US3199612A - Cartridge-powered impact wrench - Google Patents

Description

Aug. 10, 1965 R, T. cA'rLlN ETAL 3,199,612

CARTRIDGE-POWERED IMPACT WRENCH Filed Oct. 30, 1962 2 Sheets-Sheet l SSII I M fila rAnPA-I Aug. 1U, 1965 R. T. cATLlN ETAL 3,199,512

CARTRIDGE-POWERED IMPACT WRENCH Filed Oct. 30, 1962 2 Sheets-Sheet 2 United States Patent O 3,199,612 CARTRIDSE-PWEREE IMPACT WRENCH Robert T. @atlin and Robert 0. Swain, Trumbull, Conn.,

assigner-s to Remington Arms tompany, Inc., Bridgeport, Conn., a corporation of Delaware Filed Get. 3G, 1952, Ser. No. 234,116 9 tlaims. (El. 173-93) This invention relates generally to a cartridge powered impact tool whereby a high velocity force is provided and transmitted to a fastening means in order to loosen or tighten the fastening means.

More specifically, the invention relates to a cartridge powered impact wrench utilizing a unique and novel tire control mechanism.

It is an object of this invention to provide a light-weight, portable impact wrench which is especially adapted to be used in the iield or in areas where there is no outside source of power such as electricity, compressed air, etc.

It is another object of this invention to provide an explosive-actuated impact wrench which is compact and which has a relatively small amount of recoil when tired.

Another obliect of this invention is to provide a novel low-cost tire control mechanism which includes a positive trigger means which can be tired after the mechanism has first been set in ready-to-iire position.

The present invention 'was conceived to satisfy a need for a portable impact wrench which requires no hose or outside source of power. By providing a cartridgepowered impact wrench it is possible to eliminate costly electrical or pneumatic equipment, as well as eliminate the necessary cables associated with electrical and/or pneumatic tools. Not only are the cables expensive and very easily damaged on construction sites but they are a constant source of trouble because of safety hazards and the provision which must be made to move men and equipment over and around the cables.

Moreover, a cartridge-powered piston can be accelerated to a higher velocity with a shorter stroke than other types of impact wrenches. This offers the following advantages over a pneumatic wrench of the same capacity: (1) lighter weight, (2) smaller, shorter, more compact, (3) higher velocity, lower mass for a given energy output which results in less wrench recoil, (4) high velocity impact will loosen or tighten to a greater degree than a low velocity blow, portable feature mentioned above.

An important additional advantage of providing cartridge-powered means to an impact wrench is that the amount of torque provided to the wrench can be varied and controlled merely by using known cartridge power loads. Thus, the amount of torque which a specific tool will produce for various cartridge power loads can be predetermined and plotted. A. user, knowing the required torque, can select the correct cartridge to give him the desired torque, and after pre-loading the wrench manually to take up the slack of the nut or fastening member, can fire the tool and consistently control the amount of torque which is applied to the fastening member.

Other features and advantages of the improved tool of the present invention will be apparent from reading the enclosed specification and claims and shown in the drawings in which:

FIGURE 1 shows a longitudinal sectional view of the preferred embodiment.

FIGURE 2 shows a front end view of FIGURE 1.

FIGURE 3 shows a sectional view of the re control mechanism in the at rest position.

FIGURE 4 shows a view of the pin and slot arrangement taken on line 4-4 of FIGURE 3.

FIGURE 5 shows a sectional view of the tire control recess 15.

3,199,612 Patented Aug. 19, 1965 mechanism in the cocked or ready to tire position.

FIGURE 6 shows a view of the pin and slot means taken on line 6 6 of FIGURE 5.

FIGURE 7 shows the fire control means after the trigger has been released.

FIGURE 8 shows a cross-sectional view taken on line 8-8 of FIGURE 7.

FIGURE 9 shows a longitudinal sectional view of a modified impact wrench.

FIGURE 10 shows a view of the cam pin and slot arrangement while the pin is in the normal forwardly biased position.

In the preferred embodiment shown in FIGURE 1, a cylindrical barrel 1 has one end connected to the tire control assembly 2 and the opposite end connected to a yoke and anvil assembly 3. The yoke assembly 3 includes a yoke 4 having an upper portion 5 parallel to and in longitudinal alignment with barrel 1 and detachably attached thereto by thread means 6. Attached to upper portion 5 and projecting transversely of barrel 1 are parallel, laterally spaced leg portions 7 and 8 (FIGURE 2) having openings 9 and 10 therein. Yoke 4 is grooved to provide angular faces 11 and 12 which with the inside faces 13 and 14 of leg portions 7 and 3 form a central (See FIGURE 2.)

An anvil 16 having a round portion 17 and an offset angular portion 1S is positioned in recess 15 and is rotatably mounted on legs 7 and 8 in a manner explained below. The angular anvil portion 18 has an impact receiving face 19 which abuts against upper yoke face 11 when in the ready-to-re position. (See FIGURE 1.)

Positioned in openings 9 and 10 of the yoke leg portions 7 and .8 and adapted to rotate therein are bushing members Ztl and 21, having square openings 22 and 23, respectively, in alignment with a similar square opening 24 inV anvil 16. Extending through the square openings 22, 23 and 24, and projecting outwardly of the spaced leg portions 7 and 8 is a square drive member 25. It will be seenV from the above that upon -anvil 16 being rotate-d, the square drive will move with the anvil as will bushings 2@ and 21. It should be appreciated that openings 22, 23 and 24 and drive member Z5 can have other angular configurations than a square and still be effective.

Longitudinally slidable within the barrel 1 and elongated opening 26 in yoke 4 is an elongated piston assembly 27 whose function it is to deliver the necessary force to the impact receiving face 19 of anvil portion 18 in order to rotate the anvil and thereby rotate the square drive member 25, in which is connected the necessary wrench socket or screw driver. Obviously, various types of fastening tools can be attached to the square drive member.

Piston assembly 27 includes an elongated rod 27a which is detachably attached to an enlarged rear head portion 27b by any well-known means such as threads 27C. Positioned intermediate the ends of the piston rod is an abutment 27d which acts as a safety means to prevent the rod from being projected out of the barrel at high velocity in case threads 27C should fail. y

Spacer member 28 is positioned within the forward portion oi barrel 1 and has its front end abut yoke 4 at 29 and its rear end in abutting engagement at 30 with an impact plate head 31. A plurality of resilient buffer blocks 32, separatedby impact plates 33, are loosely mounted on rod 27 to permit relative sliding movement and are designed to absorb the initial shock and to return the piston rod to its original position as shown in FIGURE 1. The spacer 28 limits the relative forward movement of the buffer and plate members.

Threadedly attached at the rear end of the barrel is a chamber 34 having a cavity 35 in which projecting rear head 36, which is integral with enlarged piston portion 27b, is positioned. An opening 37 is provided through chamber 34 in which a chamber bushing 38 is placed, said chamber bushing being adapted to'receive an explosive cartridge 39. Chamber 34 also has an end portion 40 of reduced diameter to which the lire control assembly 2 is threadedly attached as at 41.

Inasmuch as the re control assembly 2 is the same in the modilications shown in FIGURE 1 and FIGURE 9, only one explanation will be made. This assembly consists of an open-end cylindrical housing 42 having closed slot means 43 and 44 provided in the sidewalls and a guide plate 45 in which an offset opening 46 is provided. A breech block 47 is slidably positioned in the open end of the housing and secured to the housing by means of a pin 43 secured to the breech block and slidably positioned in slot 43 of the housing.

Breech block 47 has three additional recesses or cavities in addition to the one .in which pin 43 is secured: (l) A large recess 49 in the forward portion of the breech which is adapted to be attached to the reduced rear end portion of chamber 34 by thread means 41; (2) an elongated tapered longitudinal cavity t) ecceutrically located in the breech to receive lower end 51 of a tiring pin 52 which has its upper end 53 slidably mounted in opening 46 and which is prevented from becoming disengaged by a nut 54 threaded on the end thereof; and (3) a narrow recess 55 (FIGURE 8) in which a Z-shaped trigger 56 is pivotally mounted at 57 and which projects outwardly through slot 44 of housing 42. A cavity 55a, which is in communication with recess 55, has a coil spring 5517 positioned therein which abuts against trigger 56 to bias the trigger into operative position. Opening 46 in plate 45 is offset from the tapered recess 50 so that when the housing 42 is pushed downwardly and rotated, the enlarged upper portion of recess 5t) is suicient to permit the firing pin 52 to move into substantial alignment as shown in FIGURES 5 and 7. Although cavity 50 is shown as being eccentrically positioned with respect to the central axis of opening 37 and chamber bushing 38, this is done because rimiire cartridges are to be used in this particular modication. It can be appreciated that centeriire cartridges might also be used in which case the eccentric positioning of the cavity 5t? would not be necessary.

It will be seen from FIGURE l that two sets of springbiasing means are provided within the lire-control assembly: (l) an outer compression coil spring 58 which bears on plate 45 and breech 47 and normally biases the breech block 47 and housing 42 apart; and (2) a smaller, inner compression coil spring 59 encircling the elongated tiring pin 52 and bearing on plate 45 and an abutment 60 on the tiring pin so as to normally bias the tiring pin towards the chamber and the explosive cartridge.

It can be seen from FIGURES 3 and 4 that slots 43 and 44 comprise longitudinally extending slots 43a and 44a and transverse slots 43h and 44b respectively in which pin 48 and trigger 56 are adapted to slide upon relative sliding and rotational movement of the breech block 47 and housing 42.

Operation Referring to FIGURES 3 and 4, the re control is in the at-rest position with the breech and breech pin 48 biased forwardly by spring 5S until the pin is stopped by the forward end of slot portion 43a. The tiring pin 52, supported in olset openings 46 and 50, is out of alignment with respect to the center line of cavity 50. (See FIGURE 3 which has been exaggeratedv for clarity.) Trigger 56 abuts against the front face of abutment 60 and prevents the tiring pin 52 from moving forwardly. Spring 59 is in a relatively uncompressed state and the breech block is under the main influence of the larger spring 58. It can be seen that the extent of travel of the firing pin can be adjusted by limit nut 54. However, in the position of FIGURE 3, releasing the trigger will NOT cause the device to re, since the tiring pin will be limited in its forward travel by nut 54.

Referring to FIGURE 5, the lire control has been cocked by depressing the housing 42 and rotating it into the locked or ready to lire position. Rotating it into the locked position has aligned the firing pin with respect to the center line of breech cavity 50, the pin 48 has moved into the transverse slot 43b, the springs 58 and 59 have been compressed, and the limit nut 54 is now longitudinally spaced from plate 45, thus permitting the firing pin to move the necessary distance with the necessary velocity in order to detonate the explosive cartridge in the chamber when the trigger is released.

FIGURE 7 shows the re control after the trigger has been squeezed and the tiring pin has dropped. The housing is then rotated into the unlocked position, at which time the fire control returns to the original position shown in FIGURE 3.

Upon ring of the cartridge, the explosive pressure generated thereby moves piston rod 27 forwardly at high speed to strike against the face 19 of the anvil 16 which rotates along with the square drive 25. Depending on what is attached to the square drive member and how it is attached, a sharp torque force is provided which can instantly tighten or loosen a fastening. Thus, a socket wrench or a screw driver (not shown) can be provided on the square drive 25 which can tighten or loosen a bolt or screw quickly. Left or right hand rotation is obtained by inverting the wrench and selecting either end of the square drive. The anvil and square drive are preloaded by rotating the handle.

It can be seen that the oifset anvil design described above is especially applicable in areas in which the distance from the work surface to an adjacent structure is less than the overall length of the tool. The tool shown in FIGURE l can be used in close quarters both effectively and eficiently.

A modified cartridge-powered impact wrench is shown in FIGURES 9 and 10. As mentioned above, the re control mechanism is similar to that described above and need not be described again. Referring to FIGURE 9, it can be seen that a cylindrical barrel 61 is provided having a chamber assembly 62 attached thereto at one end as explained above. A piston assembly 63 is slidably positioned within the barrel and extends through openings in buffer blocks 64, impact plate 65, and head impact plate 65. Head impact plate 66 abuts spacer member 67, whose forward movement is limited by a muzzle cap 68 which is attached to the front end of the barrel by thread means 69.

An open-end cylindrical housing 76 is then positioned within spacer 67 and held thereon by a pin and slot arrangement consisting of retaining pin 71 which is inserted through aligned, horizontally-extending slots 72 and in the sidewalls of the spacer and barrel, respectively, and through a transverse elongated opening 74 in the housing 70. This structure permits a limited amount of relative longitudinal movement between the housing and the spacer and barrel and prevents rotational movement between the parts.

Positioned within the housing 70 and projecting.

through the open end thereof and through an opening 75 in the muzzle cap is an impact driver 76. The outer end 77 of the impact driver is adapted to be connected to a socket wrench or any other fastening part or tool which is desired to be turned. The inner end of the driver 76 telescopes within the housing and is connected thereto by a transverse cam pin '78 which extends through opening 79 in the driver and into opposed V-shaped slots 80 and 81 located in opposite sidewalls of the housing. Grooves SBR, 801.. and 81K, 81L (not on drawing) are positioned on opposite sides of the apex of each V- shaped slot for a purpose explained below. Coil spring 2 is placed within cavity 83 ofthe housing and biases the driver 76 forwardly so that the cam pin 78 will ride in the V-shaped slots 80 and 81 in whichever leg of the V that the pin happens to be positioned. FIGURE shows the pin 78 placed in groove 80L for left hand movement of the driver 76.

Operation of modz'jczztion Upon squeezing of the trigger, the cartridge is red as explained above and the explosive pressure moves pistion 63 forwardly at high speed to impact against the rear end of housing 70. The impact is absorbed by buffers 64 Whose forward movement isrstopped when head impact plate 66 abuts the rear end of spacer 67. Housing 70 is thrust forwardly by the impact of the piston rod and is stopped when the retaining pin 71 reaches the forward ends of slots 72 and 73 in the spacer and the barrel. Prior to releasing the trigger and depending on whether a right or left-hand turn is desired, the driver 76 is rotated to position cam pin 73 in the appropriate inclined slot and groove. Thus, as can be seen in FIGURE l0, the pin 78 is biased forwardly and positioned in groove SGL so that upon forward longitudinal movement of the housing 70, the pin 78 will be cammed in the left 80A of the V-shaped slot 80 and the driver 76 will be forced to turn in a counter-clockwise or lefthand direction. If a clockwise (right direction) direction is desired, the pin 78 is positioned in groove SGR prior to actuating the re control assembly. The buffer means will then return the piston to its required position.

What is claimed is:

1. An impact-turning tool having means at one end thereof adapted to be detachably connected to a member toAbe turned, means in operable engagement with said detachable means to translate a longitudinally-acting force into a rotational force, a cartridge-powered firing mechanism adapted to provide an explosive, longitudinally-acting force to said translating means, said liring mechanism comprising a chamber means in which an explosive cartridge is positioned, a breech block detachably connected to said chamber means, said breech block having an eccentrically positioned opening therethrough, sleeve means mounted on said breech block having an opening therein which in the non-tiring position is laterally oiset from said breech block opening, a ring pin having its lower and upper ends slidably positioned in the breech block opening and the sleeve opening respectively, means permitting relative movement of said sleeve and breech block` wherein said tiring pin can be moved into and held in iring position whereby the longitudinal axis of said iiring pin is in substantial alignment with the longitudinal axis of said breech block opening, and means operable to release said tiring pin in order to strike said explosive cartridge and release explosive pressure thus providing the longitudinal force required to actuate said translating means.

2. An impact-turning tool as recited in claim 1 wherein means are provided between said sleeve and firing pin to bias said tiring pin toward said explosive cartridge, said means operable to release said tiring pin including lever means which normally abut said firing pin but which can be manually pivoted out of the way to permit said tiring pin to move forward and strike said cartridge.

3. An impact-turning tool as recited in claim 2 in which said lever means is pivoted to the breech block.

4. An impact-turning tool as recited in claim 1 wherein said means permitting relative movement of said sleeve and breech block comprises pin and slot means including a longitudinally extending slot and a connecting transverse slot which permit a limited amount of relative longitudinal and rotational movement.

5. A re control mechanism for a powder-actuated tool comprising chamber means having an opening therein adapted to receive an explosive cartridge, breech means Y 6 detachably connected to said chamber means and supporting said cartridge therebetween, a longitudinally extending opening in said breech means, sleeve means mounted on said breech means, said sleeve means having a transverse member longitudinally spaced from said breech means, said member having an opening therein laterally offset from said opening in said breech means, a longitudinally-extending firing pin having its lower end portion slidably mounted in said breech opening and its upper end portion slidably mounted in said transverse member opening, means to bias said ring pin towards ysaid cartridge, co-acting means on said breech means and said sleeve means to permit limited relative longitudinal and rotational movement of said breech means and said sleeve means whereby, upon said sleeve means being moved axially and rotated, the longitudinal axis of said iiring pin moves into substantial alignment with the longitudinal axis of said breech opening, and means normally holding said tiring pin in non-tiring position but manually operable to release said pin to strike and detonate said explosive cartridge.v

6. A re control mechanism as recited in claim 5 in which said coacting means comprises slot means on said sleeve means, and a pin extending outwardly from said breech means slidable in said slot means.-

7. A tire control mechanism as recited in claim 5 wherein said tiring pin hold-release means comprises an angular lever means pivoted on said breech means and normally abutting said firing pin against the force of said firing pin biasing means.

8. A iire control mechanism for an explosive-actuated tool comprising sleeve means having an open end therein, breech means mounted in said open end, a cavity in the outer end of said breech means, chamber means detachably mounted in said breech cavity, a longitudinally-extending bore in said chamber means in which an explosive cartridge is placed, an opening in the inner end portion of said breech means communicating with said cavity and said explosive cartridge, the longitudinal axis of said breech opening parallel to but laterally spaced from the longitudinal axis of said chamber bore, tiring pin means having its upper end portion pivotally connected to said sleeve means and its lower end portion slidably positioned in said breech opening s0 that in the normal safe position the longitudinal axis of said ring pin is at an angle to the longitudinal axis of said breech opening, means to bias said breech means and said sleeve means apart, means to bias said firing pin down into said breech opening, coacting means between said breech means and said sleeve means to permit a limited amount of relative movement thereof in an axial and transverse rotary directions to av ready-to-iire position, and trigger means engaging said firing pin to limit movement through said breech opening by said firing pin biasing means, said trigger means operable to be pivoted outwardly in order to release the tiring pin, thus tiring the device.

9. AV lire control mechanism as recited in claim 8 wherein said coacting means comprises an inverted L- shaped slot means in said sleeve means and a pin meansV mounted on said breech means slidable in said slot means.

References Cited by the Examiner UNITED STATES PATENTS Packard et al. 42-70.6

(Other references on foiiowing page) *2f FOREIGN PATENTS 692,741 5/40 Germany.

6/54 Conrad. 8/54 Matthews.

FRED E. ENGLETHALER, Primary Examiner.

8 Smyres. Belsky. Hoffman. Hoffman.

JULIUS E. WEST, Examiner.

Claims (1)

1. AN IMPACT-TURNING TOOL HAVING MEANS AT ONE END THEREOF ADAPTED TO BE DETACHABLY CONNECTED TO A MEMBER TO BE TURNED, MEANS IN OPERABLE ENGAGEMENT WITH SAID DETACHABLE MEANS TO TRANSLATE A LONGITUDINALLY-ACTING FORCE INTO A ROTATIONAL FORCE, A CARTRIDGE-POWERED FIRING MECHANISM ADAPTED TO PROVIDE AN EXPLOSIVE, LONGITUDINALLY-ACTING FORCE TO SAID TRANSLATING MEANS, SAID FIRING MECHANISM COMPRISING A CHAMBER MEANS IN WHICH AN EXPLOSIVE CARTRIDGE IS POSITIONED, A BREECH BLOCK DETACHABLY CONNECTED TO SAID CHAMBER MEANS, SAID BREECH BLOCK HAVING AN ECCENTRICALLY POSITIONED OPENING THERETHROUGH, SLEEVE MEANS MOUNTED ON SAID BREECH BLOCK HAVING AN OPENING THEREIN WHICH IN THE NON-FIRING POSITION IS LATERALLY OFFSET FROM SAID BREECH BLOCK OPENING, A FIRING PIN HAVING ITS LOWER AND UPPER ENDS SLIDABLY POSITIONED IN THE BREECH BLOCK OPENING AND THE SLEEVE

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