Incremental Gear For Bar Clamp

Abstract

The invention relates to a stepping gear for a clamping and/or spreading tool having a stationary jaw and a support to which said stationary jaw is fixedly connected and on which a push or pull rod is slideably supported, a movable jaw being fixedly arranged on the push or pull rod, wherein said stepping gear is designed to displace said push or pull rod together with said movable jaw relative to said fixed jaw in an advance direction step-by-step with at least two different stepping sizes and comprises at least one operating arm operateable with at least two lever configurations defined by at least two active levers on said operating arm, wherein a mechanism for switching from a first lever configuration to a second lever configuration is provided and upon an activation of the switching means, particularly in a predefined operating condition, the respective active lever can be activated directly instantaneously. At least two active levers are engageable with said push or pull rod via said at least two drivers according to the respective lever force transmission and at least one driver is connected to said operating arm via a coupling structure, said switching means being formed as a means for detaching said coupling structure.

Description

Further advantages, features and properties of the invention will now be detailed by the description of two preferred embodiments of the invention with reference to the drawings in which:

FIG. 1 is a side view of a tool in accordance with the invention in the configuration as a bar clamp including a dual mode incremental actuator, shown in the idle position;

FIG. 2 is a side view of the tool as shown in FIG. 1, showing the end of an actuating stroke of the large-increment distance actuation mode;

FIG. 3 is a side view of the tool as shown in FIG. 1, but with the small-increment force actuation mode activated;

FIG. 4 is a side view of the tool as shown in FIG. 1, showing the force actuation mode at the end of the stroke;

FIG. 5 is a side view of the tool as shown in FIG. 1 showing the distance actuation mode reinstated;

FIG. 6 is a diagrammatic side view but depicting realistic lever configurations of a tool in accordance with the invention in the configuration of a bar clamp in which a dual-mode incremental actuator is in an idle position;

FIG. 7 is a side view of the tool as shown in FIG. 6 showing a force trigger positioned in a counterbearing position;

FIG. 8 is a side view of the tool in accordance with the invention as shown in FIG. 6 showing a distance trigger in an actuated operating condition as indicated by the dotted line;

FIG. 9 is a side view of the tool in accordance with the invention as shown in FIG. 6 showing a positive contact between the fixed and movable jaws;

FIG. 10 is a side view of the tool in accordance with the invention as shown in FIG. 6 showing the force trigger in an actuated operating condition, and

FIG. 11 is a side view of the tool in accordance with the invention as shown in FIG. 6 showing how jaw tension is released by actuating a release lever.

The bar clamp 1 as shown in FIGS. 1 to 5 includes a carrier or support 3 comprising a fixed jaw 5, a housing 7 and a handle grip 9, and a slide bar or push rod 11 movably mounted on the carrier 3, at the end of which a movable jaw 13 is fixedly attached, for example, by means of rivets or releasably by a quick-action latch mechanism. The jaws 5 and 13 may be arranged facing each other (clamping tool) or facing away from each other (spreading tool). The fixed jaw 5 and movable jaw 13 are arranged on a clamping side 15 of a longitudinal centerline of the slide bar 11. The handle grip 9 is arranged on an actuating side 17 of the longitudinal centerline of the slide bar 11.

The housing 7 defines a cavity 19 dimensioned to accommodate, at least in part, the members of a dual-mode incremental actuator 21 having two different increments. Referring now to FIG. 1 there is illustrated the fixed jaw 5 and movable jaw 13 in an open position relative to each other, a clamping zone 23 being defined between the jaws 5, 13. It is in this clamping zone 23 that an item (not shown) can be clamped.

For simple manufacture of the bar clamp in accordance with the invention the fixed jaw 5 and housing 7 and handle grip 9 are made in one piece, more particularly injection molded in plastics material.

The slide bar 11 as well as the movable jaw 13 are defined movable to the effect that they can be moved relative to the carrier 3. The slide bar 11 is shiftingly mounted axially on the carrier at two radial mounting portions 25, 27 for introducing radially acting mounting forces from the slide bar 11 into the carrier 3 or from the carrier 3 into the slide bar 11.

The incremental actuator 21 is designed for incremental displacement of the movable slide bar 11 including the movable jaw 13 in an advance direction V. The incremental actuator 21 in accordance with the invention comprises as a drive a trigger or operating arm 31 which is pivotally mounted via a pivot mount 33 on the carrier 3.

In a non-actuated operating condition of the trigger 31 (FIG. 1) a portion of the side of the trigger 31 facing away from the handle grip 9 is stopped by a stop formed by a portion 35 of the carrier 3 at the actuating side.

The trigger 31 has a handle grip inlay 37 made of a material having a high friction coefficient, such as rubber. On operation of the bar clamp 1 an operator (not shown) clasps the handle grip 9 such that the handle grip inlay 37 is gripped by at least the middle finger and/or index finger whilst the handle grip 9 rests in the palm of the hand as a counterhold.

The incremental actuator in accordance with the invention has a force follower or driver 39 and a distance follower 41. Both followers 39 and 41 comprise a through passage 43 and 45 respectively, the dimensioning of which in each case is dimensioned relative to the constant cross-section of the slide bar 11 such that the slide bar 11 is adapted in clearance to the longitudinal centerline of the slide bar 11 in a vertical position of the followers 39, 41.

Biasing the distance follower or driver 41 is a return spring 49 located as a coil spring about the slide bar 11 and which is supported on one hand by the inner side of the slide bar mount 25 and biasing on the other hand the distance follower 41 contrary to the advance direction V. In the non-actuated operating condition of the incremental actuator 21 as shown in FIG. 1 too, the return spring 49 biases the distance follower 41.

Arranged in a substantially parallel orientation to the return spring 49 at the clamping side 15 is a return spring 51 which is supported on the one hand in a blind hole location provided in the carrier 3 and on the other hand biases the force follower 39.

In the non-actuated operating condition of the incremental actuator 21 as shown in FIG. 1 the return spring 51 is urged against a clamping side 15 portion of the force follower 39. The force follower 39 is formed by two plates dimensioned the same, one plate engaging the return spring 51, the other plate cooperating with the trigger 31 operationally as detailed below.

The distance follower 41 comprises at the actuating side (17) an elongation accommodating a load-dependent decoupling means 53. The decoupling means 53 serves to permit scissors action of the trigger 31 with the distance follower 41 when a predefined actuating force threshold, i.e. a load threshold acting on the decoupling means 53 is exceeded. The elongation of the distance follower 41 comprises a recess for receiving a biasing spring 55 biased. The biasing spring 55 acts on a ball 57 which in the deactivated condition (FIG. 1) of the decoupling means 53 is urged against a dished end portion of a coupling rod 59. The end portion of the coupling rod 59 is provided with a dished operator receiving a pin 61 via the biasing spring 55 in the deactivated condition (FIG. 1) of the decoupling means 53. The predefined load threshold of the force release threshold can be predefined by the spring rate of the biasing spring 55 as well as the dimensioning of the pin 61 and of the dished end portion of the coupling rod 59.

The operating condition of the incremental actuator 21 in which the decoupling means 53 is activated in permitting scissors action of the trigger 37 with the distance follower 41 is detailled further on.

The coupling rod 59 prevents in the deactivated condition (FIG. 1) of the decoupling means 53 a relative movement between the distance follower 41 and trigger 31. Due to a hinge-like pin and dished arrangement on the one hand and a hinged link 63 on the other, the coupling rod 59 forms a two-hinged link chain for coupling the trigger 31 to the distance follower 41, resulting in stationary force transmission locations (65).

The hinged link 63 defines a permanent distance active lever ww which is effective when the decoupling means 53 is deactivated, i.e. the trigger 31 is coupled to the distance follower 41. The length of the distance active lever ww relevant for the large increment distance operation mode of the incremental actuator 21 is determined by the spacing of the pivot mount 33 of the trigger 31 and the hinged link 63.

The second operating condition (FIGS. 3 and 4) of the dual mode incremental actuator 21 is defined by a force active lever wk, the length of which is determined by the spacing of the pivot mount 33 from a force transmission location on the trigger 31 formed by a force transmission location 65 secured to the trigger.

An actuating lever b_max is the same for both operating conditions, i.e. distance operating condition and force operation condition, reference being made in this case merely to the longest actuating lever by corresponding operation, for a better understanding of the Figs., as defined by the spacing of the pivot mount 33 of the trigger 31 away from the end 67 of the trigger 31 at the free actuating side.

Provided at the side of the housing 7 facing the clamping zone 23 is a lock 71 which prevents displacement (backslip) of the slide bar 11 contrary to the advance direction V. The lock 71 comprises an actuating portion 73 and a mounting part 75 pivotally mounted in a C-shaped recess configured in the carrier 3. A biased locking spring 77 urges the lock 71 into the position as shown in FIGS. 1 to 4 inclined to the longitudinal centerline of the slide bar 11 passing through the lock 71 in a through passage (not shown) adapted in clearance to the dimensioning of the slide bar 11.

In the inclined position as shown in FIGS. 1 to 4 the lock 71 with its lateral edges (not shown) is tilted with the slide bar 11 such that the clamping forces produced at the tilted portions by means of the locking spring 77 prevent the slide bar 11 from being returned contrary to the advance direction V (backslip) in thus maintaining the clamping forces produced at the fixed jaw 5 and movable jaw 13.

Provided at the actuating side 17 of the slide bar 11 is a recoupling means 81 shiftingly mounted as an elongated component in a mounting recess in the carrier portion 35. The locking spring 77 forces the elongated component into contact with the actuating portion 73 of the lock 71. A detailed description of the function of the recoupling means 81 is given below.

Individual, more particularly independent aspects of the invention will now be described as relating more particularly to the functional relationship of the individual components of the incremental actuator 21 in accordance with the invention and the tool in accordance with the invention.

Distance Operation of the Incremental Actuator 21

As indicated above, the incremental actuator in accordance with the invention has two increments or two different advance distances for a full actuating stroke of the trigger 31. The operating condition will now be explained in which large advance distances are achieved on an actuating stroke as defined by the angle between the handle grip 9 and the trigger 31.

In distance operation for displacing the slide bar 11 together with the movable jaw 13 the distance active lever ww is effective. No forces occur at the fixed jaw 5, as a result of which actuating the trigger 31 is already possible with a small force which, however, is not sufficient to activate the decoupling means 53, i.e. to urge the pin 61 from the dished recess of the coupling rod 59 by the biasing spring 55 being compressed.

Pivoting the trigger 31 displaces the slide bar 11 via the distance follower 41 tilted with the slide bar 11 in the advance direction V by the increment of the distance operation coupled to the return spring 49. The return spring 49 must only be dimensioned strong enough that it communicates in none of its compressed conditions a force to the distance follower 41 which is stronger than the release force threshold needed to activate the decoupling means 53.

On completion of the full actuating stroke (see FIG. 2) the trigger 31 contacts the handle grip 9 and the return spring 49 is in its maximally compressed position. When the operator releases the trigger the return spring 49 urges the trigger 31 via the distance follower 41 coupled thereto into its idle position as shown in FIG. 1 in which it rests against the stop on the actuating side portion 35.

Referring now to FIGS. 1 and 2 illustrating the idle position and the end position of the trigger in distance operation of the incremental actuator 21 it is evident that also during large increment distance operation the force transmission location 65 of the trigger 31 engages the force follower 39 and thus in distance operation of the trigger 31 too, the force follower 39 is shifted in accordance with the actuating stroke of the trigger 31 and the force active lever wk in the advance direction V. Although the advance of the force follower 39 in the advance direction V does not effectively determine the displacement of the slide bar 11 in distance operation of the incremental actuator 21, because the advance rate of the slide bar 11 during distance operation is substantially higher than the advance rate could be effective by the displacement of the force follower 39 in accordance with the force lever configuration during distance operation, operating the trigger 31 in distance operation of the incremental actuator moves both the distance follower 41 as well as the force follower 39 in the advance direction V. In this arrangement the slide bar 11 has no movement relative to the distance follower 41 during distance operation but the slide bar 11 is displaced relative to the force follower 39.

Accordingly, the lever configuration (force active lever wk) responsible for force operation of the incremental actuator 21 is also in function during distance operation without, however, acting on the slide bar 11 in any lever force transmitting way. Thus the spacing between the force follower 39 and the distance follower 41 as shown in FIG. 2 does not represent the actual displacement increment of the incremental actuator in distance operation, because the force follower 39 is also displaced by roughly the product of the force active lever wk and the sine of the angle α. The actual increment of the incremental actuator 21 in distance operation is roughly determined by the product of the distance active lever ww and the sine of the angle α.

Force Operation of the Incremental Actuator 21

In force operation of the incremental actuator 21 the slide bar 11 is displaced in the advance direction V only in small increments, resulting in lighter increases in tension between the fixed jaw 5 and movable jaw 13.

In force operation the force active lever wk of the trigger 31 is effective. Referring now to FIG. 3 there is illustrated the decoupling means 53 in its activated condition. The pin 61 is urged from the dished mount so that the distance follower 41 can be shifted by the return spring 49 unobstructed contrary to the advance direction V to the pivot mount 33 by the distance follower 41 no longer being forced in a tilted position by the rigid coupling by means of the coupling rod 59.

The decoupling means 53 is then activated when a force is communicated to the trigger 31 by the operator which exceeds the release force threshold preset by the decoupling means 53. This actuating force is applied operationally only when a clamping force is needed between the fixed jaw 5 and movable jaw 13, namely when an item to be clamped is to receive clamping forces. This scenario is indicated in FIG. 3 by the contact of the jaws 5, 13.

Due to the coupling rod 59 being uncoupled from the distance follower 41 the distance active lever ww of the trigger 31 is no longer effective.

As explained above, the trigger 31 at the force transmission location 65 (force active lever wk) is permanently in contact with the force follower 39 throughout full operation of the incremental actuator as is produced by the return spring 51. This results in the force lever configuration becoming directly effective in achieving a continual advance of the slide bar 11 without interruption by the change-over due to decoupling on continued actuation of the trigger.

Due to the small force active lever wk it is evident that when the trigger 31 is actuated by an actuating stroke (α) a much smaller increment is achieved than in distance operation with the distance active lever ww as described above.

Referring now to FIG. 4 there is illustrated how actuating the trigger 31 in force operation by an actuating stroke (α) results in the trigger 31 being in contact with the handle grip 9. Releasing the trigger 31 results in it being returned to the idle position because of the return spring 51. This is evident from FIG. 3. Since the return spring 49 urges the deactivated distance follower 41 against the force follower 39 the pin 61 is unable to return latch into the dished end portion of the coupling rod 59 in thus making a repeat actuating stroke possible without delay with this force lever configuration.

Releasing the Clamping Force and Recoupling

Referring now to FIG. 5 there is illustrated how to release the clamping force effective between the fixed jaw 5 and movable jaw 13 the lock 71 needs to be actuated by its actuating portion 73 at the actuating side in the advance direction V so that the actuating portion 73 is pivoted at the mounting part 75 and the tilt is released with the slide bar 11 which is responsible for maintaining the clamping force between the jaws 5 and 13 because of the closed force circuit from one jaw via the lock 71 into the slide bar 11 and further into the other jaw 13.

Again as indicated in FIG. 5 actuating the lock 71 simultaneously actuates the recoupling means 81, resulting in the elongated component of the recoupling means 81 being urged in the advance direction V in overcoming the bias of the locking spring 77.

As evident from FIG. 3, in the idle position of the trigger 31 in force operation of the incremental actuator 21 the distance follower 41 is in contact with the free end of the elongated component so that actuating the lock 71 directly affects the distance follower 41. When the lock 71 is actuated the return spring 49 causes the distance follower 41 to pivot about the end portion of the return spring 49 at the distance follower 41 so that the pin 61 is able to couple into the dished end portion of the coupling rod 59, as evident from FIG. 5.

Again as indicated in FIG. 5 a follower 85 results in release of the permanently tilted force follower 39. By releasing the lock 71 and tilting the force follower 39 the bar can be shifted contrary to the advance direction V to part the jaws 5 and 13 in preparation for a new clamping zone 23.

Permanently Tilted Force Follower 39

As explained above, the force follower 39 is maintained in a permanently tilted position relative to the slide bar 11 to permit force operation at any location along the slide bar 11.

The tilted position of the force follower 39 permits changing from the large increment mode to the small increment mode of the incremental actuator 21 even during an actuating stroke of the trigger without any loss of actuating distance.

The distance follower 41 too, is maintained in a permanently tilted position relative to the slide bar 11 by the coupling rod 59 cooperating with the return spring 49 when the decoupling means 53 is deactivated.

Referring now to FIGS. 6 to 11 there is illustrated a second preferred embodiment of the tool in accordance with the invention and incremental actuator in accordance with the invention respectively. The tool is illustrated in the configuration of a bar clamp 101, including a carrier 103 comprising a fixed jaw 105 and a housing 107, a reciprocating slide bar 111, at the one end of which a clamping jaw 113 is fixedly attached. The fixed jaw and the housing 107 may be made in one piece, more particularly injection molded in plastics material. The jaws 105, 113 are provided on a clamping side 115 of the slide bar 111, the opposite side of the slide bar 111 being termed the actuating side 117.

The housing 107 defines a cavity 119 in which organs of a dual-mode incremental actuator 121 are accommodated. at least in part, providing two operating conditions, namely distance operation characterized by large displacements of the slide bar 111 and a force operation configured by small displacements for producing high clamping forces between the jaws 105 and 113.

In FIG. 6 the jaws 105 and 113 are shown separate from each other, between which a clamping zone 123 is definable in which an item to be clamped can be inserted.

The incremental actuator 121 with its two increments comprises a distance trigger 125 indicated by a dotted line for pivoting about a pivot mount 127. The pivot mount 127 is arranged at the actuating side 117 on the carrier 103.

The distance trigger 125 comprises an inset grip inlay 129 featuring a high friction coefficient. In addition, the distance trigger 125 comprises a first portion 131 with the grip inlay 129 and a second portion 132, the two portions 131, 132 being arranged at an angle of approx. 125 deg.

The distance trigger 125 comprises a non-variable permanent lever configuration defined by the active lever ww. The length of the active lever is determined by the spacing of the pivot mount 127 from a force transmission location 128.

In addition, the incremental actuator 121 in accordance with the invention comprises a force trigger 137 for pivoting about a pivot mount 139 arranged at the clamping side 115 on the carrier 103. The force trigger 137 comprises a grip inlay 141 located at the side of the force trigger 137 facing away from the distance trigger 125. As evident from the arrangement of the grip inlay 141, grip inlay 129 the bar clamp 101 can be gripped either by the force trigger 137 or by the distance trigger 125.

The force trigger 137 comprises a first arm portion 143 and a second arm portion 145 located at an angle of approximately 160° to each other. The lever configuration of the force trigger 137 is defined by the force active lever wk, the length of which is definable by the spacing of the pivot mount 139 of the force trigger 137 from the force transmission location 135, configured as a pin secured to the force trigger 137.

The incremental actuator in accordance with the invention comprises a sole follower 151 formed by two parallel plates. The follower 151 comprises a through passage (not shown) through which the slide bar 111 can pass with a clearance. The distance trigger 125 and force trigger 137 are engaged by a follower 151 at the clamping side 115.

The return spring 153, surrounding the slide bar 111 as a coil spring, is supported on the one hand by the inner side of the radially mounting portion of the carrier 103 whilst on the other it biases the follower 151 contrary to the advance direction V.

Referring now to FIG. 6 there is illustrated the idle position of the force trigger 137 in which the force trigger 137 contacts a stop (not shown) of the housing 107 at the actuating side 117 so that the force trigger 137 as well as the force transmission location 135 cannot be pivoted contrary to the advance direction V. Due to the return spring 153 the follower 151 is urged contrary to the advance direction V against the force transmission location 135 in assuming a tilted position in which the follower 151 is tilted with the slide bar 111. It is in this way that a tilted position of the follower 151 is made available in the non-actuated condition of the force trigger 137.

Provided at a side of the housing 107 facing the clamping zone 123 pivotally mounted is a lock 155 comprising a actuating portion 157. A pivot portion 159 cooperates with a recess provided at clamping side of the housing 107 such that the lock 155 is held on the housing 107 for pivoting about the pivot portion 159.

The lock 155 has a through passage through which the slide bar 11 can pass with a clearance. A locking spring 161 forces the lock 155 into a position permanently tilted relative to the slide bar 111 so that the lock 155 is tilted relative to the slide bar 111 in preventing a displacement (backslip) of the slide bar 111 contrary to the advance direction V.

The actuator in accordance with the invention also comprises a means 163 for releasing the tilted position, arranged on the actuating side on the housing 107. The means 163 is formed as an elongated component shiftingly mounted on the housing portion at the actuating side and biased by the locking spring 161 contrary to the advance direction V.

Distance Operation of the Incremental Actuator 121

Referring now to FIGS. 6 to 8 there is illustrated three operating positions for distance operation of the incremental actuator, FIG. 6 showing a non-actuated position, FIG. 7 an intermediate position and FIG. 8 an actuation end portion.

In the starting position as shown in FIG. 6 the bar clamp 101 is gripped so that the distance trigger 125 lies in the palm of the hand and the force trigger 137 is gripped by at least the middle finger and/or index finger.

Due to the permanently tilted position of the follower 151 even the smallest actuating stroke of one of the triggers 125 or 137 results in a displacement of the slide bar 111.

Referring now to FIG. 7 there is illustrated how before the distance trigger 125 becomes active, the force trigger 137 is pivoted about a pivot range □ to bring the force trigger 137 into its counterposition in which the force trigger 137 contacts the pivot mount 127 of the distance trigger 125 by its side facing the distance trigger 125. In the counterposition the force trigger 137 cannot be further pivoted towards the distance trigger 125. The follower 151 is already displaced in the advance direction V by the force lever configuration coupled to the force active lever wk in this first actuating phase of the force trigger 137. It is to be noted that this displacement corresponds to the increment in force operation.

Once the force trigger 137 has attained the counterposition as shown in FIG. 7 the large increment displacement, the same as in distance operation of the incremental actuator 121, can be attained. As evident from FIG. 8 the distance trigger 125 is pivoted towards the stationary force trigger 137 in accordance with the distance lever configuration in which the distance active lever ww is effective.

Referring now to FIG. 8 there is illustrated how in a full actuating stroke of the distance trigger 125 the return spring 153 is compressed. Releasing the force actuating the distance trigger 125 (FIG. 9) results in the return spring 153 urging the follower 151 from its tilted position in returning it to the force trigger 137, more particularly to the force transmission location 135. This return of the follower 151 takes place in continual contact with the force transmission location 128 of the distance trigger 125 at the end thereof at the clamping side.

If the item to be clamped (not shown) has yet to be gripped (see FIG. 7) the distance trigger 125 can be again actuated after having attained the position as shown in FIG. 7, until the jaws 105 and 113 have gripped the item to be clamped (not shown).

Force Operation of the Incremental Actuator 121

Referring now to FIGS. 8 to 10 small increment force operation of the incremental actuator will now be detailed. Force operation is particularly good for application when high clamping forces need to be applied by the jaws 105 and 113 as is indicated in FIGS. 8 to 10 by the jaws 105, 113 being in direct contact.

Once the two jaws 105, 113 are in contact no further actuation of the distance trigger 125 is possible since the large distance active lever ww requires enormous forces to achieve a displacement of distance increment. Accordingly, the distance trigger 125 in force operation of the incremental actuator is to be appreciated as a counterarm with respect to which the force trigger 137 can be pivoted.

Before the force actuating stroke is achievable the force trigger 137 needs to be moved from its end portion as shown in FIG. 7 into the starting position as shown in FIGS. 6 and 9. For this purpose the force trigger 137 is to be released so that the return spring 153 is able to produce the necessary pivoting movement about the pivot mount 139 into the starting position via the follower 151 and the force transmission location 135.

In force operation of the incremental actuator 121 the distance trigger 125 is used as a counterarm. The force trigger 137 is pivoted until the side of the force transmission location 135 facing the distance trigger 125 engages the pivot mount 127 of the distance trigger 125 as shown in FIG. 10. The force lever configuration produces small increments of constant actuating stroke so that the desired clamping forces can be induced in the jaws 105 and 113.

This action can be repeated by the force trigger 137 being released from the fingers of the operator (not shown), resulting in the return spring 153 returning the trigger to its starting position in readiness for a new force actuating stroke, as shown in FIG. 9.

Releasing the Clamping Force and Tilting

To release the clamping force between the jaws 105, 113 as maintained by the lock 155, the actuating portion 157 of the lock 155 needs to be actuated in simultaneously actuating the means 163 to release the tilt of the follower 151. When the lock 155 is actuated the elongated component of the means 163 urges the portion of the follower 151 at the actuating side, resulting in it being pivoted about the force transmission location 135 of the force trigger 137 to thus defeat its tilted position relative to the slide bar 111.

Deactivating the lock 155 and activating the means 163 permits displacing the slide bar 111 together with the movable jaw 113 contrary to the advance direction V.

It is understood that the features of the invention as disclosed in the above description, in the drawing as well as in the claims may be substantial to achieving the invention in its various embodiments both individually and in any combination.

Claims

1. A stepping gear for a clamping and/or spreading tool having a stationary jaw and a support to which said stationary jaw is fixedly connected and on which a push or pull rod is slideably supported, a movable jaw being fixedly arranged on the push or pull rod, wherein said stepping gear is designed to displace said push or pull rod together with said movable jaw relative to said fixed jaw in an advance direction step-by-step with at least two different stepping sizes and comprises at least one operating arm operateable with at least two lever configurations characterized in that a mechanism for switching from a first lever configuration to a second lever configuration is provided, whereby upon an activation of the switching means, particularly in a predefined operating condition, the activated lever configuration enters engagement directly instantaneously.

2. A stepping gear according to claim 1, characterized in that the switching means is a mechanism for detaching a coupling structure between the operating arm and a driver via which the operating arm is engageable with the push or pull rod, whereby especially the decoupling means is designed as a load-dependent release means.

3. A stepping gear according to claim 1 or 2, characterized in that said recoupling means is provided to reinstate the detached coupling structure between said driver and said operating arm, wherein in particular that recoupling means is actuable via a locking means for blocking displacement of the push or pull rod opposite to the advance direction.

4. A stepping gear according to one of the claims 1 to 3, characterized in that a permanently activated lever configuration is provided, particularly for a small stepping size displacement wherein, in particular if said detaching means is deactivated, an overriding or priority lever configuration, in particular for a displacement in a large stepping size, determines operation of said stepping gear and more particularly, if the detaching means is activated, the lever configuration having a large stepping size is deactivated and the lever configuration having a small stepping size is activated.

5. A stepping gear, in particular according to one of the claims 1 to 4, for a clamping and/or spreading tool having a stationary jaw and a support to which said stationary jaw is fixedly connected and on which a push or pull rod is movably supported, a movable jaw being fixedly arranged on the push or pull rod, said stepping gear being designed to displace said push or pull rod together with said movable jaw relative to said stationary jaw step-by-step in an advance direction and comprising two separately operateable operating arms which upon activation realize a displacement of the push or pull rod in the same advance direction.

6. A stepping gear according to claim 5, wherein said at least two lever configurations are alternately operateable, particularly alternately exclusively effective.

7. A stepping gear according to claim 5 or 6, wherein said two operating arms are pivotably linked to said support such that said operating arms feature opposing actuating directions.

8. A stepping gear according to one of the claims 5 to 7, wherein a force operating arm having a small stepping size is pivotably linked on an actuating side of said push or pull rod and is engageable on said actuating side of the push or pull rod with a driver via which the force operating arm cooperates operationally with said push or pull rod, wherein in particular a distance operating arm having a large stepping size and said force operating arm having a small stepping size are adapted to each other such that when one of the operating arms is operated the other acts as a counter arm.

9. A stepping gear, in particular according to one of the claims 1 to 8, for a clamping and/or a spreading tool, in particular for a bar clamp, the clamping and/or spreading tool comprising a stationary jaw and a support to which said stationary jaw is fixedly connected and on which a push or pull rod with a movable jaw fixedly connected thereto is movably supported, said stepping gear being designed to displace said push or pull rod in an advance direction step-by-step and comprising at least one operating arm to be operated in an operating direction, the operating arm being engageable with the push or pull rod according to a lever force transmission via a driver displaceable against a resetting or return spring, characterized in that said operating arm is pivotably mounted on a clamping side of the push or pull rod and said operating arm has a location for introducing force into said driver, positioned on said clamping side of the push or pull rod such that said operating direction of the operating arm is substantially the same as the advance direction of said push or pull rod.

10. A stepping gear according to claim 9 characterized by an overload protection which is designed to detach a coupling of the driver with the operating arm as soon as a force release threshold is violated.

11. A stepping gear, in particular according to one of the claims 1 to 10, for a clamping and/or spreading tool, in particular for a bar clamp, wherein the clamping and/or spreading tool comprises a stationary jaw and a support to which the stationary jaw is fixedly connected and on which a push or pull rod with a movable jaw fixedly connected thereto is movably supported, the stepping gear being designed to displace said push or pull rod in an advance direction step-by-step and comprising at least one operating arm pivotably mounted on said carrier for engaging said push or pull rod in accordance with a lever force transmission via a driver displaceable against a reset spring, characterized in that a pivot bearing of said operating arm is arranged on an operating side of the push or pull rod and said operating arm has a location for introducing force into said driver on a clamping side of said push or pull rod opposite to the actuating side.

12. A stepping gear, in particular according to one of the claims 1 to 11, for a clamping and/or spreading tool, in particular for a bar clamp, the clamping and/or spreading tool having a stationary jaw and a support to which said stationary jaw is fixedly connected and on which a push or pull rod with a movable jaw fixedly connected thereto is movably supported, said stepping gear being designed to displace said push or pull rod in an advance direction step-by-step and comprising an operating arm and a driver via which said operating arm is engageable with said push or pull rod according to a lever force transmission, said operating arm being connected to the driver by a coupling member ensuring a stationary force transmission, characterized by a means for detaching the coupling between the driver and the operating arm.

13. A stepping gear according to claim 12, characterized by a recoupling means for reinstating a detached coupling between said driver and said operating arm.

14. A stepping gear, in particular according to one of the claims 1 to 13, for a clamping and/or spreading tool, in particular for a bar clamp, said clamping and/or spreading tool having a stationary jaw and a support to which a stationary jaw is fixedly connected and on which a push or pull rod is being movably supported, said push or pull rod having a movable jaw fixedly arranged thereto, said stepping gear being designed to displace said push or pull rod in an advance direction step-by-step and comprising an operating arm and a driver via which the operating arm is engageable with said push or pull rod, characterized by a constraint or forcing means maintaining said driver, at least in the inoperative operating state, canted to said push or pull rod and in permanent contact to the operating arm and a means for releasing the cant of said driver.

15. A stepping gear according the claim 14, characterized in that said release means is operateable by a locking means blocking the displacement of the push or pull rod in an opposite direction of the advance direction.

16. A clamping and/or spreading tool, in particular a bar clamp, comprising: a push or pull rod,a stationary jaw,a support to which the stationary jaw is fixedly connected and on which the push or pull rod is movably supported,a movable jaw fixedly arranged on the push or pull rod anda stepping gear configured according to one of the claims 1 to 15.