US2729380A

US2729380A - Package filling machine

Info

Publication number: US2729380A
Application number: US163249A
Authority: US
Inventors: Clarence J Malhiot
Original assignee: Redington Co F B
Current assignee: F B REDINGTON Co; Redington Co F B
Priority date: 1950-05-20
Filing date: 1950-05-20
Publication date: 1956-01-03
Anticipated expiration: 1973-01-03

Description

Jan. 3, 1956 c. J. MALHIOT PACKAGE FILLING MACHINE 4 Sheets-Sheet 1 Filed May 20, 1950 J n- 3. 1956 c. J. MALHIOT PACKAGE FILLING MACHINE 4 Sheets-Sheet 2 Filed May 20, 1950 j Z dfffzf 3, 1956 c. J. MALHIOT PACKAGE FILLING MACHINE 4 Sheets-Sheet 3 Filed May 20, 1950 Jive/2 0/- (Yarerzcef (fr/Q05 zwzmw ear Jan. 3, 1956 Filed May 20, 1950 c. J. MALHIOT 2,729,380

PACKAGE FILLING MACHINE '4 Sheets-Sheet 4 WHIII United States. Patent 2,729,380 7 PACKAGE FILLING MACHINE Clarence J. Malhiot, .OakZPark IIL, assignor toF. B.

Redington Co., Chicago,.;lll., a corporation of Delaware Y Application May 20,1250, Serial No. 1 6 3,249

3 Claims. (Cl. 226-102) vThe present invention relates to improvements in package filling mechanism adapted for use in receiving packages in open-ended condition, i. e. with their upper end flaps distended to expose the inside of the packages, from the delivery end of a package forming machine, for the purpose of filling the packages with a marketable commodity of a granular or comminuted nature, which is flowable in the aggregate, prior to conducting the filled packages to a suitable sealing machine.

More particularly, the invention relates to a continuously operable package filling machine of the general type in which a series of measuring pockets are adapted to receive a quantity or charge of the material to be packaged at a pocket filling zone and to transfer the charges from the pocket filling zone to a package filling zone where the charges are deposited in a series of open ended packages or containers which are successively brought into register with respective pockets at this latter zone.

It is an object of the present invention to provide a new and improved package filling machine of the character outlined above in which the material-receiving packages and the measuring pockets are brought into register with each other at the package filling zone and are moved in unison through the package filling zone while maintaining such register for an appreciable period of time in order to allow sufficient time for transfer or How of all the material constituting the charge in each measuring pocket into the respective package with which it is in register.

Another object of the invention is to provide a machine of this character in which the measuring pockets which pass through the pocket filling zone are provided with relatively wide marginal surfaces surrounding the open upper ends thereof which receive thereon any extraneous particles of the material to be packaged distributed to the pockets but not entering the pocket openings and in which means are provided for raking or sweeping the extraneous material into the pocket openings before the pockets leave the pocket filling zone preparatory to traveling to the package filling zone.

A further object of the invention is to provide a machine of the general type outlined above in which the packages to be filled'and the measuring pockets by means of which the packages are filled are conducted by separate endless conveyor mechanisms which are so arranged relative to each other that the measuring pockets traveling along a straightaway portion or run of one conveyor are brought into register with the packages traveling along a straightaway portion or run of the other conveyor to establish the package filling zone, with the two straightaway portions or runs overlapping in this manner throughout an appreciable distance to atford a long period of registry between the respective measuring pockets and packages for filling purposes.

The provision of a package filling machine which is relatively simple in its construction; one which is extremely efiicient in its operation; one which is comprised of a minimum number of moving parts and which consequently is unlikely to get out of order;.one which is rugged and durable, and one which is well adapted to perform the services required of it at speeds .which are appreciably higher than has heretofore been possible,

ice

are further desirable features that have been borne in mind in the production and development of the present invention.

In the accompanying four sheets forming a part of this specification, a preferred embodiment of the invention has been illustrated.

In these drawings:

Fig. 1 is a fragmentary plan view of a package filling machine constructed in accordance with the principles of the present invention. Fig. 2 is a fragmentary front elevational view of the machine illustrated in Fig. 1.

Fig. 3 is a sectional view taken substantially along the line 3-3 of Fig. 2, and

Fig. 4 is a fragmentary perspective view of a portion of the package filling machine taken in the vicinity of the package feeding zone thereof.

In general, the present invention contemplates the provision of a package filling machine in which a series of open-ended, empty packages proceed in single file, straight line formation directly from a package forming machine wherein'they are formed with their upper end flaps unfolded through a package filling zone wherein the material to be packaged is inserted into the open ends thereof. During passage of the packages through the package filling zone, the open upper ends thereof are brought into register with the lower open ends' of a series of open-ended measuring pockets which have previously been filled with the material undergoing packaging and the material in the measuring pockets released for delivery by gravity into the packages, the flow of the material from each measuring pocket to its respective underlying package taking place during movement of 'thepackage and pocket through the package filling zone with the measuring pocket and package being maintained-in register throughout their duration of travel through .the zone for such filling purposes. By thus maintaining the measuring pockets andpa'ckag'es in register over a period of time, higher machine speeds and consequently increased production is made possible over machines in which registry between the measuring pockets and packages is maintained only momentarily.

During passage of the packages through the package filling zone, the series of measuring pockets travel in a closed path which repeatedly conducts them past a pocket filling zone wherein they receive their measured charge or complement of the material undergoing packaging and from thence they travel to the packaging filling zone wherein they discharge their contents into the respective packages with which they are brought in register duringtravel through this latter zone. At the pocket filling .zone the upper open ends of the measuring pockets are brought into register with the discharge end of a hopper containing the material to be packaged and the material is distributed in and about the open ends of the pockets to cause the latter to become filled with the material while any excess material discharged from the hopper and failing to fall into the pocket openings is raked or guided into the pocket openings by suitable rake mechanism forming a part of the present invention.

In the past, package filling machines have been employed in which the packages are successively conducted to a package filling station and brought into register, each with a previously filled measuring pocket which discharges its contents into the package at the filling station prior to removal of the package to make way for the next succeeding package. Since the packages and measuring pockets are in register in only one position at the filling station and for a brief period of time, complete discharge of the contents of the pocket into its respective package, and thus complete filling of the package is frequently not attained and the various packages emerge from the machine at the discharge end thereof with contents which varies. in quantity.

Another factor that may contribute toward unequal filling of the packages in machines of this character is the inability of the measuring pockets to receive their full quota of material at the pocket filling station. According to the present invention, by conducting the measuring pockets through a pocket filling zone wherein they are in register with the discharge end of the material-containing hopper for a relatively long period of time, and by bringing the pockets and packages into register and maintaining them in register for a relatively long period of time during their passage through the package filling zone, a full and equal quota of the material to be packaged is supplied to each successive package passing through the package filling zone.

Referring now to the drawings in detail, the improved package filling machine involves in its general organization a stationary framework which supports portions of a conveyor assembly 12 by means of which a series of open-ended packages 2 (Fig. 4) are conducted from a package forming machine (not shown) to a package filling zone Z (illustrated by dimensional arrows in Fig. 1) wherein they are brought into register with a series of measuring containers 14, commonly termed and hereinafter referred to as measuring pockets. The measuring pockets 14 are carried by a conveyor assembly 16 likewise supported by the framework 10 and are adapted to move in a closed path past a pocket filling zone Z1 wherein they receive a quantity of the material undergoing packaging from the discharge end of a hopper 18 for transfer as measured charges to the package filling zone Z.

The packages p are of conventional form and may be of the usual store carton variety in which various items of a flowable granular or comminuted nature such as coffee, tea, pepper, small candy granules, dry cereals, dried beans and the like are adapted to be packaged by the present machine. The packages may be of rectilinear design and the packages illustrated include side flaps fs and a cover flap fc at the open upper end thereof as shown in Fig. 4.

The conveyor 12, by means of which the packages p are conducted from the package forming machine to the filling zone Z is of the vertical chain type, which is to say that the supporting sprocket wheels therefor are disposed in a vertical plane and are rotatable about a horizontal axis. The conveyor 12 includes a driving sprocket wheel 20 mounted on a shaft 22 which is journalled in the machine framework 10 for rotation about a horizontal axis. An endless conveyor chain 24 (Fig. 4) passes around the driving sprocket 20 and includes a plurality of pairs of inner links 26 and outer links 28 connected together in endless fashion by pins 30 having spacing collars 32 loosely disposed thereon and which are adapted to ride upon a supporting track or guide bar 34 carried by themachine framework 10.

A series of U-shaped package-carrying cradles 36 are secured to the conveyor chain 24, the cradles being secured in any suitable manner as, for example, by rivets 38 to the outer links 28 of each pair thereof. The various cradles 36 are adapted to slide upon and be supported by a guide bar or rail 40 which, in combination with three other

similar guide rails

42, 44 and 46 (Fig. 3), suitably mounted on the machine framework 10, provides a longitudinally extending guideway through which the various packages p, each nested within its respective cradle 36, is adapted to pass through the package filling zone Z. The side arms 37 of the various cradles 36 are adapted to extend between the upper and

lower guide bars

46 and 40 respectively and these bars serve to constrain the cradle arms between them and guide the cradles through the package filling zone Z. A horizontal plate or shelf 48 extends laterally from the guide bar 46 and overlies the upper run of the conveyor chain 24.

The guide rail 42 (Figs. 3 and 4) is L-shape in crosssection and is provided with a horizontal shelf portion 49 upon which the bottoms of the various packages 2 which are nested within the package-conducting cradles 36 are adapted to rest and slide during passage through the package filling zone Z. The individual packages p are thus confined within a guideway which consists of the inner surfaces of the

various rails

40, 42, 44 and 46 and are caused to travel therealong by means of the cradles 36 within which they are also confined and which move through the package filling zone Z as the conveyor 12 is driven.

The conveyor 16, by means of which the measuring containers or pockets 14 are repeatedly conducted from the pocket filling zone Z1 to the package filling zone Z, is of the horizontal type, which is to say that the supporting sprockets 50 and 52 therefor are disposed in a horizontal plane and rotate about a vertical axis. The conveyor 16 includes a conveyor chain 54 (Fig. 4) having a series of inner links 56 (Fig. 4) and a series of paired outer links 58 connected together by pins 60.

The various measuring pockets 14 are adapted to be carried by and to move with the conveyor chain 54 and toward this end, each measuring pocket has secured thereto a plate 61 (Fig. 4) to which there is secured a pair of upper and lower L-

shaped brackets

62 and 64 respectively, each bracket being secured to one of the conveyor chain link connecting pins 69. The measuring pockets T4 are generally of rectilinear design and each is in the form of an open-ended tubular member which is provided at its open upper end with a comparatively wide rim or flange portion 66, the transverse edges of adjacent measuring pockets existing in substantially contiguous or abutting relationship when the pockets move along the inner and outer runs or straightaway portions of the conveyor 16 which pass through the pocket filling zone Z1 and package filling zone Z respectively.

The conveyor chain 16 is supported throughout its inner straightaway portion upon U-shaped channel or guide members 68 and is confined within the channel portion thereof by means of retaining plates 70. A similar channel or guide member 72 and retaining plates 74 serve to support the conveyor chain 16 in the outer straightaway portion or run thereof.

The lower open ends of the various measuring pockets 14 are slidably supported upon a supporting plate or shelf 76 (Figs. 2, 3 and 4) which completely surrounds the conveyor 16 and which is provided with an elongated slot 78 therein which is coextensive with the package filling zone Z but the plate is impcrforate throughout the remaining regions thereof. The plate 76 is disposed at a level slightly above the level of the open ends of the vari ous packages which pass through the package filling zone and its outer edge region is supported upon a longitudinal bar 89 forming a part of the machine framework. A bar 82 underlies the shelf 76 and serves to slidably engage the cover flaps fc of the packages 2 to maintain the same extended horizontally as shown in Fig. 3 While the side flaps fs thereof assume an inclined position as shown in Fig. 4 during passage of the packages through the package filling zone Z.

Referring now to Fig. 3, the feed hopper 18 is in the form of a sheet metal container which in its upper regions is provided with vertical walls 84 and in its lower regions includes an inwardly inclined rear wall 86, an inwardly inclined front wall 33, a forwardly and downwardly inclined central bottom section or wall 9%) and forwardly. inwardly and downwardly inclined bottom walls 92 and 94 on each side of the central bottom wall 90. The forward edge of the bottom wall and the lower edge of the front wall 88 define a discharge opening 96 there between which is adjustable in size by means of an ad justable gate member or plate 98 which is adapted to be clamped in any desired position of adjustment by means of a clamping stud and wing nut assembly 100. A manipulating bar 102 carried by the gate member 98. projects through a slot 104 provided in the front wall 88 and provides manual means whereby the elevation of the gate member 98 may be adjusted to vary the size of the discharge opening 96. p

The hopper 18 is supported from the machine framework by means of a plurality of vertical standards or supports 99 the upper ends of which have secured thereto a band-like strap 101 of rectangular configuration which encompasses the upper regions of the hopper 18 as shown in Fig. 3.

As shown in Figs. 1 and 3, the discharge opening 96 of the hopper 18 is disposed in the vicinity of the pocket filling zone Z1 so that material issuing from the hopper 18 is discharged by gravity into'the open upper ends of such measuring pockets as are in register with the discharge opening 96 or as happen to be passing through the pocket filling zone Z1. Actually the material is discharged in the vicinity of the filling zone upon the upper surfaces of the various flange portions 66 of the pockets 14 in the vicinity of the open upper ends of the same so that much of the material enters the pockets to substantially fill the same while a certain amount of the material piles up, so to speak, on the bordering flange portions 66. In order to impel or rake the accumulated material resting on the flange portions 66 of the pockets 14 passing through the pocket filling zone Z1 into the pocket filling zone Z1 into the pocket openings, a third conveyor 110 is suitably mounted in the machine framework 10 and overlies the conveyor 16. The conveyor 110 is of the horizontal type and is provided with a belt-driving pulley 112 and an idler pulley 14 both of which are mounted for rotation about a vertical axis and which serve to support therebetween a belt 116, the lower edge of which rests upon and is slidably supported by the upper surfaces of the various moving flange portions 66. The belt 116 has secured thereto at spaced points therealong a plurality of rake or scraper elements 118 of lobe shape design and having flat bottom surfaces 120 adapted to rest squarely upon the upper surfaces of the flange portions 66 of the pockets 14 and angularly disposed surfaces 122 which are so disposed that they will, upon relative movement between the pockets 14 and belt 116, traverse the upper ends of the pockets and scrape or rake the excess material resting on the flange portions 66 and, by a camming action impel the particles of the material into the pocket openings. The belt 1.16 is driven in such a direction that the inner straightaway portion or run thereof moves in a direction opposite to the movement of [the inner straightaway portion or run of the pocket carrying conveyor 16, all in a manner and for a purpose that will be made clear presently.

The package-carrying conveyor 12 and the pocket carrying conveyor are driven in timed relationship to each other in such a manner that the packages and pockets traveling through the package filling zone Z move through the zone in pairs and in register with each other as will be described subsequently, While the conveyor 110 is independently driven.

Accordingly the

conveyors

12 and 16 are driven from a common drive shaft 130 (Figs. 1, 2 and 3), one end of which is supported in a bearing block 131 mounted on the machine framework, and on which there is mounted a bevel gear 132 which meshes with a similar bevel gear 134 carried on the shaft 22 on which the driving sprocket wheel 20 of the conveyor 12 is mounted. The gear train leading from the shaft 130 to the sprocket wheel therefore consists simply of the two gears 132 and 134.

The shaft 130 carries a second bevel gear 136 which meshes with a bevel gear 138 mounted on a vertical shaft 140 rotatably mounted in bearings 142 supported on the machine framework 10 and on which shaft the driving sprocket 50 of the conveyor 16 is mounted. The gear train leading from the drive shaft 130 to the sprocket Wheel 50 consists of the two

gears

136 and 138.

The shaft .130 is adapted to be driven either continuously or intermittently in step-by-step fashion as desired. Where the package carrying conveyor 12 constitutes a part of, or is common to, the package forming machine and where the requirements of thewrapping operation require intermittent operation of the conveyor, as for example to facilitate a particular bendingor folding operation, such intermittent operation is imparted thereto by the drive shaft 130. Otherwise the shaft may be continuously driven to effect smooth and unvarying movements of the package carrying conveyor 12 and of the pocket carrying conveyor 16.

The conveyor 110 is adapted to be continuously driven from a suitable source of power, as for example an electrical motor (not shown) which transmits power through a driving chain 144 which passes over a driving sprocket.

146 mounted on a shaft 148 suitably journalled in a sup porting plate 149 (Figs. 1' and 3) forming a part of the machine framework. The shaft 148 has mounted thereon a bevel gear 150 which meshes with a bevel gear 152 carried on a shaft 154 journalled in bearing blocks 156 and 157 mounted on the framework 10 and one end of the shaft 154 has mounted thereon a bevel gear 158 which meshes with a bevel gear 160 mounted on a vertical shaft 162 which has its lower end piloted as at 164 in a hub 166 which constitutes a part of the driving pulley 112 of the conveyor assembly 110.

From the above description of parts it will be seen that the drive for the conveyor 110 exists from the driving chain144 through the sprocket wheel 146, and from thence through the bevel gears 150, 152, shaft 154'and gears 158 and 160 to the driving shaft of the conveyor 110. The direction of rotation of the sprocket wheel 146 and consequently of the conveyor belt 116 is suchthat the various rake elements 118 pass'through the pocket filling zone Z1 from right to left as viewed in Fig. 2 and traverse the upper ends of the various pockets 14 due to the relative opposite movements of the rake elements and pockets.

In order, insofar as practicable, to confine the material undergoing packaging to the limits of the pocket filling zone and prevent egress of the same therefrom, a circular brush 170 is mounted upon the shaft 154 (Figs. 1, 2 and3) and is adapted to rotate in a counterclockwise direction as viewed in Fig. 2. The peripheral region of the brush 170 is substantially tangential to the horizontal plane of the upper surface of the flange portions 66 of the various pockets 14 and the brush 170 is so situated relative to the conveyor 16 that the ends of the brush bristles will sweep the material lodged on the flange portions 66 of the pockets 14 inwardly of the pocket filling zone and thus assist the rake elements 118 in directing the material lodged on the flange portions 66 of the pockets 14 into the pocket openings. Abaflle 172 overlies the conveyor 16 at the right-hand end of the pocket filling zone Z1 and has its lower end in close proximity to the plane of the upper surfaces of the flange portions 66 of the pockets 14 and prevents any stray particles or granules of the material undergoing packaging from escaping from the pocket filling zone 21 at the end thereof opposite the brush 170.

In the operation of the machine, the material to be packaged is placed within the hopper 18 and the gate member 98 is adjusted to secure the desired flow of material through the gate opening 96 in the vicinity of the pocket filling zone Z1. The cross sectional area of the discharge opening 96 will vary in accordance with numerous factors as, for example, character and size of the individual particles or granules which cooperate to make up the bulk of the aggregate to be packaged, the composition of the particles and the consequent flowability" of the-mass or aggregate as a whole, the rate of movement of the pockets through the pocket filling'zone, etc.

It will be noted from an inspection of Fig. 3 that the forward edge regions of the inclined bottom wall 90 of the hopper 18 extends beyond the lower edge of the, gate 98 so that extreme edge or lip thereof. overlies a portion of the upper surface of, the flange portions 66. of the pockets 14 as the-latter pass through the pocket filling zoneZl. The forward-edge of the hopper bottom wall 90 extends substantially to the inner edge of the pocket openings so that much of the material discharged from the hopper through the discharge opening 96 is discharged directly into the pocket opening. Such material as may fall on the outer surface regions of the flange portions 66 is engaged by the rake members 118 which, by moving through the pocket filling zone in a direction. opposite to the, movement of the pockets therethrough, traverse the fiange portions 66 and rake the material into the pocket openings.

Any material remaining on the upper surface regions of the fiange portions 66 of the pockets 14, as the pockets pass from the pocket filling zone and move into the arcuate end regions of the conveyor 16, are swept inwardly or back into the medial regions of the zone by the action of the circular brush member 1 70 while the baffle 172 I catches any particles that may be thrown against it, either by the action of the brush 170 or by any turbulence of the aggregate within the pocket filling zone.

The filled pockets 14 leaving the zone Z1 pass around the end of the conveyor 16 with their open bottoms or lower ends resting on and bearing closely against the imperforate shelf 76 in sealing relationship with respect thereto. As the pockets enter the outer straightaway portion or run of the conveyor 16, each of them becomes aligned with one of the oncoming cradles 36 approaching the package filling zone Z on the conveyor 12 and, since the

conveyors

12 and 16 are operated in timed relationship so that their respective chains 24 and 54 move at the same rate of speed, this alignment of pockets and cradles remains in effect throughout the entire extent of m therpackage filling zone Z,

Since each cradle 36 contains an individual empty package to become filled during passage through the package filling zone Z, the packages are moved in succession toward and through the package filling zone Z with their open upper ends disposed beneath the shelf 76. As soon as the pockets 14 move over the elongated slot 78 provided in the shelf, and the forward edge of which establishes the beginning of the package filling zone, the material contained therein discharged by gravity through the slot 78 and into the open upper ends of the various packages. Because of the fact that the extent of the slot 78, and consequently of the package filling zone, is comparatively great, ample time is afforded for complete discharge of the contents of each pocket into the respective pocket which it overlies.

The slot 78 in the shelf 76 is discontinued at the end of the package filling zone and the various pockets 14, now emptied of their contents, move onto the imperforate end region of the shelf 76 and travel again toward the pocket. filling zone where the; filling operation is repeated. The filled packages 2 proceed in a straight line away from the package filling machine on the conveyor 12 and may be conducted to a package sealing machine where a series of operations may be performed on the open ends thereof to close and seal the fiaps thereof to produce the marketable packages.

The invention is claimed as follows: ,1. .In a package filling machine, an endless movable conveyor, a series of measuring pockets on said conveyor, saidpockets having open upper and lower ends and movable by the conveyor in succession in a horizontal closed path through a pocket filling zone in one direction to receive charges of material to be packaged therein through the open upper ends thereof and through a package filling zone to discharge said charges through the lower ends thereof into respective packages conducted. through said latter zone, means at said pocket filling zonefordelivering material in and about the open. upper ends of. the pockets passing therethrough,. the open upper end of each pocket being provided with a surrounding rim portion presenting a substantially flat upper surface area designed for reception thereon of excess material not delivered into said pocket at the pocket filling zone, an endless conveyor, 3 series of rake members on said endless conveyor movable through said pocket filling zone across the upper surface of said rimportions for impelling said excess material into the open ends of said pockets, and means for moving the rake members mounted on said conveyor.

2. In a package filling machine, an endless moving conveyor, a series of measuring pockets on said conveyor, said pockets having open upper and lower ends movable by said conveyor in succession in a horizontal closed path through a pocket filling zone in one direction to receive therein charges of material to be packaged through the open upper ends thereof and through a package filling zone to discharge said charges through the lower ends thereof into respective packages conducted through said latter zone, means at said pocket filling zone for delivering material in and about the open upper ends of the pockets passing therethrough, the open upper end of each pocket being provided with a surrounding rim portion, the rim portions of adjacent pockets abutting one another during passage of the pockets through the pocket filling zone and presenting an unbroken fiat surface area surrounding the open ends of the pockets passing through the pocket filling zone for reception thereon of excess material not delivered into said pockets at the pocket filling zone, an endless conveyor, a series of rake members on said latter conveyor movable through said pocket filling zone across said. unbroken fiat surface area in a direction opposite to the direction of movement of the pockets through said pocket filling zone for impelling said excess material into the open ends of said pockets, and means for moving said rake members mounted on said latter conveyor.

' 3. In a package filling machine means establishing a pocket filling zone, means establishing a package filling zone, an endless conveyor having a straightaway portion leading past said pocket filling zone and a straightaway portion leading past said package filling zone, a plurality of pockets having open upper and lower ends carried by said conveyor and movable with the later along one straightaway portion through said pocket filling zone to receive material to be packaged and movable along the other straightaway portion through the package filling zone to deliver the material at the latter, means at said pocket filling zone for delivering material in and about the open upper ends of the pockets passing therethrough, each pocket including a relatively wide rim portion surrounding its respective open upper end and presenting a substantialy flat horizontal surface, the rim portions of adjacent pockets abutting each other during passage of the pockets through said pocket filling zone to present an unbroken flat surface area surrounding the open ends of the pockets for reception thereon of excess material not delivered into said pockets at the pocket filling zone, a second endless conveyor having a straightaway portion leading past said pocket filling zone, a series of rake elements carried by said second conveyor and movable along said latter straightaway portion through said pocket filling zone in contact with the unbroken surface presented by said rim portions for impelling said excess material into the 'open ends of said pockets, and means for driving said. conveyors in opposite directions whereby said pockets and rake elements pass through the pocket filling zone in-op- 'posite directions.

References Cited in the file of this patent UNITED STATES PATENTS 584,891.