US3030838A - Hydraulic pump-up tool - Google Patents

Description

April 24, 1962 M. KLINGLER 3,030,838

HYDRAULIC PUMP-UP TOOL Filed Feb. 24, 1955 2 sheets-sheet 1 INVENTOR. Martin Lmanglev Aprll 24, 1962 Mv. l.. KLINGLER 3,030,838

HYDRAULIC PUMP-UP TOOL Filed Feb. 24, 1955 2 Sheets-Sheet 2 Matn L. Khngler 3,030,838 HYDRAULIC PUMP-UP TGL Martin L. Klingler, Hershey, Pa., assigner 'to AMP Incorporated, a corporation of New Jersey Filed Feb. 24, 1955, Ser. No. 490,377 Claims. (Cl. 81-15) This invention relates to hand-operated hydraulic tools for crimping a connector onto an electric wire.

The crimping of a connector onto an electric wire has developed into a highly specialized art. To obtain maximum efliciency in an electrical circuit, it is necessary to attach the connector to the wire in such a manner that the resistance at the junction of the wire and the connector is at least as low as the resistance of the wire. This is accomplished by crimping the connector onto the wire with a force great enough to cause a compaction of the metal of the wire and the connector so that the result is a jointure of the two. While it is possible to exert a large crimping force in a machine press, it is not always convenient to employ such a machine. Thus, it is particularly advantageous to provide a hand-operated crimping tool capable of producing the large force necessary to effect an ecient crimp (i.e. a force in the neighborhood of six tons). Certain hydraulic hand tools now in use have, for one example, the disadvantage of developing a vacuum in the iluid chamber of the tool which tends to prevent Vthe free flow of fluid.

An object of the present invention is to provide a hydraulic, hand-operated crimping tool which has a means for insuring the free ow of fluid within the tool at all times.

Another object of this invention is to provide a hydraulic, hand-operated crimping tool which has a linkage between the body of the tool and the handles so as to provide a mechanical advantage.

Another object of this invention is to provide a hydraulic, hand-operated crimping tool which employs a special type of uid release mechanism that prevents the operator from inadvertently emptying the fluid from the tool.

Other important features and objects of the invention to which reference has not been made hereinabove will appear hereinafter when the following description and claims are considered with the accompanying drawings, in which:

FIGURE l shows a fragmentary cut-away plan view of a tool embodying the concepts of this invention;

FIGURE 2 is a cross-sectional w'ew taken at 2-2 of FIGURE l;

FIGURE 3 is an exploded view of a part of the hydraulic system used in this device;

FIGURE 4 is a cross-sectional view taken along line 4 4 of FIGURE'I. This view 4represents the initial stage of the operation;

FIGURE 5 is a view similar to FIGURE 4, illustrating the ram-cylinder during the intake stage; and

FIGURE 6 is a View similar to FIGURE 4 showing the relationship of parts in the linal stage of the operation.

The particular crimping tool shown in the drawings includes an upper nesting head generally shown at A, a main body B and handlesC. v

The nesting head A constitutes a part of the crimping means. This head forms the subject matter of a separate application Serial No. 389,983, tiled November 3, 1953 in the name of Henry W. Demler for a Crimping Device, now Patent No. 2,762,414, and will only be described in general terms. In brief, it acts to receive the connector and wire during the crimping operation and supports the connector so that the mating die can effect the crimp.

In the preferred embodiment here illustrated, the main body B as shown in FIGURE 4 includes a tubular barll Patented Apr. 24, 1962 rel 10 which forms a cylinder 11 to receive a piston member l2. A cap 14 is threaded at 16 into the outer end of tubular barrel lt). A set screw 18 prevents cap 14 from inadvertently unthreading from barrel 10. A piston rod 2t) projects through the cap and carries a crimping die 22. A spring 24 extends between a shoulder 26 on the inside of the cap and piston 12 to bias the piston away from the cap. A spline 28 on the inside of the cap engages a keyway 30 on the piston to prevent rotational movement of the piston but permits longitudinal movement. Sealing ring 32 forms a Huid-tight seal between piston 12 and cylinder 11. A closure plate 34 with an orifice 36 therein extends across the inner end of cylinder 1l. A hardened insert 38 is positioned in the opening. A cylinder 40 depends from closure plate 34 to form a chamber for receiving a ram 42. The opening 36 in the closure plate forms a luid passageway between cylinder 11 and ram cylinder 40.

In the modication shown and described, a one-way check valve 44 (IFIGURE 5) is urged against a valveseat 46 in passageway 36 by a spring 48 to permit iluid to flow from ram cylinder 4t) to piston-chamber l1, but prevents ilow in the opposite direction.

A second cylinder Si? is coaxially aligned with the first cylinder lt) at the lower surface of closure plate 34. A plate 52 surrounds ram cylinder 40 and has a shoulder 54 which engages the lower edge of the second cylinder 50. A nut 56 threaded over the outwardly projecting end of the cylinder 40 engages plate 52 `and thereby forces shoulder S4 against cylinder 5l) to secure the cylinder against closure Vplate 34. This structure also forms a hollow reservoir `for the reception of liquid. Within the reservoir is an elastic, tubular member 58 which contains the liquid to be used in the system. In this particular modification one end of the elastic tubular member is seated in a recess 60' formed in closure-plate 34. The elastic member is held in place by means of a neoprene O ring 62. The lower end of the elastic tubular member 58 is secured to plate 52 in a similar manner. A breather hole 64 is provided in cylinder 5t)` to permit free expansion and contraction of the elastic tubular member 58. A second liquid passageway 66 connects the reservoir with the ram. A second one-way valve 70 is positioned on a valve seat 72 and urged toward said Valve seat by a spring 74, to allow the liquid to tlow from the reservoir to the ram cylinder but to prevent flow in the opposite direction. Valve seat 72 is threadedly attached to the closure plate and has a guard 76 surrounding it. The guard is comprised of a tubular member having one open end which receives the valve seat. The other end of the guard is closed and an opening 7 8 is positioned in one side of the guard. The opening in the guard is `located in the vicinity of the longitudinal axis of the tool body. This guard prevents the elastic member 58 from blocking the passageway of valve seat 72 when the liquid is pumped out of the reservoir and the elastic tubular member 5S is partially collapsed. By placing the guard opening in the vicinity of the longitudinal axis of the tool body, a supply of liquid is available `for use in the system regardless of the position of the tool. If the opening were placed on the left side of the guard, as viewed in FIGURE 4, and the tool were used with the left side facing upwardly, the liquid would seek its own level and the passageway would suck air into the system. ABy placing the opening near the center of the tool, this condition is avoided.

In the preferred modilication a bottom plate 80 is Secured to the plate 52 by filler cap screws 8l. The bottom plate 80 has an opening 82 to accommodate the ram. A pair of ears 83, 84 depend from plate 80 and support a pair of pivot pins 86, 88, A pair of links 90, 92 are pivotally secured to pivot pins 86, 88, i.e. one link to each pin. The opposite ends of the links are pivoted to handles 94, 96 by pivot pins 98 and t100 respectively. The handles are also commonly pivoted to the ram 42 by means of a pivot pin 102. This toggle linkage between the handles 94 and 96 provides a mechanical advantage when the handles are operated to actuate the ram.

A passageway extends through the bottom plate 80 and the plate 52 to provide a means for filling the reservoir. The filler cap screw 81 threads into this passageway. Several of these passageways are provided so that one passageway will act as a breather when the liquid is supplied to another passageway.

The modification shown in the drawings has a by-pass passageway 106 provided between the opening 36 in the closure plate and the elastic tubular member 58. Seated in by-pass passageway i106 is a release valve comprised of a valve body 108 which is urged against valve seat 110 by a threaded member 112. Unthreading member 112 approximately one revolution releases valve body 108 from valve seat 110, permitting the liquid to by-pass valve 44 and flow through passageway 106 into the elastic tubular member 58. A spring-loaded stop member 114 (see FIGURE 2) engages a stop member 116 on threaded member 112, thus preventing threaded member 112 from completing more than one revolution. Stop member 116 is composed of a screw which threads into and projects through a tapped bore in threaded member 112.

In the preferred embodiment threaded member 112 is a screw-like member with a plurality of tapped bore holes in the head. In assembly member 112 is threaded into an opening 118 which communicates with by-pass opening 106. The threaded member 112 is tightened until the inner end of the threaded member seats the valve tightly against the valve body. Then stop member 116 is threaded into the bore hole in the head that is closest (in a counter-clockwise direction) to the spring-loaded stop member 114. This enables the operator to rotate threaded member 112 approximately one revolution in a counter-clockwise direction and no farther-thus insuring against the possibility of inadvertently removing screw member 1112.

An overload-release valve 120 (see FIGURE l) is also provided to protect the hydraulic system from too great a pressure. A second by-pass passageway 122 is provided between the opening 36 and the elastic tubular member 58. A conically shaped valve body 124 is urged against a complementary valve seat 128 by a spring 13-0 which acts against a backing piston 132. Thus, when a predetermined pressure builds up in the system, the liquid exerts a force against valve body 124 to overcome the pressure exerted by spring 130 against valve piston 132. This causes the valve body to unseat and `'allows the liquid to escape into the elastic tubular member 58.

As shown in FIGURE 3, the elastic tubular member 58 is belled outwardly in the central portion. Thus, when it is confined within the cylinder 50 the elastic member will be somewhat wrinkled (see FIGURES l and 4) and will not be ilush with the cylinder 50. Confining the elastic under pressure causes the elastic to exert a force on the liquid to provide a free flow of liquid `through the system. This arrangement also prevents the elastic member from adhering to the cylinder 50 and provides for the free contraction of the elastic member.

It is noted that sealing means are provided wherever necessary throughout the tool.

Operation The tool is lled with liquid and assembled to the state shown in FIGURE 4. A terminal is inserted between the upper and lower dies. With release valve 108 etc. closed, handles 94, 96 are alternately separated and then brought together. When the handles are separated ram 42 is moved downwardly (see FIGURE 5), drawing liquid from the reservoir through opening 78 into guard 76, through one-way valve 70, 72, through the passageway 66 and into ram cylinder 40. When the handles are brought together again, the ram is moved upwardly. The one-way valve 70, 72 prevents the liquid from returning to the reservoir. Thus, the liquid is forced through opening 36, past one-way valve 44, 46 and moves piston 12 against the action of spring 24. A series of strokes on the handles will cause the liquid to be extracted from the elastic tubular member 58 with a corresponding deformation of this member, see FIGURE 6. The liquid will raise the piston 12, and force die 22 against the die nest with a pressure sufficient to provide an extremely efficient crimp; in the particular tool shown herein the die exerts a force on the order of six tons opposed by the die nest.

As the resistance of the crimping action becomes greater, the effort required to make strokes will increase. Because of this fthe strokes may advantageously be made shorter as the ram becomes more difcult to work. This will permit `the operator to utilize all the power in a series of short strokes, since the work is performed in an area close to the body, and with the toggle mechanism operating through the range where it generates the maximum force multiplication. A sudden decrease in the eort required to make the stroke denotes that the maximum pressure has been attained and the overload by-pass valve has been opened. When this condition occurs the operator knows that the crimp is secure. This arrangement assures that a crimp of optimum tightness shall be made automatically.

To release the tool the by-pass release valve 108 etc. is opened by rotating screw member 112 in a counterclockwise direction. Stops 114 and 116 will prevent it from being turned more than one revolution. This releases valve body 108 from valve seat 110. The spring 24 urges the piston 12 downwardly to force the liquid out of the piston chamber, through opening 36 in the closure plate, through passageway 106 and back into the elastic tubular member 58. The one-way valve 44 prevents liquid from being forced back into ram cylinder 40. Then the release valve is closed and the tool is ready for another operation.

It is noted (see FIGURE 6) that the contraction of the elastic tubular member 58 does not block the fluid passageway. This is due to the presence of guard 76 which prevents the elastic tubular member from covering the opening in valve seat 72.

Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective against the prior art.

I claim:

l. In a hydraulic hand tool for crimping an electrical connector onto a conductor, of the type having a body member with a crimping die which is urged toward a die nest by hydraulic means, the hydraulic means being actuated by a hand operated pump, the subcombination comprising valving means in said tool body for causing said hydraulic means to urge said crimping die by a plurality of increments: a longitudinally movable ram mounted in the body of the tool, a pair of handles, link means pivoted between the body and each of said handles, and the handles also being pivoted to the ram to form a toggle linkage.

2. A hydraulic hand tool `for crimping electrical connectors, including a tool body, handle means associated with the body means, piston operated means in the tool body for crimping the connector, and means for operating said piston operated means including a fluid chamber longitudinally disposed in said tool body, a ram movable in the chamber, toggle linkage means connected to said handle means and said ram `for actuating the ram, said toggle linkage means comprising a link means in pivotal engagement with the body and said handle means, a lluid reservoir communicating with the chamber, means for causing uid to be transported from the reservoir to the chamber when lthe ram is moved in one direction, and causing it to be transported to the piston operated means under pressure when the ram is moved in the 0pposite direction, valving means in said tool body communicating with said chamber for causing the fluid to be transported in a plurality of increments and means for returning the fluid to the reservoir after the crimp is completed.

3. The `device of claim 2 wherein the uid reservoir is elastic and contracts when fluid is taken from the reservoir and expands when fluid is returned to the reservoir.

4. The `device of `claim 2 including a fluid inlet in the chamber, said inlet located near the longitudinal axis of the tool.

5. In a portable hydraulic ram type tool having Work engaging elements, a pair of handles lying in a single plane, a body member containing a ram feed pump, and a closed luid system including the ram cylinder, the feed pump and a iluid reservoir, valving means in said tool body communicating with said chamber for causing the fluid to be transported in a plurality of increments, said feed pump being disposed with its plunger disposed between and in the plane of the handles and substantially parallel to the axes of said handles, and a variable mechanical advantage linkage between the handles and the ram, including at least one of said handles in pivotal engagement with the ram, and link means pivoted between said handles and said body.

References Cited in the le of this patent UNITED STATES PATENTS 343,780 Tewksbury June 15, 1886 2,096,574 Denny Oct. 19, 1937 2,352,390 Kirkland June 27, 1944 `2,555,421 Ronan June 5, 1951 2,696,850 Peterson Dec. 14, 1954 2,714,250 Twedt Aug. 2, 1955 2,729,063 Hoadley Ian. 3, 1956 2,765,688 Evans Oct. 9, 1956 2,869,407 Swanson Ian. 20, 1957 FOREIGN PATENTS 1,097,092 France Feb. 9, 1955 233,340 Great Britain Mar. 18, 1926

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