US831527A

US831527A - Vacuum can-sealing machine.

Info

Publication number: US831527A
Application number: US15352503A
Authority: US
Inventors: Julius A Landsberger
Original assignee: HERMETIC CLOSURE Co
Current assignee: HERMETIC CLOSURE Co
Priority date: 1903-04-20
Filing date: 1903-04-20
Publication date: 1906-09-18
Anticipated expiration: 1923-09-18

Description

PATENTED SEPT. 18, 1906. J. A. LANDSBERGER. VACUUM CAN SEALING MACHINE.

APPLICATION FILED APB-- 20, 1903.

4 SHBETSSHEET 1.

No. 831,527. PATEFITED sB'PTfiis, 1906.

J. A. LANDSBERGER'. VACUUM CAN SEALING MACHINE.

APPLICATION FILED APR. 20, 1903.

4 SHEETS-SHEET 2.

En11c3565 T611167 No. 831,527. PATENTED SEPT. 18, 1906.

A J. A. LANDSBBRGER.

VACUUM CAN SEALING MACHINE.

APPLICATION FILED APR. 20, 1903.

4 SHEETS-SHEET 3.

yon/9 5 0 f flw 6 a? M 6 mm v .1 00 L L No. 881,527. PATENTED SEPT. 18, 1906. J. A. LANDSBERGER.

VACUUM CAN SEALING MACHINE.

APPLIOATION FILED APR. 20 1903.

4 SHEETS-SHEET 4.

STATES rarer TWICE.

JULIUS A. LANDSBERGER, OF ALAMEDA, CALIFORNIA,. ASSIGNOR TO HERMETIC CLOSURE COMPANY, OF CHICAGO, ILLINOIS.

VACUUM GANG-SEALING MACHINE.

Specification of Letters Patent. J

Patented Sept. 18, 1906.

Application filed April 20. 1903- Serial No. 153,525.

To (1 7/ 1071 0721 it may concern:

Be it known that I, JULIUS A. LANnsBEn- GER, a citizen of the United States, residing at Alameda, in the county of Alameda and State of California, have invented a certain new and useful Improvement in Vacuum Can-Sealing Machines, of which the following is a specification.

Itis a common practice in one form of sealing cans," under which term is included cans, jars, and receptacles generally, to employ a vacuum-seal which ordinarily and in a general way is obtained by placing the can, with the cover and packing held in place by a spring-clamp, in a receiver from which the air is first exhausted and then readmitted. The cover by reason of the resiliency of the springclamps acts, in effect, as a valve, enabling the air to be removed from the can as the receiver is exhausted and preventing the roentrance of the air into the can when the air is readmitted, with the result that the cover is forced into tight contact by the pressure of the atmosphere, making an effectual hermetic seal. This method of sealing is obj ectionable in regard to the production of a perfect and uniform vacuum in eachinstance, the objection arising from the fact thatwith a heavy spring there must necessarily be a loss of vacuum equi valent to the pressure exerted by the spring-clamp, which would force the cover to place prior to the creation of a vacuum within the can corresponding to the vacuum in the receiver, and with a light spring for the clamp a comparatively higher or lower vacuum in the can than that in the receiver will be obtained, depending on the uniformity of the gasket and of the sealingsurface of the can and cover, both of which directly afiect the valve action of the cover. The result with a heavy spring would be a minimum loss of vacuum, dependent on the strength of the spring used, and with a light spring the resultant effect would be erratic and varying with the relationship of the memhere one to the other.

The primary object of my invention is to insure the same degree of vacuum within the can as that obtainable in the receiver, em-

ploying for this purpose mechanicallyoperated means which will at the sametime enable the sealing of the can to be quickly and economically attained; to enable the air to be sure applied to the cover of the can, so that the cover practically offers no obstruction to the free exit of the air from within the can, and when the air is exhausted from the can to then force the cover into tight contact by mechanical means located within the receiver and operated from the exterior of the receiver; to enable a cover with which is employed a solid compressible packing to have initially applied thereto a pressure materially greater than that of the atmosphere to force the gasket or packing to shape itself in con-,

formity to and with any irregularity of the can or cover, so that when the air is readmitted to the receiver a perfect air-tight oint is formed; to employ a mechanical presser located within the receiver and arranged to engage with and initially force down the cover and actuate it mechanically by means operative outside of the receiver; to govern andcontrol the movements of the presser in applying the cover to the can by means operating to aply the pressure at the particular moment and for Whatever duration of time may be desired, by which the principle of the invention is applicable to automatic machines generally; to govern and control the movements of the presserwithin thereceiver bya cam actuated by a foot or hand lever and so arranged and operated as to ap lygreat power with the application of but Tittle force on the lever or other actuating device to increase the efficiency of the devices for use with a composition gasket or packing by arranging a plate electrically heated or otherwise and operating to soften the gasket or packing, so that with the readmission of air into the receiver the softened gasket or packingwill be pressed closely against the can and cover; to regulate and equalize the application of the pressure from the mechanically-actuated presser on the cover of the can by interposing a resistance-spring, which can be regulated so as to control the pressure between the rod applying the power and the plunger or presserhead which applies the pressure to the cover, the spring having a fixed tension by which the application of a too great pressure or a more positive pressure than is requisite is prevented, which pressure might tend to break or deform the can or cover; to render the appliance suitable for different heights of cans by means of an adjustable plate raised null "r1 r1 1 .1 1- A 7 '1 ed stem operated from the exterior of the receiver; to furnish a supporting-plate and a resser-head both located within the receiver and between which the can is placed and to so arrange the plate and the head as to allow the cover to rise sufficiently for permitting the air to esca e freely from the can without any liability o displacing the cover; tomaintain the relative movement of the supporting-plate and the head down to a minimum in order to apply the proper pressure to the cover at the time and during the eriod required'to force the cover to place, and to automatically open and close the valve for controlling the production of the vacuum within the receiver and readmitting air into the receiver.

The accompanying drawings show machines having embodied therein the essential features of the invention, the machine shown being of a type operated by hand or foot levers as regards the movements of the mechanically-actuated presser within the receiverfor applying force to set the cover before readmitting air into the receiver; but

it is to be understood that the essential features of the invention can be applied to and are operative with power-actuated machines.

In the drawings, Figure 1 is a sectional elevation showing a simple form of construction and arrangement of the several elements entering into the machine as a whole;

tion shown in Fig. 2, a sectional elevation showing a modification in the arrangement of the 'plate on which the bottom of the can rests and the resser-head for forcing the cover tightly against the packing on the can after the vacuum has been produced in the can; Fig. 3, a side elevation of the cam and .lever for forcing down the. resser-head in the construcig. 1 Fig. 4, a side elevation of a modified construction, showing means for operating the controlling-valve for creating a vacuum and readmitting air, one of the means being carried by the door for closing the receiver, and showing also a controlling- .sprin'g against which the operating-cam acts; Fig. 5, a sectional elevation of the construction and arrangement shown in Fig. 4; Fig. 6, a frontelevation of the construction and Fig. 4.; Fig. -7, a side elevation of the receiver with the standard or sufpport therefor in section, showing a modi cation of the construction and arrange- I ment of means-for automatically opening and closing the-valve controlling the produc- .tion of a vacuum and the readmission of air into the receiver, said means'being operative from ayfoot lever or treadle which actuates the cam by which the resser-head is advanced,- an showing also means for automatically opening and closing the door from the vmovements of-the foot lever or treadle; Fig.

8, a sectional elevation of the receiver shown receiver or box a can and its cover.

down the cover on in Fig. 7-with the meansfor operating the controlling-valve for the vacuum and for read mitting air into the receiver; Fig. 9, a detail in cross-section of the valve for creating a vacuum and readmitting air into the receiver withthe reciprocating rod of Fig. 7 by which. the valve is turned; Fig. 10, an elevation of the head shown in Fig. 8; Fig. 11, a sectional elevation of the head of Fig. 10; Fig. 12, a detail showing the .02. having therein one-half of the socket for t e ball of the thrcaded'stem of Figs. .10 and 11; and Fig. 13, aplan view showing the construction oi'resistance-coil or rheostat.

The receiver or vacuum-box A is made of.

any suitable material and isconstr'ucted so as to be perfectly air-tight and .has on one side an opening a for placing within and withdrawing from the vacuum-chamber of the I One side of the box has a cover A with. apacking a to encircle the opening a and insure a tight joint around the opening when the cover is closed,-

and, as shown, the coveris attached by a suitable hinge a to the top of the box; but the cover could be otherwise hinged or attached. A. plate B, as shown in Fig. 1, is locatedwithin the chamber of and adjacent to the bottom of the box and is of a dimension to receive a can thereon and furnish a support for the can. The plate B, as shown, is carried by a screw-threaded stem B, passing through .a suitable stuffing-box b, so as to make an airtight joint around the stem, and the stem, as shown, .has a hand-wheel ,b, by means of which it can be turnedto raiseand lower the plate and locate the same in proper relation to the presser-head for thelength of can, and thus enable cans of diflerent heights to be placed between the resser-head and plate and operated upon in the vacuum-box.

The presser-head C or the head for pressing v the top of the can is constructed, as shown in Fig. 1, so as to be heated and has on its under side a circular rim or rib c to engage the cover and through the heat applied to the presser-head soften a composition packing within the cover to an extent suflicient to insure the compression of the packing and the firm seating thereof around the edge of the can andagainst the under face of the cover so as to fill any irre ularities between the' can and cover. 'Fhe presser-head C is carried by a support D,'having, as shown, a sidewall d, t readed onto the lower end of which is an angle-strip d, the horizontal portion of which forms a, rest fpr the presser-head when in the support, and

a stem or red E by means of an outer nut d and an inner nut (1 but other attaching means can be employed. The inner nut d as shown, engages or contacts an abutment c on the presser-head to force the presser-head down and, as shown, between the presserhead and its support D is a resistance-spring D, having suflicient force to furnish a cushion and prevent damaging, breaking, or otherwise injuring the can and cover from any quick, sudden, or hard or over depression of the presser-headI The stem E extends through a stuiling-box e, which forms a ti ht joint around the stem, and the upper endlof the stem E has thereon a head 6, between which and the stuiiing-box is a coiled spring E, which serves to return the support and the presser-head carried thereby to normal position after each operation of applying a cap or cover to a can.

A cam F is mounted on a shaft or rodf, supported in standards F, extending u from the top of the vacuum-box, and this cam F has a circular acting face f and an eccentric acting facef for the face f to engage with the head e when the parts are normal and for the eccentric acting face f 2 to engage with the head 6 and force down the presser head, and, if desired, the eccentric face f after the point where a downward movement of the presser-head should cease can be formed on a true circle, so that a further movement of the cam will not force the presser-head against the cap or cover. The cam in the construction of Fi 1 is turned by a handlever F but could be turned by any other suitable means, and the cam should be so formed and should be under such control as to apply great power with the exertion of but little force and to apply the pressure on the cover at the particular moment and for whatever duration of time may be required to seat the cover firmly in place and hold it there until the air is again readmitted to the vacuum-chamber.

A pipe G, having a shutoff valve g, is entered into the vacuunnbox in connnunication with the chamber thereof, and from the valve 9 a suitable pipe leads to a vacuumpump or an exhausted chamber, (not shown,) so that when the door A is closed a vacuum can be created in the vaccum-box and the can. A pipe H, having a shut-off valve 72, is entered into the vacuum-box in communication with the chamber thereof, and leading from the valve h is a nozzle or pipe in communication with outside air, so that at the completion of the vacuum and when the cover has been applied by the presser-head air can be admitted to the chamber with the presser-head holding on the can-cover by closing the valve g and opening the valve h for the admitted air to operate and by its own pressure hold the cap firmly on the can,

in creating a vacuum it will be understood that the valveh is to be closed. The arrangement shown. hasconductors I'ancl 1 leading from a dynamo or other source of electric energy, (not shown,) and these conductors are connected by wires 1' and i, respectively, with the binding-post of a resistance-coil or rheostat in the presser-head (J for the heat produced from the passage of the current through the resistance-coil or rheostat to heat the presser-head sufficiently to soften the packing, if so desired. i

The resistance-coil or rheostat employed is shown in one form of construction in Fig. 13. The wire I of the resistance-coil or rheostat is bent zigzag or sinuous, so as to run back and forth in a parallel series concentrically with the circumference of the presser-head, and in order to prevent the wire of the resistance coil or rheostat coming in contact with the metal of the head, which would short-circuit the current, the wires are embedded in a non-conductor 11 which may be plaster or other suitable material. One end of the zigzag wire of the resistance-coil or rheostat is attached by an insulated wire 2' with a binding-post i, to which is connected one of the wirest' or 2", and the other end of the zigzag wire of the resistance-coil or rheostat is connected by an insulated wire with a binding-post i, to which is attached the other wire i or 2", by which the conductors I and I are connected with the resist ance-coil or rheostat. It will be understood that the fine wire of the resistance-coil or rheostat is heated, as usual, by the resistance offered to the electric current, and'this heat in turn is transmitted to the non-conducting plaster in which the wire is embedded, and the plaster in turn contributes the necessary heat to the head for softening the gasket, as hereinbefore described.

The operation with the construction. of Fig. 1 is as follows: The plate B is raised or lowered to properly adjust the space between the plate and presser-head for the height of the can. A can when the door A is open is placed on the plate and the door A closed, tightly sealing the chamber of the vacuuml)OX. A vacuum is then created in the vacuum-chamber and at the same time in the can L, the cover L resting free on the top of the can, so as to rise for the air to escape from the can. At the completion of the vacuum the cam or eccentric F is turned for its eccen tric actirg face f to ez'igage the head e and force down the stem E, pressing the head C against the cover and carrying the cover down to contact at all points with the packing Z and force the packing closely against the top of the can, making a tight sealing of the can by the packing and the cap or cover, the cover shown having a depending flange Z to slip over the top of the can and hold the owing to the vacuum in the can, as usual, and l packing in place while the coverand packing ICC is-being pressed into position on the top of the can. When the ,cap or cover has been seated or carried down to the extent required for the production of a tight joint and with the presser-head still engaged with the cover, air is admitted to the chamber of the vacuum-box, breaking the vacuum for the ressure of the admitted air to vacuum-seal and tightly hold the cap or cover in place, after which the resser-head can be raised and the can withdrawn with the certainty that the cover will remain on the can and the can will be perfectly sealed. This machine enables a loose or slip cover to be applied to a can by and through mechanical pressure, the force for doing which is exerted from outside of the vacuum-box, and the cap or cover is applied without any impingement or binding of the flange of the cap or cover against the body of the can and with the assurance that the cover will be held firmly in place and vacuum-sealed onto the can.

The construction shown in Fig. 2 has the plate B, forming the shelf or table which carries the can, mounted on the end of a sliding stem B which stem passes through the stuffing-box b, and between the stuffing-box and a pin or flange b is a coiled spring b which serves to hold the lower end of the stem against the acting face of an eccentric or-cam I J, mounted on a ournal pin or pivot y and operated by a foot-lever J, so that by pressing down on the tread of the foot-lever the shelf or table can be raised to force the cover against a presser-head for the contact to press the cover with the packing therein tightly against the to of the can, so as to make a tight joint an seal the can, as described, for the construction of Fig. 1. The presser-head C in the construction shown in Fig. 2 is formed of a plate a and a cushion or yielding section 0 against which the cover of the can is brought into contact with the raising of the shelf or table. The resser-head C in the construction of Fig. 2 is carried by a screwthreaded stem E passing through a stuflingbox a and having a hand-wheel e, by means of which the stem can be turned to raise and lower the resser-head and bring it in proper relation to the movement of the can from the plate B to insure the coverbeing pressed down properly. The resser-head and the plate constitute, in efiect, the two members of a clamp, one of which is to be movable to engage the cover and press it to place on the can and the other one of which can be adjustable or stationary so long as the arrangement is such as to enable the movable member to be actuated outside of the vacuum-box and supply mechanical pressure to seat the cover. As shown in Fig. 1, the presser-head is movable and. the plate B is held in: a fixed posi* tion after it is adjusted, and, as shown in Fig. 2, the resser-head is'helcl in a! fixed position 6 so far as relates to the general construction and arrangement of the means for obtaining a mechanical pressure on the cover of the can is the same as the construction shown in Fig. 1, except as follows: The doorA is hinged at the bottom instead of at the top, and extending downwardly from the hinge is a rod a carrying a counterbalance-weight a for the door, so as to make, in effect, the door a balanced one. The cam F works against a crosshead E having at each end a slide e, moving on the standards or uprights F, and the crosshead has at its center a boss e encircled by a spring E the lower end of which surrounds the upper end of the stem E and contacts with an adjustable nut e on the thread of the stem, which nut when adjusted is held in place by a lock-nut 6 so that by adjusting the nut e the spring E can be more or less compressed, so as to furnish a resistance an a cushioning effect against operating the presser-head too quickly or with too hard a ressure and create damage. The door A has pivotally mounted thereon a shaft M, held in position by ears m and encircled between the ears by a coil-spring M, one end of which is fixedly attached to the shaft and the other end of which is attached to the door for the spring to have a back action or throw and return the shaft to the normal position. (Shown in Fig. 4.) The shaft has an arm m with a lateral extension m which lies clear of the plane of the edge of the door. The extension 'm of the arm of the shaft is arranged to engage an arm N, fixedly attached to a stem 9 of a controllingvalve hereinafter described, and the arm N has an extension n, to the outer end of'which is attached the end ofa pull-spring n the other end of which is attached to the side of the vacuum-box, sothat with the depression of the arm N by the engagement therewith of the arm of the shaft M the valve will be opened for the creation of a vacuum within the chamber of the box and will remain open as long as the arm of the shaft M is maintained in engagement to depress the arm the door closed the movement of the shaft is continued forwardly, ushing down the arm N and opening the va ve for the creation of a vacuum.

The valve is illustrated in detail in Fig. 9. This valve G is a three-way valve and consists of a shell or easing g, a cylindrical plug g within the-casing, the plug having a crossassage 9 running from which is a passage g, lieading to the exterior of the plug. Entered into a boss on the shell of the valve is a short tube G, which leads into the vacuu1n-cham ber of the box, and a pipe G is entered into a boss on the opposite side of the valve shell or casing, and this pipe is connected by a hose or other suitable means with an exhausted chamber or a vacuum-pump. The passage y when the plug of the valve is in the osition shown in Fig. 9, which is the norma position, communicates with a port 9 in the Wall of the valve, and the passage 9 communicates with a port g in line with the pipe G for admitting atmospheric air into the vacuumchamber to break the vacuum. The downward movement of the arm N turns the passages g and 9% out of communication with the ports 9 and g, respectively, and brings the passage 9 into communication with the ports 9 and 9 the latter of which is in line with the pipe G, establishing coinmunication between the chamber of the vacuumbox and the exhausted chamber or vacuumpump to create a vacuum in the chamber of the vacuum-box when the door A is closed. The construction of Figs. 4, 5, and 6 enables the valve G to be actuated when the door A is closed by causing the arm of the shaft M to depress the arm N and turn the plug of the valve to establish communication for creating a vacuum in the box, and with the release of the arm of the shaft by the operator the spring t returns the arm N to normal position, admitting air to the vacuum-chamber. This construction and arrangement makes the operation of the controlling-valve for creating a vacuum and admitting air dependent on the closing of the door and the will of the operator, and with this construction a single pipe is all that is required for both creating a vacuum and breaking a vacuum.

The construction shown in F i s. 7 and 8 has the movable member of the clamp in the plate B as in the construction of Fig. 2. The plate is carried by a stem B, around which is a coiled spring I), located between the stuffing-box and an adjusting-nut I), contacted by a lock-nut 6 both the nuts operating on the threaded end of the stem B so that by adjusting the nut more or less force can be given to the spring 5 in returning the plate B to normal position. The plate B is raised by the upward movement of a sliding stein B, the lower end of which is engaged by the acting face of the cam J, and between the stems B and B is a cushioning-spring b, engaged at its upper end with the nut b and engaged at its lower end with an adjusting-nut b heldwhen adjusted by a lock-nut 6 both nuts operating on the threaded end of the stem 13*, so that by adjusting the nut b the necessary resistance can be given to the spring I) for the prevention of an excess of pressure. The sliding stem B is supported in guides 1), extending out from a standard 0, on which the vacuum-box is mounted in the arrangement shown. The presser-head C of Fig. 8 in order to allow the head to be forced into contact with the cover of the can has its screw-threaded stem E terminating in a ball 6 entered into a socket e, one portion of which is formed in the top plate of a cap such top plate having therein a slot 0 leading from its periphery to the half-socket e in its under face, as shown in Fig. 12. The

' other half of the socket e" is formed in the upper face of a boss extending up from the top of the presser-head C, as shown in Fig. 11, and the cap (J is locked to the boss 0 by a bolt or screw 0 passing through .the side wall of the cap and entered into the boss. This ball-and-soeket connection of the actuating-stem E with the presser-head C enables the threaded stem to be rotated in either direction without rotating the resserhead, so that in advancing and reee ing the Presser-head the connection of the electriccurrent conductors I and I with the resistance coil or rheostat is non-affected by the movements of the presser-head. The construction of Figs.7 and 8 employs means for automatically closing the door and opening the controlling-valve G to create a vacuum with the raising of the shelf to bring the ar into position. The means shown consists of of a rod K, having in its body a slot It, into which projects a pin Ir on the end of an arm K, attached to the door at its hinging-point. The body of the stem at the slot K is surrounded by a spring le the lower end of which engages the end of the arm K and the upper end of which engages an adjustingnut it, held in place when adjusted by a locknut it, both nuts operating on a thread of the stem, so that by adjusting the nut is the required amount of force will be exerted by the spring for the downward movement of the rod K, which is attached to the foot-lever J to cause the spring to act on the arm K and close the door, the spring allowing of a continued downward movement of the rod K after the door is fully closed for such downward movement to open the valve G for the creation of a vacuum.

The upper end of the rod K has a springfork is, with a slot it, which slot receives the arm N, which operates the plug of the valve. The downward movement of the rod K causes the shoulders at the outer-end of the slot it to engage the arm N and turn the valve into position for the passage 9 to be in communication with the ports g and g and the rod K can be carried down sufliciently far for the forked end k to slip off the end of the arm N, when the spring vn will act, returning the arm N to normal position and o ening the valve G to admit outside air to t e vacuum-chamber and break the vacuum. This construction makes the closing of the door and the actuating of the controllingvalve for creating and breaking a vacuum automatic at the will ofthe o erator throu h the depression of the lever by which t e cam J is operated to raise the plate B, as with the initial upward movement of the plate the rod K, through the spring k will depress the arm K and close the door and with the further movement upward of the plate B with the door closed the arm N will be depressed to 0 en the valve for creating a vacuum before t e limit of upward movement of the plate is reached, by which the cover will be pressed onto the can from the engagement with the resser-plate, and when the cover is in place the arm N has been carried down to a point where its end will be passed by the end of the rod K in the further descent of the rod K, releasing the arm N from its engagement with the rod K and allowing the spring to act and return the arm N to normal position and admit air into the chamber of the vacuum-box to break the vacuum, so that with the release of the foot-lever the door can open and the jar, with the cover thereon vacuum-sealed, can

be removed. The spring-fork at the upper end of the rod K opens for the arm N to pass into the slot k as the foot-lever and the rod return to normal position.

It will thus be seen that with the construction of the machine or apparatus of the present invention a uniformity of operation is secured and the same degree of vacuum within the can is attained as is obtainable in the vacuum-box, enabling the cans to be vacuumsealedquickly and economically by mechanical pressure operative from the exterior of the box; that the air' is exhausted from the vacuum box or receiver before any pressure is applied on the cover of the can; that the cover of the can does not offer any obstruction to the free exit of the air from within the can; that mechanical pressure is applied to close the can after the vacuum has been created therein, and this pressure is maintained until after the atmosphere has been admitted into the vacuum box or receiver to break the vacuum; that the application of the pressure is mechanically obtained and is not dependent on the admission of the atmos here to force the cover into contact with t e can before readmitting the atmosphere into the top of the vacuum box or receiver proper; that a solid compressible packing can be softened, thereinsur' the close fitting of the packin or gasket to t e cover and can and also enabling the packingor gasket to shape itself so as to conform with any irregularities of the can or cover; that the control of the valve is placed ent upon the closing or the door'of the vacuum-box; that the application of the mechanical pressure 18 had trom the exterior of the box and is under controlling means, by which a sufficiency of pressure is all that is obtainable for use in setting the cover onto the can; that the pressure can be applied at the time required and for whatever duration of time may be necessary and no more; that a cushioning action is secured by which overpressure that might create damage will be overcome and prevented; that cans of different heights can be operated upon'by simply adjusting the parts of the clamp to suit the height of the can; that the members of the clamp can be brought into operative relation for the point of pressure to be in close proximity to the cover during the exhausting process, allowing the cover to rise sufliciently, howeverfr'or the escape of the air freely from the can and at the same time preventing the cover from rising so highas to become displaced, leaving close the cover onto the can by the application of the mechanical pressure at the proper 'time; that the relative movements of the members of the clamp in their relation one to the other can be maintained at aminimum and can be changed at pleasure, and that the operation of the several parts can be made automatic in the matter of causing the members of the clamp to approach each other, closing the door and operating the valve controlling the production of a vacuum and the admission of air to break the vacuum. All these features are found in the construction of the present machine and are desirable in the operation of vacuum can-sealing ma chines.

What I regard as new, and desire to secure by Letters Patent, is-

1. In a vacuum can-sealing machine, the combination with a vacuum-box having a chamber for the placement therein of a can having a loose cover to be vacuum-sealed on the can, of a resser-head within the chamber arranged to engage, press down, and apply the cover on the can, a stem carrying the presse -head and extending through. the box, a cam engaging with the end of the stem, a spring between the outer end of the stem and the box and encircling the stem, and means for turning the cam a predetermined distance to advance the head in applying the cover to the can, substantially as described.

2. In an apparatus for sealing receptacles in vacuo, a vacuum-chamber, a swinging door therefor, a valve for controlling the exhaustion of air from and admission of air to the said chamber, and means, carried by the door for operating said valve. 1

. under the will of the operator and is 'dependa minimum of movement to IIO 3. In an apparatus for sealing receptacles in vacuo, a vacuum-chamber, a swinging door therefor, a valve for controlling the eX- haustion of air from and admission of air to the said chamber and means, carried by the door, for controlling said door and operating said valve.

4. In an apparatus for sealing receptacles in vacuo, a vacuum-chamber, a door for the same, a valve for exhausting and readmitting air from and to the same, a lever for controlling the door, and a lever for opening the valve; the valve-opening lever being operated by the door-controlling lever.

5. In an apparatus for sealing receptacles in vacuo, a vacuum-chamber, a door for the same, a valve for exhausting and readmitting air from and to the same, a handle carried by the door for controlling the same, and a valveopening lever operated by said handle.

6. In an apparatus for sealing receptacles in vacuo, a vacuum-chamber, a door for the same, a valve for exhausting and readmitting air from and to the same, a valve-lever, and a handle journaled on the door for closing and opening said door, and adapted, after imparting the closing movement to said door to operate said valve.

7. In an apparatus for sealing receptacles in vacuo, a vacuum-chamber, a door for the same, a valve for exhausting and readmitting .the air from and to the same, a valve-lever, a

handle j ournaled on the door for closing and opening said door and having a movement of its own independently of the door; whereby after imparting a closing movement to the door the said handle can continue its movement and operate the valve-lever.

8. In an apparatus for sealing receptacles "in vacuo, a vacuum-chamber, a door for the same, a valve for exhausting and readmitting air from and to the same, a valve-lever movable in one direction for opening said valve and having a spring for moving it automatically in the other direction for closing said valve, a handle on the door for operating both said door and said valve-lever, and a spring for retracting said handle.

JULIUS A. LAN DSBERGER.

Witnesses:

' WALKER BANNING,

SAMUEL W. BANNING.