US3818539A

US3818539A - Desoldering implement

Info

Publication number: US3818539A
Application number: US00364082A
Authority: US
Inventors: W Fortune
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-05-25
Filing date: 1973-05-25
Publication date: 1974-06-25
Anticipated expiration: 1991-06-25
Also published as: IT1010021B; BE815531A; SE392226B; GB1419724A; DE2424233A1; FR2230424B1; FR2230424A1; JPS5815631B2; JPS5016363A; DK236274A; DK141546B; DK141546C; CH571780A5; CA1002710A

Abstract

A hand held, hand operated tool is disclosed which has an outer cylindrical body and an inner, spring loaded plunger-piston assembly. The piston may be cocked and then held by a trigger mechanism in a forward position next to a nozzle or tip member. When the trigger is released, the piston flies back rearwardly drawing a sharp impulse of air into the cylindrical body through the nozzle member. A cocking shaft affixed to the plunger extends rearwardly out of the body and may be pushed forwardly into the body for each desired cocking stroke. A sheath for the cocking shaft is also carried by the body and is movable axially thereon. The rearward end of the sheath is closed and is engaged by the hand of the operator to push the cocking shaft into the cylindrical body of the implement. The cocking sheath is then returned by a second, light spring to its fully extended position, while the cocking shaft is held forwardly by the trigger mechanism. The cocking sheath provides both a handle and a protection covering for the cocking shaft. The tip element is frictionally held within the forward end of the cylindrical body and is cleaned with each cocking stroke by the passage therethrough of a cleaning shaft affixed to and extending forwardly from the piston. When the cocking shaft is urged extraordinarily forwardly, the tip is particularly thoroughly cleaned and by further pushing of the cocking plunger, the tip member is ejected as for inspection, cleaning, or replacement. A reading of the complete specification is recommended for a full understanding of the principles and features of the disclosed tool.

Description

United States Patent [191 Fortune 5] June 25, 1974 DESOLDERING IMPLEMENT William S. Fortune, 14250 Dearborn St., Panorama City, Calif.

[22] Filed: May 25, 1973 [21] Appl. No.: 364,082

[76] Inventor:

[52] US. Cl 15/341, 15/339, 15/344,

228/20 {51] Int. Cl. A471 5/02, A471 5/24 [58] Field of Search 15/341, 344, 339; 228/20 [56] References Cited UNITED STATES PATENTS 12/1963 Fortune 15/341 X 8/1966 Fortune 228/20 Primary Examiner-Harvey C. Homsby Assistant ExaminerC. K. Moore Attorney, Agent, or Firm-Daniel T. Anderson drawing a sharp impulse of air into the cylindrical body through the nozzle member. A cocking shaft affixed to the plunger extends rearwardly out of the body and may be pushed forwardly into the body for each desired cocking stroke. A sheath for the cocking shaft is also carried by the body and is movable axially thereon. The rearward end of the sheath is closed and is engaged by the hand of the operator to push the cocking shaft into the cylindrical body of the implement. The cocking sheath is then returned by a second, light spring to its fully extended position, while the cocking shaft is held forwardly by the trigger mechanism. The cocking sheath provides both a handle and a protection covering for the cocking shaft.

The tip element is frictionally held within the forward end of the cylindrical body and is cleaned with each cocking stroke by the passage therethrough of a cleaning shaft affixed to and extending forwardly from the piston. When the cocking shaft is urged extraordinarily forwardly, the tip is particularly thoroughly cleaned and by further pushing of the cocking plunger, the tip member is ejected as for inspection, cleaning, or replacement. A reading of the complete specification is recommended for a full understanding of the principles and features of the disclosed tool.

4 Claims, 8 Drawing Figures 1 DESOLDERING IMPLEMENT BACKGROUND OF INVENTION Field of the Invention The invention relates generally to removing or lifting or drawing away, by air suction technique, small quantities of particulate, liquid, or molten matter and particularly to apparatus improvements in hand held, hand operated vacuum stroke cleaning devices. The present invention finds particularly useful application in the field of soldering, desoldering, and rewiring in electronic laboratories, maintenance shops, factories, or hobbyists benches; and although, in the case of clarity and brevity, much of the following discussion and description of examples of the invention are directed theretoward, it is expressly to be understood that the advantages of the invention are equally well manifest in other fields wherever and whenever substances are to be removed or cleaned from an object such, for further example, in medical or dental fields as in removal of foreign objects or unwanted substances from portions of the body including the eye, ear, nose, throat, or open wound or the like.

Background of the Invention In the electrical arts as mentiondgit, is often desired to desolder an electrical connection such as, for example, a wire wrapped terminal, a wirci to circuit board eyelet, or the like. The removal from the connection, of the molten solder without dropping or spattering it onto other portions of the equipment is generally essential. Blowing or shaking the molten metal away is therefore not an acceptable practice; and, in combination with its high mass density, the high surface tension associated with the solder makes its removal particularly difficult. Furthermore, the problem is aggravated by the requirement that the solder be removed quickly and without application of cooling means before the mechanical connection such as a wire-wrapped terminal may be taken apart.

Various non-portable central vacuum systems and highly portable and efficient hand held vacuum stroke tools have advanced the state of the art and have solved certain aspects of the desoldering problems outlined; however, the former suffer from disadvantages of cost, complexity, lack of versatility, and non-portability while the latter suffer from some disadvantages, to a lesser extent, of cost and complexity, and, in some applications, undesirable recoil due to the flyback action of the piston cocking shaft-knob assembly during the vacuum stroke. Typically, in these prior art devices the cocking shaft which functions as a connecting rod between the piston and the cocking knob must be relatively massive to be strong enough to cock the piston against a relatively strong loading spring. Also the cocking knob is typically large and soft, and therefore massive, for comfortable repeated cocking cycles by the hand of the operator. These criteria cause the flyback mass to be relatively large compared to the thinwalled cylindrical housing body; consequently, the outer housing suffers a recoil causing a deflection of the solder inlet tip away from the location of the molten solder.

This recoil caused displacement is particularly intolerable in medical applications such as in removing foreign matter from a childs eye.

Another disadvantage of the abrupt flyback of the shaft and knob is that the eye of the operator during the vacuum stroke is typically disposed near thereto in a position causing risk of eye injury.

It is, accordingly, an object of the present invention to provide improved vacuum stroke, cleaning apparatus which is not subject to these and other disadvantages and limitations of the prior art.

It is another object to provide such apparatus which, while providing consistently a highamplitude of impulse air flow, has no exposed flyback portion and a verylow inertia associated with the flyback portions thereof causing a negligible deflection of the tool during its vacuum stroke.

It is another object to provide such apparatus which has a conveniently lockable and unlockable, compact, space saving configuration for shipping and storage.

It is another object to provide such apparatus which is low in cost and simple, rugged, and reliable in its structure and performance.

It is another object to provide such apparatus which is automatically self-cleaning with each cocking cycle.

It is another object to provide such apparatus having readily removable and replaceable tip means particularly in medical uses for assuring the effective sterility of the implement.

SUMMARY OF INVENTION Briefly, these and other objects are achieved in accordance with the structural aspects of an example of the invention in which a hand held, hand operated vacuum stroke cleaning implement is provided which includes a shroud body which holds a cylinder member and a cooperating piston-plunger member axially reciprocally movable therewithin. The piston-plunger member is biased by a mainspring in a direction, hereinafter denoted rearwardly, away from the nozzle or vacuum tip end of the cylinder member.

The plunger member includes a cocking shaft extending rearwardly through the end of the cylinder member opposite from its tip or nozzle end. The cocking shaft also extends rearwardly out of the shroud body and has a length to permit its use to urge the piston-plunger member fully forwardly against its mainspring to a position contiguous to the tip or nozzle end of the cylinder member. A trigger mechanism carried by the shroud body engages the piston-plunger cocking shaft assembly and holds it in the forward position until the trigger mechanism is released permitting the piston to flyback and create a high magnitude impulse of air flow through the tip nozzle member and into the interior of the cylinder member.

A cocking sheath, also carried by the shroud body, includes skirt portions which extend along retainer slots internally of the shroud body and are axially slidable therealong. The rearward, external end of the cocking sheath is effectively closed and, when the cocking sheath is inserted fully within the shroud body, the closed end engages the rear end of the cocking shaft and forces it forwardly to its cocked position. Thusly, the cocking shaft is operated, or cocked, without direct contact by the hand or finger of the operator and therefore needs no massive knob or cushion carried thereby.

Once the cocking shaft is driven fully forward to its cocked position, a cocking sheath return spring replaces the sheath to its rearward, fully extended, or relatively fully withdrawn position. The trigger may then be released, when desired, for a rapid flyback of the piston and cocking shaft. Because the cocking shaft is within the fully extended cocking sheath, there is no danger or risk of injury to the operator even though the cocking shaft is bare of any protective knob or cushion. The safety and low inertia advantages of the cocking shaft cocking sheath subcombination are accordingly manifest.

Sheath locking means are provided for holding the sheath in its fully inserted, forward position in a compact configuration for shipping and for bench or toolbox storage. The compact arrangement also provides additional protection to the sheath and cocking shaft during periods of non-use.

Further details of these and other novel features and their operation and cooperation as well as additional objects and advantages of the invention will become apparent and be best understood from a consideration of the following description taken in connection with the accompanying drawing which is provided by way of illustrative example only.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of an example of a vacuum stroke cleaning implement constructed in accordance with the principles of the present invention, the implement being illustrated in an uncocked or unloaded configuration;

FIG.,2 is a similar view partially broken away to reveal interior detail of portions of the major elements of the instrument;

FIG. 3 is a longitudinal sectional view of the structure of FIG. 2 taken along the section reference lines 3-3 thereof;

FIG. 4 is a plan view of the apparatus of FIG. 1 illustrated during the cocking cycle;

FIG. 5 is an exploded view of that portion of the structure of FIG. 2 indicated by the reference numerals 5-5 thereof;

FIG. 6 is a longitudinal sectional view of the trigger portion of FIG. 3 taken along the section reference lines 6-6 thereof;

FIG. 7 is a plan view of the structure of FIG. 1 shown in a storage configuration; and

FIG. 8 is a plan view like that of FIG. 4 in which a tip ejection operation is illustrated.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT With specific reference now to the figures in detail; it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and structural concepts of the invention. In this regard, no attempt is made to show structural details of the apparatus in more detail than is necessary for a fundamental understanding of the invention. The description taken with the drawing will make it apparent to those skilled in the mechanical arts how the several forms of the invention may be embodied in practice. Specifically, the detailed showing is not to be taken as a limitation upon the scope of the invention which is defined by the appended claims forming, along with the drawing, a part of this specification.

In FIG. 1, the example of the vacuum stroke cleaning implement 10 illustrated includes a cylindrical body member 2 having an open forward end 14 and a substantially closed, plunger shaft journal supporting rear end 16. A trigger assembly 18 which cooperates with the plunger shaft is carried by the rear end 16 of the body member 12.

A vacuum cylinder 20 is carried by and partially enclosed within the body member 12. In this example, the cylinder 20 is molded of a rigid transparent plastic for visibility therewithin as for inspection purposes. A tip and

nozzle assembly

22, 24 is removably carried by the forward end 26 of the cylinder 20.

A cocking sheath 28 is also carried by the body member 12 and has a pair of retainer

tongue side members

30, 32 which extend forwardly, axially slidingly into retaining channels (shown in subsequent figures) of the body member 12. The rear end portion 34 of the cocking sheath is essentially closed and is formed to include a cocking shaft engaging anvil surface 36. A cocking sheath return spring 38 is axially compressively retained within the cocking sheath between the end portion 34 and the rear end 16 of the body member 12. Each of the retainer

tongue side members

30, 32 is provided with a latching aperture 40 which cooperates with a latching lug (shown in subsequent figures) carried on the inner surface of each of a pair of flexible locking tabs 44 carried by the rear end of the body member 12. The latching lugs may be inserted into the latching apertures 40 when desired to retain the cocking sheath in a protective, compact relation with the body member 12 as for shipping or toll box storage of the tool, the cocking sheath being otherwise returned to its axially extended position, as shown, by the return spring 38. i

In FIG. 2 further details of the major elements of the tool 10 are shown in a partially cut-away version of the previous figure. For example, the entire length of the transparent cylinder 20 is exposed and it may be noted that the cylinder is a simple, hollow and thin walled, right circular cylinder open at both ends, the only irregularity being a pair of locking shoulders 46 which slide along guiding channels, not shown, formed in the inner surface of the body member 12, and achieve a bayonet type of locking engagement with mating structure, shown in subsequent figures, of the body member 12 and disposed at the rear end 16 thereof.

Also exposed in FIG. 2 is the forward end of one of the retainer tongue members 32. The cocking sheath 28 is held to the body member 12 by a retainer lug 48 molded integrally with the forward tip end of each of the tongue members. The retainer lugs slide axially along respective cooperative grooves formed in the inner surface of the body member 12 and are held from ejection to the rear by a stopping edge 50 on the body member 12. The latching lug portion 52 of the flexible latching tab 44 is also shown.

The piston-plunger assembly 54 is shown and includes a piston 56 and piston o-ring 58 disposed in vacuum pump relation within the cylinder 20. A tip cleaning rod 60 is carried by the plunger assembly and extends forwardly therefrom into the nozzle 20 when the piston is pushed into its cocked position. A relatively stiff vacuum stroke or recoil spring 62 is connected axially in tension between the piston 56 and the rear end portion 16 of the body member 12.

In FIG. 3, the retaining, guide

channels

64, 66 in the body member 12 for the retaining lugs 48 of the

tongue members

30, 32 are shown. The retaining and guiding channels are molded in the inner surface of the body member 12 and may extend essentially for the entire length thereof. Also to be noted from this view is the sheath-like nature of the body member 12 with respect to the cylinder 20. The annular spacing 67 between the two cylindrical elements serves two particularly useful functions: first, the space provides a guideway for the axially slidable tongue,

side members

30, 32 of the cocking element 28; and, secondly, the space serves as a baffle for the output of air from the vacuum pump stroke of the piston plunger 54. Exhaust air from the cylinder is released into the annular space 67 through an exhaust aperture 68 near the rear of the cylinder 20. From there, the air is forced abruptly forwardly along the outer surface of the cylinder and finally into the surrounding atmosphere about the tip of the instrument. The baffling tends to cause the precipitation within the annular space 67 of tiny bits of solder or droplets of lubricant or other foreign matter. Thus delicate electronic circuitry and the like is protected from contamination or other such damage. As is apparent from later figures, the surfaces bounding the annular space may be readily cleaned of the collected foreign matter.

With reference to the piston-plunger assembly 54, it may be understood from this view that the cleaning rod 60 is a forwardly directed extension of a plunger mounting rod 70 upon which the piston 56 is mounted and which has a rearwardly extending cocking rod 72, the end 74 of which is engaged by the anvil surface 36 of the cocking sheath 28 suring the manual cocking stroke of the piston assembly. lnlaid within or otherwise affixed to the outer surface of the rear 34 of the cocking sheath may be a soft rubber bumper element 75 for added gripping when the tool is cocked by engaging the end 34 against the workbench and pushing the cocking sheath into the body member 12.

The cocking or vacuum stroke spring 62 is suspended over the plunger mounting rod 70 in tension between its hook end 76 affixed to the rear end portion 16 of the body member I2 and its forward hook end 78 affixed to the rear of the piston 56. When the piston assembly is pushed forward, in its cocking stroke, against the tension of the cocking spring 62, the trigger assembly engages the cocking shoulder 80 of the cocking plunger 72 and holds the piston assembly in its forward disposition, as shown in FIG. 4 until the trigger 82 is pressed to release it and permit it to fly back to its rear, uncocked disposition at the rear of the body member 12.

Also to be noted in FIG. 4 is that in the cocked mode, the tip cleaning rod extension 60 is automatically inserted into the bore 83 of the nozzle 22 thusly to clean it of any foreign material deposited there as during the previous vacuum stroke In FIG. 5, the assembly-disassembly of cylinder 20 and the body member 12 are illustrated. The bayonet type locking shoulders 46 slide axially into guide slots 84 formed, as indicated, in the inner surface of the body member 12. During assembly as, for example, after cleaning and lubricating the cylinder 20, the legend push in" on the cylinder 20 is aligned with the legend in on the barrel of the body member 12; this aligns the locking shoulders 46 with the guide slots 84. Full insertion is then made and the cylinder is rotated a few degrees clockwise to lock the assembly by bayonet type engagement with the dog-leg portions 86 of the rear end of the slots 84.

Also illustrated in FIG. 5 and to be distinguished from the cylinder guide slots 84 are

the'guide slots

64, 66 for the

tongue extensions

30, 32 of the cocking sheath 28.

The exhaust port 68 in the side of the cylinder 20 is shown to be disposed, in this example in line with one of the slots 84 whereby the exhaust air from the vacuum stroke is further confined to flow therealong and be controlled as it leaves the vicinity of the tool. It should be noted that the exhaust port deliberately is not disposed at the extreme rear end of the cylinder 20. As shown most clearly in FIG. 3, the port is forward of the piston ring 58, in the uncocked mode, whereby during the flyback stroke of the piston, a cushion of air is trapped behind the piston to decelerate it gradually and thereby minimize the impact impulse when the spring would otherwise slam against its coiled self and the rear of the body member 12. The cushioning effect minimizes the recoil effect and, consequently, the displacement of the nozzle 22 away from its desired point of application on the work piece.

The trigger mechanism 18 illustrated in FIG. 6 includes a housing formed integrally with the rear portion 16 of the body member 12. A trigger plunger 88 is retained in the bore 89 of the housing by virtue of the plunger mounting rod 72 passing through an opening 90 therein. The opening 90 has a retaining lip 92 which engages the retaining shoulder on the rod 70-72 when the latter is pushed forwardly during the cocking strode. The lip 92 edge may be reinforced by a metal disc 94 emplaced, as shown, on the lower surface of the opening 90. The retaining edge 92 of the trigger plunger 88 is held in engagement with the shoulder 80 by a compression spring 96 retained between the bottom of the bore 89 and the bottom of the trigger plunger 88. When the trigger plunger is depressed, the spring 96 is further compressed and the edge or retaining lip 92 is displaced away from its retaining contact with the shoulder 80. This then permits the flyback of the piston plunger assembly.

When it is desired to displace the rod 70-72 further forwardly as for thorough cleaning of the bore 83 of the tip 22 or for ejecting the tip element 24 by pushing it with the piston 56 (all as shown in FIG. 8), the ratchet action of the trigger retaining lip 92 permits further forward movement of the rod without permitting inadvertent flyback of the piston assembly; since, when released, the retaining shoulder 80 will again be held by the lip 92 until the trigger plunger 88 is deliberately depressed.

Referring to FIG. 7, the flexible latching tabs 44 on the body member 12 are shown with their latching lug portions 52 engaged within the latching apertures 40, not shown, of the tongue members. The latching lug portions 52 are retained within the apertures 40 by the compression of cocking sheath return spring 38. When it is desired to release the cocking sheath from this storage or shipping configuration, one need merely push the cocking sheath forwardly slightly; this permits the resilient tabs 44 to pop outwardly and automatically disengage the latching lugs 52 from the aperture 40. In

turn, then, the cocking sheath 28 is returned by the spring 38 to its fully extended position as shown in FIG. 8.

There has thus been disclosed and described an example of a vacuum stroke cleaning implement which exhibits the advantages and achieves the objects set forth hereinabove. Of particular note are the advantages of low recoil due to the low mass of the piston assembly and the safety to the operator due to the cocking plunger being sheathed during the flyback stroke. The packing-locking features of the cocking sheath are also of special note because of the protection afforded the instrument and the more compact configuration of the tool for storage.

What is claimed is: 1. Vacuum stroke cleaning implement comprising: an elongate body member having a rear, journal end, cylinder means disposed at least partially within said body member; piston means carried by said cylinder means in air pump cooperation relation therewith; piston shaft means affixed to said piston means and having a rear, engaging end portion extending rearwardly therefrom through said journal end of said body member; cocking spring means carried by said body member and being of the character to urge said piston means rearwardly in said cylinder means; first trigger-latch means carried by said body member and being actuable from the exterior thereof; second trigger-latch means carried by said piston shaft means and being cooperative with said first trigger-latch means to retain said piston shaft means in a forward disposition against said urging of said cocking spring means until external actuation of said first trigger-latch means, thereupon providing rearward flyback of said piston means in said cylinder means; cocking sheath means carried by said body member and being axially slidable with respect thereto and having a rear, substantially closed end portion disposed to engage said rear, engaging end portion of said piston shaft means for pushing it forwardly along said cylinder means against said urging of said cocking spring, cocking sheath return spring means disposed compressively between said cocking sheath and said body member for returning said cocking sheath rearwardly and out of engagement with said piston shaft'means; said cocking sheath including retainer-guide portion extending forwardly in engagement with said body member;

said body member including an external shroud portion extending forwardly from said rear, journal end over at least a portion of said cylinder means and defining therebetween cocking sheath retaining slot means for axially slidably receiving and retaining said retainer-guide portion of said cocking sheath means.

2. The invention according to claim 1 which further includes a tip and nozzle member carried by the forward end portion of said cylinder means; and

tip cleaning means including a cleaning rod element carried by and extending forwardly from said piston means and insertable within said nozzle member when said piston means is pushed forwardly against the influence of said cocking spring means.

3. The invention according to claim I in which said cylinder means is of the character to be removably inserted within said body member and includes first cylinder locking means and in which said body member includes second cylinder locking means for cooperatively engaging said first cylinder locking means to lock said cylinder means within said body member.

4. The invention according to claim 1 in which said retainer-guide portion of said cocking sheath includes at least one elongated tongue member.

Claims

1. Vacuum stroke cleaning implement comprising: an elongate body member having a rear, journal end, cylinder means disposed at least partially within said body member; piston means carried by said cylinder means in air pump cooperation relation therewith; piston shaft means affixed to said piston means and having a rear, engaging end portion extending rearwardly therefrom through said journal end of said body member; cocking spring means carried by said body member and being of the character to urge said piston means rearwardly in said cylinder means; first trigger-latch means carried by said body member and being actuable from the exterior thereof; second trigger-latch means carried by said piston shaft means and being cooperative with said first trigger-latch means to retain said piston shaft means in a forward disposition against said urging of said cocking spring means until external actuation of said first trigger-latch means, thereupon providing rearward flyback of said piston means in said cylinder means; cocking sheath means carried by said body member and being axially slidable with respect thereto and having a rear, substantially closed end portion disposed to engage said rear, engaging end portion of said piston shaft means for pushing it forwardlY along said cylinder means against said urging of said cocking spring, cocking sheath return spring means disposed compressively between said cocking sheath and said body member for returning said cocking sheath rearwardly and out of engagement with said piston shaft means; said cocking sheath including retainer-guide portion extending forwardly in engagement with said body member; said body member including an external shroud portion extending forwardly from said rear, journal end over at least a portion of said cylinder means and defining therebetween cocking sheath retaining slot means for axially slidably receiving and retaining said retainer-guide portion of said cocking sheath means.

2. The invention according to claim 1 which further includes a tip and nozzle member carried by the forward end portion of said cylinder means; and tip cleaning means including a cleaning rod element carried by and extending forwardly from said piston means and insertable within said nozzle member when said piston means is pushed forwardly against the influence of said cocking spring means.

3. The invention according to claim 1 in which said cylinder means is of the character to be removably inserted within said body member and includes first cylinder locking means and in which said body member includes second cylinder locking means for cooperatively engaging said first cylinder locking means to lock said cylinder means within said body member.