US3101838A

US3101838A - Vent control

Info

Publication number: US3101838A
Application number: US162852A
Authority: US
Inventors: Boulay Edward Alphonse
Original assignee: Individual
Current assignee: Individual
Priority date: 1961-12-28
Filing date: 1961-12-28
Publication date: 1963-08-27
Anticipated expiration: 1980-08-27

Description

E. A. BOULAY VENT CONTROL Aug. 27, 1963 2 Sheets-Sheet 1 Filed Dec. 28, 1961 INVENTOR. BEYDWARD A. BouLAY ATTORNEY Aug. 27, 1963 E. A. BOULAY 3,101,833

VENT CONTROL Filed Dec. 28, 1961 2 Sheets-Sheet 2 lhl. :7 H 23 A\ l I F IG. 3

INVENTOR.

EDWARD A. BOULAY ATTORNEY United States Patent 3,101,838 VENT CONTROL Edward Alphonse Boulay, Concord, NH. Filed Dec. 28, 1961, Ser. No. 162,852 8 Claims. (Cl. 199-32) This invention relates to a vent control, and more specifically to a vent control device for use in a slug casting machine.

In a slug casting machine such as the Linotype or Intertype the matrices are assembled on the assembly elevator with the spacebands for the, line of type, from which they 'are lifted and transferred to the casting elevator for presentation to the molding apparatus. The transfer mechanism includes a delivery slide which is movable laterally to deliver the matrices and spaceband's to the casting elevator, and two control fingers which are preset to establish the length 'of the type line. The movement of the delivery slide is rapid and his arrested at the end of its stroke by an air cylinder or dash pot. However, the vent of the cylinder is suficient only to prevent the buildup of pressure therein which would prevent operation of the delivery slide, and does not control the abrupt halting of delivery slide motion at the end of the stroke. It is this abrupt stop which causes the long finger to jump out of engagement with the line of matrices and spacebands when said line is 'a short one and the finger stops before engagement with its stop device. Hence some of the matrices will at times be caused to drop out of the line being transferred as the finger moves out of engagement at the end of a stroke.

It is therefore a main object of this invention to provide apparatus for the absolute control of the motion of the delivery slide in a slug casting machine.

It is another object to provide regulatory means for the motion of the delivery slide wherein the control may be adjusted.

A further object is to control the motion of the delivery slide and arrest such motion incident only to conditions when such motion is excessively rapid.

A further object of this invention is to provide a multiple stage automatic control over the operation or the arresting cylinder in a slug casting machine.

Another main object of this invention is to provide apparatus for controlling the venting of fluid pressure from a dashpot.

Other objects and advantages will become apparent from the following detailed specification.

In carrying out these and other objects there is provided a vent control for a fluid pressure cylinder comprising a casing defining a chamber in communication with the cylinder, a primary vent from the chamber, 'apiston slide in the chamber operable to open or close the primary bent, and a secondary vent opposite one end of the piston slide for controlling the movement of the piston slide ,in the chamber.

In the drawings: I

FIG. 1 is a fragmentary perspective view of the delivery slide apparatus of a slug casting machine and such devices incident to the operation of the delivery slide.

FIG. 2 is anenlarged longitudinal sectional view of a vent control according to this invention, the vent being in the closed position.

FIG. 3 is an enlarged longitudinal sectional view similar to FIG. 2, showing the vent control in the open position.

FIG. 3 illustrates the delivery slide mechanism of a line casting machine. It is to be understood that the mechanism is normally mounted in the face plate of the machine (not shown) and in position over the assembly elevator in which the matrices are conveyed from their magazines in response to actuation of a keyboard. The

3,101,838 Patented Aug. 27, 1963 matrices and spacebands (not shown) are then carried by the delivery slide mechanism to the casting elevator, thence to the casting and molding mechanism of the machine. The delivery slide comprises two line engaging fingers designated herein as the long finger 39 and the short finger 40 which 'are assembled on the slide bar 44. The fingers 39 and 40 are spaced along a notched adjusting rod 42, and a latch 43 is movable into and out of the notches in the rod 42- to lock the long finger 39 at any predetermined point along the rod 42 The slide bar 44 is mounted for movement in a lateral direction so as to be carried by blocks 41. During the delivery stroke of the slide bar 44, the bar moves to a point where it is stopped by the stop 34, which is mounted on the face plate of the machine (not shown). A delivery lever .36 is connected to the slide bar 44 by means of link 38 for actuation of the slide bar 44. The other end of the lever 36 is connected to a shaft 35. Spring 37 is connected to the shaft 35 for turning same to act upon the lever 36.

Also connected to the shaft 35 is a link 33, the end of which is fastened to the end of a piston rod 32 of piston 31. The piston 31 is disposed in an air cylinder 30 or dashpot. This cylinder 30 acts as a speed arrester for the motion of the delivery slide bar.

During operation, release of the delivery slide mechanism permits the spring 37 to turn the shaft 35 and thus move lever 36 against line 38. The line 38 operates the slide bar 44 toward the stop 34, carrying a composed line of matrices and spacebands which are held by the fingers 39 and 40. It is to be understood that the composed line (not shown) will be engaged first by the short finger 40 during movement of the delivery slide bar 44 and is thus moved into engagement with the long finger 39, the whole thence being moved toward the viewers left. The motion of the delivery slide is normally rapid, and it is the function of the cylinder 30 to arrest this rapid motion by building up air pressure therein before the delivery slide reaches the stop 34. The conventional vent in the cylinder 30 can be adjusted to permit a gradual increase of pressure, which will not prevent the slide bar 44 from striking the stop 34 hard enough to cause some of the matrices to become dislodged from the composed line. Conversely, the vent can be adjusted so as to prevent the rapid enough and efiicient motion of the slide bar 44. Should the slide bar 44 not transfer properly due to the vent being too small, a following line of matrices and spacebands can enter the assembly elevator before the completion of the delivery cycle. Moreover, it will be apparent that the motion of the delivery slide mechanism will be very rapid during the initial part of the stroke until buildup of sufiicient pressure within the cylprises a casing 11 defining a chamber 12 therethrough.

An adapter 13 is fastened in one end of the casing 11 as by screw threads, and the other end of the adapter 13 is threaded into the end of the cylinder 30. An inlet 14 is provided through the adapter .13 to the chamber 12. A primary vent 15 is formed through the side of the casing in communication with the chamber 12, thence in communication with the interior of the cylinder 30. A slide valve 16 is substantially freely disposed within the chamber .12, and is shaped to conform to the shape of the chamber 12, being of nearly the same dimension.

In the outer end of the body 11 is disposed a knob 19 having a long threaded shank 20. Mating threads are formed in the Wall of the chamber 12 to receive the shank 20 of knob .19. A second chamber 21 is formed through the knob 19, and a scondary vent 22 is formed between the chamber 21 and the atmosphere. An adjusting screw 23 is disposed in the end of the chamber 21 to a point to control the size of the opening from the chamber 21 to the secondary vent -22.

Depending from the slide valve 16 is a small piston 17. The size and cross section of the piston 17 are complementary to that of the chamber 211 formed in the knob 19, so as to form a close sliding fit of the piston 17 in the chamber 21 similar to that of the slide valve 16 in the chamber 12. A spring 118 is disposed around the piston 17 to urge the piston and slide valve to the viewers right in FIG. 2, which is toward the closed position of the vent control. By a comparison of FIGS. 2 and 3 it will become apparent that the knob 19 may be adjusted longitudinally by means of its threaded shank 20 within the chamber 12 to preset the distance of maximum travel of the piston 17 to the viewers left, or toward the open position of the vent control. This adjustment of the knob 19 controls the degree to which the slide valve 16 will uncover the primary vent 15 to permit the escape of fluid pressure therethrough.

Adjustment of the screw 23 controls the size of the opening from the second chamber 21 to the secondary vent 22, thus controlling the degree to which air or fluid pressure in the chamber 21 may be forced through the secondary vent 22 during movement of the piston 17 toward the left, or open position. Fluid pressure entering into the chamber 12 from the inlet 14- moves the slide valve similar to a piston, and against the urging of the spring .18.

The operation of the vent control according to this invention is as 'follows: It is to be assumed that this vent control has been installed in communication with the interior of the cylinder 30 by means of the adapter 13 as shown in FIG. 1, and that all adjustments of the knob 19 and the screw 23 have been made, and that the delivery slide of the machine is about to begin a new cycle of delivering a composed line of matrices and spacebands to the casting elevator. Thus, all pants of the apparatus are in the relative positions as shown in FIGS. 1 and 2.

As the delivery slide apparatus is released for transfer motion, the power of spring 37 operates the lever 36 to move the slide bar; and also operates lever 33 and piston rod 32 of the cylinder 30. This action causes the piston 31 of the cylinder 30 to move upwardly, increasing the fluid pressure in the cylinder.

A slight increase in pressure in cylinder 30 is communicated through the inlet .14 to the chamber 12 in the vent control body 1 1. Due to the relatively smaller size of the chamber 12 with respect to that of the cylinder 30, only a slight movement of the piston 31 is required to operate the vent control 10. However, due to the rapid movement of the delivery slide by the spring 37, the buildup of pressure in chamber 12 is severe, causing a quick starting movement of the slide vent .16 and piston 17 toward the left, or open position. Since the second chamber 21 is substantially smaller in size than the chamber 12, an even more rapid and severe increase of pressure occurs in the chamber 21 to arrest the initial motion of the slide valve 16 and piston 17.

The initial arrest or slowing down of the slide valve 16 prevents any great escape of fluid pressure through the primary vent 15. The fluid pressure in the cylinder 30 is merely relieved to some extent by expansion into chamber .12. Simultaneously, the gradual escape of fluid pressure through the secondary vent 22 permits the piston 17 to move slowly to the left, also moving the slide valve 17 to slowly uncover more of the primary vent 15. This gradual opening of the vent 15 occurs in direct proportion to the increase of fluid pressure within the cylinder 30, and thus serves to provide a constantly proportionally controlled venting of said fluid pressure.

When the piston .17 reaches its maximum stroke to the left, as governed by the position of the knob 19 in the end of the chamber 12 of the body 11; the primary vent 15 is opened to the degree required for the proper venting of the cylinder 30 incident to the desired speed of the delivery slide apparatus in delivery of a line of composed matrices and spacebands. At this time, the piston 17 and slide valve 16 are in the relative position illustrated in FIG. 3. It will be understood that the complete operation of the vent control 10 takes place in a very short time. However, the following advantages are inherent in this improvement:

Firstly, the vent control 10 according to this invention permits a very rapid buildup of fluid pressure in the cylinder 30 due to the primary vent being closed. Secondly, the rapid increase of pressure in the cylinder 30 means that the least possible movement of the delivery slide bar 44 is required to gain the necessary fluid pressure in the cylinder 30 and its vent control '10 to achieve complete control over the motion of the slide bar 44. Third, the initial motion of the delivery slide bar 44 may be controlled. This is achieved through the adjustment of the screw 23 in the vent control knob 19. Fourth, the overall speed of the delivery slide bar 44 may be precisely controlledi This is achieved through the adjustment of the slide valve travel by the position of the knob 19 in the end of the body 1 1,-thus regulating the size of the opening from the chamber 12 past the slide valve 16 to the primary vent .15. Fifth, the acceleration of the slide bar 44 is controlled to be gradual, resulting in a gentle rather than an abrupt stop of the slide bar 44 against the stop 34 summarily, the invention contemplates an improvement to all dashpot construction involving the need for a controlled venting of fluid pressure from a chamber or the like. The invention, in its broader aspects provides for the control of venting where the resistance to the escape of pressure is propontional to the rate of increase of the pressure. The fluid pressure does not escape through the movable member of the vent control, or past the movable member; but merely travels to the member to actuate same. Because of the regulatory feature of the secondary vent, the main or primary vent is controlled proportional to the increase of pressure since a more severe increase of pressure will aflect the movement of the slide valve 1 6 the same as a gradual increase of pressure.

A preferred embodiment of the invention having been shown and described, it is to be understood that the embodiment disclosed is tor purposes of illustration only, and the invention is to be construed in the true spirit and scope of the appended claims.

I claim:

1. A vent control for fluid pressure comprising a casing defining a first chamber, a fluid pressure inlet into said first chamber, a primary vent formed from said first chamber, -a slide valve slidably disposed in said first chamber, a second chamber in communication with said first chamber, a secondary vent from said second chamber, and a piston depending from said slide valve and disposed in said second chamber.

2. A vent control for fluid pressure comprising a casing defining a first chamber having formed therefrom a primary vent, a slide valve slidably disposed in said chamber for opening and closing said primary vent, a second chamber formed axially from said first chamber, a secondary vent formed from said second chamber, and a piston depending from said slide valve and being disposed in said second chamber slidably therein, the length of said second chamber being variable.

3. A vent control according to claim 2; and a means for varying the opening from said second chamber to said secondary vent.

4. A vent control for fluid pressure comprising a casing defining a first chamber having fiormed therefrom a primary vent, a slide valve disposed in said first chamber, a second chamber formed from said first chamber, and a secondary vent formed from said second chamber, a piston depending from said slide valve and being disposed in said second chamber, said slide valve and piston being slidable respectively in said chambers simultaneously in response to an increase of fluid pressure in said first chamber for opening said primary vent.

5. A vent control for fluid pressure comprising a casing defining a first chamber having formed therefrom a primary vent, a second chamber formed from said first chamber, a secondary vent formed from said second chamber, a slide valve disposed in said first chamber and a depending piston from the slide valve disposed in said second chamber, said valve and piston being slidable in said chambers, and adjustment means for varying the opening from said second chamber to. said secondary vent.

6. A vent control for fluid pressure comprising a casing, a first chamber defined by said casing, a primary vent formed from said first chamber, a fluid pressure inlet formed in an end of said casing, a movable member disposed in the other end of said casing, said movable member defining a second chamber in communication with said first chamber, a secondary vent formed from said second chamber, adjustable means for varying the opening from said second chamber to said secondary vent, a slide valve disposed in said first chamber and a depending piston from said slide valve and integral therewith disposed in said second chamber, said slide valve and piston being movable from a position normally closing said pri- 6 mary vent responsive to an increase in pressure in said first chamber.

7. In a slug casting machine, the combination of a composed line delivery slide, power means for moving the slide, and means connected to said power means for arresting the movement of said slide, said arresting means comprising a dashpot and a vent control for said dashpot; said vent control comprising a casing defining a first chamber, a primary vent formed from said first chamber, a second chamber in communication With said first chamber, a secondary vent formed from said second chamber, and a slide valve disposed in said first chamber and a depending piston from said slide valve and integral therewith disposed in said second chamber.

8. In a slug casting a machine, the combination of a composed line delivery slide, power means for moving the slide, and means connected to said power means for arresting the movement of said slide, said arresting means comprising a dashpot and a vent control for said dashpot; said vent control including a casing defining a chamber, a vent formed from said chamber, and a slide valve slidably disposed in said chamber, said slide valve being movable in response to an increase of pressure in said chamber from a position normally closing said vent.

References Cited in the file of this patent UNITED STATES PATENTS

Claims

7. IN A SLUG CASTING MACHINE, THE COMBINATION OF A COMPOSED LINE DELIVERY SLIDE, POWER MEANS FOR MOVING THE SLIDE, AND MEANS CONNECTED TO SAID POWER MEANS FOR ARRESTING THE MOVEMENT OF SAID SLIDE, SAID ARRESTING MEANS COMPRISING A DASHPOT AND A VENT CONTROL FOR SAID DASHPOT; SAID VENT CONTROL COMPRISING A CASING DEFINING A FIRST CHAMBER, A PRIMARY VENT FORMED FROM SAID FIRST CHAMBER, A SECOND CHAMBER IN COMMUNICATION WITH SAID FIRST CHAMBER, A SECONDARY VENT FROMED FROM SAID SECOND CHAMBER, AND A SLIDE VALVE DISPOSED IN SAID FIRST CHAMBER AND A