US 2860404 A
Description (OCR text may contain errors)
M. ALDEN WORK CENTER Nov. 18, 1958 5 Sheets-Sheet 1 Filed June 22, 1954 Filed June 22, 1954 M. ALDEN 2,860,404
WORK CENTER 5 Sheets-Sheet 2 2 .8 ,INVEVNTOR G6 fl/z/fokA/r/ /z BY a: \G7 69 b7 ATTORNEYS M. ALDEN Nov. 18, 1958 WORK CENTER 5 Sheets-Sheet 3 Filed June 22, 1954 ATTORNEYS v Nov. 18, 1958 M. ALDEN 2,860,404
WORK CENTER I Filed June 22, 1954 5 Sheets-Sheet 4 INVENTOR M175) A/rkzz ATTORNE 3 M. ALDEN WORK CENTER Nov. 18, 1958 5 Sheets-Sheet 5 Filed June 22, 1954 km M R/ W mA M N 7 R I M M YW United States Patent WORK CENTER Milton Alden, Wellesley, Mass.
Application June 22,.1954,.Serial No. 438,451
Claims. (Cl. 29-200) Although, the advantages of logical. and systematic layout of production lines and planning have long been recognized and used in mass production industries such as. automobile and electrical appliance manufacturers, the. time and money-saving techniques developed by these industries have not been adaptable to light manufacture of a relatively small number of articles because of the time, cost and inflexibility of a conventional production line.
Itis therefore the objects of this invention to provide a production system which permits a production line to be set up and removed quickly and easily, which permits a logical layout of work stations or centers, which requires a minimum of floor space, which is attractive in appearance, which increases the productivity of the workers which facilitates the installation of small tools and fixtures, which, permits the various services to be. con-- nected and disconnected readily, which provides means for transporting the articles being manufactured. between work centers, which provides means of storing of components and inventory control at the various work, centers, and which advances the manufacturing arts generally.
According to my present invention: the production system comprises a plurality of work stations or centers which are a standard. size insofar as each center has a similar sized work top or pallet. The pallets are. ofconsiderably smaller size than has been. previously thought possible. by using containers which. store the pieces or components required by the operator in a container located. in. a generally vertical plane rather thanin bins or tote boxes fanned. out around the operator as is usually done. Further saving in the space required isobtained by grouping all the services required in a generally vertical enclosure or housing running along the back of a framework. which supports a row of pallets forming the work surfaces for the work centers. On each pallet is permanently mounted the tools and fixtures. and component containers required. to perform the operation of the particular work center. The pallets are made as cheaply as possible, for example, .of wood cores, covered with masonite so that mounting holes, cut-outs, or other alterations necessary can be made to accommodate the fixtures and tools, The low cost of the pallets also makes it'possible to leave the tools and fixtures permanently attached so that whenever a run on a particular article or device is completed and the operations performed at one or more of thecenters are temporarily no longer required, the pallet and, attached tools and fixtures are removed and stored as a unit until the operations they are arranged to perform are again needed. To facilitate such changeover the pallets. are arranged to be readily removedfrom their supporting frame and the connections to the services are made by electrical plugs, flexible hoses and quick disconnect joints. To facilitate the movement of components and partiallycompleted articles from one Work center to another, a belt conveyor is located adjacent either the front or back of the pallets.
2,860,404 Patented Nov. 18, 195.8
The conveyor support or frame is preferably made, up. of a plurality or interconnecting elements each having, a length which is equal to the. width of a pallet,v the cross section of the frame being I-shaped with a horizontally disposed web upon either side of which the belt is carried.
These and other objects and aspects of the. invention will be. apparent from the. following; description of, aspecific embodiment. of the. invention which refers to drawings wherein:
Fig, l is anisometric view of four adjacent, workcenteIs;
Fig. 2 is an isometric view of two work centers show.- ing one pallet partially removed;
Fig. 3. is anisometric view of the supporting framefor the. work centers shown. in Fig. 1;;
Fig. 4 is a section; view on line. 4-4 of. Fig. 3;;
Fig. Sis a sectional view on line. 5-5. of Fig. 4;
Fig. 6 isa rear isometric view of. a. supporting frame with a section. of the duct for the services removed;
Fig. 7. is an isometric view of the belt conveyor;
Fig. 8. is an explodedv isometric view of two. frame sections;
Fig. 9. is. an enlarged. fragmentary view showing the ramps for loading and. unloading the conveyor;
Fig. 10 is. an. isometric view ofa container or hopper for. components;
Fig. 11 is anexploded isometric view. of the container;
Fig. 12 is anisometric view of a. foot for the container;
Fig, 13. is, an isometric view showing the arrangement of several containers on a pallet; and
Fig. 1.4. is a. diagrammatic. view showing the. manner in which the. containers are, stored and distributed.
A preferred. embodiment of the. invention shown in Fig, I. comprises a supporting frame. 2.0..upon which are c rr ed removable work. tops, such as. the wooden pallets 22, to; form a. continuous. table. or bench havinga back wall which. is. a hollow vertical, enclosure. such as the duct. 24"., Within the. duct.2.4are carried the lines. for services such as electricity, compressed air, gas,.and exhaust as are required. for the various, manufacturing operations. The. duct 24 also. acts, as. ananchor for stanchions 26 for florescent lamp fixtures28.
Each of. the'Pall'ets. 22. forms. a station or work center where one particular manufacturingor assembling operation is. carried. on, Accordingly, the. first station on. the left of Fig.1 is provided. with an arbor press 30 which is bolted. to its pallet, 22. A. work center at which slow or complicated. operations. are performed requiring. a longer time to complete 1118 .35, if. necessary, be duplicated at one or more stations. such as. the second. work center where there is. also, mounted. an arbor press. 30. At. the third station is locatedv an air, operated press 32which is connected to a, compressed air line (not shown). within the duct, 24 by means of a flexible hose 3.4. as.will.b e-. de-
scribed later. The. fourthstation is provided. with a fly press 36.- and a vertical container or. hopper 3.8 for components which will; be described indetail hereinafter...
Transportation of the. partially completed devices. or
articles of manufacture (not shown), between. different work centers is accomplished by a. belt conveyor-40,- located either abutting. the front edges. of the pallets. 22, as
shown in, Fig. 1, or, alternatively, on the top of the pallets, adjacent the service; duct 24 at the rear of the, work center. The. conveyor 40,. which is. described inv detail the outlets 46 in the service duct 24... The flexible lead to the fluorescent lamps 28 is also plugged into another of the outlets 46'. Any electricalpower required in the "manufacturing operations either for motors, soldering irons, or heating units is similarly obtained from electrical busses located in the service duct 24.
Although only four stations or work centers are shown in Fig. 1, it will be evident that my invention is not so limited and that the maximum number of centers in one row need be limited only by the space available in the work room or the number of operations required in the production lines. When more centers are needed than can be accommodated by the longest dimension of the work room more than one row of centers is used. Con versely, less than four stations may be used, as is illustrated in Fig. 2, it having been found that support frames 20 with only two or three work centers and provided with bare pallets are ideally suited for laboratory benches because of the convenient location of the various services in the rear duct 24.
Fig. 2 also serves to illustrate the manner in which a pallet 22 may be simply slid from the supporting frame 20 without the necessity of removing the attached tool 48. This feature permits great flexibility because of the ease with which the operation at any station can be changed so that many of the benefits and advantages of production techniques can be realized by small shops which ordinarily could not aflord the time and money to set up a conventional production line to manufacture items with a limited production. Once the elements of the support frames 20 are bolted together in place, a production line is set up for any particular item by securing the necessary tools, fixtures and component containers 38 required for each step to the top of a pallet 22 either while the pallet is in place in the frame22 or in a separate assembly area or room. The various service connections are made to the busses and lines in the service duct 24 by extension cords and flexible hoses so that the skill and time required is reduced to a minimum.
While planning is, of course, required, it can be kept to a minimum because any difficulty or bugs which may occur can be worked out with a minimum of disruption of the production line either by duplicating stations or altering their location in the line or by changing the particular tools at one or more stations simply by sliding out one pallet and substituting another. Once a production line for a particular product or article has been set up it is a simple matter to either remove it or to set up at a second later time when more articles must be produced. This is accomplished by removing and storing the pallets 22 with the tools and fixtures in place, for examples, in racks (not shown) from which the pallets can betaken and slid back into the supporting frames 20 when the production line is to be set up again. While the pallets 22 are stored, other pallets with different or similar tools and fixtures for performing a second series of operations are in the supporting frames so that another article or device can be manufactured and assembled.
The flexibility of my system is not limited to replaceable pallets 22, as the supporting frames, the service ducts 24, and belt conveyor 40 are all standard modular units built up as multiples of a single work center having'one pallet work surface as described below. This makes it possible to adapt the system to existing conditions and buildings and to alter the arrangement of the supporting frames 20 to accommodate a different type of manufacturing method or product.
The structural details of the frame 20 can best be seen in Figs. 3 to 5 wherein two spaced horizontal angle mem bers 50 and 52 are of sufficient length to accommodate two adjacent pallets 22. The adjustable legs for supporting the angle members 50 and 52 each comprise a channel-shaped member 54 the ends of whose flanges 56 (Fig. 5) are bent inwardly as to reentrant lips 58. At the lower end of the channel-shaped member 54 a cover plate 60 is attached by cap screws 62 which pass through apertures in the lips 58. The upper end of the channel member 54 is reenforced by a bracket 64 which is also channel-shaped so as to fit inside the end of the member.
The height of the pallet 22 is adjusted by means of a channel-shaped leg extension 66 which telescopes into the bottom of the leg member 54. The lower end of the extension 66 is closed by an end plate 67 having apertured bosses 69 for securing the bench to the floor. The extension 66 is secured in adjusted position by four bolts 68, two of which pass through the front flange 56 of the leg member 54, the other two bolts similarly passing through the rear leg. The bolts 68 also pass through corresponding slotted apertures in the flanges of the extension 66 to engage nuts 70 (Fig. 5).
The angle members 50 and 52 are attached to the top of the channel members 54 either directly, as at either end leg, by bolts 71 which pass through the vertical flange of the respective angle member, the flange of the adjacent channel member and the end of the stiffening bracket 64; or as at the center leg by means of a threehole strap 72 which is secured to the channel member 54 by a bolt 74 passing through its center hole. Bolts 76 connect the strap 72 with the abutting ends of two angle members 52 (or 54). As can best be seen in Fig. 4, the rear angle member 54 has a longer vertical flange than the front angle member 52 so that the pallet 22 can he slid under the rear angle member and rest upon the top of the front angle member.
The service duct 24 at the rear of the work centers comprises a channel-shaped member 78 (Fig. 4) whose flanges have reentrant lips 80. The channel-shaped member 78 is formed in sections which are each as long as two adjacent pallets 22 and is supported in place by bolting to the rear angle member 54. To save valuable floor space the height of the channel member 78 is preferably made at least several times its horizontal width and the tubing and electrical conduits for the various services are installed by means of clamps (not shown), one above the other, as is best illustrated in Fig. 6 wherein one of the rear panels 82 has been removed. The panels 82 are secured at their lower edge by clips 84 and at their upper edge by screws 86 which engage the channel lips so that the panels are readily removable to allow the connecting and disconnecting of the flexible hoses from the Ts in the conduits such as 87 (Fig. 6). The opposite ends of each row of work centers is preferably finished by triangular end plates 88 secured to the end legs by cap screws 90.
The details of the conveyor 40 are shown in Figs. 7 to 9 wherein a continuous belts 92 passes upon the opposite sides of the horizontal web of a supporting frame or guide 94 which has an I-shaped cross section as is best shown in Fig. 9. The belt guide 94 is made up of a plurality of interconnected elements each of which has a length equal to the width of one pallet 22 so that the conveyor can be assembled to correspond to the overall length of a row of any required number of work centers by joining the required number of elements.
As is shown in Fig. 8, each guide element consists of a channel member 96 arranged with its web portion in ahorizontal plane and its flanges extending downwardly. Welded respectively to the channel flanges are two side pieces 98 whose width is greater than the width of the flanges so that the upper edges of the side pieces extend up beyond the top of the channel web. To give greater stiffness and stability to the guide 94 the side pieces 98 are offset or staggered with respect to the channel member 96 of each guide element so that the projecting end of each channel is interposed between the side plates of the adjacent member when in assembled position. The belt guide elements are maintained in assembled relationship by straps 100 which bridge the abutting ends of the side pieces 98 and are connected thereto by bolting.
The first and last frame elements are modified to receive the-belt motor M (Fig. 7) and the slack take-up device 102 (Fig. 8) respectively. To this end the side pieces 98' of the first frame element are extended the entire length of the channel and the projecting ends 5. notched, or recessed. to journal a. shaft 104 carryinga belt roll (not shown). The shaft 10.4 is connected with the speed reduction. unit of the. motor M which, is supported upon a shelf 106 welded to. thebottom of the end guide element. The projecting. ends. of the side pieces 98. of the last guide element are foreshortened and provided with horizontal slots to receive the shaft of a take up roll- 108 (Fig. 8);. The; roll 102 is biased outwardly by a spring 110.-wound around a rodof a clevis 112 whose arms engage the shaft on either side. of the roll. The clevis rod is guided by an. aperture in a, plate 114 extending between the side plates. 98", the. plate also acting as. the stationary seat for the spring 110.
The endless belt 92 is of such a length that it will pass around the driven and take-up rolls and lie above and below the web of the: guide. channelmembers 96. Any slack is taken up bythe spring biased roll 108 so that operation of the motor M causes the top of the belt 92'. to move past the successive work centers and thus act as a conveyor. To facilitate the loading and unloading of articles from the conveyor, certain of. the side plates .98 are. notched at appropriate locations to accommodate loading and. unloading chutes or ramps, 116 and 118. as shown in Fig. 9. The loading chute 1 16 consists of a channel member with its flanges extending. upwardly. One end of the channel is inserted in the notch in the side piece 98.. and its other end is raised by an upright 120 so. that any article deposited on. the channel slides downwardly onto the belt'92. The unloading chute is also formed of an upwardly facing channel with one end inserted in, a notch in the side piece 98; from which the chute inclines downwardly away from the belt 92. To cause an article being carried by the belt 92 to be deposited upon the chute, the further flange of the chute channel is carried arcuately across the belt in a direction opposed to the travel of the belt to engage the opposite side piece 98 so that an article carried by the belt engages the arcuate flange portion and is forced onto the chute down along which the article slides to a box or work surface.
In Fig. 13 are shown several article containers or hoppers 38 and 38' arranged in a semi-circle on the top of a pallet 22 at a work center which is being used to assemble the components held in the containers. It will be noted that because of their compactness and the small supporting area required, the containers can be conveniently grouped so as to save waste motion on the part of the operator.
As can be seen in Figs. and 11, each container 38 comprises a channel member 122 whose web and flanges form three sides of a rectilinear housing. The fourth side 124 of the housing is slidable in grooves 126 formed adjacent the reentrant edges of the flanges of the channel member 122. The top of the housing is covered by a cap 128 and the bottom by a declivous bottom piece 130 which extends angularly upward from the lower end of the slidable wall 124 to an intermediate location upon the opposed wall formed by the web of the channel 122 so that lifting of the movable wall permits the articles stored in the container to flow downwardly and outwardly under the influence of gravity when the housing is in an upright position.
To facilitate the discharge of articles from the container 38 a mounting foot 132 (Fig. 12) is screwed or otherwise permanently fastened to the pallet 22 or other work surface. The foot 132 has a declivous portion 134 which is proportioned so as to insert in the cavity formed beneath the bottom piece 130 and abut such piece when the container is lowered onto the foot. Formed integrally with the declivious portion 134 is a channel-shaped chute 136 whose flanges 138 converge to direct articles discharged from the container into a depression 140 in the channel web portion from which the articles can be readily taken by an operator.
A window for visually checking the number of components in the container is provided, preferably by making the entire movable wall 124 of a transparent material such as glass, but it is to be understood that a window could also be obtained by making all or part of any of the walls of a transparent or translucent material. To facilitate such a check, indicia marks 142 (Fig. 10) which are related to the normal hourly or daily rate of an operator are marked on the reentrant edge of the flange of the channel member 122. A holder 143 for a card bearing identifying data is attached to the front of the container.
Fig. 14 diagrammatically illustrates the manner in which the containers 38- facilitate the distribution of components to various work centers. Tote boxes 144 are provided which are proportioned to receive eight or ten containers. The tote boxes 144 in turn slide into a stock room rack 146 in a manner similar to a drawer. The stock room attendants fill the component containers 146 at any convenient time and store the loaded containers in tote boxes 144 placed in the rack, 146. Whenever components are required at. the production line a. tote box 144 is withdrawn and carried or transported to the appropriate work center. At the work center the container 38 is taken from the tote box 144 and dropped on the mounting foot 132 at the work center. As the container descends onto the foot 132 the tops of the flanges 138 engage the bottom of the movable wall 124 so that the wall is slid upwardly and the components descend down the chute 136 to the depression where they are picked up by the operator.
it should be understood that the present disclosure is for the purpose o-fillustration. only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims.
1. A manufacturing setup for the carrying out of a multiplicity of related operations comprising a plurality of rectilinear pallets having substantially the same dimensions, each of said pallets forming a respective work station and holding the tools used at the corresponding station; and one or more supporting frames for said pallets each including a pair of horizontal side members spaced to accommodate the width of said pallets and adapted to be aligned with the corresponding side members of the adjacent frames, the length of the side members being an integral multiple of the length of the pallets so that the members support the pallets in abutting end to end relationship, a channel member of substantially the same length as the rear side member attached respectively to each thereof with its web vertically disposed adjacent the rear sides of the pallets to form a backing therefor and a panel interposed between the flanges of the channel member to form a rectangular duct for the lines furnishing services, such as power, light and compressed air, to the tools carried by the pallets at the various stations.
2. A manufacturing setup according to claim 1 wherein the side members are of angular cross section, one leg of each of which is vertically disposed, the other legs being turned inwardly towards each other to form two spaced horizontal bearing surfaces upon which the pallets rest.
3. A manufacturing setup according to claim 1 wherein the supporting legs each comprise a vertically disposed channel whose web is approximately the same width as that of the pallets, a second channel telescoping within the first channel and means for adjustably securing the channels in their telescoped relationship whereby the height of the frame is variable.
4. A manufacturing setup according to claim 3 wherein the securing means for the channels include a plurality of fasteners with shanks which pass through the abutting flanges of the channels.
5. A manufacturing setup including a plurality of work station supports and a conveyor system for transporting articles to be manufactured at said plurality of work station supports comprising a belt conveyor including a plurality of elongated guide elements which are interconnected in end to end relationship, the guide elements have an I-shaped cross section, a continuous belt which runs on each side of the web of the I-shaped section lengthwise of the interconnected guide elements, a roller journaled respectively at each of the extremities of the interconnected guide elements about which the belt passes, power means for rotating one of the rollers to move the belt, and a supporting frame including a plurality of pairs of aligned horizontal side members between which the work station supports are located, each of the front side members being of approximately the same length and having a corresponding guide element attached thereto whereby the belt moves adjacent the work station supports.
6. A manufacturing setup according to claim wherein each conveyor guide element includes a channel member arranged with its flanges extending downwardly from its Web, and two side members attached to the respective flanges of the channel, the flanges extending upwardly beyond the top of the web so that the cross section of the conveyor is I-shaped.
7. A manufacturing setup according to claim 6 wherein the side pieces have the same length as the channel member but are longitudinally olfset with respect thereto so that the abutting joints of adjacent channel members are staggered with respect to the abutting joints of adjacent side pieces.
8. A manufacturing setup according to claim 6 wherein one or more of the side pieces are notched to accommodate loading and unloading ramps.
9. A manufacturing setup according to claim 6 wherein the loading ramp comprises a channel member arranged with its flanges extending upwardly with one end engaging the notch in the side piece, the member being tilted downwardly toward its notch engaging end so an article placed thereupon will slide onto the conveyor belt.
10. A manufacturing setup according to claim 6 wherein the unloading ramp comprises a channel member arranged with its flanges extending upwardly with one end engaging the notch in the side piece, and a transverse piece is provided which extends between the opposed side pieces adjacent the notch and immediately above the belt so that it shunts articles traveling upon the belt onto the ramp, the channel member being tilted downwardly from its notch engaging end so that articles shunted thereon will slide down the ramp away from the belt.
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