The present disclosure relates to a self-centering vise that has two moveable jaws mounted on a base, and driven by a single actuating screw to move together or separate, depending on the direction of screw rotation to provide work piece holding force in both directions of jaw movement. The jaws have clamping faces on opposite sides thereof and can be used for clamping internal surfaces of a work piece or conventional clamping of a work piece on external surfaces. A jaw nut is provided with a jaw engaging drive that ensures down pressure on the vise jaws in either direction of clamping movement.
The use of self-centering jaws on vises has been known, and for example, U.S. Pat. No. 5,649,694 illustrates a vise that can be used without fixed jaws for reaction, and can clamp work pieces between the moveable jaws.
The use of single screws for moving two jaws simultaneously toward and away from each other is also known in the prior art, for example in U.S. Pat. No. 4,934,679.
The vise of the present disclosure has the ability to provide clamping with self-centering moveable jaws in either direction of movement of the jaws, that is moving together or expanding, and has a drive which provides adequate down pressure on the jaw support or guideway surface of the vise body, to provide adequate holding or clamping forces.
The present invention relates to a machine vise that has a vise body and as shown, a pair of moveable jaws that are mounted for sliding movement along suitable support surfaces or guideways on the vise body. A single actuator screw with opposite hand or lead threads for the respective jaws, or other convenient drive, moves jaw nuts. Each jaw nut has a head member that extends into a recess or cavity in the associated moveable jaw. The head member has a projection seated in a groove or recess on a first clamping wall of the respective jaw formed by the cavity, with a tapered drive surface on the projection facing the guideways and engaging a mating drive surface of the groove for driving the jaw in one direction. Each jaw nut also carries an adjustable jaw drive member or plunger that has an end portion that is seated in a groove or recess on a second opposite clamping wall of the respective jaw formed by the cavity and has a tapered drive surface engaging a mating drive surface formed on the groove in the second clamping wall, for driving the jaw in an opposite direction. The drive surfaces that engage between the jaw nut and the respective moveable jaw are angled to provide a downward force on the jaw to urge the jaw toward the jaw guideway in either direction of movement of the jaw. The adjustable jaw drive member in each jaw is linearly adjustable so as to ensure that there is engagement between the jaw nut and the respective moveable jaw in either direction of movement of the jaws. The adjustable jaw drive member is retractable so the projections of the head members can be moved to clear the surfaces of the cavities when the head members are inserted into the cavities for assembly.
A single jaw nut and moveable jaw using the drive for clamping in opposite directions also can be used with a vise body that has fixed jaws at one or both opposite ends of the vise base, with the moveable jaw in the center portions of the vise body.
The self-centering vise assembly indicated at 10 includes a vise body 12. The vise body 12 has a base 14, and a pair of spaced apart vise side rails 16 that extend upwardly from the base 14 and have upper surfaces indicated at 18 that form jaw support ways or guideway surfaces for slidably mounting and supporting a first moveable jaw 20 and a second moveable jaw 22. The jaws 20 and 22, as shown, have lower support surfaces that are supported on both of the guideways, and slide along the guideways.
The jaw 20 has a first clamping surface 20A and a second clamping surface 20B. The second jaw 22 has a first clamping surface 22A and a second clamping surface 22B. The clamping surfaces 20A and 22A face each other, and the clamping surfaces 20B and 22B are facing outwardly toward the opposite ends of the vise body 12. The clamping surfaces are shown as being planar and perpendicular to the plane of the guideway surfaces 18, but the clamping surfaces could be carved or sculpted to mate surfaces of a piece part to be clamped.
A vise screw or other jaw drive 24 is positioned in a recess formed between the vise side rails 16 and base 14, and is supported on a vise screw support flange 28 for rotation, and is held in place axially on the flange 28 with suitable collars 30. A removable crank (not shown) is used for rotating the vise screw 24. Thrust bearings can be provided between the flange and the collars as desired on opposite sides of the flange 28. The flange 28 is secured to an end of the vise body 12.
The vise screw 24 drives a first jaw nut 34 and a second jaw nut 36, which are threadably mounted on threaded sections of the vise screw 24. The vise screw 24 has a first threaded section 24A for driving the first jaw nut 34, and a second threaded section 24B for driving the second jaw nut 36, which threaded sections are separated at the center portion of the vise screw, and are of opposite hand or opposite lead. This means that when the vise screw 24 is rotated the jaw nuts will either move together or apart, depending on the direction of rotation of the screw. A hydraulic or electric linear actuator or actuators can be used for driving the jaw nuts simultaneously in opposite directions.
Each of the moveable jaws is provided with a recess or cavity on an underside thereof facing toward the guideway surfaces 18 and toward the base 14 of the vise body, which is considered downwardly. The cavities open to the support surfaces of the moveable jaws. The first moveable jaw 20 has a recess or cavity 20C, and the second moveable jaw 22 has a recess or cavity 22C, both open in direction toward the surfaces 18. The jaw nut 34 has an integral head member 34A that extends up into the cavity 20C of the first moveable jaw 20. The jaw nut 36 has an integral head member 36A that extends up into the cavity 22C of the second moveable jaw 22. The cavities 20C and 22C form chambers receiving the head members of the jaw nuts.
The cavity 20C forms opposite end wall portions 20F and 20G, adjacent the clamping surfaces 20A and 20B, respectively. The cavity 22C forms opposite end wall portions 22F and 22G, adjacent the clamping surfaces 22A and 22B, respectively. Interior surfaces of the end wall portions 20F, 20G, 22F, and 22G form ends of the cavities that receive the head members of the respective jaw nut. The end wall portions 20F and 20G have transverse “V” shaped grooves 20H and 20K formed therein, respectively (see
Each of the head members 34A and 36A of the jaw nuts 34 and 36 has machined side surfaces that fit between side surfaces of the top part of the vise side rails 16, and also fit between the side surfaces of the cavities 20C and 22C respectively, as shown typically in the broken away part on one side of the vise in
Each of the head members 34A and 36A also is shaped to include a drive projection 34B and 36B, respectively, at the end of the head member facing the end wall portions 20F and 22F, and thus at the end adjacent the clamping surfaces 20A and 22A. Each of the drive projections 34B and 36B is formed to fit in grooves 20H and 22H (with clearance) respectively, and each drive projection has a downwardly facing tapered drive surface 34C and 36C, respectively that are made to mate with and engage a corresponding upwardly facing driven surface 20D and 22D formed in the respective end wall portion 20F and 22F of the respective cavity adjacent the clamping surfaces 20A and 22A that face each other when mounted on the vise base.
The driven surfaces 20D and 22D are formed by machining the “V” shaped grooves 20H and 22H in the end wall portions 20F and 22F of the respective moveable jaw formed by the recesses or cavities 20C or 22C.
It can be seen that the head members 34A and 36A have an axial length (in direction along the axis of the vise screw) shorter than the axial length of cavities 20C or 22C into which the head members extend so the head members will fit into the respective cavity as explained below. Each head member is provided with a pair of separate spaced apart bores 34D and 36D, each of which receives an identical plunger assembly 40. The plunger assemblies 40 will be identically numbered and are mounted in the respective head member 34A and 36A in the provided bores. Each of the plunger assemblies comprises an adjustable member and includes a plunger housing or sleeve 42 that is slidably mounted in the respective bore 34D or 36D, and each of the plunger housings 42 has an outer end projection portion that is formed to fit, with clearance, within grooves 20K and 22K. The outer end projection portion of the plunger housing 42 has a tapered surface comprising a downwardly facing drive surface 44 that mates with driven surfaces 20E or 22E in the respective grooves in the end wall portions 20G or 22G of the moveable jaws 20 and 22. The outer end projecting portion or end of the housing 42 is generally V-shaped, as shown, and each plunger can be retracted into the bore in which it fits, and also lengthened. The respective surfaces 44 and 20E and 22E engage for driving the respective moveable jaw in direction to separate.
The plunger housing 42 is a sleeve and has an interior threaded bore 46 that threadably receives a plunger screw 48 that fits within the respective bore 34D and 36D of the associated jaw nut. The plunger screw has a head 50 that bears against the interior end of the respective bore 34D and 36D. The overall length of the plunger assembly or adjustable member 40, from the head 50 to the end of tip of the driving surface 44 can be varied by threading or rotating the plunger screw 48 relative to the plunger housing 42. Each of the plunger housings 42 also has an external groove 52 that is engaged by a set screw 54 threaded through the wall of the respective head portion 34A and 36A, in line with the bores 34D and 36D, to keep the plunger housings 42 from rotating about their axes in the bores. The set screws 54 keep the surfaces 44 properly positioned to drive against surfaces 20E and 22E. The plunger housings 42 will, however, slide along the bores 34D and 36D while restrained from rotating by the setscrew 54 sliding in the grooves 52. The plunger screw 48 of the plunger assembly 40 has an internal hex shaped socket 56 at the inner end of the screw, that is aligned with a bore 58 in the outer end of the respective plunger housing 42. When the plungers are in position as shown in
In assembling a jaw nut and associated moveable jaw, the lengths of the two plunger assemblies 40 used in each moveable jaw are shortened by threading the plunger screws 48 into the threaded bores 46 so that the outer end portions of the plunger housings having the drive surfaces 44 will be retracted sufficiently (entirely in the mounting bores) so that the rear surface of the head member and the end of the respective drive projections 34B or 36B of the respective moveable jaw head member will clear the interior surface of the end wall portion 20F and 22F of the respective cavity, 20C or 22C. The surfaces of the moveable jaw head members at the end opposite from the projections 34B and 36B are spaced from the interior surfaces of the end wall portions 20G and 22G when the jaw nuts are in working position, as shown in
For assembly, the respective movable jaw can be placed over the associated jaw nut head member and the head member 34A or 36A will fit into the cavity 20C or 22C of the respective moveable jaw. When the moveable jaw is in place over the respective head member, the drive projection 34B or 36B can be seated into the associated groove 20H or 22H against the respective surface 20D or 22D. To adjust the length of each plunger assembly 40, the hex shaped cross section shaft of an Allen wrench is inserted through the bores 60 and 58 and through the interior of the threaded bore 46 and into the hex socket 56 of the screw of the plunger assembly being adjusted, to thread or rotate the plunger screw 48 to extend the overall length of the plunger assembly until the drive surface 44 engages and bears against the driving surface 20E or 22E, and the drive surface 34C or 36C of the projection 34B or 36B of the respective head member is snuggly fitting against the driven surface 20D or 22D of the respective moveable jaw.
When the movable jaws 20 and 22 are mounted as shown in
When a movable jaw is to be removed from its associated jaw nut, the plunger screw of each plunger assembly 40 can again be used to retract the plungers into the mounting bores, and the projections 34B and 36B backed out from the grooves 20H and 22H, so there is clearance for removal of the movable jaw.
The present structure provides for ease of assembly of the moveable jaws onto the respective jaw nut, and the ability to insure the jaw is securely and snuggly held in the jaw nut for operation in either direction of movement, and for applying adequate clamping forces in the selected direction of movement that is either on the interior surface of the work piece or on the exterior surface of the work piece.
The drive shown for the moveable jaw can be used with only one movable jaw, for clamping against fixed jaws at opposite ends of a vise body, with the moveable jaw between the fixed jaws. The clamping force is applied through angled surfaces that provides a force on the movable jaw toward the guideway surfaces.
The use of two laterally spaced plunger assemblies 40 on each moveable jaw applies force on opposite sides of the center line of the vise so the clamping surfaces of moveable jaws 20 and 22 are square with the longitudinal axis of the screw or the axis of the vise, by properly adjusting the plunger length. The plunger assembly bores, and the plunger assemblies 40 are on opposite sides of a plane perpendicular to the plane of guideway surfaces 18 and passing through the longitudinal axis of screw 24.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.