US3829265A

US3829265A - Device for connecting and disconnecting core tubes to a trolley in concrete casting machines

Info

Publication number: US3829265A
Application number: US00293197A
Authority: US
Inventors: J Holm
Original assignee: JESPERSEN A AND SON INT
Current assignee: JESPERSEN A AND SON INT
Priority date: 1972-09-28
Filing date: 1972-09-28
Publication date: 1974-08-13
Anticipated expiration: 1991-08-13
Also published as: DE2348515A1; DE2348515C3; DE2348515B2

Abstract

From US Pat. No. 3,642,419 it is known to pervey a concrete casting machine with more core tubes than necessary for a single mold. Therefore at each casting a number of core tubes are retained, while the other core tubes are moved on a trolley towards and into the empty mold. Now the said core tubes are retained in their most retracted position by means of twin-arm levers , engaging either a fix hook in a link member connected to the core tube; this gives a reliable connecting and disconnecting possibility which is vastly automatically controlled.

Description

United States Patent 11 1 1111- 3,829,265 Holm 1451 Aug. 13, 1974 [54] DEVICE FOR CONNECTING AND 1,977,374 10/1934 Brooke et al. 425/468 DISCONNECTING C TUBES o A 3,534,450 10/1970 lpsen 425/457 TROLLEY IN CONCRETE CASTING 3,642,419 2/1972 Toksvig 425/457 MACHINES Primary Examiner-Robert D. Baldwin lmemori ig ls Holm, Hellerup, Assistant Examiner-John McQuade enmar Attorney, Agent, or Firm-Browne, Beveridge, [73] Assignee: A. Jespersen & Son International DeGrand' & Klme A/S, Copenhagen, Denmark 221 Filed: Sept. 28, 1972 [57] ABSTRACT From US Pat. No. 3,642,419 it is known to pervey a [21] Appl' 293197 concrete casting machine with more core tubes than necessary for a single mold. Therefore at each casting [52] US. Cl 425/161, 425/ 162, 425/171, a number of core, tubes are retained, while the other 425/185, 425/468 core tubes are moved on a trolley towards and into the [51] Int. Cl. B28b 7/30 empty mold. [58] Field of Search 425/457, 468, 182l86, Now the said core tubes are retained in their most 425/249! 4691 262; 249/631 177 retracted position by means of twin-arm levers engaging either a fix hook in a link member connected [56] References C'ted to the core tube; this gives a reliable connecting and UNITED STATES PATENTS disconnecting possibility which is vastly automatically 1,437,537 12/1922 Mazer 425/468 controlled- 1,460,299 6/1923 Whitehouse 425/457 1,514,980 11/1924 Mathis 425/468 21 Clam! D'awmg 44 37 -'E 64 11 14 1s 20 I 5 38 WI i 30 23 925 1 1 l1 E i i g 35 in L i I1 "1. 1 7 1 11 11, 24 1 36 26 E 11 I I 5 l HI22 111 43 *3 "M I r I||1|11 11111 1 "H 27 111 1 l 4)? 17 W 1 1| ll ll m z J} J K PAIENTED N16 1 31974 SHEET '4 (IF 8 PAIENTED 3.829.265

sum 8 [IF 8 The present invention relates to a device for connecting and disconnecting core tubes connected to a trolley which inserts the tubes and retracts them from a concrete mold which serves for making cast blocks or slabs. A similar trolley with core tubes is arranged at the opposite end of the mold.

U.S. Pat. No. 3,642,419 discloses a device for the said purpose, in which some of the core tubes of the casting machine, which are not to be used in the current production are permanently retained in their retracted position. Each core tube in the known plant comprises a hinged swingable rear arm having a fastening device enabling the core tube to be secured either to a fixed transverse beam or to the trolley, but said device is for manual operation and will hardly lend itself to mechanical switching.

The object of the invention is to provide a mechanically switchable device to enable the'machine to be switched from one type of mold to another type of mold from a control desk, either by hand or automatically depending on the type of operation desired. Another object of the invention is to provide a switching device which requires little space in width and height both during operation of the machine and when connecting and disconnecting core tubes. Thereby is achieved a compact machine capable of accommodating a large number of core tubes, which is important as in such casting machines there are frequently used molds of various width and shape. Now on one side it is frequently a question of molds requiring generally cylindrical cores, now on the other molds requiring cores of other cross section.

In such cases it is desirable to let the machine change automatically between the two sets of core tubes.

The device according to the invention is so arranged that each tube is connected through a link member with a twin-arm lever which by means of hooks provided on the arms may alternately engage behind a fixed stop and in front of a projection provided on the trolley. Such a twin-arm lever may not only be of a rugged construction so as to be capable of transferring the necessary forces substantially appearing as tension in the lever, but it also requires little space for its switching motion, and it further affords a high degree of protection against functional errors in the switching. Furthermore it may be constructed with such small switching motion that rapid switching is possible, and to this should be added that it is possible to actuate the lever to effect switching bysimple mechanical means, which may be controlled automatically.

Said means may be designed so as to require little space, thereby allowingsuch a compact disposition of the core tubes that these may be arranged closely together in two or possibly more layers.

One embodiment of the device according to the invention is shown in the drawings, in which FIG. 1 is a plan view of the rear end of some core tubes, in a casting machine, each of said core tubes being connected to its respective device for connecting and disconnecting the core tubes.

FIG. 2 is a sectional view taken on line A-A of FIG. 1 with core tube, disconnected from the trolley and connected to the fixed stop.

FIG. 3 is a perspective view of the lever of the device in the same position, as shown in FIG. 2.

FIG. 4 is a part sectional view corresponding to FIG. 2 after the trolley is advancing again with the core tube disconnected.

FIG. 5 is a corresponding sectional view after the trolley has returned and with the core tube connected thereto.

FIG. 6 is a perspective view of the lever in the same position as in FIG. 5.

FIGJ7 is a sectional view taken in line A-A of FIG. 1 after having moved the trolley with the connected core tube a short distance away from the position shown in FIG. 5.

FIG. 8 is a sectional view taken on line A-A of FIG. 1 after the trolley has returned with the core tube to its advanced end position, to which it returns during operation when'no core tubes are to be connected or disconnected.

FIG. 9 is a sectional view taken on line BB of FIG. 1 and FIG. 10 is a diagram of the automatical control devices.

In the

drawings

11, 12, and 13 is illustrated the rear end of a number of core tubes of the type designated 5 in U.S. Pat. No. 3,642,419. In FIG. 1 the rearend of each core tube is connected by a link pin 14 through a rubber sleeve 15 to a link member 16 which is entered from the rear into a horizontal U-shaped beam 17 on a trolley 18, one wheel 19 of which is shown in FIGS. 1 and 9 on a rail 47.

The beam 17 is formed with a hole 20 which is sufficiently large to pass over the core tube 11, see FIG. 2. The linkmember 16 has a U-shaped portion 21, FIG. 1 which is cut under an angle at the top and at the bottom so as to be able to engage the inclined surfaces within the beam 17.

The rear end of the

member

16,21 supports a tubular extension 23 having a horizontal pin 24 to allow a tilting movement of a twin-arm lever 25. As willbe seen from FIG. 3, the lever may by means of a hook 26 provided thereon, engage a fixed stop 27, while the front of the lever supports a cross bar 28, the ends 29 of which may be guided behind a pair of projections 30 on the beam 17, FIGS. 1 and 2.

When the trolley is advanced towards the casting mold in the direction of arrow 31, the core tube 11,

shown in FIG. 2 will be immovably held as,a result of the engegement of the hook 26 behind the stop 27. FIG. 4 shows the trolley advancing in the direction of the arrow 31, whereby the beam 17 with its hole 20 will pass over the core tube 11.

The trolley does, however, carry additional core tubes which are inserted into the casting mold, FIG. 10 and thereby forming'the desired cores in the cast element. After the casting the trolley will retract said core tubes. Assuming mold of another type is to be cast in which the core 11 is to be used, the trolley is returned to its fully retracted position shown in FIGS. 1 and 2. It is now required to disengage the hook 26- from the stop 27 and a cylinder 32, FIG. 5 is actuated to lift its piston rod 33 with pressure clamp 34, while turning cam 36 on shaft 35 clear of the lever 25. The latter is thereby depressed by a spring 38, located in the wall of housing 39 on the member 23 into the position shown' in FIG. 5, where the cross bar 28 is moved down in front of the projections 30 on the beam 17 as shown in FIG. 6. The core tube 11 will thereby be disconnected from the stop 27 and connected to the beam 17 and thus take part in the future movements of the trolley 18.

It is common practice to have in such a casting machine two sets of core tubes, having different cross sections. It is then possible for the machine to operate with casting molds requiring core tubes either of one type or the other. One could then have the cylinders 32 pressing their clamps 34 against the levers of one set of core tubes when the second set of core tubes is to be used and vice versa. It would, however, be easier to provide two sets of

cams

36 and 37 on the shaft 35. By turning the shaft it is then possible to lock one or the other set of core tubes in the retracted position. On the other hand, the pressure clamps 34 cannot be dispensed with as there at times are casting molds where one or more core tubes of a set are to be used. In such case there core tubes are retained by actuating the associated cylinders 32, and by means of sensor, it will be possible automatically to adapt the choice of core tubes to the mold introduced into the machine, as it will be explained below.

FIG. 7 shows the beam 17 with core tubes 11 connected after the trolley has been moved a short distance away from its end position.

When the trolley returns and no changes in number of the

core tubes

11, 12, and 13 are to be made, because the next following operation requires casting in a mold identical to the one just used, the trolley is not moved back to the aforesaid fully retracted position, but to an advanced end position as shown in FIGS. 8 and 10. The buffer 46 of the trolley 18 will not engage a fixed buffer 40 but a block 41, which meanwhile has been lowered by a pressure cylinder 42 from position 41 indicated by dotted lines in FIG. 10.

It will be seen that the extended portion 23 of FIG. 8 may rest on a rigidly mounted supporting roller 43. It will further be seen that when moved into the position shown in FIGS. 2 and 5, the member 23 will also be supported by an upper supporting roller 44, adjacent to the position of the horizontal cross pin 24. Said supporting

rollers

43 and 44 serve to support the entire link member during connection or disconnection of the

core tubes

11, 12, 13 etc.

After a casting operation the trolley must always be returned to the advanced end position, shown in FIG. 8. There is only a need for moving the trolley 18 back to the fully retracted position, FIGS. 2 and 5, when the changing numbers or type is to take place.

Now the full mold is replaced by an empty mold 48 being introduced in the direction of an arrow 49, FIG. 10.

If this mold is of a type B, i.e. of another type than the previous mold and lower, a sensor 52 on a shaft 51 which turns in a fixed bearing 68, will cause a lever 53 to actuate a limit switch 54, which lights a lamp 54' on a panel 55, at the control desk of the machine. The limit switch 54 will also actuate a solenoid valve 71, which gives a pressure fluid acces to the lower end of a cylinder 42, the stem 75 of which carries the block 41, which is now lifted up to the position 41 This will allow the trolley to drive against the buffer 40, as explained below. The stem 75 has a side bar 76 with a projection 77, which actuates a limit switch 72, closing the solenoid valve 71, when the block has reached its upper position 41 The limit switch 72 closes a contact 78 which causes a slow movement of the trolley 18 backwards against the buffer 40, in which position the guide bracket 56 on the trolley 18 will actuate a limit switch 60 which actuates a solenoid valve 70, which opens for admission of pressure fluid to the right end of the cylinder, FIG. 10, which is supported turnable on a pin 62, on a rigid arm 63 on the beam 64. Thereby the stem 79 of the cylinder 61 pushes through a pin 80 against a L-shaped lever 67 on a shaft 35 which is thereby turned. The shaft 35 has two sets of

cams

36 and 37. When turning, the earns 37 are pressed down on the levers 25, locking them in engagement with the stops 27 and at the same time the front end of the levers will disengage the projections 30, FIG. 3. Thereby the core tubes, which should be applied in connection with molds of type A will be retained, when the trolley 18 is driven forwards. Oppositely will the core tubes which have been hitherto retained be released from the stops 27 and connected to the trolley 18, because the corresponding cams 36 will release the corresponding levers 25, which will thereby be tilted by their spring device 39 from the position shown in FIG. 6.

The piston stem 79 carries a side bar 81, having a projection 82. This projection contacts a limit'switch 83, and the movement is stopped, because the switch will close valve 70. When later on the core tubes are substituted by the other set of tubes, the signal from limit'switch 60 will cause the valve 70 to admit pressurized fluid to the left end of the cylinder, cf. FIG. 10.

Hereby the shaft 35 is turned back to the position shown in FIG. 10, said movement being stopped as the projection 82 contacts a limit switch 84 which closes the valve 70.

The

cams

36 and 37 of shaft 35 will either retain the core tubes to the type A-molds or the core types to the B-molds.

Each of said twin-armed levers 25 will as the hook 26 thereof engages with the corresponding stop 27, actuate limit switch 45 which lights a lamp 45' of the panel 55. Hereby it is possible to ascertain those core tubes that are retracted.

By actuation of a switch 85 the trolley 18 is connected to the power supply. The trolley moves then forwards in the direction of the type B-mold 48 and the corresponding core tubes into the mold through the openings 87 of the end-wall 50. As the guide bracket.

56 during this procedure passes the limit switch 86, the latter will produce a signal for the valve 71. Hereby the valve is opened for pressure to the upper end of the cylinder 42, which involves that the block 41 is moved down to position 41 of FIG. 10, in which position it will stop because the projection 77 contacts limit switch 73 which closes valve 71.

If the empty mold 48 is of type A, a second limit switch 59, working with the lever 53, will be actuated, whereby a lamp 59 on the panel is lighted. In this case no changing of core tubes will be made. The block 41 will not be lifted, because the trolley 18 will not be moved beyond the position shown in FIGS. 8 and 10. No signal is given to the valve 70, because it is the same limit switch 59 which is actuated as at the previous mold. The limit switch 59 actuates a relay 90, but may not transfer its signal to the valve 71, because the relay already by an earlier signal has moved a switch 89 to the position shown in FIG. 10. When the lever 53 passed limit switch 54 on its way to or from limit switch 59 a time delay-relay 94 inserted in the circuit to the switch 89 will prevent an impulse from passing until say 3 seconds have elapsed.

By manual operation of the switch 89 it is possible if desired to move the trolley 18 back to the retracted position. If no simultanous turning of the shaft 35 is desired, a switch 91, inserted in the connection 92 passing from valve 71 to the valve 70, is opened. This is necessary if a mold which differs somewhat from the two mold types is to be cast. A single, some or all of the core tubes, not held by the

cams

36 or 37 may be retained by means of the pressure clamps 34 mentioned above. Each pressure cylinder 32 may be actuated by pressing its particular press button 32 on the panel 55, whereby the corresponding lamp 45 is lighted. All of the buttons 32' may be released by pressing a re-set button 132, whereby all clamps 34 are lifted, thereby freeing the hooks 26.

What I claim is:

1. In a concrete block and slab molding apparatus including a plurality of core tubes having a forward end adapted to be projected into a mold at a mold station and a rear end, a trolley movable on a track toward and away from a mold at said molding station between an extended position in which said core tubes project into the mold at said mold station and a fully retracted position in which said core tubes are withdrawn from said molds,and connecting means operable to selectively connect the rear end of said core tubes to said trolley for movement therewith and to connect said tubes to a stationary support when said trolley is in said fully retracted position, the improvement wherein said connecting means comprises a linkage assembly on each said core tube, said linkage assemblies each including an elongated link member having one end connected to the rear end of a core tube, a lever pivotally mounted on said link for movement between a first position and a second position, first and second hook means on said lever, fixed stop means adapted to be engaged by said first hook means when said lever is in said first position to retain the core tube against movement with said trolley, and projection means on said trolley adapted to be engaged by said second hook means when said lever is in said second position to connect said core tube to said trolley for movement therewith.

2. The molding apparatus according to claim 1 wherein said connecting means further comprises a spring member located between said lever and said link and normally urging said lever away from said first position and out of engagement with said fixed stop.

3. The molding apparatus according to claim 2 further comprising a movable member located adjacent said fixed stop and adapted to press against said lever in the area of said hook to cause the latter to engage said fixed stop and disengage from said projection on said trolley when said core tube is to be connected to said fixed support.

4. The molding apparatus according to claim 1 wherein said second hook means comprises a cross bar mounted on and having its ends projecting laterally from said lever for engaging said projection means on said trolley on each side of said lever.

5. The molding apparatus according to claim 4 wherein said trolley includes a beam extending generally transverse to the direction of movement of the trolley, said link having two outer surfaces inclined toward each other in the direction of said core tube and said beam having complementary inclined inner surfaces positioned to engage and support said inclined surfaces on said link when said second hook is in said second position connecting said core tube to said trolley, said projection means also being located on and supported by said beam in position to be engaged by said cross bar.

6. The molding apparatus as defined in claim 1 further comprising movable stop means for engaging and stopping movement of said trolley at a partially retracted position in which the core tubes carried thereon are withdrawn from a mold at said molding station and in which the linkage assembly on the core tubes connected to said trolley are spaced from said stationary support whereby the trolley is prevented from movement to said fully retracted position when it is not desired to change the core tube configuration carried thereby, and means for moving said stop means to permit the trolley to move to said fully retracted position when it is desired to change the core tube configuration carried thereby.

7. The molding apparatus according to claim 6 wherein said links comprise an elongated tubular member extending rearwardly from said core tube, said lever being pivotally mounted within said tubular member for movement about a horizontal axis, and guide roll means positioned beneath and engaging a first guide surface on said tubular member for guiding said linkage assembly during movement of said trolley between said partially retracted position and said fully retracted position.

8. The molding apparatus according to claim 7 wherein said spring member is located within said tubular member.

9. The molding apparatus according to claim 7 wherein said tubular member includes a second guide surfaceextending along the top portion thereof adjacent its rear end, and a supporting roller mounted in fixed bearings in position to engage said second guide surface as said trolley and said core tubes are moved between said fully retracted position and said partially retracted position.

10. The molding apparatus according to claim 3 further comprising an elongated cam shaft extending across all of said levers at said fully retracted position, cams mounted on said cam shaft in position to engage said levers, and means for rotating said shaft to engage said cams with said levers to press the hooks there into engagement with the corresponding fixed stops.

11. The molding apparatus according to claim 10 further comprising two sets of core tubes adapted to be selectively connected to said trolley for movement therewith, and wherein said cams on said shaft include two sets of cams each adapted to engage the levers of one set of said core tubes, said shaft being rotatable between positions alternatively connecting one or the other of said sets of core tubes to said trolley for movement therewith.

12.-The molding apparatus according to claim 11 wherein said means for rotating said cam shaft includes an arm and a fluid cylinder operable to oscillate said arm and said cam shaft about the longitudinal axis of said shaft.

13. The molding apparatus according to claim 12 further comprising a solenoid actuated valve operatively connected in a fluid circuit controlling operation of said first fluid cylinder, and means controlling actuation of said solenoid valve to rotate said cam shaft to press either one or the other of said sets of cams against their associated levers to thereby connect the core tubes to said stationary support.

14. The molding apparatus according to claim 1 further comprising a first limit switch mounted in position to be actuated by each said lever, and a plurality of lamps on a control panel connected one to each said limit switch for signaling when the respective levers have their hooks connected with said fixed stops.

15. The molding apparatus as claimed in claim 1 further comprising clamp means mounted adjacent each said lever at said fully retracted position for clamping the lever to its fixed stop.

16. The molding apparatus as claimed in claim wherein said clamp means comprises a piston rod of a fluid pressure cylinder, said fluid pressure cylinder being operable to maintain the hook on the associated lever in engagement with said fixed stop regardless of the position of said cam shaft.

17. The molding apparatus as claimed in claim 9 further comprising a stationary buffer for stopping movement of said trolley at said fully retracted position, said movable stop including a block adaptable to be moved into position to engage said trolley ahead of said stationary buffer whereby said trolley may be stopped in said partially retracted position.

18. The molding apparatus as claimed in claim 17 wherein said molds are moved seriatim past said molding station, sensor means mounted in position to engage said molds at said molding station, and means responsive to said sensor means for moving said block in response to a condition sensed by said sensor means.

19. The molding apparatus as claimed in claim 18 wherein said sensor means comprises a pair of limit switches mounted in position to be actuated depending upon the height of the molds moved into said molding station for sensing a change in mold size and for producing a signal controlling movement of said block from its normal position ahead of said buffer at said first actuation of a limit switch after a change of mold size.

20. The molding apparatus as claimed in claim 12 further comprising a further limit switch mounted in position to be actuated-by said core tube carrying trolley when said trolley is in said fully retracted position, said furtherlimit switch being connected in a circuit including a signal lamp on said control panel and a solenoid actuated valve operably connected to said first fluid cylinder for rotating said cam shaft whereby said shaft is turned upon movement of said trolley to said fully retracted position.

21. The molding apparatus as claimed in claim 17 further comprising switch means mounted for actuation by movement of said trolley toward said fully retracted position and operably connected to said means for moving said movable block whereby said block is moved away from said fixed buffer.

Claims

1. In a concrete block and slab molding apparatus including a plurality of core tubes having a forward end adapted to be projected into a mold at a mold station and a rear end, a trolley movable on a track toward and away from a mold at said molding Station between an extended position in which said core tubes project into the mold at said mold station and a fully retracted position in which said core tubes are withdrawn from said molds, and connecting means operable to selectively connect the rear end of said core tubes to said trolley for movement therewith and to connect said tubes to a stationary support when said trolley is in said fully retracted position, the improvement wherein said connecting means comprises a linkage assembly on each said core tube, said linkage assemblies each including an elongated link member having one end connected to the rear end of a core tube, a lever pivotally mounted on said link for movement between a first position and a second position, first and second hook means on said lever, fixed stop means adapted to be engaged by said first hook means when said lever is in said first position to retain the core tube against movement with said trolley, and projection means on said trolley adapted to be engaged by said second hook means when said lever is in said second position to connect said core tube to said trolley for movement therewith.

9. The molding apparatus according to claim 7 wherein said tubular member includes a second guide surface extending along the top portion thEreof adjacent its rear end, and a supporting roller mounted in fixed bearings in position to engage said second guide surface as said trolley and said core tubes are moved between said fully retracted position and said partially retracted position.

12. The molding apparatus according to claim 11 wherein said means for rotating said cam shaft includes an arm and a fluid cylinder operable to oscillate said arm and said cam shaft about the longitudinal axis of said shaft.

16. The molding apparatus as claimed in claim 15 wherein said clamp means comprises a piston rod of a fluid pressure cylinder, said fluid pressure cylinder being operable to maintain the hook on the associated lever in engagement with said fixed stop regardless of the position of said cam shaft.

20. The molding apparatus as claimed in claim 12 further comprising a further limit switch mounted in position to be actuated by said core tube carrying trolley when said trolley is in said fully retracted position, said further limit switch being connected in a circuit including a signal lamp on said control panel and a solenoid actuated valve operably connected to said first fluid cylinder for rotatiNg said cam shaft whereby said shaft is turned upon movement of said trolley to said fully retracted position.