US 2886849 A
Description (OCR text may contain errors)
May 19, 1959 Filed July 3. 1957 K. BRIERLEY POWDER-COMPRESSING MACHINES 2 Sheets-Sheet l INVENTOR KENNETH BRIERLEY ATTORNEYS y 9, 1959 K. BRIERLEY 2,886,849
POWDERCOMPRESSING MACHINES Filed July s, 1957 2 Sheets-Sheet 2 IN VENTOR KENNETH BRIERLEY BY ATTORNEYS United States Patent POWDER-COMPRESSING MACHINES Kenneth Brierley, Letchworth, England Application July 3, 1957, Serial No. 669,738
1 Claim. (Cl. 18-16) This invention relates to powder-compressing machines, such as are used for example in the compression of cosmetic powder into a cake for putting into powder compacts.
In the compressing of powder, it is necessary in the compressing device to provide means for escape of the air contained in the loose powder, when the bulk of the powder is reduced during the compression action. It is the object of the present invention to provide an improved construction of compression head whereby an escape path for the expelled air is provided in a simple and convenient manner.
According to the present invention, a compression head for a powder compressing machine, that is to say a fixed member against which a quantity of powder may be com pressed by any suitable compressing device, comprises a rigid block, and two or more layers of sheet material arranged in contact and against a pressure face of the block to receive the powder forced against it, the layer adjacent the powder being made of porous material. When pressure is applied to the loose powder to force it into a cake, for example in a shallow receptacle known in the art as a godet, the air escapes laterally through the layer of porous material and emerges at the edges thereof.
In order that the powder-contacting layer may be made of relatively thin material, without preventing the escape of the air, the second layer is preferably also made of porous material. By way of example, the powder-contacting layer may be made of thin and relatively cheap paper strip, and the second layer of a strip of woven nylon.
Means are advantageously provided for presenting a fresh portion of the powder-contacting layer from time to time, e.g. at each time of compression of powder against the block. Such layer may be in the form for example of a roll fed from a feed roll past the pressure face of the block to a take-up roll, means being provided to shift the layer at each time of operation of the compressing means.
In one convenient form of construction the take-up roll is coupled by a uni-directional drive device to a member reciprocated in synchronism with the compression of the powder.
The second layer may also be shiftable to present a fresh portion at the pressure face of the block from time to time. However, it is not normally necessary to change the working position of the second layer except at infrequent intervals, and as the nylon which is conveniently used for this purpose is costly a considerable reduction in Working costs is thereby obtained.
In order that the nature of the invention may be readily ascertained, part of a construction of powder-filling machine is hereinafter particularly described with reference to the figures of the accompanying drawings, wherein: Fig. 1 is a front elevation; Fig. 2 is a side elevation, partially in section.
In these figures, the apparatus includes a stationary machine frame 1 having a front portion 2 arranged to overhang the edge area of a rotary horizontal platform or table 3 rotatable about an axis situated at a point off the extremeleft-hand edge of Fig. 2. The platform 3 includes a number of apertures 4 spaced at intervals about its circumference, and any suitable step-by-step drive means (not illustrated) is provided to bring these apertures in turn into the position shown. The overhanging portion 2 of the frame has a vertical bore in which is slidably arranged a column 5 having at its lower end a compression element 6, the arrangement being such that each aperture of the rotary platform is brought in turn into exact alignment with the compression element. The upper end of the column 5 has a flange 7 and a compression spring 8 is arranged between the flange 7 and a cross-slide 9 so as to urge the compression element upwardly into its raised position shown. The cross-slide 7 has an inclined cam surface 10 abutting against a correspondingly inclined cam surface on the compression element 6 so that when the cross-slide 7 is moved to the left in Fig. 2, by any suitable drivemeans (not shown) the compression element 6 is moved down- Wardly, the extent of movement beingarranged so that the circular raised central area 11 is brought down very near to the upper rim of the aperture 4. In the aperture 4 is seated a shallow metal receptacle 12 into which it is intended to compress a quantity of powder (not shown) placed loosely in the upper part of the aperture 4 and lying on the receptacle. The latter is seated on the upper surface of a plunger 13 mounted on a stem 14 which can be forced upwardly by any suitable driving means such as a hydraulic ram disposed beneath the platform 3.
When the quantity of powder is compressed from the loose form into a solid cake, it is necessary to allow means for escape of the air which is dispersed among the grains of powder. Thus it is impossible to merely close the upper end of the aperture 4 and then raise the plunger 13 carrying the receptacle. This difiiculty is overcome by placing a layer of a suitably porous material over the surface of the compression element 6, the porosity of the layer of material allowing escape of the air laterally through the layer as the powder is compressed. It would be possible to utilise a single layer of porous material such as paper strip disposed against the underside of the compression element 6 but the necessary grade of paper must be specially made and is relatively very costly. Moreover, the action of compressing the powder and receptacle against the underside of the compression element tends to cut out circles from the layer of porous material, or otherwise to damage it so that the appearance of the compressed cake is spoiled. In the present construction, two separate layers of porous material are placed over the lower surface of the compression element. A first layer is of a strip of woven material made from nylon. For this purpose there are provided a feed roller 15, atake-up roller 16, and a strip 17 of nylon fabric passed from roller 15 down to and under the surface of the compression element 6, and thence to the take-up roller 16. The second layer is of paper and a strip 18 is fed from a feed roller 19 past the compression element 6 to a take-up roller 20. In use, it is found that the paper strip tends to be damaged at substantially each time of operation. Accordingly means are provided to shift the paper by a suitable length at each time of compression. For this purpose there is provided a chain 21 which is reciprocated by any suitable driving means (not shown) operated in synchronism with the compression means. The chain passes about a sprocket wheel 22 and is secured to a tension spring 23. The sprocket wheel is coupled by a unidirectional drive, eg. a pawl and ratchet wheel device of well-known kind, to the take-up roller 20. Thus, at each time of pulling of the chain 18, the take-up roller 20 is moved through a portion of a turn sufficient to bring a fresh portion of the paper strip 18 into position under the compression element 6. A loaded roller 24 bears on the paper on the take-up roller to provide a frictional drive.
arisen-ta It is found in practice that the nylon strip 17 can stand up to a large number of operations before it becomes cut or otherwise damaged, and accordingly need only be shifted from time to time by the operator of the machine, this being performed for instance by turning the take-up roller 16 by hand.
In this way, the relatively expensive nylon strip is preserved to the utmost. On the other hand, the paper strip 18 can be of a common type readily available on the market at a low price which is such that there is no appreciable extra cost in production involved in the use of a fresh portion for each time of filling a receptacle with powder.
In a machine for the filling of godets with a cake of compressed cosmetic powder, a machine frame, a horizontal rotatable table, mounted on the frame and having a plurality of bores with vertical axes, a plurality of compression plungers arranged one in each bore of the table and serving to carry a godet, means for inserting a charge of loose cosmetic powder in the bores above the godet, a block arranged above the table and positioned so that by rotation of the table the bores therein may be brought in turn in alignment beneath a face of the block to close the upper end of the bore, means for raising the plungcrs in their bores to compress the powder therein, a strip of paper arranged across the closing face of the block to be contacted by the powder, said paper permitting the passage of air normal to its surface over the whole area of the end of the bore but preventing the passage of powder, means for moving said strip in step by step motion across the face of the block in synchronism with the rotation of the table to present a fresh piece of paper at each compression operation, and a second layer of porous woven material disposed between the paper and the block to support the paper strip during compression and allow escape latterally of air forced through the paper during compression of the powder.
References Cited in the file of this patent UNITED STATES PATENTS 2,350,971 Pecker et a1. June 6, 1944 2,512,275 Hawk June 20, 1950 2,573,141 Heinrich Oct. 30, 1951