US2859029A

US2859029A - Apparatus for treating metal parts

Info

Publication number: US2859029A
Application number: US513435A
Authority: US
Inventors: Clarence L Joy
Original assignee: Holcroft and Co
Current assignee: Holcroft and Co
Priority date: 1955-06-06
Filing date: 1955-06-06
Publication date: 1958-11-04
Anticipated expiration: 1975-11-04

Description

Nov. 4, 1958 c. 1.. JOY

' APPARATUS FOR TREATING METAL PARTS 5 Sheets-Sheet 1 Filed June 6. 1955 8 r w/r m m H A Z a p Y B \v c. L. JOY 2,859,029 APPARATUS 'FOR TREATING METAL PARTS 5 Sheets-Sheet 2 Nov. 4, 1958 Filed June 6. 1955 'Nov.4, 1958 GEL. Jo 2,859,029

APPARATUS FOR TREATING METAL PARTS Filed June 6. 1955 I 5 Sheets-Sheet 3 Nov. 4, 1958 c. L. JOY

APPARATUS FOR TREATING METAL PARTS Filed June 6. 1955 5 Sheets-Sheet 4 Ill h L m 2w w MH L H m INVENTOR.

ATTOR/VfYS m at! Z. Jar WW WW Nov. 4, 1958 c. L. JOY 2,859,029

APPARATUS FOR TREATING METAL PARTs Filed June 6. 1955 5 Sheets-Sheet 5 I l l IN V EN TOR.

v Cum-M2- 1 Jo) United States Patent a "ice 2,859,029 APPARATUS FOR TREATING METAL PARTS Clarence L. Joy, Detroit, Mich., assignor to Holcroft & Company, Detroit, Mich., a corporation of Michigan Application June 6, 1955, Serial No. 513,435

4 Claims. (Cl. 266-4) This invention relates to an improved method and apparatus for treating metal parts, and is a continuation-inpart of my co-pending application for Method and Apparatus for Treating Metal Parts, Serial No. 166,287, filed June 5, 1950, now U. S. Patent No. 2,716,989.

In treating certain metal parts such for example as cast iron parts, it is customary to anneal or heat the metal parts to the stress relieving temperature of the metal and to clean the parts by a descaling or desanding operation. There are several current processes for accomplishing the two above operations, but in each process the annealing and cleaning operations are performed at the same time by submerging the metal parts into a fused alkali bath. In following either of these processes, it is essential to not only heat the bath to the required stress relieving temperature of the parts, but to also allow the metal parts to remain in the bath for a sufficient time to properly heat the parts. Thus tanks of some considerable size were necessary, and care had to be taken to keep the temperature of the bath below the temperature at which decomposition of the salt takes place.

With the above in view, it is an object of this invention to heat treat or anneal and clean the metal parts in steps which although separate are nevertheless continuous. In accordance with this invention the parts are heated to the desired temperature within a furnace, and are advanced directly from the furnace into the cleaning or fused alkali bath. Thus heat treating of the parts is accomplished prior to introducing the same to the cleaning bath, and the parts are at elevated temperatures when submerged into the bath. As a result no time need be allowed in the cleaning bath for heating the parts and the cleaning operation is not only expedited, but the size of the tank for the bath may be materially reduced.

Cleaning processes embodying fused alkali baths ordinarily require the parts to be introduced into several rinsing and acid baths. templates a unique apparatus for automatically handling the parts so that the operation is continuous regardless of the number of baths provided.

The foregoing as well as other objects will be made more apparent as this description proceeds, especially when considered in connection with the accompanying drawings, wherein:

Figure 1 is a side elevational view partly in section of a heat treating furnace forming a part of the apparatus of the present invention;

Figure 2 is a fragmentary top plan view of the furnace shown in Figure 1;

Figure 3 is a cross-sectional View taken substantially on the line 3-3 of Figure 1;

Figure 4 is a semi-diagrammatic side elevational view of the metal cleaning part of the apparatus;

Figure 5 is a top plan view of the construction shown in Figure 4;

Figure 6 is a cross-sectional view taken on the line 66 of Figure 4;

To this end the invention conthese trays into the furnace.

Patented Nov. 4, 1958 the apparatus shown in Figure 4.

For the purpose of illustrating the present invention, it will be assumed that the apparatus to be presently described serves to anneal or heat treat metal castings to the stress relieving temperature of the metal, and also to descale, desand or otherwise clean the metal castings. It will, ofcourse, be understood as this description proceeds that the apparatus and particularly various parts of the apparatus may be employed for heat treating and/ or cleaning metal parts other than castings.

In general, metal parts are supported on trays 20 and the trays are advanced through a furnace 21 to a cleaning unit 22. During advancement of the trays 20 through the furnace 21', the metal articles carried by the trays are heated to the stress relieving temperature of the metal from which the articles are formed. The heated articles delivered from the furnace are conveyed directly to the cleaning unit 22, and are successively submerged into various baths to be presently described in detail.

With' the above in view, reference is made more in detail to the drawings. The furnace 21 shown in Figures 1 to 3 inclusive of the drawings embodies an elongated tunnel 23 open at both ends and heated in any suitable manner, such for example, as by gas-fired burners not shown herein; The entrant end 24 of the furnace is normally closed by a door 25, and the delivery end 26 is normally closed by adoor 27. The two doors are suitably supported for vertical sliding movement and are respectively operated by fluid motors 28. In accordance with conventional practice, the fluid motors 28 are supported with the cylinders extending vertically, and the pistons are connected to flexible cables 29. The flexible cables 29 extend upwardly over pulleys 30 and are secured to the pulleys 30. Upon reference to Figure 2 of the drawings, it will be noted that the pulleys 30 are respectively secured to cross shafts 31 which are journalled on suitable frame structure 32 at the top of the furnace. The opposite ends of the doors are respectively connected to cables 33, and these cables extend upwardly over pulleys 34 on the respective shafts 31. The upper ends of the cables are secured to the pulleys 34 so that rotation of the shafts by the fluid motors 28 raises the doors to their open positions. The two

doors

25 and 27 move by gravity to their closed positions when the fluid motors are exhausted.

The hearth of the furnace comprises a plurality of laterally spaced longitudinally extending rails 35, and the rollers 36 are supported on the rails in spaced relation to each other longitudinally of the rails. The rollers 36 provide an anti-friction support for the trays 20, and enable the same to be readily advanced through the furnace.

It will be noted from Figures Land 2 of the drawings that a loading platform 37 is supported at the front end of the furnace. The loading platform 37 is provided with longitudinally extending rails 38, which in eifect, form continuations of the rails 35 and provide supports for a plurality of rollers 39.

The rollers 39 support a series of trays 20 beyond the entrant end of the furnace, and these trays are successively moved into the furnace by pushers 40. Each pusher 40 hasa fluid motor 41 supported beneath the rollers 39 with thecylinder in a horizontal position, and having the piston connected to a head 42. Suitable dogs 43 are respectively pivotally connected to the heads in positions'to engage the front edges of the trays supported immediately adjacent the entrant opening 24 to move The succeeding trays are successively advanced to positions immediately in rear -adjacent the delivery opening 26 in the furnace.

of the dogs 43 by dogs 44. The dogs 44 are pivoted to slides 45, and respectively engage the front edges of adjacent trays 20. An additional dog 46 is pivoted to each slide 45 in rear of the dog 44, and the purpose of this dog is to advance the adjacent tray to the rear side of the corresponding dog 44.

It follows from the foregoing that when the heads 42 are moved rearwardly by the respective fluid motors 40, the dogs 43 move the adjacent trays into the furnace 21 through the entrant opening 24. At the same time the dogs 44 move adjacent trays over the dogs 43 to position the trays at the rear sides of the dogs 43 where they may be engaged by the dogs 43 during the next cycle of operation. Also at the same time the dogs 46 move the adjacent trays 20 over the dogs 44 to positions at the rear sides of the latter dogs, so that these trays may also be engaged by the dogs 44 during the next cycle of operation.

It will be noted from Figure 1 of the drawings that when the trays 20 assume positions within the furnace 21, adjacent side edges of the trays contact one another, so that each time the dogs 43 push trays 20 into the furnace, all of the trays in the furnace are advanced a distance approximating the length of one tray. It will, of course, be understood that when this operation takes place, both

doors

25 and 27 are in their open positions in order to not only enable trays from the loading platform to be inserted into the furnace, but to also permit the trays adjacent the delivery opening 26 to be moved out of the furnace.

The trays within the furnace adjacent the delivery opening 26 are moved out of the furnace by slides in the form of racks 48 shown particularly in Figures 1, 2 and 4. The rear ends of the racks are respectively engaged by gears 49 secured in proper spaced relationship on a cross shaft 50 which is connected at one end to a source of power 51. The front ends of the racks project into the rear end of the furnace below the door 27 and below the plane of the trays in the furnace. Suitable dogs 52 are respectively pivotally connected to the racks 48 in positions to engage shoulders at the rear edges of the trays 20 as the latter assume positions Thus rearward movement of the racks 48 enables the dogs 52 to advance the trays through the furnace delivery opening 26 to the position indicated by the numeral 53 in Figure 1 of the drawings. The trays 20 at the position 53 are engaged at the front edges thereof by dogs 54 respectively pivotally supported on the racks 48 adjacent the rear ends of the latter. Upon rearward movement of the racks 48 by the power means 51, the dogs 54 advance the trays at the position 53 to the cleaning unit 22.

Cleaning unit Upon reference to Figure 4 of the drawings, it will be noted that the cleaning unit 22 comprises a plurality of tanks spaced from each other in a row extending in the direction of advancement of the trays 20 through the furnace. The first tank 55 is adapted to contain a fused alkali bath, and this bath is maintained at the proper temperature for cleaning the parts by heating units 56. The next adjacent tank 57 contains a bath comprising preferably water, and the following tank 58 contains an acid bath which serves to remove any salt from the metal parts remaining thereon after being subjected to the water bath in the tank 57. The acid is removed from the metal parts by a fourth bath contained in a tank 59, and a lubricant or rust preventive is applied to the articles by submerging the latter into a bath of soluble oil contained in the last tank 60 in the row.

The article supporting trays 20 are submerged into the baths by

elevators

61, 62, 63, 64 and 65. These elevators are respectively supported above the

tanks

55, 57, 58, 59 and 60 for vertical movement into and out of the baths. The elevators are operated as a unit by two pairs of fluid motors 66 and 67 supported above the cleaning unit on suitable frame 68.

As shown in Figure 6 of the drawings, the opposite ends of the elevator 64 are connected to the lower ends of flexible cables 69 having the upper ends reeved over pulleys 70. From the pulleys 70 the cables 69 extend forwardly, and are respectively connected to the pistons of the pair of fluid motors 66. The pulleys 70 are secured to a cross shaft 71, which in turn, is journalled on the frame structure 68, so that movement of the pistons in the fluid motors rearwardly rotates the pulleys 70 in the direction of the arrow 72 and causes the elevator 64 to move downwardly into the tank 59.

The elevator 65 is connected at opposite ends to flexible cables 73, and these cables are secured at their upper ends to pulleys 74. The pulleys 74 are secured to a cross shaft 75 which is journalled on the frame structure 68 and has a pulley 76 secured thereto. The pulley 76 is connected 'by a belt 77 to a pulley 78 fixed to the shaft 71, so that rotation of the shaft 71 in the direction of the arrow 72 by the fluid motors 66 imparts rotation to the shaft 75 in a'corresponding direction to lower the elevator 65 into the tank 60.

The elevator 63 is connected at opposite ends to flexible cables 79, and the upper ends of the cables are secured to pulleys 80. The pulleys 80 are fixed to a shaft 81 also journalled on the framing 68 and having a pulley 82 secured thereto. The pulley 82 is connected by a belt 83 to the pulley 78 on the shaft 71, and as a consequence, the elevator 63 is lowered into the tank 58 when the shaft 71 is rotated in the direction of the arrow 72. Of course, it will be understood that movement of the pistons in the fluid motors 66 in a forward direction raises the

elevators

63, 64 and 65 as a unit.

The elevator 61 is connected at opposite ends to flexible cables 84 having the upper ends respectively fixed to pulleys 85 secured to a cross shaft 86. Pulleys 87 are secured to the shaft 86, and are respectively connected to flexible cables 88. The cables 88 extend rearwardly from the pulleys 87, and are connected to the fluid motors of the pair 67. The shaft 86 also has a pulley 89 secured thereto, and this pulley is connected by a belt 90 to a pulley 91 secured to a cross shaft 92. The cross shaft 92 is journalled on the frame 68 directly above the elevator 62, and a pair of pulleys 93 are secured to the shaft 92. The pulleys 93 are respectively connected to opposite ends of the elevator 62 by flexible cables 94.

With the above construction, it will be noted that forward movement of the pistons in the fluid motors 67 provides for rotation of the shafts 86 and 92 in the direction of the arrows shown in Figure 4 of the drawings. As a result the

elevators

61 and 62 are re pectively lowered into the tanks 55 and 57. Rearward movement of the pistons in the fluid motors 67 rotates the shafts 86 and 92 in the opposite direction, and causes the

elevators

61 and 62 to return to their uppermost positions shown in Figure 4 of the drawings. The two pairs of fluid motors are operated as a unit so that all of the elevators are simultaneously moved into and out of their respective tanks, depending upon the direction of movement of the pistons in the fluid motors. When the elevators are in their raised positions shown in Figure 4 of drawings, the top surfaces thereof lie in a common plane which includes a tray supporting surface 95. The tray support 95 extends between adjacent elevators, and is in the form of a grating as shown in Figure 5 of the drawings. In fact it will also be noted from Figure 5 that the tray supporting surface of each elevator is also in the form of a grating 96 arranged to form a continuation of the grating 95 when the elevators are in their raised positions.

The trays 20 leaving the delivery end of the furnace 21 are successively positioned on the elevators 61 to 65 inclusive by a propelling device 97. The propelling device 97 comprises a rectangular frame having side rails 98 secured in lateral spaced relationship by cross members 99. The frame 97 extends for substantially the full length of the row of tanks, and the cross members 99 correspond in number to the number of elevators or tanks provided.

The frame 97 is supported for sliding movement along the support 95, and in the forwardmost position shown in Figures 4 and 5 of the drawings, the cross members 99 assume positions atthe front sides of the respective elevators. These cross members are also positioned to respectively engage the front edges .of the article supporting trays 20 on the respective elevators to advance the trays from one elevator toward the next adjacent elevator.

The frame 97 is reciprocated by a pair of racks 100 respectively secured at opposite-sides of the frame and extending in the general direction of length of the frame. The racks are also respectively engageable with a pair of gears 101 mounted on a cross shaft 102 in the manner shown in Figure 7 of the drawings and connected to a driving unit 103.

Referring again to Figure 4 of the drawings, attention is called to the fact that the tanks 55 and 57 are spaced from each other a greater distance than the distance between the other tanks, and accordingly the cross members 99 associated with the

elevators

61 and 62 are spaced from each other a distance greater than the distance between other cross members. By reason of the spacing of the cross members 99 shownin Figure 4 of the drawings, the article supporting tray on thefirst elevator 61 is transferred from this elevator to a position on the supporting surface 104 at the rear side of the elevator 61, while the article supporting trays on the following elevators are actually transferred from one elevator to the other, upon rearward movement of the frame 97 from its forwardmost position shown in Figure 4 of the drawings. This arrangement provides for a drainage station 105 between the

elevators

61 and 62. The draining station merely comprises a plate 106 supported below the por tion 104 of the support 95 in a position to receive drain age from the articles removed from the first elevator 61, and the plate is inclined to direct the drainage back into the tank 55.

The power unit 103 is operated in timed relation to the fluid motors 66 and 67 by any suitable control circuit not shown herein. It will suffice to point out that the elevators are in their raised positions when the device 97 is moved rearwardly, and the device remains in its rearwardmost position until the elevators are lowered into the respective tanks. At this time the device 97 may be returned or moved forwardly without interference between the cross members 99 and the article supporting trays 20 on the elevators. When the device 97 is moved forwardly, the article supporting tray at the drainage station 105 is merely shifted forwardly by the adjacent cross member 99, and remains in this position until it is advanced by the preceding tray on the elevator 61 to a position on the elevator 62. This action of course takes place when the device is again moved rearwardly after the elevators are raised to their uppermost positions.

Operation The power unit 51 for the racks 48 at the delivery end of the furnace 21 is operated in timed relation to the power unit 103, and in timed relation to the fluid motors 28 by a control circuit which forms no part of the present invention, and is not disclosed herein. This is also true of the operation of the fluid motors 40 for the

dogs

43, 44 and 46. It will suflice to point out that after the heating cycle, the

doors

25 and 27 are raised, and the racks 48 are operated to move the article trays 20 at the delivery end 26 of the furnaceto the positions 53. At the same time the fluid motors 40 are operated to advance trays 20 into the entrant end 24 of the furnace. The

doors

25 and 27 are then closed, and the next heating cycle is started.

. cross members to the next adajacent elevator.

As the racks 48 move rearwardly to withdraw trays from the delivery end of the furnace, the dogs 54 transfer trays from the position 53 to the elevator 61. Prior to movement of the racks 48 rearwardly, the propelling device 97 is moved to its rearwardmost position wherein the cross members 99 are positioned at the rear sides of the elevators. It will be understood that during the rearward movement of the device 97, the trays 20 on the elevator 61 are advanced to a position on the portion 104 of the support 95, and the trays previously deposited on the portion 104 are advanced by the preceding tray to a position on the elevator 62. p Also the trays formerly on the

elevators

62, 63 and 64 are advanced by the adjacent The trays on the last elevator 65 are advanced by theuadjacent cross mcmber99 onto a delivery platform 106.

It follows from the above that when the trays 20 are advanced by the dogs 54 to positions on the elevator 61,

i the following elevators also have trays thereon. As soon as trays 20 are transferred from the position 53 to the elevator 61, all of the elevators are lowered into their respective tanks. The articles supported by the trays on the elevator 61 are at elevated temperatures due to the heat treating operation accomplished in the furnace 61, and accordingly, need be retained in the alkali bath for only a relatively short length of time.

Prior to movement of the elevators to their raised positions, the device 97 is moved forwardly by the power unit 103 to again locate the cross members 99 to positions in advance of the adjacent elevators. After the device 97 is moved to its forwardmost position, the elevators are raised by the fluid motors 66 and 67.

As soon as the elevators assume their uppermost positions, the device 97 is again moved rearwardly to transfer the trays from the elevator 61 to a position on the portion 104. The trays on the remaining elevators are successively advanced by the adjacent cross members 88 to the next adjacent elevator, and the trays on the elevator 65 are deposited on the delivery platform 106. It is pointed out at this time that as the trays are transferred from the elevator 61 to the portion 104 of the support 95, these trays engage the trays previously deposited on the support, and advance the latter trays to positions on the elevator 62.

It follows from the above that the cleaning unit 22 operates in conjunction with the furnace 21 in a manner such that the heat treating and cleaning operations are continuous. It will also be understood that the articles are at elevated temperatures when submerged into the alkali bath in the tank 55, so that this bath is not relied upon to heat the articles. As a consequence, the articles need be retained in the bath only a relatively short period, and this is desirable in that it reduces the time required for the cleaning cycle to a minimum.

What I claim as my invention is:

1. Apparatus for treating articles, comprising a plurality of receptacles spaced from each other in a for Wardly and rearwardly extending row and open at the top and each containing a bath, elevators respectively supported for downward and upward movement as a unit into and out of the baths through the open tops of the receptacles and having generally co-planar article supporting surfaces, a support for the articles positioned above the receptacles and having portions between the elevators providing continuations of the article supporting surfaces of the elevators in the raised positions of the elevators, means for moving the articles rearwardly from one elevator to another in succession comprising an article propelling device supported above the support for sliding movement in forward and rearward dircctions along the row of receptacles, said device having laterally spaced bars extending along the rows of receptacles and longitudinally spaced members connecting said bars respectively positioned at the front sides of the elevators, means for moving the device in a rearward direction along the row of receptacles in the raised positions of the elevators to move articles by said members from said article supporting surfaces in a rearward direction and for moving the device in a forward direction in a lowered position of the elevators to return the members to their positions at the front sides of the elevators.

2. The apparatus set forth in claim 1 in which the spacing between two adjacent elevators and the stroke of the propelling device is such that the articles are successively moved rearwardly from one of said adjacent elevators to the other across the intervening portion of said support upon each rearward stroke of the propelling device.

3. The apparatus set forth in claim 1 in which the spacing between two adjacent elevators exceeds the stroke of the propelling device to transfer articles from the supporting surface of the forwardmost of said adjacent elevators onto the portion of the support between said two adjacent elevators, and in which means is provided for returning drainage from the articles deposited on the last-mentioned portion of the support back into the preceding receptacle.

4. Apparatus for treating articles comprising a receptable containing a bath and open at the top, an elevator supported for downward and upward movement into and out of the bath through the open top of the receptacle and having an article supporting surface, an article support having portions extending rearwardly from the rear side of the path of travel of the elevator and forming a continuation of the article supporting surface of the elevator in the raised position of the latter, an article propelling member supported above the support for forward and rearward movement across the article supporting surface of the elevator, means for moving the member rearwardly from a position at the front side of the elevator across the article supporting surface of the elevator in the raised position of the latter to move an article from said article supporting surface rearwardly onto the support and for returning the member to the front side of the elevator when the latter is in a position below the support, and means associated with the support for conveying drainage from the article on the support into said bath.

References Cited in the file of this patent UNITED STATES PATENTS 294,441 Chess Mar. 4, 1884 586,858 Mesta July 20, 1897 1,959,215 Owen May 15, 1934 2,223,603 Darrah Dec. 3, 1940 2,248,732 Albrecht et a1. July 8, 1941 2,254,913 Roth Sept. 2, 1941 2,477,561 Holden Aug. 2, 1949 2,633,855 Ransoholf Apr. 7, 1953 2,639,047 Ipsen May 19, 1953 2,654,462 Todd Oct. 6, 1953 FOREIGN PATENTS 616,151 Great Britain Ian. 17, 1949