Portable Sifting Apparatus

Abstract

A compact, portable, power-driven sifter is provided for use in sifting flour or the like, and is particularly suited for restaurant and institutional use. A basket having replaceable screens is mounted in a housing for horizontal oscillatory movement by means of a motor-driven eccentric linkage, the basket being supported on rollers and guided by sheave rolls against lateral displacement. The housing is supported in a highly raised position by elongated legs to permit pans, trays and the like to be moved in and out from under the unit from any side thereof.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to power sifting equipment and more particularly is directed towards a compact, low-cost, portable sifter for use in restaurants and the like.

2. History of the Prior Art

Various types of commercial sifters for restaurant and institutional use have been available for many years. However, sifters of this type heretofore have been rather large, heavy and expensive machines usually requiring considerable floor space and permanently installed. It is, therefore, an object of the present invention to provide a low cost, portable, compact and power-driven sifter suitable for commercial use and which may be located and used with convenience on any suitable flat supporting surface such as a table top counter top or the like.

SUMMARY OF THE INVENTION

This invention features a power-driven portable sifting apparatus comprising a housing supported above a table surface or the like on elongated legs to provide access from four sides thereof for pans and the like to the discharge under the housing. The housing encloses a basket with interchangeable screens and is horizontally oscillated by means of a motor-driven eccentric coupling, the basket being supported by cooperating rollers for smooth, friction free operation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view in perspective, partially broken away, showing a sifter made according to the invention,

FIG. 2 is a view in side elevation, partly in section, of the FIG. 1 apparatus,

FIG. 3 is a detailed view in front elevation showing the roller support assembly, and,

FIG. 4 is a view in perspective of a replaceable screen employed in the sifter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In the drawings the reference character 10 generally indicates a sifting apparatus comprising a boxed housing 12 set on elongated legs 14 which support the housing 12 at a substantial height above a supporting surface such as a table or counter top, for example. Typically, the legs 14 maintain the housing 12 perhaps 5 or 6 inches or so above the supporting surface. A leg is mounted at each corner of the housing and preferably is of a relatively narrow cross section to permit a maximum amount of access space between adjacent legs. Each leg preferably is provided with a suction cup foot 16 for stabilizing the unit of its supporting surface.

The top of the housing 12 is provided by a hinged cover 18 the larger portion of which encloses a sifting basket 20 while the smaller portion encloses a motor 22 and drive assembly 24. Typically, the cover is provided with a surrounding gasket 25.

The sifting basket 20, as shown best in FIGS. 2 and 3, is in the form of an open rectangular receptacle having generally upright sidewalls 26, preferably of sheet material such as stainless steel or the like. The walls 26 are formed at the bottom with an inwardly facing lip 28 which supports the outer margin of an open mesh screen 30 spanning the otherwise open bottom of the basket 20. The upper portion of the wall 26 is formed with an outwardly extending lip 32 by which the basket rests on a rectangular frame member 34 extending about the basket 20. Tabs 33 are provided for use in lifting the basket from the frame. In the preferred embodiment the frame 34 is formed from right-angle stock which serves as a holder for the removable basket and also serves as a track and support for the basket 20 which undergoes vigorous oscillatory movement when in operation. The horizontal portion of the frame 34 extends out from the side of the basket 20 and rests on spaced rollers 36 located along opposite sides of the basket and mounted to the housing 12 by means of a block 38. The rollers 36 preferably are of a durable plastic material such as Teflon which provides low frictional support, are quiet and enjoy a relatively long and trouble-free life. Obviously, other materials may also be used. The axes of the rollers 36 lie in a horizontal plane perpendicular to the path of travel of the basket 20.

In order to guide the basket against lateral or vertical displacement sheaves or pulley guide rollers 40 are provided, preferably in proximity to the rollers 36, and mounted to the housing 12 so as to engage the outer edge of the horizontal portion of the frame 34. This is best shown in FIG. 3 where it will be seen that the guide roller 40 is mounted to an upper flange 42 of the housing 12 for rotation about a vertical axis and it will be understood that there is at least one guide roller 40 on each side of the basket and preferably two, one near each corner thereof and serving to guide the basket during oscillation and to prevent spurious movements thereof. Again it is desirable that the guide roller 40 be fabricated from a low-friction material such as Teflon or the like.

The basket 20, as indicated previously, is provided with a screen 30 across the bottom thereof and in practice the screen 30 is of a relatively wide mesh with finer sifting being available by the use of accessory screen inserts 44 such as shown in FIG. 4. The screen 44 may be of any desired mesh according to the material being sifted. The accessory screen 44 preferably is formed with a rectangular frame 46 to which is mounted mesh screen material 48 reinforced by cross ribs 50. Upwardly extending posts 52 are provided at each end to facilitate insertion and removal of the accessory screen from the basket. Each post may be provided with a gripping head 54. Mounted across each end of the frame 46 are bumpers 56, preferably of rubber or other resilient material, which may be readily formed from split tubing or the like. The bumpers 56 serve to hold the screen insert squeezed in position at the bottom of the basket and prevent the screen inserts from banging about as the gasket is oscillated. In practice, each sifting unit would be provided with a set of screen inserts of various mesh sizes.

The basket 20 is oscillated by means of the motor 22 and drive linkage 24. The motor, as previously indicated, is mounted in the rear position of the housing and typically is provided with a reduction gear assembly 58 to provide an output of approximately 300 r.p.m., for example. The reduction gear assembly is provided with a drive shaft 60 eccentrically keyed to the inner race of a bearing 62 mounted in one end of a connecting rod 64. Typically the eccentric is three sixteenths inches off center to provide a 3/8-inch stroke of the rod 64. The opposite end of the connecting rod is drivingly connected to the basket frame 34 by means of a shaft 66 passing through a ball bearing assembly 68 with the ends thereof supported in spaced blocks 70 and 72 secured to the basket frame 34. It will be understood that when the motor is energized the rotation of the shaft will cause, through the eccentric connection, the basket to be oscillated back and forth in the direction of the connecting rod. The material to be sifted is placed in the basket and discharges from the bottom. By raising the housing in the manner shown, pans or other receptacles may be placed in under the housing to collect the sifted material as it drops from the sifting basket. Since the shifting unit is raised entirely by means of the elongated legs the unit may be placed on almost any supporting surface and be used conveniently since pans or the like may be slipped under the housing between any of the legs from any side thereof.

Claims

Having thus described the invention what I claim and desire to obtain by Letters Patent of the United States is:

1. Sifting apparatus, comprising

a. a housing, having a discharge opening formed in the bottom thereof,

b. spaced elongated legs mounted to said housing for elevating said housing above a supporting surface at a height sufficient to permit access under said housing and from any side thereof,

c. an open frame mounted for oscillation in said housing,

d. spaced juxtaposed rollers mounted to said housing and engaging opposite sides of said frame for horizontal movement thereof,

e. a foraminous basket removably mounted in said frame,

f. a motor mounted at one end of said housing, and

g. an eccentric coupling connecting said motor to one end of said frame whereby operation of said motor will oscillate said frame and said basket,

h. said frame being formed with a horizontal flange extending at least along the sides thereof,

i. said rollers including spaced rollers mounted for rotation about horizontal axes and engaging the underside of said flange and spaced annularly grooved rollers mounted for rotation about vertical axes and engaging the edges of said flange.

2. Sifting apparatus according to claim 1 including a removable screen mounted in said basket, said screen being coextensive with said basket, resilient bumpers mounted along the edges of said screen and upright posts mounted at the ends thereof.