Level control system for liquid solder

Claim 2

In apparatus for applying solder to an article: a tank for containing molten solder, the tank having an entry section; means for advancing the article past said entry section and then into contact with the solder; a block of heat radiating material; means mounting the block partially submerged within said entry section for movement downwardly to raise and upwardly to lower the surface level of the solder, the mounting means positioning the block in juxtaposition to the path of advance of the article to radiate heat and preheat the article prior to advance of the article into contact with the solder; and means responsive to variations in the level of the solder for moving the block selectively into and out of the solder to maintain the level of the solder within predetermined upper and lower limits.

Claim 3

In apparatus as set forth in claim 1 means rendered effective during movement of the block and responsive to solder attaining a predetermined level intermediate said predetermined upper and lower limits for terminating movement of the block to maintain the solder at said predetermined intermediate level.

Claim 4

In a dragline soldering apparatus: an elongated solder tank; a block of heat radiating material positioned at one end of said tank to be heated by molted solder in the tank; means for advancing an article past the heated block and then into contact with molten solder in the tank; means mounting the block for vertical movement in said tank; means rendered effective upon the level of solder in said tank falling below a predetermined lower limit for displacing the block downwardly to raise the level of solder in said tank; and means rendered effective upon the level of solder in said tank rising above a predetermined upper limit for displacing the block upwardly to lower the level of solder in said tank.

Claim 5

In a dragline soldering apparatus: an elongated solder tank; a block of heat radiating material positioned at one end of said tank to be heated by molted solder in the tank; means for advancing an article past the heated block and then into contact with molten solder in the tank; means mounting the block for vertical movement in said tank; means rendered effective upon the level of solder in said tank falling below a predetermined lower limit for displacing the block downwardly to raise the level of solder in said tank; and means rendered effective upon the level of solder in said tank rising above a predetermined upper limit for displacing the block upwardly to lower the level of solder in said tank.

Claim 6

In apparatus as set forth in claim 3: said means for displacing the block downwardly comprising a first probe extending to a first vertical level in the tank corresponding to said predetermined lower limit; and said means for displacing the block upwardly comprising a second probe extending to a second vertical level in said tank corresponding to said predetermined upper limit.

Claim 7

In apparatus as set forth in claim 3: means effective with the block being displaced in said tank and responsive to the level of solder in the tank attaining a predetermined normal upper working level between said predetermined lower limit and said predetermined upper limit for terminating displacement of the block in said tank.

Claim 8

In apparatus as set forth in claim 5: said means for displacing the block downwardly comprising a first probe in said tank; said means for displacing the block upwardly comprising a second probe in said tank at a lower level than said first probe; and said means for terminating displacement of the block comprising a third probe in said tank intermediate said first and second probes.

Claim 9

In a system for controlling the height of a variable level, electrically conductive, fluent material in a reservoir: means associated with the reservoir for electrically grounding the fluent material contained therein; an upper probe of electrically conductive material extending into the reservoir to a predetermined maximum level limit for the fluent material; , a lower probe of electrically conductive material extending into the reservoir to a predetermined minimum level limit for the fluent material; an intermediate probe of electrically conductive material extending into the reservoir to a predetermined operating level for the fluent material intermediate said maximum and minimum levels; means electrically insulating said three probes from the reservoir and from each other; means including an electric circuit respoNsive to a grounding of said upper probe through the fluent material for lowering the level of fluent material in the reservoir; means including an electric circuit responsive to a removal of ground from said lower probe by removal of the fluent material therefrom for raising the level of fluent material in the reservoir; and means including an electric circuit responsive to a change in condition of said intermediate probe to remove ground from said intermediate probe or to ground said intermediate probe for deactivating said level lowering means and said level raising means.

Claim 10

In a system for controlling the height of a variable level, electrically conductive, fluent material in a reservoir: means associated with the reservoir for electrically grounding the fluent material contained therein; an upper probe of electrically conductive material extending into the reservoir to a predetermined maximum level limit for the fluent material; , a lower probe of electrically conductive material extending into the reservoir to a predetermined minimum level limit for the fluent material; an intermediate probe of electrically conductive material extending into the reservoir to a predetermined operating level for the fluent material intermediate said maximum and minimum levels; means electrically insulating said three probes from the reservoir and from each other; means including an electric circuit respoNsive to a grounding of said upper probe through the fluent material for lowering the level of fluent material in the reservoir; means including an electric circuit responsive to a removal of ground from said lower probe by removal of the fluent material therefrom for raising the level of fluent material in the reservoir; and means including an electric circuit responsive to a change in condition of said intermediate probe to remove ground from said intermediate probe or to ground said intermediate probe for deactivating said level lowering means and said level raising means.

Claim 11

In a level control system as set forth in claim 7, wherein the fluent material in the reservoir is molten solder; said level lowering means and said level raising means both including a block of heat radiating material displaced vertically in the molten solder to vary the solder level in the reservoir; and means for conveying an article first past said block to be heated by radiation therefrom and then into contact with the molten solder in the reservoir.

Claim 12

In apparatus for applying solder to an article: a tank for containing molted solder, the tank having an entry section; means for advancing the article across said entry section and then into contact with solder in the tank; a body of heat radiating material; means for mounting the body of heat radiating material partially submerged in molten solder in said entry section to transmit heat from the solder to the article advance across the entry section toward contact with the solder; and means responsive to a variation in the level of solder in the tank across a predetermined limit level for moving the body of heat radiating material vertically in a direction selected to bring the level of solder in the tank within said predetermined limit lever.

Claim 13

In apparatus for applying solder to an article: a tank for containing molted solder, the tank having an entry section; means for advancing the article across said entry section and then into contact with solder in the tank; a body of heat radiating material; means for mounting the body of heat radiating material partially submerged in molten solder in said entry section to transmit heat from the solder to the article advance across the entry section toward contact with the solder; and means responsive to a variation in the level of solder in the tank across a predetermined limit level for moving the body of heat radiating material vertically in a direction selected to bring the level of solder in the tank within said predetermined limit lever.

Claim 14

In a system for soldering articles successively advanced into contact with molten solder in a bath: first sensor means for generating a signal indicative of a level of the solder in the bath below a predetermined lower limit; second sensor means for generating a signal indicative of a level of the solder in the bath above a predetermined upper limit; third sensor means for generating a signal indicative of a change in the level of solder in the bath to vary across a predetermined intermediate level between said predetermined lower and upper limits; a displacement block mounted for vertical movement in the bath; means responsive to a signal from said first sensor means for lowering and displacement block to raise the level of solder in the bath; means responsive to a signal from said second sensor means for raising the displacement block to lower the level of solder in the bath; and means rendered effective during movement of the displacement block and responsive to a signal from said third sensor means for terminating movement of the displacement block.

Claim 15

In a system for soldering articles successively advanced into contact with molten solder in a bath: first sensor means for generating a signal indicative of a level of the solder in the bath below a predetermined lower limit; second sensor means for generating a signal indicative of a level of the solder in the bath above a predetermined upper limit; third sensor means for generating a signal indicative of a change in the level of solder in the bath to vary across a predetermined intermediate level between said predetermined lower and upper limits; a displacement block mounted for vertical movement in the bath; means responsive to a signal from said first sensor means for lowering and displacement block to raise the level of solder in the bath; means responsive to a signal from said second sensor means for raising the displacement block to lower the level of solder in the bath; and means rendered effective during movement of the displacement block and responsive to a signal from said third sensor means for terminating movement of the displacement block.

Claim 16

In a system as set forth in claim 10, the molten solder in the bath having a first temperature and the articles successively advanced into contact therewith having an initial second temperature lower than said first temperature: said displacement block being composed of a heat radiating material disposed projecting partially out of the molten solder in the bath toward the advancing articles to preheat the advancing articles above said second temperature prior to contact of the articles with the solder.

Claim 17

In an apparatus for solder-coating elements projecting from the under surface of a planar mounting board; a tank holding molten solder; a block of heat radiating material partially submerged in the solder and having an upper heat radiating surface which is at an acute angle with respect to the surface of the solder; a conveyor for advancing mounting boards along a path which is parallel to the heat radiating surface and then parallel to the surface of the solder; and means responsive to changes in the level of the solder for movinG said block to maintain the level of the solder at a height sufficient to submerge the projecting elements while the mounting board is advancing parallel to the surface of the solder.

Claim 18

In an apparatus for solder-coating elements projecting from the under surface of a planar mounting board; a tank holding molten solder; a block of heat radiating material partially submerged in the solder and having an upper heat radiating surface which is at an acute angle with respect to the surface of the solder; a conveyor for advancing mounting boards along a path which is parallel to the heat radiating surface and then parallel to the surface of the solder; and means responsive to changes in the level of the solder for movinG said block to maintain the level of the solder at a height sufficient to submerge the projecting elements while the mounting board is advancing parallel to the surface of the solder.