US3024744A

US3024744A - Sieves or screens

Info

Publication number: US3024744A
Application number: US835570A
Authority: US
Inventors: Tunley Allan Ashmead
Original assignee: Baker Perkins Ltd
Current assignee: Baker Perkins Ltd
Priority date: 1958-08-28
Filing date: 1959-08-24
Publication date: 1962-03-13
Anticipated expiration: 1979-03-13

Description

March 13, 1962 A. A. TUNLEY SIEVES OR SCREENS Filed Aug. 24, 1959 3 Sheets-Sheet 1 wllli iwr W? 4,44% M,MWW

March 13, 1962 A. A. TUNLEY 3,024,744

SIEVES OR SCREENS Filed Aug. 24, 1959 3 Sheets-Sheet 2 March 13, 1962 A. A. TUNLEY SIEVES OR SCREENS 3 Sheets-Sheet 5 Filed Aug. 24, 1959 nite States atent 3,924,744 Patented Mar. 13, 1962 3,024,744 SIEVES OR SCREENS Allan Ashrnead Tunley, Peterburough, England, assignor to Baker Perkins Limited, Peterborongh, England Filed Aug. 24, 1959, Ser. No. 835,570 Claims priority, application Great Britain Aug. 23, 1958 6 Claims. (Cl. 10744) This invention relates to a sieve or screen construction of the type in which the sieve or screen is formed by an arrangement of bristles or brush tufts. Sieves or screens of this construction are found, for example, in machines for separating cast sweets, such as peppermint creams, from the powdered starch in which they are cast, the sweets being carried over the sieve or screen by vibration and the starch falling through the spaces between the bristles or brush tufts.

It has been previously proposed to employ bristles or brush tufts to form sieves or screens for the confectionery purpose mentioned above by arranging lines of brush tufts (formed by bristles) at an acute angle to the sieve or screen surfaces in overlapping relationship analogous to the reeds of a thatched house.

It is an object of the present invention to provide an improved or alternative construction of sieve or screen employing bristles or brush tufts, which is cheaper and quicker to manufacture and which gives an improved through-pass of the sieved or screened-oif material.

It is a further object of the present invention to provide an improved or alternative construction of sieve or screen employing bristles or brush tufts, which enables bristle or brush tuft replacement to be carried out quickly and easily.

The invention consists in a sieve or screen incorporating brush means as the sieving or screening medium in which each brush means comprises bristles or brush tufts extending generally radially of a bristle-supporting spine and spaced therealong and shaped so as to provide a brush of generally cylindrical form, a plurality of such brush means being mounted on a sieve or screen frame with their spines in spaced parallel or substantially parallel relationship such that the brush bristles of one brush means are in contact with, or overlap the bristles of the adjacent brush means.

According to a preferred form of the invention, as set out in the preceding paragraph, the bristles of each brush means extend along the brush spine in a closely pitched helical path. Thus, for example, each brush means may be formed, in known manner, by forming the brush spine from two or more metal wires or rods having brush bristles distributed evenly therebetween and at right angles to the wires or rods and twisting the Wires or rods around each other to trap the bristles and locate them on a helical path.

The invention further consists in a sieve or screen as set out above wherein the spine of each brush means extends beyond the terminal bristles to provide spigots for mounting the brush means in the frame. According to one convenient construction, the frame comprises two spaced parallel longitudinal members joined across at their ends into a rectangular frame by transverse members and a central bearer spanning the distance between the longitudinal members spaced equidistantly from both the transverse members, and the space on each side of the central bearer is filled with brush means, as set out above, by providing apertures along the central bearer spaced at intervals equal to or slightly less than the radius of a brush means and having their axes in, or par allel to, the plane of the frame, and apertures along the transverse members spaced at intervals equal or slightly less than the diameter of a brush means and having their axes transverse to the plane of the frame, the brush means spigots, formed by the projecting spines of the brush means at one end, engaging alternately from opposite sides the apertures in the central bearer, and the spigots at the other end being downturned to engage in the ap rtures in the transverse members. By suitable spacing of the apertures in the central bearer and in the transverse members, the bristles of each brush means may be made to touch or overlap the bristles of the adjacent brush means.

A plurality of such sieve or screen frames may be assembled, for example in line with their transverse members adjacent, means such as apertures being provided, for receiving additional brush means to bridge the gap between the two frames.

As a modification to the above described mode of mounting the brush means in the frame, the outward spigots or spindles of the brush means are not turned down but are received in apertures in the transverse members co-axial with those in the central bearer, so that the brush means may be turned, if required, on their axes, means such as flanges or set screws being provided to keep the brush means in place.

In the case of a sieve or screen for use in a machine for separating starch from cast sweets as mentioned above, where it is usual to employ sieves or screens which are downwardly slightly concave, the sieve or screen construction according to the present invention has particular utility since the brush means may be disposed so as to extend at right angles to the concavity of the sieve or screen so that straight brush means may be employed, the concave section being obtained by forming the transverse members and central bearer of each frame with the desired curvature in elevation.

In the accompanying drawings:

FIGURE 1 is a plan view of a sieve or screen frame in which the sieve or screen is formed by a plurality of brush means, according to the present invention,

FIGURE 2 is an end elevation of the sieve or screen frame and brush means shown in FIGURE 1,

FIGURE 3 is a side elevation of one of the brush means forming the sieve or screen in FIGURE 1,

FIGURE 4 is a sectional view taken on the line 4-4 of FIGURE 1,

FIGURE 5 is a fragmentary plan view of a sieve or screen frame having a sieve or screen formed by a modified construction of brush means, and

FIGURE 6 is a side elevation of one of the modified brush means shown in FIGURE 5.

In carrying the invention into effect according to one mode by way of example the sieve or screen comprises a framework made up of longitudinal tubular members I linked at each end by transverse members 2, preferably of flat strip section. The transverse members 2 may be curved as shown in FIGURE 2 so as to provide a sieve or screen having a concave face for use in known manner in confectionery casting machines. In the centre of the framework, parallel to and between the transverse members 2 is a central bearer member 3 which is preferably of strip section and disposed on edge.

The sieve or screen itself is provided by a plurality of cylindrical brushes 4, the bristles 5 of which extend generally radially from a central rigid spine 6. Conveniently the brushes 4 are made up, in known manner, by placing bristles between two or more straight wires or rods and twisting the latter about a common axis so that the bristles are trapped and located on a. helical path as shown in the drawings.

The brushes 4 are located in the framework so that they extend parallel to the longitudinal members 1 and are spaced so that the bristles of one brush touch those of the adjacent brush or brushes, see FIGURE 1. Alternatively the brushes 4 may b spaced still closer so that the bristle tips of adjacent brushes overlap.

According to one convenient mode of mounting the brushes 4 in the above manner in the framework, the spine 6 of each brush is extended at each end beyond the termination of the bristles to provide spigots 7 and 8 of which the spigot 8 is preferably bent at right angles to the axis of the spine 6 (see FIGURES 3 and 4) so as to prevent turning of the brush when mounted as will be described. The central member 3 of the framework is formed with apertures 9, see FIGURE 4, each spaced apart by a distance equal to half the spacing between successive brushes 4 on either sid of the central member 3 and the straight spigot ends 7 of the brushes 4 pass through the apertures 9 from alternate sides of the central member 3 to locate and secure the inward ends of the brushes 4. Thus the axes of the spines 6 of the brushes 4 on one side of the central member 3 are staggered with respect to those on the other side. The transverse members 2 at each end of the framework are formed wtih apertures 10,

see FIGURE 4, extending at right angles to the axes of the apertures 9 in the central member 3', and the apertures 10 are spaced apart by a distance equal to the pitch between successive brushes 4 and accommodate the down-bent spigot ends 8 of the brushes 4 to locate and secure the outward ends of the brushes 4 and prevent the brushes from turning. In order to lock the brushes 4 in place the extreme end 11 of the bent-down spigot ends 8 are bent over as shown in FIGURE 4.

In an alternative embodiment of the invention, see FIGURES and 6, the sieve framework is substantially the same as already described, but the spines 6a of the brushes 4a are lengthened to provide an extended portion 7a, free of any bristle. Thus, in FIGURES 5 and 6 the portion of each brush 4a to the left of th central member 3 is equipped with bristles 5a formed as before and the spine portion 7a of each brush to the right of the central member 3 is bare. The two ends of the spine 6a are downturned into spigot portions 8a which are received, as described previously, in apertures in the transverse members 2. By this arrangement the bare portions 7a of each brush lie between the peripheries of the bristle portions 5a of the two adjacent brushes and serve further to inhibit the passage of unwanted material through the sieve or screen.

In order to strengthen and stabilize the brush structure forming th sieve or screen, binding wires 12 or the like may be successively laced round the

brush spines

6 or 6a, although this has only been shown in FIGURES 5 and 6 for the brush spines 6a.

Where the sieve or screen means, according to the present invention are to be used end-to-end to provide a sieve or screen of extended length, as in a confectionery casting machine, the sieve or screen may be extended over the junction between one framework and the next by the provision of special end brush lengths 13, hearing bristles 14 along their entire length and securable substantially over the transverse members 2 of each frame. The spine 15 of each end brush 13 is downturned to provide fixing and locating spigots 16 receivable in apertures 17 at the junction of the longitudinal members 1 and transverse members 2.

I claim:

1. A sieve or screen incorporating brush means as the sieving or screening medium in which each brush means comprises bristles extending generally radially of and around a bristle-supporting spine and spaced therealong and shaped so as to provide a brush member of generally cylindrical form, a plurality of such brush means being mounted on a sieve or screen frame with their spines in spaced parallel or substantially parallel relationship such that the brush bristles of one brush means are in contact with the bristles of the adjacent brush means, the spine of each brush member extending beyond its bristles to provide spigots for mounting the brush members on the frame.

2. A device as claimed in claim 1, wherein the frame comprises two spaced parallel longitudinal members joined across at their ends into a rectangular frame by transverse members and a central bearer spanning the distance between the longitudinal members spaced equidistantly from both the transverse members, and wherein the space on each side of the central bearer is filled with said brush members, said central bearer having apertures spaced apart at intervals no greater than the radius of a brush member and having their axes in the plane of the frame, said transverse members having apertures spaced at intervals no greater than the diameter of a brush member and having their axes transverse to the plane of the frame, the spigots at the ends of the brush members adjacent said central bearer engaging alternately from opposite sides the apertures in the central bearer, and the spigots at the other ends of said brush members being downturned to engage in the apertures in the transverse members.

3. A device as claimed in claim 2, wherein the spine of each brush member is extended, but does not carry bristles, at its non-downturned end to span the space on the side of the central bearer opposite to that spanned by the bristle-bearing portion of the brush, the arrangement being such that between the bristles of adjacemt pairs of brush members on either side of the central bearer the non-bristle-bearing spine section of a brush member on the other side of the central bearer is interposed to inhibit further the passage of unwanted material through the device.

4. A device as claimed in claim 1, wherein flexible tie means are successively laced round the spines of said brush members from one longitudinal member to the other in order to strengthen and stabilize the brush members.

5. A device as claimed in claim 1 including transverse cylindrical brush means extending over the width of the frame at right angles to said brush members and located over each transverse member such that when two similar frames are located end-to-end, the transverse brush means of each frame inter-engage to screen the junction between the two frames.

6. A sieve or screen device comprising frame means; a plurality of generally cylindrical brush members each composed of a spine and bristles secured to and radiating from said spine; and means mounting said brush members non-rotatably on said frame in substantially parallel relation with the bristles of said brushes in contact with one another, said bristles providing'a supporting surface for articles.

Dye Sept. 15, 1925 Rapisarda Oct. [22, 1935