With the arrangement of parts described, the liquid in the outer tub will move up its outer wall and flow outwardly through the openings 41 into the chamber 3, from which it will be pumped out of the machine through the screened inlet 8 to the pump 7. The liquid in the inner tub 47 will move upwardly along the wall 50, through the openings 60, then outwardly between the upper edge of wall 50 and the cover section 65. This liquid will be directed generally radially outwardly over wall 92 and then over the protective member 88 by the vanes 91 and into the chamber 3, from which it also will be exhausted from the machine by pump 7. Toward the end of each centrifugal extraction operation only a trickle of liquid will be flowing out of the inner tub through the openings 60. The slots 62 provide paths for this liquid so that it will not have to flow around the edges of tabs 61.

The wall section 65, wall 92 and protective member 88 perform an additional function. At the conclusion of each fill operation, the recess 86 will be filled with liquid. As the inner tub 47 oscillates this liquid will be directed outwardly. The wall section 65, wall 92 and protective member 88 will guide this liquid into the chamber 3. The same action will occur if, by chance, liquid emitted from openings flow onto the top of the cover.

The foregoing is a description of an illustrative embodis ment of the invention and it is applicants intention by the appended claims to cover all forms and equivalent variations which fall within the scope of the invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. For use in a vertical axis washing machine having an outer, open top tub to receive liquid and fabrics to be washed in that liquid, an inner substantially imperforate, open top tub mounted within the outer tub to receive liquid and fabrics to be Washed in that liquid and liquid inlet means positioned to direct a stream of liquid into registry with the top of the inner tub; a cover structure adapted to substantially close the top of the inner tub, including:

(a) a pair of vertically spaced walls defining a passageway positioned in the upper portion of the inner tub,

(b) the upper of said walls defining entrance means to said passageway for liquid emitted by the liquid inlet means,

(c) the lower of said walls defining exit means for liquid to flow from said passageway to the inner tub,

(d) circumferentially extending wall means projecting from one of said upper and lower walls toward the other between said entrance means and said exit means, l

(e) whereby liquid will flow through said passageway into the inner tub until the liquid therein rises to the level of said passageway and thereafter will be directed into the outer tub.

2. The invention as set forth in claim 1 wherein said circumferentially extending wall means projects from said upper wall.

3. The invention of claim 2 wherein said circumferentially extending wall means comprises a plurality of radially spaced ribs.

4. The invention as set forth in claim 1 wherein said entrance is formed as a plurality of openings spaced circumferentially around said upper wall and a ring shaped float is contained within said passageway to rise and close said openings when the level of liquid in the inner tub rises to said passageway.

5. For use in a vertical axis washing machine having an outer, open top tub to receive liquid and fabrics to be Washed in that liquid, a movably mounted agitator extending upwardly in the outer tub; drive means to effeet a washing motion of the agitator, an inner substantially imperforate, open top tub mounted on the agitator to receive liquid and fabrics to be washed in that liquid and liquid inlet means positioned to direct a stream of liquid into registry with the top of the inner tub; a cover structure adapted to substantially close the top of the inner tub, including:

(a) an upper wall spaced slightly above the outer wall of the inner tub, said upper wall extending downwardly and inwardly across the inner tub, a ring of flexible material extending inwardly from said upper wall to firmly engage the inner wall of the inner tub;

(b) a lower wall spaced slightly below said upper wall to form a passageway therebetween;

(c) a plurality of openings spaced circumferentially around said upper wall as an inlet to said passageway for liquid emitted by the inlet means;

(d) a plurality of openings spaced circumferentially around said lower wall as an exit for the liquid from said passageway to the inner tub; said exit openings being radially offset from said inlet openings;

(e) whereby liquid will flow through said passageway into the inner tub until the liquid therein rises to the level of said passageway and thereafter will be directed into the outer tub;

(f) and a plurality of radially spaced, circumferentially extending walls projecting from said upper wall toward said lower wall in said passageway between the inlet openings and the exit openings to form a labyrinth therebetween.

6. The invention as set forth in claim 5 wherein a ring shaped float is contained within said passageway to rise and close said openings in said upper wall when the level of liquid in the inner tub rises to said passageway.

7. The invention as set forth in claim 5 wherein circumferentially spaced dams extend outwardly across the upper surface of said upper wall, thereby to prevent circumferential flow of liquid around said upper wall.

References Cited UNITED STATES PATENTS 2,246,104 6/1941 Osuch 683 X 3,039,284 6/1962 Shelton et al. 68-3 3,324,688 6/1967 Hubbard 68-4 WILLIAM I. PRICE, Primary Examiner U.S. C1. XR.