US3001548A - Apparatus for driving lockbolts and the like - Google Patents

Description

Sept. 26, 1961 G. J. VAN HECKE 3,001,548

APPARATUS FOR DRIVING LOCKBOLTS AND THE LIKE Filed June 10, 1959 3 Sheets-Sheet 1 INVENTOR- fieorye .7, K477 flea/1e,

7 Sept. 26, 1961 APPARATUS FOR DRIVING LOCKBOLTS AND THEVLIKE Filed June 10, 1959 3 Sheets-Sheet 2 WWW INVENTQR.

50 [:85 V56 /4 George J. 14 ficie APPARATUS FOR DRIVING LOCKBOLTS AND THE LIKE Filed June 10, 1959 Sept 26, 1961 G. J. VAN HECKE 5 Sheets-Sheet 3 Patented Sept. 26, 1961 This invention relates generally to apparatus for driving lockbolts and the like and more particularly to an improved control unit for controlling operation of the driving apparatus.

It is desirable, in apparatus for driving lockbolts and similar fasteners, to have an available control unit which can be connected to any suitable source of current and hydraulic power so that a hydraulic fastener applying tool can be operated and controlled by the unit. The control unit of this invention controls the supply of fluid to the tool so as to prevent excessive pressures in the tool and to limit the pressures to only those required for satisfactory tool operation. It is an object of the present invention, therefore, to provide a control unit capable of performing these functions and which is of a compact portable construction by virtue of the inclusion in the unit of a compact multiple function hydraulic valve unit.

A further object of this invention is to provide a control unit which is simple in construction, economical to manufacture and efiicient in operation in controlling the supply of fluid pressure to a fastener applying tool.

Further objects, features and advantages of this invention will become apparent from a consideration of the following description, the appended claims and the accompanying drawing in which:

FIGURE 1 is an elevational view of the control unit of this invention, shown in assembly relation with a fastener applying tool, with some parts broken away and other parts shown in section for the purpose of clarity;

FIG. 2 is an enlarged sectional view taken substantially along the line 22 in FIG. 1;

FIGURE 2a is a fragmentary view of the portion designated 2a in FIGURE 2 with the valve shown therein in a position off the associated valve seat;

FIG. 3 is a sectional view looking along the line 33 in FiG. 2;

FIG. 4 is a sectional view looking the line 4-4 in FIG. 2;

FIG. 5 is a sectional View, illustrated similarly to FIG. 4, showing the valve spool in a moved position relative to the position shown in FIG. 4; and

FIG. 6 is a diagrammatic view of the hydraulic circuit in the apparatus of this invention.

With reference to the drawing, the control unit of this invention, indicated generally at 10, is illustrated in FIG. 1 in assembly relation with a fastener applying tool 12. The tool 12 includes a nose assembly 14 having gripping jaws 16 associated with a piston 18 which is mounted for reciprocal movement in a cylinder portion 20 of the tool 12. A depending handle 22 on the tool 12 carries a trigger 24 mounted for operating a switch 26 for a purpose to appear presently.

When fluid under pressure is supplied through a passage 28, hereinafter referred to as the pressure passage, to the cylinder portion 20, the piston 18 is moved in a direction to move the jaws 16 inwardly of the nose assembly 14. Such movement, when the jaws have been applied to a fastener, is effective to either fully or partially set the fastener. The piston 18 has a valve member 30 extended therethrough and urged by a spring 34 toward a seat 32 formed on the piston. Movement of the piston 13 toward the rear end of cylinder portion 20 is terminated by engagement of the valve member 30 with a stop memsubstantially along ber 36 which moves the valve member 30 oh? the seat 32 so as to fluid-communicate opposite sides of the piston 18. When fluid under pressure is supplied to the cylinder portion 20 through a passage 38 in the handle, hereinafter referred to as the return passage, the fluid is applied to the opposite side of the piston so that the piston is moved in a return direction to move the jaw 16 in a direction outwardly of the nose assembly 14 for application to another fastener.

The switch 26 is electrically connected to the unit 10 by a conductor 40 which is plugged into a socket42 on a casing 44 for the unit 10. The pressure passage 28 is connected by a flexible line 46 to the unit 10 and the return passage 38 is connected by a corresponding flexible line 48 to the unit 10.

The unit 10 consists of the casing 44 which is provided with a handle 47 to facilitate transport thereof, and a hydraulic valve unit 49, a step-down transformer 50, and a relay 52, which are mounted on and enclosed within the casing 44. The valve unit 49 consists of a valve body 54 (FIGS. 2, 3 and 4) which is provided with a main fluid passage 56 connected through a transverse passage 62 to a pump, indicated diagrammatically at 58 in FIG. 5 and illustrated as being driven by a motor 60.

A tank 64 is connected by a line 66 to the pump 58 and by a line 68 to the valve body 54. The line 68 is connected to a pair of passages 70 and 72 in the valve body 54 which communicate with the main passage 56 on opposite sides of the pump passage 62.

The pressure line 46 communicates through a passage (not shown) with passages 74 and 76 which connect with the main passage 56 at a position between the supply passage 62 and the tank passage 72. The return line 48 communicates through a passage (not shown) with passages 78 and 80 which connect with the main passage 56 at a position between the supply passage 62 and the tank passage 70. A valve spool member 82 is mounted for reciprocating movement in the main passage 56 and is provided with lands 84, 86 and 88 which are of a diameter to flt within reduced portions 90, 92, 94, 96 and 98 of the main passage 56 in a substantially fluid-tight relation therewith.

The spool member 82 is connected at one of its ends to a solenoid assembly 100 mounted on the valve body 54. The opposite end of the spool 82 is formed with an axial cavity 101 in which one end of a spring 102 is positioned and the opposite end of which is retained on the body 54 by a cap 104. The spring 102 continually exerts a force on the spool member 82 which urges the spool member 82 upwardly as shown in FIG. 2. When the solenoid 100 is deenergized, the spring 102 maintains the spool member 82 in the position shown in FIG. 2 in which a flange 1% at the spring-urged end of the spool engages a shoulder 108 on the body 54. In this position of the spool member 82 the land 86 is positioned in the passage portion 24 so as to block communication of the pump passage 62 with the pressure passage 80 which is in communication with the tank passage 70. The land 84 is positioned in the main passage portion so as to block communication of the tank passage 72 with the return passage 76 which communicates through the main passage 56 with the pump passage 62.

When the solenoid is energized, the spool 82 is moved to a position shown in FIG. 5 in which the flange 106 engages the cap 104 and the land 86 is within the passage portion 92 so as to block communication of the return passage 76 with the pump passage 62 which is then in communication with the pressure passage 80. The land 88 is positioned in the cylinder portion 6 so as to block communication of the tank passage 70 with the pressure passage 78. The tank passage 72 communicates with the return passage 76 through the main passage 56,

A bore 110 in the body 54 parallel to the main passage 56 communicates through a passage 112 with the tank line 68. An idler valve member 114 is mounted in the bore 110 for reciprocating movement and is urged by a spring 116, which is retained in the bore 110 by a cap 118, is a downward direction as viewed in FIG. 2. Aplug member 120 inserted in the lower end of the bore 110 has a passage 122 which connects the bore 110 with the return passage 74. The valve member 114 has a reduced and tapered lower end portion 124 which is urged by the spring 116 into a seated position on the plug 120 in one end of the passage 122. Because the portion 124 which seats on the end of the passage 122 is of a reduced size, a greater pressure is required to move the valve member 114 ofl its seat than is required to maintain the valve member 114 in a position oif its seat.

A second bore 130, which is perpendicular to and is located to one side of the main passage 56, communicates through a passage 132 with the bore 110 and through a passage 134, with main passage 56. As shown in FIG. 3, the passage 134 intersects the main passage 56 at a position diametrically opposite the pump passage 62. A relief valve member 136 is mounted for reciprocal movement in the passage 130 and is urged by a spring 138, that is held on the body 54 by a retainer cap 139, toward a position seated in one end of a passage 140 formed in a plug memher 142 inserted in the bore 130. The plug passage 140 communicates with the passage 134 so that when the relief valve member 136 is moved off its seat, the pump passage 62 communicates with the tank passage 112.

In the use of the control unit 10, the conduit 40 is plugged into the socket 42 and the transformer 50 and relay 52 are connected to a source of 110 volt current. The transformer 50 steps this voltage down to about 24 volts to reduce the electrical hazard at the tool 12 and the relay 52 has contacts which are closeable to provide for the necessary 110 volts to operate the solenoid assembly 100. When the trigger member 24 is operated to close the switch 26, the solenoid assembly 100 is energized to move the spool member 82 to the position illustrated in FIG. 5 so that fluid at a relatively high pressure flows from the pump 58, through a filter 141, through the pump passage 62, the main passage 56, the pressure passages 78 and 80, the pressure line 46, and the pressure passage 28 in the tool 12 to the cylinder portion to move the tool piston 18 in a direction to move the jaws 16 inwardly of the tool. Fluid in the cylinder portion 20 on the opposite side of the piston 18 is forced through the return passage 38, and the return line 48 to the valve unit 49. This fluid enters the valve unit 49 through the passages 74 and 76 and flows to the main passage 56 from which it flows through the tank passage 72 to the tank line 68.

During operation of the tool 12, in the event the fluid pressure rises above a predetermined safe limit at any time, due to an abnormally high breakneck strength of the fastener, or for any other reason, the Valve member 136 will be moved off its seat on the plug 142 so as to communicate the pump passage 62 with the tank passage 112 to thereby reduce the fluid pressure in the cylinder portion 21).

When the trigger 24 is released, so that the switch 26 is opened, the solenoid assembly 100 is deenergized so that the spring 102 is efiective to move the spool member 82 to the position illustrated in FIG. 2. In this position, fluid from the pump passage 62 is supplied through the main passage 56 to the return passage 74 from which it flows through the return line 48 and the return passage 38 in the tool 12 to the cylinder portion 20 for moving the piston 18 in a direction to move the jaws 16 outwardly of the tool 12 to a position in which they can be applied to another fastener. Since the return passage 74 communicates through the passage 122 with the idler valve member 114, and the fluid pressure in the pump passage 62 is at the same high pressure required for operation of the tool 12, the fluid in the passage 74 is at a sufiiciently high pressure to move the valve member 114 off its seat to the broken line position shown in FIG. 2, which position is more clearly shown in FIGURE 2a, so that the tank passage 112 is in leaking communication with the passage 122. Consequently, the fluid pressure in the return passage 74 drops to only the pressure required to maintain the valve member 114 in an unseated position in which fluid leaks past valve member 114 into passage 112. This pressure is substantially below the pressure utilized to move the piston 18 in a working direction but is entirely adequate to move the piston in a return direction. As a result of this arrangement, the tool 12 is not subjected to unnecessarily high fluid pressures during the return of the piston 18 to thereby improve the service life of the tool 12.

From the above description, it is seen that the control unit 10 of this invention is connectible to the tool 12 and to a suitable source of electrical power and fluid pressure so as to provide for a controlled operation of the tool 12. One of the main advantages of the control unit 10 is the fact that it is of a compact construction and thus readily portable. The valve unit 48 is in effect three different valves incorporated in a single valve body. It includes the idler valve member 114, the relief valve member 136 and the control valve having the spool 82. This construction of the valve member 48 reduces its size and thereby contributes to the compactness of the unit 10.

Although the invention has been described with respect to a preferred embodiment thereof, it is to be understood that it is not to be so limited, since changes can be made therein which are Within the scope of the invention as defined by the appended claims.

What is claimed is:

1. In apparatus for driving lockbolts and the like which includes a hydraulically operated tool; a valve body having an inlet for fluid under pressure and a return to tank outlet, a first valve member mounted in said body for movement between two positions for controlling the flow of fluid to said tool, a second valve member mounted in said body and fluid-communicated with said first valve member and said inlet in only one of said positions, said second valve member communicating with said outlet and being movable to an open position by a fluid pressure above a predetermined pressure exerted thereon, and a pressure relief valve member mounted on said body and communicating with said inlet in both positions of said first valve member.

2. In apparatus for driving lockbolts and the like which includes a hydraulically operated tool; a valve body having an inlet for fluid under pressure and a return to tank outlet, at first valve member mounted in said body for movement between tWo positions for controlling the flow of fluid to said tool, a solenoid assembly mounted on said body and connected to said first valve member for moving the valve member to one of said positions, a second valve member mounted in said body and fluid-communicated With said first valve member and said inlet in only one of said positions of said first valve member, said second valve member communicating with said outlet and being movable to an open position by a fluid pressure above a predetermined pressure exerted thereon, and a pressure relief valve member mounted on said body and communicating with said inlet in both positions of said first valve member.

3. In apparatus for driving lockbolts and the like which includes a hydraulically operated tool; a control unit comprising a casing, a valve body mounted on said casing and having an inlet for fluid under pressure and a return to tank outlet, a first valve member mounted in sa d body for movement between two positions for controlling the flow of fluid to said tool, a solenoid assembly mounted on said body and connected to said first valve member for moving the valve member to one of said positions, a second valve member mounted in said body and fluid-communicated with said first valve member and said inlet in only one of said positions of said first valve member, said second valve member communicating with said outlet and being movable to an open position by a fluid pressure above a predetermined pressure exerted thereon, a pressure relief valve member mounted on said body and communicating with said inlet in both positions of said first valve member, a step-down transformer mounted on said casing, and a solenoid control relay mounted on said casing and operatively associated with said solenoid and said transformer.

4. In apparatus for driving lockbolts and the like Which includes a hydraulically operated tool; and a valve body having an inlet for fluid under pressure and a return to tank outlet and an outlet connectible to said tool, a first valve member mounted in said body for movement between two positions for controlling the flow of fluid to said tool, means forming a valve seat on said body in fluid-communication on one side with said inlet, a second valve member movable to a seated position on said seat, spring means urging said second valve member toward said seated position, passage means communicating said return to tank outlet with the opposite side of said seat so that the amount of fluid flowing into said passage means is proportional to the extent of movement of said second valve member in a direction opposed to said spring means, and a pressure relief valve member mounted on said body and communicating with said inlet in both positions of said valve member.

5. In apparatus for driving lockbolts and the like which includes a hydraulically operated tool; a valve body having an inlet for fluid under pressure and a return to tank outlet, a first valve member mounted in said body for movement between two positions for controlling the flow of fluid to said tool, means forming a valve seat on said body in fluid-communication on one side with said inlet, a second valve member movable to a seated position on said seat, spring means urging said second valve member toward said seated position, passage means communicating said return to tank outlet With the opposite side of said seat so that the amount of fluid flowing into said passage means Varies in accordance with the extent of movement of said second valve member in a direction opposed to said spring means, and a pressure relief valve member mounted on said body and communicating with said inlet in both positions of said first valve member.

References Cited in the file of this patent UNITED STATES PATENTS 1,987,561 Wiegand Jan. 15, 1935 2,377,278 Stephens May 29, 1945 2,825,353 Voytech Mar. 4, 1958

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