US2372755A

US2372755A - Impregnating apparatus

Info

Publication number: US2372755A
Application number: US458277A
Authority: US
Inventors: Walter P Abell
Original assignee: United Shoe Machinery Corp
Current assignee: United Shoe Machinery Corp
Priority date: 1942-09-14
Filing date: 1942-09-14
Publication date: 1945-04-03
Anticipated expiration: 1962-04-03

Description

April 3, 1945.

w. P. ABELI.

IMPREGNATING APPARATUS Filed sept. 14, 1942 4 Sheets-Sheet l April 3, 1945. w p ABELL 2,372,755

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IMPREGNATING APPARATUS Patented Apr..3, 1945 v IMPREGNATING APPARATUS Walter P. Abell, Quincy, Mass., assigner to United Shoe Machinery Corporation, Flemington, N. J., a corporation of New Jersey Application September 14. 1 942, Serial No. 458,277 zz claims. (ci. 91-46) The purpose of the present invention is to provide improvements in impregnating apparatus of the type in which power-operated mechanism is used to immerse the work in a liquid impregnant and to remove the work therefrom.

One of the features provided by the invention consists in means for regulating the depth of immersion of articles of work that require immersion of one portion but not of another. An example of this requirement is that of wetting or waterproofing the foreparts and shanks of unattached leather soles without immersing the heel seats thereof. To this' end the improvement under consideration includes a holder or container for supporting the work, power-operated mechanism for carrying the holder down and up, and adjustable means for arresting-the downward travel of the holder at any one of various levels without disturbing the carrying mechanism or modifying its range of action.

The invention also provides means for auto-` matically yreplenishing the liquid impregnant to' a predetermined initial level to counteract the quantities absorbed by the work. This replenishing means is capable of being regulated to vary the initial level above mentioned, and such regulation may also be used to vary the depth of immersion.

Still another improvement consists in a novel combination including the aforesaid power-operated mechanism, means for automatically interrupting the operation thereof, and timing means for restarting such operation at the conclusion of one or more measured intervals of dwell. This combination provides for giving the work one or more measured periods of dwell in the liquid impregnant with or without one or more measured periods of dwell out of the impregnant. For

tempering leather soles with water it is desirable to leave them in the water long enough to load their surfaces with water but not so long as to render their surfaces sodden, then to remove them from the water for a period long enough to enable capillary action to carry the water from their surfaces into the interior vof the leather, and in some circumstances to repeat such treatment as many times as may be necessary to condition the soles for the usual series of bottoming operations on welt shoes and McKays as practiced in shoe factories.

The features above mentioned and others hereinafter described are organized in the illustrated embodiment ofthe invention to lower and raise the articles of work within the conilnes of a treatment chamber in the upper portion of which warm water-vapor may be used-'to supplement the treatment effected by immer-sing the soles in water in the lower portion of the chamber. In this respect the apparatus may be used to practice the method disclosed by W. E. Phinney in Letters Patent of the United States, No. 2,348,413, grant; ed May 9, 1944.

Referring to the drawings,

Fis. 1 is a vertical section of an impregnating apparatus embodying the invention in a form designed for tempering unattached leather soles;

Fig. 2 is a horizontal section on a larger scale of the structure within the range of line II-II in F18. 1:

Fig. 3 is a vertical section of the apparatus in a plane at right angles to that of Fig. 1. The plane of Fig. 3 is front to rear, while that of Fig. 1 is side to side;

Fig. 4 is a vertical section on a larger scale of an operating connection otherwise represented in Fig. 3:

Fig. 5 is a top plan view of a mechanism for carrying the work into and out of a liquid impregnant and includes means for producing intermittent operation thereof;

Fig. 6 is a front elevation projected from Fig. 5, of timing means for interrupting and restarting the work-carrying mechanism;

Fig. '7 is a vertical section on a larger scale of the structure within ,the range of line VII-VII in Fig. 6;

Fig. 8 is a vertical section ofa valve mechanism intersected by line VIII-VIII in Fig. 7;

Fig. 9 is a sectional view of a relief valve in the plane indicated by the line IX-IX in Fig. '7;

Fig.`10 is an elevation of an assemblage cornprising two mercury switches for controlling electrical circuits;

Fig. 11 is an elevation of an individual mercury switch that operates in series with one of the switches represented in Fig. 10;

tank included in Fig. 3 and provided for the pur- 2 pose of replenishing the impregnating chamber with liquid impregnant;

Fig. 16 is an elevation of a counting unit by which all operation of the apparatus is stopped at the conclusion of a predetermined number of work-carrying cycles; and

Fig. 17 is a sectional view in the plane indicated by line XVII-XVII in Fig. 5.

Referring to Figs. 1 and 3. a metallic tank 20 and a domed cover 2i form a closed impregnating chamber 22 for holding a body of liquid impregnant 23. The tank is superposed upon a hollow base I9 that enclosesl a mechanism for moving the work up and down in the tank. 'I'he cover 2|.is connected to the tank 20 by hinges such as that indicated at 24 and the hinges are provided with

cooperative stop portions

25, 25 arranged to maintain the cover in an upright position when it is opened as far as it will'go:

For purposes of description but, not of limitation, it ywill be assumed that the apparatus is to be used for impregnating unattached leather soles with water in accordance with the usual requirements of shoe-bottoming operations in shoe factories. Proceeding on this basis, the tank 20 is of a size to accommodate a cage 21 for containing a suitable number of cases of soles 28 loosely tied with cords 29 to maintain them in stacked relation. To provide for immersing the foreparts and the Shanks of the soles in the water 23 without immersing the heel` seat portions, the soles will be stood on their toe ends as shown in Fig. 3.

To guide the cage 21 in the desired path, each v of the two side walls of the tank 20 is provided with a pair of vertical guiding strips 30 of L- section (see Fig. 2). These strips may be welded to the tank or secured thereto by rivets. The strips of each pair are spaced one from the other to form a guiding channel. Two blocks or shoes 3i are aillxed to the cage at diametrically opposite points near the top thereof (Fig. l) to run in the guiding channels, and two pairs of blocks or shoes 32 are afiixed to the cage near the bottom, but these are arranged to run on the outer surfaces of the strips 30 (Figs. 2 and 3) instead of running in the channel between the strips. Each channel is occupied by a vertically adjustable strip 33 having an inwardly projecting block 34 at its lower end and an outwardly projecting block 35 at its upper end. The blocks 35 project through vertical slots 36 in the tank. each ilanked by a pair of strips 31 welded to the outer surface of the tank. The blocks 34 constitute stops for the shoes 3i, but the blocks 35 serve as handles by which the blocks 34 may be adjusted up and down to varrest the descent of the cage at various levels. Each strip 31 is provided with a series of holes 38 to receive a pin 39 (Fig, 2) which may be inserted in any desired pair of holes. When the blocks 35 are located above the pins they will be supported by the latter. The stops 34 will be adjusted with due regard to the l length of the soles to be impregnated and with regard also to the level of the water and the depth of immersion desired.

The bottom ofthe cage comprises a series of slats 4| and a work-supporting grid 40 of coarse wire fabric resting on them. The slats are preferably arranged to prevent'spattering the soles with liquid when the cage is elevatedbut at the same time, they will permit vapor to rise through the bottom of the cage and to circulate freely between and around the soles.

To provide for heating the liquidI the tank 20 lzontal crosshead 64.

is provided with a series of electric heating units 42 (Fig. 3) encased in metal tubes 43 and arranged to be immersed in the liquid as shown in Fig. l. The open end of each tube 43 is fastened to a wall of the tank to form a water-tight joint. This wall is provided with openings i not shown) to receive electrical conductors by which current will be supplied to the heating units. The units are connected in parallel in a. circuit 44 that also includes a thermal regulator or switch 45 (Fig. 13). The thermal element 46 of this regulator is arranged to be immersed in the water 23 (Figs.

varying the maximum temperature of the liquid.

Figs. 3 and l5 illustrate means for automatically replenishing the liquid in the tank 20 as quantitics thereof are, used in the treatment of the work. y For this purpose a replenishing tank 50 is aiilxed to the rear wall of the tank 20. A pipe 5i provides communication between the tanks by which the liquid in both is maintained in equilibrium. Water under a suitable head is supplied to the tank 50 by a pipe 52 provided with a manually operable shutoff valve 53. The discharge of water into the tank 5U is automatically controlled by a ball cock 54 operated by a iioat 55. The lever 56 operated by the float is provided with a thumb screw 51 for closing the ball cock and for regulating the level at which it will be closed.

A mechanism for periodically immersing the soles in the water 23 is illustrated in Figs. 1, 3 and 5. It comprises an assemblage of gearing mounted in an open frame structure 53 of generally rectangular form in which bearings are provided for two crank

shafts

53, 59, two

countershafts

50, 60 and a driving shaft 6i. The adjacent ends of the shafts 59 are spaced one from the other and provided with

spur gears

62, 62 that carry at steel rings 63, 53. These rings are also spaced one from the Aother to provide a clear, unobstructed path for vertical movement of a hori- This head is aiilxed to the lower end of a plunger 55 that extends through a stuiiing box 66 formed on the bottom oi' the tank 20. The head 54 bears on the upper sides of two cooperative antifriction rolls 51, 61 (Fig. 4) carried respectively by the rings G3. The rings and rolls constitute a crank, although the rolls are arranged to travel in' individual paths to enable them to clear each other when the ring 63 are rotated in opposite directions. A strap 58 of steel is affixed to the ends of the head 641 (Fig. 1) and arranged to be engaged by the undersides .of the cranks to insure downward movement of the plunger 65 despite the friction due to compression of the packing in the stuffing box 66.

The

cranks

53, 61 are located and driven to operate in synchronism with each other but-they are driven in opposite directions at equal speeds. This duplex construction of the crank balances the forces applied to the head 64 at all stages and relieves the plunger 35 from bending strains that would be unavoidable if only one roll were used.

v-beit'u (Fig. a). This belt is driven by an electric motor provided with a driving pulley 18.

The upper end of the plunger 8l carries a spider 11 that provides a platform for supporting the cage 21. 4'I'he spider may be afllxed to the plunger 65 or to the cage 21 but not to both. because the stops 34 may be adjusted to arrest the downward travel of the cage before the plunger has reached the lower limit of its range of travel. Referring to Fig. 13. the motor 18 is included in an electrical circuit 18 that also includes a mercury switch 18 and a mercury switch 80 arranged in series. To characterize these switches by their functions. the switch 18 may be cony sidered theprimary or starting switch. and the switch 80 may be considered the interrupting switch by which the operation ofthe work-carrying means is to be periodically interrupted during a process of impregation. In Figs. 10 and 13 the primary switch 18 is represented in the-closed position while the interrupting switch 80 is represented in the open position in Figs. 3, 11 and 13. These are the positions they occupy when the operation ofthe work-carrying mechanism is temporarily interrupted at an lntermediatestage in a process of treatment. The primary switch 18 is closed manually and opened by automatic means, but the interrupting switch 80 is opened and closed only by automatic means.

The interrupting switch 80 is also represented in Fig. 3. It lis clamped in a holder 8| amxed to a' rockshaft 82 that has a range of angular movement indicated by a double-headed arrow In Fig. 12. An arm 83 secured to the rockshaft carries a trip latch 84 connected thereto by a pivot 85. The force of gravity of the parts carried by the rockshaft 82 is sufficient to rock the switch 80 to the closed position when the latch 84 is released from restraint. but Figs. 1l and 12 show how the switch is held in the open position by cooperation of a shoulder 86 of the latch and a pin 81 carried by another arm 88. This arm is one element of a power-operated mechanism by which the switch 80 is tilted from the closed position to the open position. The, arm 88 is affixed to a rockshaft 88 which also carries a finger 90. This linger is actuated twice in every workcarrying cycle to interrupt the operation of the motor I5v once when the plunger 65 is at or near its lowest| position and once when it is at or near its highest position.

For the purpose last mentioned, the frame 58 (Figs. 1 and 7) is provided with bearings for a vertically movable bar 9| that receives short downstrokes and upstrokes alternately from the head 64. The bar is normally Supported midway between its limits of travel by an arm 88 affixed thereto and a compression spring 82 surrounding the bar and seated on the lower bearing in which the barslides. The spring enables the bar to be depressed below and raised above its median position. In Fig. '1 the median position of the arm 93 is indicated by dotted lines and the correspending position of the lower end of the bar 8| is also indicated by dotted lines. The strokes of the bar are utilized not only to open the switch 80 but also to control a timing apparatus by which the switch is closed to restart the motor 15.

Again referring to Fig. 1, an arm 84 ailixed to the upper end of the bar 8Iis provided with a screw 95 to be engaged and raised by the head 84. The arm 84 has sliding engagement with a stationary pin 85,' the purpose of which is to prevent turning movement of the bar 8| about its own axis. For the purpose of depressing the bar ing IIT.

8| below its median position, the lowertend of the bar is provided with an arm 81- arranged to be engaged by the strap 88 aiiixed to the head B4.

Referring to Fig. 7, the upper portion of the bar 8I is provided with two oppositely inclined camming surfaces 88 and 98, each arranged` to displace a follower |00 to the left against the force of a tension spring 0| (Fig. 12) that 'nort mally pulls down the arm 88 and thereby presses rying mechanism permits the bar to return to its median position the arm 88 (Fig. '12) will be drawn down by the spring |0| but the next stroke of the bar in either direction will raise the arm 88 to the position represented in this figure, thereby rocking the interrupting switch to its open position.

The intervals of interruption in the operation of the motor 15 are measured by pneumatic vtiming means under control of the vertically movable bar 8|.' For this purpose a piston |05 (Fig. 12) is arranged to travel up and down in a pneumatic cylinder |06, the upper end of which is located adjacent to the trip latch 84 and is provided with a central vent |28. When the piston is at the upper limit of its travel, a pin |01 carried thereby projects through the vent to engage and actuate a rocker |08 mounted on the cylinder head and connected thereto by a pivot |08. This rocker is weighted to stand normally in the position shown in Fig. 12 but when it is actuated by the .pin |01 it displaces the trip latch 84 with a movement suiiicient to disengage the shoulder 88 from the pin 81. When this occurs, the switch 80 is tilted to its closed position by the weight of the elements carried by the rockshaft 82, with the result that the motor 15 is restarted. Almost lmmediately the bar 9| (Fig. 7) returns to its median position, thereby permitting the spring |01 (Fig. l2) to pull down the arm 88. Thepin 81 is thus carried to a level below the shoulder 86 of the trip latch, whereupon the force of gravity tilts the latch to place the shoulder in the path of the pin. The next upward movement of the pin returns the trip latch to the position shown in Fig. 12, the camming surfaces 88 and 88 (Fig.

'- 7) being effective alternately produce this result.

The piston |05 starts to descend at the moment when the arm 88 is pulled down by the spring Consequently, the trip latch has ample time in which to swing over the pin 81 before the next upward movement of the arm 88.

Referring to Fig. 3, air above atmospheric pressure is supplied by a centrifugal pump I I0 that receives rotation from an electric motor to which it is connected by a' belt II2 that runsl on a driving pulley |I3 and a driven pulley |I4. A pipe I I5 connected to the output side of the pump conducts air to a duct I I6 (Fig. 8) in a valve cas- This valve casing is afllxed to the frame 58 adjacent to the vertically movable bar 8|. Two horizontal ducts I I8 and I I8 receive air from the duct IIB and they deliver the air to two individually adjustable needle valves |20 and |2|, but at points between the supply duct lI I8 and the needle valves the flow of air through the ducts The follower slides in a bore in the bearl H8 and ||9 is controlled by individuallly movable slide valves |22 and |23. These valves are normally closed by springs |24 but they are both closed at the same time only when the bar 9| stands in its median position. The valves |22 and |23 are aligned with each other and when both are closed the gap between their adjacent ends is just equal to the thickness of a portion of the arm 93 that projects between them. In Fig. 8 the arm 93 is at the upper limit of its range of travel, and the valve |22 is thereby shifted to its open position to permit air to flow to the needle valve |20. Under these conditions the valve |23 is closed to prevent air from ilowing -to the needle valve |2|. On the other hand, when the arm 93 is depressed to its lowest position, represented by dotted lines in Fig. 8, it will open the valve |23 while the valve |22 remains closed.

The needle valves |20 and |2| vregulate the quantity of air `that may flow through branches |26 and |26 of a common feed pipe connected to the lower end of the pneumatic cylinder |06. A

A diagrammatic representation of these pneumatic elements is provided in Fig. 14.

The piston has a close but easy running fit in the cylinder |06 to enable the force of gravity to return it to the lower end of the cylinder whenever the column of air below itis released. Since the air supply is Aconducted alternately through two branches, each having an individual needle valve, the latter may be adjusted to produce unequal rates of upward travel of the piston |05. For this purpose the needle valves are provided with handles |21 and |28. Consequently, it isl possible, for example, by adjusting the needle valves, to produce a dwell of four minutes of the work-carrying mechanism when the work is out of the liquid and a dwell of only two minutes when the work is in the liquid.

Referring to Figs. 3 and 14, the pump ||0 supplies air also through a pipe |33, a portion of which is in the form of a coil and is located in the tank '20 below the heating units. Many small perforations are provided in the coil and are represented by dots in Fig. 14. These perforations emit small jets of air in the water 23 to amplify the output of lvapor from the water. The air forced through the pipe |33 is obliged to ow through a valve |34 which is normally closed by the force of gravity and arranged to be opened by the pressure of air. This valve insures a sufficient pressure in the cylinder |06 to operate the piston |05 but enables all the available supply of air not delivered to the cylinder to escape in the water 23. Consequently, the soles in process of treatment will be subjected alternately to immersion in the water and to intermediate stages of treatment with water vapor when the cage 21 is out of the water.

The motor for driving the air pump is '-.lcluded in an electrical circuit |35 that also includes a mercury switch |36. This switch remains closed throughout a process of treatment, irrespective of the number of work-carrying cycles included in a course of treatment. In this respect, the duty of the switch |36 is like that of the primary switch 19 in the circuit that includes the motor 1-5. Accordingly, the'switches 19 and |36 are both secured in a common holder |31 (Figs. 1, 5 and 10). This holder is affixed to a horizontal rockshaft |36 and is controlled manually to initiate a run of the apparatus but is operated by a counting unit to open both of the circuits 18 and |35 at the conclusion of a 'predetermined number of work-treating cycles.

Referring to Figs. 1 and 16 the casing of the counting unit |40 encloses a ratchet wheel of which a few of the ratchet teeth are indicated at |4|. This ratchet wheel is located behind an adjustable dial |42 capable of being turned manually to any position according to the number of work-carrying cycles desired in a run of the apparatus. The ratchet wheel is advanced one tooth foreach work-carrying cycle of the apparatus. A pawl (not shown) for operating the ratchet wheel receives its operating motion from upward movement of a rod |43. The lower end of this rod is connected to a rocker |44 mounted on a fulcrum pin |45 and provided with an arm that stands in the path of the vertically movable head 64. A spring |46 normally pulls down this arm of the rocker |44 to raise the rod. |43 when the head 64 starts to descend from its highest position, but the operating pawl is shifted to another tooth of the ratchet wheel at the conclusion of each upward stroke of the head 64.

' Assuming that the dial |42 has been adjusted to provide for four work-carrying cycles, the mechanism last described will advance the ratchet wheel three steps without producing any the head 64 begins its next down stroke the ratchet mechanism will depress a rod |41 to stop both motors 15 and while the Work is still a considerable distance above the water 23. The lower end of the rod |41 is connected to an arm |46 affixed to the'rockshaft |38 (see Figs.,5 and 10). Referring to Fig. l, a torsion spring |49 is arranged to hold the arm |49 normally in a position to maintain the switches 19 and |36 in` their closed positions (Figs. 10 and 13) but the force of thisk spring is inferior to that of the spring |46 which, at the conclusion of a run, furnishes the power for rocking the switches to their open positions.

The described control .and operation of the switches 19 and |36 insures a stage of treatment withl vapor after the final stage of immersion in the liquid but before operation of-the air pump is stopped.

When the apparatus has been stopped as last described, an attendant may open the closure 2|, remove the treated soles, replace them with untreated soles, return the closure to its closed position and initiate another course of treatment by depressing a trigger |50 (Fig. 16)'that has a short range of travel in a slot |5| in the casing of the counting mechanism. This trigger retracts the operating pawl and a retaining pawl from the ratchet wheel which, upon being released, is returned to an initial position by a The wiring diagram represented ,in Fig. 13 includes feed" wires |51*l yfor supplying current to the circuits M, 18, and |35. lThis figure also in'- cludes a double-pole switch |53 operable manually to connect the source' of -current with the three circuits described. Since the circuit 44 is automatically controlled by a thermo-regulator itis not Vnecessary to disconnect this circuit from the source of current except when the' apparatus is to be out of use for long periods of time. Under these circumstances, the manually operable switch |53 will serve to disconnect the circuit ,44.

Having thus described my invention,y what I claim as new and desire to secure by kLetters Patent of the United States is:

l. An impregnating apparatus comprising a tank for holding a body of liquid impregnant,v

means for carrying work into and out of the liquid, a motor for operating said carrying means,

means operable by said carrying means for stopping the motor, and timing means controlled by the carrying means for restarting vthe motor at the conclusion of' a measured interval of` dwell of the carrying means.

2. An impregnating apparatus comprising a tank for holding a body of liquid impregnant, means for carrying work into and out oi the liquid, a motor for operating said carrying means, means operable by said carryingmeans for stopping the motor when the work is in the liquid and again when it is out of the liquid, timing means controlled by the carrying means, means controlled by the timing means for restarting the motor'after an interval of dwell following each such interruption thereof, and adjustable means for regulating the timing means to determine the duration of the intervals of motor interruption.

3. An impregnating apparatus comprising a tank for holding a body of liquid impregnant, a motor, means operable bythe motor for carrying the work into and out of the liquid repeatedly, manually operable means for starting the.

motor, means operable by the carrying means for stopping the motor at the conclusion of each cycle of carrying movement, and timing means controlled by the carrying means for restarting the motor after measuring the duration of the intervals of motor interruption.

4. An impregnating apparatus comprising a tank for holding a body of liquid impregnant. a motor, repeating means operable by the motor for carrying the work into and out of the liquid,

counting means operable by the carrying-means to count the carrying cycles thereof, means operable by the mounting means to stop the motor at the conclusion of a predetermined number of carrying cycles, means operable by the carrying means for interrupting the motor at intermediate stages in a run of the counting means, and timing means for restarting the motor after measuring the duration of the intervals of such motor interruption.

5. An impregnating apparatus comprising a tank for holding a body of liquid impregnant. a motor, repeating means operable by the motor for carrying the work into and out of the liquid, means operable by the carrying means` for interrupting the motor twice in each carrying cycle, once while the work is in the liquid and once while out of the liquid, timing means for. restarting the motor after measuring the duration oi' the intervals oi' such motor interruption, and

adjustable means for regulating the duration of f alternate intervals without ailecting the duration oi' the other intervals of motor interruption.

6. An impregnating apparatus comprising a tank yfor holding a body oi' liquid impregnant. an electrical circuitincluding a switch and a motor controlled thereby, means operable by the motor for carrying the work into and out of the liquid, means operable by the carrying means i'or opening the switch at a predetermined point inthe carrying cycle, and timing means controlled by the carrying means for closing said switch after measuring the duration of an interval of motor interruption. i

` 7. An impregnating apparatus comprising. a tank for holding a body of liquid impregnant, an electrical circuit including a switch and a motor controlled thereby. means operable by the motor for carryingthe work into and out ofthe liquid, repeating means operable by .the carrying means twice in each carrying cycle for opening the switch, once when the work is in the liquid and once when out of the liquid, and timing means controlled by the carrying means for closing said switch after measuring the duration of eachinterval of motor interruption produced by said switch.

8. An apparatus as defined in claim 7 in which the electrical circuit also includes a primary starting switch in series with the switch rst mentioned, and counting means operable by the carrying means for opening the primary starting switch at the conclusion of a predetermined number of carrying cycles.

9. An impregnating apparatus comprising a tank for'holdlng a body oi liquid impregnant, a work-supporting cage, power-operated mechanism for carrying the cage into and out of the liquid, and stationary means arranged to arrest downward travel of the cage at any one of a plurality of levels above the lowest level in the range of said carrying mechanism without arresting the latter.

10. An impregnating apparatus comprising means forming a treatment chamber and a replenishing chamber in communication with each other for holding a liquid impregnant in equilibrlum, means including a ball cock in said replenishing chamber for supplying the latter with liquid toa minimum level, means movable down and up in said treatment chamber for carrying work into and out of the liquid, power-driven means for lowering and raising said carrying means, and adjustable means arranged to detain said carrying means at a variable level while said lowering and raising means continues through a portion of its cycle.

11. An impregnating apparatus comprising means forming a treatment chamber and a replenishing chamber in constant open communicatlon with each other for holding a liquid impregnant in equilibrium, meansincludinga ball cock in said replenishing chamber for supplying the latter with liquid to a minimum level, means movable down and up in said treatment chamber forcarrying Work into and out of the liquid, means for operating said carrying means, and means for emitting air under pressure in the liquid in said treatment chamber.

12. An impregnating apparatus comprising.

means forming a treatment chamber and a replenishing chamber in communication with each uid to'a minimum level, means movable down and up in said treatment chamber for carrying work into and out of the liquid, means `for operating said carrying means, and adjustable means arranged to arrest and detain said carrying means at a minimum level without arresting said operating means.

13. An impregnating apparatus comprising means forming a closed treatment chamber, means for supplying warm water vapor to the upper part of said chamber while a body of water is maintained in the lower part thereof, means for carrying work into and out of the water in said chamber, a motor for operating said carrying means,v means actuated by said carrying means to interrupt the motor when the work is out of the liquid, and timing means controlled by the carrying means for restarting the motor at the conclusion of a measured interval of motor interruption.

14. An imprcgnating apparatus comprising means forming a closed treatment chamber forA enclosing a body of water and a vapor space above it, an electrical circuit including a motor, an air pump driven by said motor, an air conduit arranged to conduct air under pressure from said pump and emit it in said body of water, means for carrying work into and out of said body of water, an electrical circuit including a motor for operating said carrying means, means operable by said carrying means for counting the carrying cycles thereof, and means controlled by said counting means for opening both of said circuits at the conclusion of a predetermined number of carrying cycles.

15. An impregnating apparatus as defined in claim 14 in which the electrical circuit for cooperating with said carrying means includes an individual switch for interrupting the motor in that circuit, and timing means controlled by said carrying means for' closing said individual switch after measuring the duration of the intervals of motor interruption.

16. An impregnating apparatus comprising means forming a closed treatment chamber for enclosing a body of water and a vapor space above it, an electrical circuit including a switch and a motor controlled thereby, means operable by said motor for carrying work into and out of the water in said chamber, means operable by said carrying v means for opening said switch, pneumatic means for supplying air above atmospheric pressure in said body of water to produce bubbling thereof, timing means operable by air from said pneumatic means for closing said switch after measuring the duration of an interval of circuit interruption, and means operable by said carrying means for opening and closing communication between said pneumatic means and said timing means.

17. An impregnating apparatus comprising a tank for holding a body of liquid impregnant, an electrical circuit including a switch and a motor controlled thereby, means operable by said motor for carrying work into and out of the liquid in said tank, means operable by said carrying means for opening said switch, pneumatic timing means for closing said switch after measuring the duration of an interval of circuit interruption, a pump for supplying air above atmospheric pressure to said timing means, another electrical circuit including an individual motor for driving said pump, means operable by said carrying means for opening and closing communication between said pump and said timing means, means operable by said carrying means for counting the carrying cycles thereof, and means operable by said counting means for opening both of said circuits.

18. An'impregnating apparatus comprising a tank for holding a body of liquid impregnant, a vertical plunger extending through the bottom wall of the tank and having a bearing therein, work-supporting means arranged to be reciprocated verticallyv in the tank'by said plunger, mechanism located under the tankfor reciprocating the plunger, and adjustable means in the tank for arresting the downward travel of said work-supporting means at various points in its maximum range afforded by said mechanism.

.19. An impregnating apparatus comprising a tank for holding a body of liquid impregnant,` a vertical plunger extending through the bottom wall of said tank and having a bearing therein, work-supporting means arranged to be reciprocated vertically in the tank by said plunger, two cooperative cranks of equal throw arranged below said tank, means for driving said cranks in synchronism but in opposite directions, and a crosshead secured to said plunger and engaging said cranks to be carried up and down thereby.

20. An impregnating apparatus comprising a tank for holding a body of liquid impregnant, a work carrier movable up and down in the tank, power-driven mechanism by which said carrier is successively reciprocated and detained in a predetermined elevated position in the tank, poweroperated means by which said mechanism is periodically stopped when said carrier is in said elevated position, and timing means by which said mechanism is restarted after an interval of predetermined duration.

2l. An impregnating apparatus comprising a tank for holding a body of liquid impregnant, a work carrier movable up and down in the tank,

power-driven mechanism by which said carrier is reciprocated and detained alternately in a predetermined elevated position and a predetermined lower position through individual periods of dwell, means operable by said mechanism for stopping the latter when said carrierv is in either `of the two positions specified, and timing means by which said mechanism is restarted in each of its stopping positions after an interval of predetermined duration,

22. An impregnating apparatus comprising a tank ior holding a body of liquid impregnant, a work carrier, a crank by which the work carrier Yis moved up and down in the tank, an electrical circuit including a motor, transmission means driven by the motor for rotating thecrank, means operable by the crank for opening said circuit twice in each cycle thereof, timing means controlled by/the crank for measuring the duration of each interval of circuit interruption, and means controlled by the timing means for closing the circuit.

WALTER P. ABELL.