US2844978A - Rivet squeezer - Google Patents

Description

y 1953 R. R. WYLAN'D ET AL 2,844,978

7 RIVET SQUEEZER Filed Oct. 8, 1956 3 Sheets-Sheet 1 I I I RICHARD R. WYLAND 66 WENDELL H. HUNTER www 1NVENTOR5- 13a 40 38 I |5 2 BY m 44,,

ATTORNEY July 29, 1958 R. R. WYLAND ETAL 2,

RIVET SQUEEZER Filed Oct. 8, 1956 3 Sheets-Sheet 2 I I I V RICHARD R. WYLAND WENDELL H. HUNTER INVENTORS BY M ATTORNEY July 29, 1958 R. WYLAND ET AL 2,844,978

' RIYET SQUEEZER Filed Oct. 8, 1956 3 Sheets-Sheet 3 Mi l If BY /j I ATTORNEY D R. WYLAND DELL H HUNTER ENTORS,

United States Patent RWET QUEEZER Richard R. Wyland, Wichita, Kans., and Wend ell H. Hunter, Ferguson, Mo., assignors to Boeing Airplane Company, Wichita, Kans., a corporation of Delaware Application October 8, 1956, Serial No. 614,415

8 Claims. (Cl. 78-42) Our invention relates to rivet squeezing and, more particularly, to a rivet squeezer powered by low pressure air. The structure includes a reciprocating airhydraulic pump operated by the low pressure air and building high hydraulic pressure by a multiplicity of strokes.

Rivet squeezers are of increasing importance, particularly in the aircraft industry. They are eflicient and reduce noise over hammer type riveting. For various purposes it has become desirable to provide a portable rivet squeezer adapted to be conveniently handled by one man. This could be provided in a relatively simple tool with high pressure air. Plants in certain industries such as airplane manufacturers are well supplied with outlets for low pressure air but have few sources of high pressure air. It is desirable to provide a portable rivet squeezer operable with the existing low pressure sources. The riveter must have minimum bulk and weight to be conveniently portable and adapted for one-manoperation.

The objectives of our invention include, therefor: to provide a portable rivet squeezer adapted to be operated by one man; to provide a structure adapted to be powered by low pressure air; and to provide such a tool with minimum weight and bulk, economy of manufacture, ease of maintenance, and efficient operation.

Our invention will be best understood, together with additional objectives and advantages thereof, from a reading of the following description, read with reference to the drawings in which:

. Figure 1 is a side elevational view of a specific embodiment of our rivet squeezer;

Figures 2, 3 and 4 are schematical views of the main operating parts showing, respectively, the position before operating, a first position during operation and a second opposite position during operation;

Figure 5 is an enlarged fragmentary view taken as shown in Figure 1, only being principally in section in an irregular cutting plane; and

Figure 6 is an enlarged fragmentary side view, principally in section, showing a portion of the upper handle structure lying principally in an irregular cutting plane above the plane of Figure 5.

Figure 1 shows a side view of a rivet squeezer 10 constructed according to our invention. To give some idea of size, the length from right to left might be approximately 20 inches and the weight might be about pounds. Principal parts are a barrel 12, a handle 14, a fixed jaw 16, supported on barrel 12 by an arm 18, and a movable jaw 20. Thejaws may be modified according to the type of riveting to which the tool is adapted. Essentially, they will operate in the manner shown in Figure 1 in which a pair of metal structural members 22, 24 are to be joined by a rivet 26 which is to be secured by a squeezing action between the bearing surfaces 28, 30 of jaws 16, 20. Movable jaw is moved to closing by the action of a piston rod having 2,844,978 Patented July 29, 1958 a bearing end 32 acting in a seat 34 formed in movable aw 20.

J A low pressure air line may be attached by suitable means to a socket 36 shown in dotted lines at the base of handle 14 and connecting with an air supply passageway 38. Low pressure air supply in aircraft factories commonly use between and pounds per square inch and our rivet squeezer is operable by air pressure in that range. If the rivet squeezer were to be powered directly by high pressure air, this probably would have to be supplied at 5000 pounds per square inch. The present rivet squeezers can be designed to reach a hydraulic pressure comparable to this high air pressure.

The structure of Figures 5 and 6 will be first described with only brief indication of functions and operating sequences. The operation will be later explained in detail in the discussion of the simplified schematical views, Figures 2-4, which are easier to follow.

The principal operating parts are a trigger valve 40, a shuttle valve 42, a fast approach piston 44, a reciprocating piston 46 and a ram piston 48. Ram piston 48 connects to piston rod 30. Reciprocating or pump piston 46 supports a pair of centrally-disposed, small slave hydraulic pistons 50, 52. A by-pass or hydraulic return valve 54 permits return of ram piston 48 by compression spring 55 between operations by connecting passageways 56 and 58 which extend respectively to the ram piston cylinder 60 behind ram piston 48 and the forward side of fast approach piston cylinder 62. Valve 54 blocks this flow in the position shown in Figure 6 while the squeezer is in operation and would be moved toward opening when trigger valve 40 is positioned as shown in Figure 6. Valve 54 is normally biased to the blocking position by compression spring 64. Trigger valve 40 is normally pressed to an inoperative position by a compression spring 66. A manually operable trigger lever 68 is pivoted to handle 14 by pivot pin 70 and activates the squeezer upon inward pressing of its bearing surface 72 against trigger valve 40.

A number of seals have been omitted from the drawings to reduce the complexity of the disclosure and it will be obvious to those skilled in the art when they will be used. Some principal seals are shown, including the O-rings 74, 76, 78 and 80 on the ram piston, pump piston,,separator wall 82 and fast approach piston, respectively. Because of theirsmall size these have not been sectioned for rubber although some such composition would be used.

Figure 5 shows a convenient construction for manufacture of the tool, including the use of an end cap 84 at one end of barrel 12 and a counterbored bearing 86 at the other end threadedly engaged with threads 88 in barrel 12. The central portion of barrel 12 is left solid at 111 and Thomas head nuts 90, 92, 94 are used to close certain bores used to form passageways in the structure. Four check valves 96, 98, 1.00 and 102 are used in the assembly and they are mounted in duo-cylindrical fittings 104 and 106, which are T-shaped in cross-section and have bored cylindrical leg portions 108, forming cylinders 112, for the slave pistons 50, 52. The check valves 96-102 are formed by balls acting under compression springs in stepped counterbored passageways within fittings 104, 106. Another check valve 110 in line '113 leading from trigger valve 40 is shown in Figure 6 to consist of a spring-pressed ball backed by a nut 114. Shuttle valve 42 is enclosed by a ported cylinder 116 threaded-1y engaged in a bore 118 in handle 14 and the rear end of cylinder 116 is closed by a plug 121.

Figures 5 and 6 show portions of passageways 56, 58, 134, 113, 124, 178, 184, 172, 192 and certain portions do not appear in either figure because some of these passageways pass between and out of the planes of Figures 5 and 6 and these cutting .planesare irregular to illustrate certain relationships. These passageways are indicated in their entireties in Figures 24.

SEQUENCE OF OPERATION The circuit diagrams Figures 2 4 will now be described,'together withthe sequence of operation. Parts appearing in Figures 5 and'6 will be identicallynumbered in the schematic views. The dottedlines in these views indicate circuits which carry hydraulic fluid and the full lines indicate circuits which carry air.

Figure 2.--Bef0re operation Low pressure air is supplied to the tool through the trigger valve 40 from supply line 38. Trigger valve 40 is normally held in return position by return spring 66. Air pressure is directed from line 38 by the spool passage 120 through line 113, past check valve 110, through line 124 to shuttle valve port 122. A ball check 126 in spool 42 prevents air passage into the spool open center 128. The open center and the opposite end port 130 are open to the atmosphere through mid opening 132 and through line 134 to trigger valve 40, port 136 and then out through the open center 138 of trigger valve 40. By these means, a pressure differential is developed maintaining shuttle valve spool 42 at the right hand side. Air pressure is also directed through line 140 to the end of hydraulic return valve 54 forcing the spool to the right end of the valve, compressing the return spring 64 and opening a hydraulic fluid return line from the high pressure hydraulic ram cylinder through line 56 by way of a spool passage 142 through line 58 into the low pressure hydraulic reservoir side 62 of fast approach piston 44. This permits hydraulic fluid flow under pressure of ram piston return spring 55 from the high pressure hydraulic ram cylinder 60 into the low pressure hydraulic reservoir side of fast approach piston 44. The pump piston 46 can be in either right or left side position before operation.

Figure 3.-Beginning operation Trigger valve 40 is actuated by finger pressure, moving the valve to the right and compressing return spring 66. The end of hydraulic return valve 54 is now open to the atmosphere through line 140 to trigger valve port 150 then through spool opening 152 and out through spool passageway 138. The spool in hydraulic return valve 54 is moved to the left by return spring 64 and hydraulic return lines 56, 58 are blocked by the land 1'54 of the spool in hydraulic return valve 54.

Air pressure is also directed by trigger valve 40 through line 134 and by spool passageway 158, thence by line 160 to the air side 162 of fast approach piston 44. (In Figure 3, the movement of fast approach piston 44 has not started and Figure 4 shows the piston in its position at the end of the stroke.)

Air pressure is also directed from shuttle spool passageway 158 through line 164 to the right side 166 of pump piston 46. Exhaust from the left side 167 of pump piston 46 is made through line 163 to shuttle valve spool passageway 170 out line 172 to the atmosphere. Pump piston 46 is moved to the left from the position shown in Figure 3. Pilot valve 174 on right hand hydraulic slave piston 52 closes as pump piston 46 moves to the left shutting off port 130 of shuttle valve 42 through lines 176, 178 to the atmosphere. Hydraulic intake for slave piston 52 is obtained through ball check valve 96 from the low pressure hydraulic reservoir side 62 of fast approach piston 44. Intake from the high pressure hydraulic ram cylinder 48 through line 56 is prevented by ball check valve 98. Pilot valve 180 on the pump left hand hydraulic slave piston 50 opens when the limit of travel to the left is completed and shuttle valve port 122 is opened through lines 182, 184 to the atmosphere.

The hydraulic fluid in the pump left hand slave piston cylinder 115 is forced through ball check valve 182 into the hydraulic ram cylinder 60. High pressure fluid is prevented from entering the low pressure hydraulic reservoir side 62 of fast approach piston 44 through line 186 by ball check valve 100,

Low pressure air against fast approach piston 44 forces hydraulic fluid from the low pressure reservoir 62 through lines 56 and 186 through the respective check valves to the high pressure side 60 of ram piston 48. Ram piston will move to the left until contact is made with the rivet being squeezed, as 26. The low pressure is insuflicient to deform the rivet. At this time hydraulic pump 46 and slave pistons 50, 52 will begin actuation to build up sufficient pressure to deform the rivet.

The shuttle valve port 122 having been opened and port 130 having been closed in the previous sequence, a pressure differential is created between port 122 and the end adjacent port 130 by air passing from the open center 1'28 of the spool through restricted opening 188 to port 130. The pressure differential causes spool 42 to move to the left to the position of Figure 4.

Figure 4.Opp0site position of operation Trigger valve 40 is still compressed and the hydraulic return valve 54 is still in closed position in Figure 4. Shuttle valve 40 has reached the limit of its travel to the left. In this position air pressure is still applied to the fast approach piston 44. Air pressure is now directed from spool passageway 153 out line 168 to the left side of pump air piston 46. Exhaust from the other side of pump piston 46 as it moves to the right is made through line 164 through spool passageway 190 and out line 192 to the atmosphere.

Pump piston 46 is forced to the right and the right hand pump hydraulic piston 52 forces high pressure fluid out past ball check valve 98, through line 56 to hydraulic ram cylinder 48. The high pressure fluid is prevented from entering the low pressure hydraulic reservoir side 62 of fast approach piston 44 by ball check 96. Pilot valve 174 on pump right hand slave piston 52 is opened when the limit of travel to the right is reached, opening shuttle valve port 130 through lines 176, 178 to the atmosphere. Also, as pump piston 46 moves to the right, the left hand slave piston draws an intake supply past check valve 100 through line 186 from hydraulic reservoir 62. High pressure fluid from hydraulic ram cylinder is prevented from entering cylinder 115 of left hand slave piston 50 by ball check'102. Pilot valve 180 on the left slave piston 50 closes as the piston travels to the right, shutting off line 182 to port 122 of shuttle valve 42.

There is now a pressure differential between the left hand end of shuttle spool 42 and the ambient pressure of port 130 causing spool 42 to move to the right limit of its travel, in which position the pump piston action as described in Figure 3 is repeated. Pressure is applied to port 122 from open spool center 128, past ball check 126 and through restricted passageway 189. This shuttling action continues until the high pressure capacity of the pump is obtained in the high pressure hydraulic ram or trigger valve 40 is released. The rivet will be deformed under the pressure of ram piston 48 in the process. Maximum pressure for this embodiment under the conditions given is calculated at 5,000 p. s. i.

Restrictions 188 and 189 at'opposite ends of theopen center 128 of shuttle valve 42 and the ball check 126 act during operation of rivet squeezer 10 to apply air pressure alternately to left and rig'hthand ends of shuttle valve 42. When pressure is applied to one end, the other end is open to the atmosphere which results in greater pressure on one end than the other although they are both supplied with air 'from open center 128. Restrictions 188, 189 preventthe end open to the atmosphere from drawing ofl enough of the supplied air pressure to prevent the shuttling operation. It will be understood that the air When trigger valve 40 is released, return spring 66 moves the valve back to the position described in Figure 2, the hydraulic fluid in ram cylinder 60 is returned to the hydraulic reservoir side 62 of fast approach piston 44 through lines 56, 58 as described in connection with Figure 2.

Having thus disclosed our invention, we do not wish to be limited to the precise details of construction shown but instead wish to cover those modifications thereof which will occur to those skilled in the art from our disclosure, and which fairly fall within the scope of our invention, as defined in the appended claims.

We claim:

1. A device having work operating means powered by external low pressure fluid supply means, comprising: a hydraulic ram piston and cylinder connected to said operating means to power the same by a stroke in one direction, a pump piston and cylinder in which the piston is mounted to reciprocate between ends of its cylinder, said external supply means being connected to the ends of said pump cylinder and control means interposed therebetween alternately directing fluid from the supply means to opposite ends of said pump cylinder to reciprocate said pump piston, a pair of slave pistons and cylinders connected to said pump piston and of smaller diameter and the slave pistons reciprocating on each reciprocation of said pump piston, a fast approach piston and cylinder having an in-put side connected to said low pressure'fluid supply means and having an out-put side connected directly to said ram cylinder by means including a one-way valve and said out-put side containing a hydraulic fluid, said out-put side of said fast approach piston and cylinder forming a source of hydraulic fluid and cylinders for said slave pistons and cylinders connected to said hydraulic fluid source and to said ram cylinder by lines having interposed valve means directing hydraulic fluid alternately from each slave piston and cylinder to said ram cylinder during a power stroke and drawing a supply of hydraulic fluid from said source during an intake stroke, whereby said fast approach piston supplies hydraulic fluid to said ram cylinder at lower pressure comparable to the pressure of said low pressure supply means in a single stroke upon initiation of operation of the device to initially move said ram piston under low pressure and said slave pistons thereafter supply hydraulic fluid to said ram cylinder at a higher pressure increasing at each stroke of said pump piston to move said ram piston under increasingly high pressure when resistance is incurred to the operation of said work operating means.

2, Portable means to squeeze a rivet operated by external low pressure fluid supply means, comprising: jaw members and jaw operating means operative to move said jaw members toward closing, a housing on which said jaw members and operating means are mounted and including handle means, a hydraulic ram piston and cylinder contained within said housing and connected to said operating means to power the same, a pump piston and cylinder contained within said housing and the pump piston being mounted to reciprocate between ends of its cylinder, said housing having a port to which a line from said external supply means may be connected and said port being connected to the ends of said pump cylinder and control means in said housing interposed between port and said ends of said pump cylinder operative to alternately direct fluid from the supply means to opposite ends of said pump cylinder to reciprocate said pump piston, a pair of slave pistons and cylinders in said housing and of smaller diameter than said pump piston and connected to said pump piston to reciprocate therewith, a source of hydraulic fluid in said housing and slave piston cylinders connected to said hydraulic fluid source and to said ram cylinder by lines having interposed valve means in said housing directing hydraulic fluid alternately from each slave piston and cylinder to said ram cylinder during a power stroke and drawing a supply of hydraulic fluid from said source during an intake stroke, whereby a high hydraulic pressure is produced in said ram cylinder by successive reciprocations of said pump piston powered by said low pressure fluid, said housing being a portable, self-contained, hand-held tool accomplishing operation of said jaw operating means by application of fluid under pressure from said external fluid supply means 3. The subject matter of claim 2 in which there is a fast approach piston and cylinder in said housing having an in-put side connected to said port and having an out-put side connected directly to said ram cylinder by means including a one-way valve and said out-put side containing a hydraulic fluid, whereby said fast approach piston supplies hydraulic fluid to said ram cylinder at lower pressure comparable to the pressure of said low pressure supply means in a single stroke upon initiation of operation of the device to move said ram piston so that said jaw members are moved to rivet engaging position and said slave pistons thereafter supply hydraulic fluid to said ram cylinder at higher pressure increasing at each stroke of said pump piston until said ram piston powers said operating means to move said jaw members to deform a rivet.

4. The subject matter of claim 3 in which said output side of said fast approach piston and cylinder forms said source of hydraulic fluid source for said slave pistons and cylinders.

5. Portable means to squeeze a rivet operated by external low pressure fluid supply means, comprising: jaw members and jaw operating means operative to move said jaw members toward closing, a housing on which said jaw members and operating means are mounted and including handle means, said housing having a barrel and a hydraulic ram piston and cylinder positioned in one end of said barrel and connected to said operating means to power the same, a pump piston and cylinder disposed in said barrel and generally coaxial with said ram piston and the pump piston being mounted to reciprocate between ends of its cylinder, said housing having a port to which a line to said external supply means may be connected and said port being connected to the ends of said pump cylinder and control means in said housing interposed between said port and said ends of said pump cylinder operative to alternately direct fluid from the supply means to opposite ends of said pump cylinder to reciprocate said pump piston, a pair of slave pistons and cylinders in said barrel and generally coaxial with said pump piston and connected thereto, said slave pistons being of smaller diameter than said pump pistons and reciprocating therewith, a source of hydraulic fluid in said housing and cylinders in said housing for said slave pistons and cylinders connected to said hydraulic fluid source and to said ram cylinder by lines having interposed valve means in said housing directing hydraulic fluid alternately from each slave piston and cylinder to said ram cylinder during a power stroke and drawing a supply of hydraulic fluid from said source during an intake stroke, whereby a high hydraulic pressure is produced in said ram cylinder by successive reciprocations of said pump piston produced by said low pressure fluid, said housing being a portable, self-contained, hand-held tool accomplishing operation of said jaw operating means by application of fluid under pressure from said external low pressure fluid supply means.

6. The subject matter of claim 5 in which there is a fast approach piston and cylinder in said barrel and generally coaxial with said ram and pump pistons and having an in-put side connected to said port and having an out-put side connected directly to said ram cylinder by means including a one-way valve and said out-put side containing a hydraulic fluid, whereby said fast approach piston supplies hydraulicfluid to said ram cylinder at lower pressure comparable to the pressure of said low pressure supply means in a single stroke upon initiation of operation of the device to move said ram piston so that said jaw members are moved to rivet engaging position and said slave pistons thereafter supply hydraulic fluid to said ram cylinder at higher pressure increasing at each stroke of said pump piston until said ram piston powers said operating means to move said jaw members to deform a rivet, said out-put side of said fast approach piston and cylinder forming said source of said hydraulic fluid for said slave pistons and cylinders.

7. A device having work operating means powered by external low pressure fluid supply means, comprising: a hydraulic ram piston and cylinder connected to said operating means to power the same by a stroke in one direction, a pump piston and cylinder in which the piston is mounted to reciprocate between ends of its cylinder,

two-position operating valve means manually operable between a non-operating position and an operating position and said valve means in said operating position connecting said supply means to opposite ends of said pump cylinder, there being a shuttle valve interposed between said operating valve means and said ends of said pump cylinder, said shuttle valve having positioning means responsive to the movement of said pump piston to alternately direct fluid to said opposite end of said pump cylinder to reciprocate the pump piston, said pump piston having smaller diameter slave pistons connected thereto to reciprocate with said pump piston, said slave pistons having cylinders, a hydraulic fluid source and said slave cylinders being connected to said ram cylinder and to said source by means including one-way valves whereby each slave piston has a power stroke supplying fluid to said ram cylinder at pressure greater than the pressure of said low pressure supply means and has an intake stroke drawing hydraulic fluid from said source, said operating valve means in said non-operating position connecting said supply means and one end of said shuttle valve biasing said shuttle valve toward the opposite end whereby a dead center position is avoided, a fast approach piston and cylinder having an in-put side and having an out-put side connected directly to said ram cylinder by means including a one-way valve and containing hydraulic fluid, said operating valve means in said operating position connectiug said supply means directly to said in-put side of said fast approach piston.

8. A device having work operating means powered by external low pressure fluid supply means, comprising: a

hydraulic, ram piston and cylinder connected to said operating means to power the same by a stroke in one direction, a pump piston and cylinder in which the piston is mounted to reciprocate between ends of its cylinder, two-position operating valve means manually operable between a non-operating position and an operating position and said valve means in said operating position connecting said supply means to opposite ends of said pump cylinder, there being a shuttle valve interposed between said operating valve means and said ends of said pump cylinder, said shuttle valve having positioning means responsive to the movement of said pump piston to alternately direct fluid to said opposite ends of said pump cylinder to reciprocate the pump piston, said pump piston having smaller diameter slave pistons connected thereto to reciprocate with said pump piston, said slave pistons having cylinders, a hydraulic fluid source and said slave cylinders being connected to said ram cylinder and to said source by means including one-way valves whereby each slave piston has a power stroke supplying fiuid to said ram cylinder at pressure greater than the pressure of said low pressure supply means and has an intake stroke drawing hydraulic fluid from said source, a fast approach piston and cylinder having an in-put side and having an out-put side connected directly to said ram cylinder by means including a one-way valve and containing hydraulic fluid, said operating valve means in said operating position connecting said supply means directly to said in-put side of said fast approach piston, a bypass line between said ram cylinder and said out-put side of said fast approach piston and cylinder, a relief valve interposed in said bypass line and having a first position in which flow through said bypass line is blocked and a second position in which flow through said bypass line is open, spring means biasing said relief valve to one of said positions and a line from said operating valve means connecting said supply means and said relief valve in one position of said operating valve means to move said relief valve to the other of said positions whereby operation of said operating valve means automatically opens said bypass line to permit return of said ram piston when the operating valve means is in said non-operating position, and spring means acting on said ram piston to return the same in an opposite direction to its power stroke.

Fischer et al Dec. 7, 1948 Sedgwick Nov. 6, 1951

Images