Device for displacing a push / pull rod in steps

Abstract

The invention relates to a tension clamp comprising a push / pull rod (1) that can be displaced in a housing (2) in steps and comprising a drive lever (3) that is supported by the housing (1) and displaces a drive element (4), which engages on the push / pull rod (1), forward in a clamping direction (S) relative to the housing (2) during an advancing actuation. The tension clamp has a blocking element (5) which is supported by the housing (1) and which prevents a reverse displacement of the push / pull rod (1) in a release direction (L) opposite the clamping direction (S) in a blocking position and which can be displaced from the blocking position into a release position by actuating a release lever (6) that engages on the blocking element (5), a displacement of the push / pull rod (1) in the release direction (L) being possible in the release position. The tension clamp also comprises a movement limiting element (7) which is struck by the blocking element (4) during a forward displacement of the drive element (4), said forward displacement carrying the push / pull rod (1). In order to improve the efficiency of the movement limiting element (7), the movement limiting element (7) is acted upon by a spring element (9) against the blocking element (5), wherein the movement limiting element (7) is arranged in a pocket (11) of the release lever (6).

Description

field of technology

[0001] The invention relates to a device for the stepwise displacement of a pull / push rod, comprising a housing with a drive lever mounted on the housing, which, upon thrust actuation, displaces a drive element acting on the pull / push rod relative to the housing in a clamping direction, comprising a locking element mounted on the housing, which in a locking position inhibits a backward displacement of the pull / push rod in a release direction opposite to the clamping direction and which can be displaced from the locking position to a release position, in which displacement of the pull / push rod in the release direction is possible, by actuating a release lever acting on the locking element, and comprising a movement limiting element against which the locking element abuts during the forward displacement of the drive element, which carries the pull / push rod along with it. State of the art

[0002] A device of the type described above is described in DE 10 2013 101 479 A1 using a clamping device as an example. The tool described therein has a housing through which a push / pull rod passes. The housing carries a fixed clamping jaw. At one end of the push / pull rod is a movable clamping jaw. The clamping jaws can be moved towards each other in one clamping direction to clamp a workpiece between the two jaws. The clamping jaws point towards each other in this position. However, the clamping jaws can also point away from each other, so that the device can be used as a spreader clamp. By pumping a drive lever that acts on a drive element, the push / pull rod can be moved incrementally in one clamping direction relative to the housing. A locking element prevents the push / pull rod from moving back in a release direction opposite to the clamping direction.A release lever allows the locking element to be moved into a release position, enabling the push / pull rod to be moved back. The release lever incorporates a cam designed to prevent the locking element from moving along with the drive element when it is advanced. During this advancement, the locking element should remain as stationary as possible within the housing to prevent the push / pull rod from shifting slightly in the release direction after the drive element has completed its advancement, i.e., after a working stroke.

[0003] Due to unavoidable wear and tear and manufacturing tolerances, this is not sufficiently guaranteed with the current state of the art. Summary of the invention

[0004] The invention is based on the objective of further developing the generic device in a way that is advantageous for use and, in particular, of specifying supplementary means by which the slight retraction of the pull / push rod after a working stroke is further reduced.

[0005] The problem is solved by the invention specified in the claims. The dependent claims not only represent advantageous further developments of the device specified in claim 1, but also independent solutions to the problem.

[0006] First and essentially, it is proposed that the movement limiting element be acted upon by a spring element against the locking element. The spring element can compensate for the aforementioned tolerances and also the wear mentioned therein. In a further development of the invention, it is provided that the locking element, in the locked position, is supported against a housing-fixed stop in the release direction. The spring element is designed and arranged such that it acts upon the locking element in the release direction. In a further development of the invention, it is provided that the movement limiting element is supported by the release lever. The release lever can be pivoted about a pivot axis or a bearing pin when it is moved from its initial position, in which the locking element performs its locking function, to its release position, in which the push / pull rod can be moved relative to the locking element in the release direction.The movement limiting element can rotate about the pivot axis together with the release lever. The spring element can be arranged between the release lever and the movement limiting element. It is preferably arranged such that the movement limiting element is spring-loaded relative to the release lever. If the movement limiting element is designed as a pivot lever, the spring element can exert a torque on the movement limiting element. If the release lever is also designed as a pivot lever, the movement limiting element can pivot against the restoring force of the spring element relative to the release lever. Preferably, the movement limiting element and the release lever are mounted about the same pivot axis. The release lever can be mounted with play about the pivot axis. For this purpose, the release lever can have a non-circular bearing eye.The bearing eye of the movement limiting element can have a round cross-section, so that the movement limiting element is mounted on the bearing journal without significant bearing play. In a further development of the invention, it is proposed that the release lever has a pocket. With respect to an axis defined by the pivot axis of the release lever, the pocket can be formed between two walls of the release lever. The release lever can have an actuating flank against which the fingers of a tool user grip to move the release lever. The pocket can have an opening formed on the side of the release lever facing away from the actuating flank. An arm of the release lever can protrude at least partially through this opening. The spring element can act on the movement limiting element such that the first arm is acted upon in one direction towards the actuating flank of the release lever, i.e., into the pocket.The spring element is preferably arranged in the pocket. A support projection can be arranged in the pocket, against which one end of the spring element, formed by a helical compression spring, is supported. The movement limiting element can form a support flank opposite the support projection, against which the other end of the helical compression spring is supported. The support flank can be formed by a second arm of the movement limiting element, which, in particular, carries a cam at its free end with which the movement limiting element acts upon an end section of the locking element. The locking element is actuated such that the end section actuated by the cam is supported against a housing-fixed stop, which can be formed by a pin. The locking element can be a steel plate with a window, the narrow edges of which have rims.In the locked position, the locking element is tilted relative to the push / pull rod, so that the window's edge edges engage the narrow sides of the push / pull rod. A spring element can engage the end section opposite the one actuated by the cam, thereby acting the locking element into the locked position. The direction in which the spring element acts on the locking element is the same direction in which the movement limiting element acts on the locking element against the stop. To advance the push / pull rod, a drive lever is pivoted about a positional axis. The drive lever can be moved towards a handle. The drive lever has a drive cam that acts against a drive element, which can have the same configuration as the locking element.The drive element can consist of one or more steel plates, each with a window through which the push / pull rod protrudes. A drive cam is located on an end section of the drive lever that projects into the housing. This cam acts against the drive element to displace it relative to the housing. This occurs in a canted position relative to the push / pull rod, causing the drive element to pull the push / pull rod along in the clamping direction. A torque is exerted on the locking element, which is supported by the movement limiting element, in its release position. This allows the push / pull rod to be pushed through the window of the locking element with slight frictional resistance. After the working stroke is completed, a spring element moves the drive element out of the canted position and back into its initial position.

[0007] The invention relates in particular to devices designed as clamping or spreading clamps. However, the invention also relates to other devices, for example, cartridge ejection devices. Brief description of the drawings

[0008] An embodiment of the invention is explained below with reference to the accompanying drawings. These show: Fig. 1 a top view of an embodiment of the invention designed as a clamping clamp; Fig. 2 the detail II in Figure 1 , however, in a clamping clamp according to the prior art, wherein a drive lever 3 assumes its initial position for displacing a pull / push rod 1 by means of a drive element 4; Fig. 3 a representation according to Figure 2, wherein the drive lever 3 has displaced the drive element 4 and the pull / push rod 1 in the direction of a clamping direction S, wherein a locking element 5 is acted against a cam 15 of a release lever 6; Fig. 4 the embodiment in a version shown in the Figure 2 The operating position shown in Fig. 5; the section along line VV in Fig. 5. Figure 1 ; Fig. 6 the section along line VI-VI in Figure 5 ; Fig. 7 a representation according to Figure 6 , however, the drive lever 3 is in one of the Figure 3 has been swivelled to the corresponding position; Fig. 8 a representation according to Figure 6 , wherein after a reversal of the drive lever 3 from the in the Figure 7 The position of the release lever 6 has been pivoted as shown; Fig. 9, section IX in Figure 6 in a first constellation, where a distance a between an arm 13 of the movement limiting element 7 and a projection 32 has a mean value; Fig. 9 leg illustration according to Figure 9a , according to which the distance a is minimal; Fig. 9 a representation according to Figure 9a , according to which the distance a has a large value; Fig. 10 an exploded view of essential elements of the embodiment. Description of the embodiments

[0009] The embodiment shown in the drawings is a clamping device comprising a housing 2 which supports a fixed clamping jaw 27. A push / pull rod 1, made of steel and having a narrow, rectangular cross-section, extends through the housing 2. A movable clamping jaw 28 is located at one end of the push / pull rod, but can also be attached to the other end of the push / pull rod 1 in a known manner, allowing the tool to be used as both a clamping device and a spreader clamp. The push / pull rod 1 extends through the housing 2.

[0010] A handle 30, which can be gripped by a user's hand, projects from the housing 2. An actuating arm of a drive lever 3 extends between a section of a release lever 6 projecting from the housing 2 and the handle 30. The release lever 6 and the drive lever 3 are each pivotally mounted on the housing 2 about bearing axes 10 and 22, respectively. The drive lever 3 forms a grip section 31, which can be grasped by the user's fingers to pivot it forward toward the handle 30. The release lever 6 has a grip section 12, which can be grasped by the user's fingers to move the release lever 6 toward the handle 30.

[0011] Inside the housing 2 is a drive element 4, which in this embodiment is formed by two steel plates, each having a window through which the push / pull rod 1 projects. A spring element 20, designed as a helical compression spring, supports the drive element 4 in a basic position against support flanks 37, which hold the drive element 4 in a position substantially perpendicular to the push / pull rod 1, so that the drive element 4 is not tilted with the push / pull rod 1. With a pivoting movement of the drive lever 3, an end section of the drive element 4 is acted upon by a drive cam 21 of the drive lever 3 such that the drive element 4 tilts relative to the push / pull rod 1. During the pivoting movement, the drive element 4 is displaced in the direction of the clamping direction S against the restoring force of the spring element 20.

[0012] State of the art ( Figures 2 and 3The locking element 5, which is also a steel plate having a window 33, is supported by a cam 15 of the release lever 6, which forms a movement limiting element with respect to the locking element 5, in that the cam reduces displacement of the locking element 5 in the direction of clamping S. A tension spring 18 engages at the other end of the locking element 5 to actuate it in the release direction L. The end of the locking element 5 acted upon by the cam 15 is supported by a stop 8.

[0013] In the case of forward displacement ( Figure 3 The push / pull rod 1 can move against a frictional force through the window 33. The edges 33' of the window 33, which are tilted against the push / pull rod 1, can slide over the narrow sides of the push / pull rod 1. However, it is not possible in the Figures 2 and 3In the position shown, the locking element 5 is to displace the pull / push rod 1 in the release direction, since in this direction the edges 33' on the narrow sides of the pull / push rod 1 tilt.

[0014] If the release lever 6 is pivoted, this canted position is lifted, so that the pull / push rod 1 can be moved through the window 33 in the release direction L.

[0015] The device according to the invention differs from the one described in the Figures 2 and 3 The device shown, which is part of the prior art, is limited by a spring-loaded movement limiting element 7.

[0016] The release lever 6 is a two-armed lever. One arm of the lever protrudes from the housing 2 through a housing opening 34. The other arm of the lever is located inside the housing 2 and forms a window through which the push / pull rod 1 is guided. The release lever 6 is mounted in the housing 2 about a pivot axis 10 that forms a bearing pin, the bearing pin 10 being inserted into a non-circular bearing eye 16 of the release lever 6. The free end of the inner arm of the release lever 6 is acted upon by a tension spring 19 in the release direction L. This free end forms a release cam 23, which, when the release lever 6 pivots, acts upon the end pointing away from the stop 8, which is acted upon by the spring element 18. The spring element 19 moves the release lever 6 back to its initial position.

[0017] The release lever 6 forms a pocket 11 which, in the exemplary embodiment, extends into the handle section 12 of the release lever 6 that projects from the housing 2. This handle section 12 forms the actuating flank 14, which is gripped by the user's fingers. The pocket 11 has an opening behind the actuating flank 14. The bottom of the pocket 11 forms a projection 32. A support projection 35 is also provided within the pocket 11. The pocket 11 has two walls arranged one behind the other in an axial direction with respect to the pivot axis 10. The movement limiting element 7, formed by a lever element and located within the pocket, extends between the two walls.

[0018] The drive lever 3 and the release lever 6, as well as the movement limiting element 7, can be made of plastic. The movement limiting element 7 forms a bearing eye 17 in which a bearing pin is arranged with virtually no play. In the exemplary embodiment, the movement limiting element 7 and the release lever 6 are pivotable about the same pivot axis 10, which is formed by a bearing pin.

[0019] The movement limiting element 7 forms a first arm 13 that extends within the pocket 11. The rear side of the arm 13 can have a distance a from the projection 32. Depending on manufacturing tolerances or wear, the distance a can vary as shown in Figures 9a to 9c. A section of the arm 13 can protrude from the pocket 11 through an opening facing away from the actuating flank 14.

[0020] The movement limiting element 7 can have a further arm which carries a cam 15 at its free end. The arm can arc around the stop 8, which can be a steel pin fixed in the housing.

[0021] A spring element 9 is provided, which acts on the cam 15 in the direction of the stop 8. The spring element 9 can exert a torque on the movement limiting element 7. The cam 15 engages directly at an end of the locking element 5 that is opposite the end of the locking element 5 where the spring element 18 engages. The end of the locking element acted upon by the cam 15 rests against the stop 8. The force of the spring element 9 is of sufficient magnitude to prevent the cam 15 from being displaced from its position fixing the locking element 5 when the drive element 4 is moved forward. The force exerted by the spring element 9 on the locking element 5 is therefore preferably greater than the force exerted by the spring element 18.

[0022] The arm of the movement limiting element 7 forming the cam 15 has a support flank 36 pointing away from the cam 15, against which the spring element 9, formed by a helical compression spring, is supported. The other end of the spring element 9 is supported against the support projection 35 of the pocket 11, so that the spring element 9 is mounted within the pocket.

[0023] The device further comprises a brake element 24, which has a window through which the pull / push rod 1 extends. A spring element 25 applies pressure to the brake element in a braking position, preventing the pull / push rod from moving freely and independently through the housing even with a slight pivoting of the release lever 6. Only when the release lever 6 is in the position indicated in the Figure 8 When the brake element 24 is pivoted into the position shown, it is moved from the braking position to a release position against the restoring force of the spring element 25.

[0024] From the Figure 8 It is further evident that when the release lever 6 is moved into the release position, the cam 15 moves out of the path of movement of the locking element 5, so that the locking element 5 can move along the pull / push rod 1 until it touches the brake element 24.

[0025] The Figure 8 Furthermore, it shows that when the release lever 6 is actuated, the spring element 9 relaxes in the release direction in such a way that the arm 13 lying in the pocket 11 rests with its rear side against the projection 32. If the release lever 6 is removed from the pocket 11, the spring element 9 relaxes in such a way that the arm 13 rests with its rear side against the projection 32. Figure 8 When the release lever is released in the position shown, it is moved back to its initial position by the tensioned tension spring 19. Simultaneously with this movement, the locking element 5 is moved back into the position shown by the tension spring 18 acting upon it. Figure 7The position shown is shifted. The cam 15 then rests against one of the broad surfaces of the locking element 5. The spring element 19 then tensions the spring element 9, since the spring element 19 acting on the release lever 6 exerts a greater force than the spring element 9. The cam 15, acting under force from the spring element 9, then rests against a broad surface of the locking element 5.

[0026] Will the relocation from the in the Figure 8 the operating position shown in the Figure 7 In the illustrated operating position, if the push / pull rod 1 is held, only the release lever 6 moves. In this position, the cam 15 can strike a narrow side of the locking element 5. If the push / pull rod 1 is subsequently released, the force of the spring element 18 causes the locking element 5 to move into the position shown in the illustration. Figure 7The position shown. The spring element 19 simultaneously moves the release lever 6 into the position shown. Figure 7 depicted position.

[0027] The foregoing statements serve to explain the inventions covered by the application as a whole, which each independently further develop the prior art at least through the following combinations of features, whereby two, several or all of these combinations of features may also be combined, namely:

[0028] A device characterized in that the movement limiting element 7 is acted upon by a spring element 9 against the blocking element 5.

[0029] A device characterized in that the locking element 5, in the locking position in the release direction L, is supported against a housing-fixed stop 8 and the spring element 9 acts on the locking element 5 in the release direction L.

[0030] A device characterized in that the movement limiting element 7 is supported by the release lever 6 and the spring element 9 is arranged between the release lever (6) and the movement limiting element 7.

[0031] A device characterized in that the release lever 6 is pivotably mounted in the housing 2 about a pivot axis 10 and the movement limiting element 7 is pivotably mounted about the same pivot axis 10.

[0032] A device characterized in that the movement limiting element 7 is arranged in a pocket 11 of the release lever 6, wherein the pocket 11 is open on a side facing away from an actuating flank 14 of the release lever 6.

[0033] A device characterized in that the release lever 6 has a handle section 12 projecting from the housing 2, in which a first arm 13 of the movement limiting element 7 is located, wherein the spring element 9 acts on the movement limiting element 7 in such a way that the first arm 13 is acted upon the actuating flank 14 of the release lever 6 in one direction.

[0034] A device characterized in that a second arm of the movement limiting element 7, which is located inside the housing 2, has a cam 15 which acts on the blocking element 5.

[0035] A device characterized in that the first arm 13 of the movement limiting element 7 protrudes partially from the pocket 11.

[0036] A device characterized in that the release lever 6 is mounted on a bearing pin forming the pivot axis 10 with a non-circular bearing eye 16 allowing some movement, and the movement limiting element 7 is mounted on the bearing pin with a round bearing eye 17 allowing essentially no movement.

[0037] All disclosed features are essential to the invention (individually, but also in combination with one another). The disclosure of this application hereby incorporates in full the disclosure content of the associated / attached priority documents (copy of the earlier application), also for the purpose of including features of these documents in the claims of the present application. The dependent claims, even without the features of a referenced claim, characterize independent inventive developments of the prior art, in particular for the purpose of filing divisional applications based on these claims. The invention specified in each claim may additionally include one or more of the features described above, in particular those identified by reference numerals and / or listed in the reference numeral list.The invention also relates to designs in which individual features mentioned in the preceding description are not realized, in particular insofar as they are recognizably unnecessary for the respective purpose or can be replaced by other technically equivalent means. List of reference symbols 1 Pull / push rod 26 bearing journal 2 Housing 27 fixed clamping jaw 3 Drive lever 28 movable clamping jaw 4 drive element 30 handle 5 Blocking element 31 Handle section 6 Release lever 32 projection 7 Movement limiting element 33 Window 33' edge 8 stop 34 Case opening 9 spring element 35 support ledge 10 Swivel axis, bearing pin 36 support flank 11 Bag 37 support flank 12 Handle section 13 arm 14 Actuation edge S Direction of tension 15 cam S Direction of tension 16 Bearing eye L Solution direction 17 Bearing eye 18 spring element 19 spring element 20 spring element 21 Drive cam 22 bearing journal 23 Loose cam 24 Brake element 25 spring element

Claims

1. Device for incrementally moving a push-pull rod (1), comprising a housing (2), a drive lever (3) mounted on the housing (2), which, when actuated to advance, moves a drive element (4) engaging the tension / compression rod (1) forward relative to the housing (2) in a tension direction (S), and a locking element (5) mounted on the housing (2), which, in a locking position, prevents the pull / push rod (1) from moving backward in a release direction (L) opposite to the tension direction (S), and which can be moved by actuating a release lever (6) engaging with the locking element (5) from the locking position into a release position, in which displacement of the pull / push rod (1) in the release direction (L) is possible, characterized in that the device comprises a movement-limiting element (7) acting on the locking element (5), which prevents the locking element (5) from being moved along with the drive element (4) during the forward movement of the drive element (4) that carries the tension / compression rod (1), and the movement-limiting element (7) is pressed against the locking element (5) by a spring element (9).

2. Device according to claim 1, characterized in that the blocking element (5), in the blocking position, is supported in the release direction (L) against a stop (8) fixed to the housing, and the spring element (9) biases the blocking element (5) in the release direction (L).

3. Device according to any one of the preceding claims, characterized in that the movement limiting element (7) is carried by the release lever (6) and the spring element (9) is arranged between the release lever (6) and the movement limiting element (7).

4. Device according to any one of the preceding claims, characterized in that the release lever (6) is pivotably mounted in the housing (2) about a pivot axis (10) and the movement limiting element (7) is pivotably mounted about the same pivot axis (10).

5. Device according to any one of the preceding claims, characterized in that the movement limiting element (7) is arranged in a pocket (11) of the release lever (6), wherein the pocket (11) is open on a side facing away from an actuation flank (14) of the release lever (6).

6. Device according to any one of the preceding claims, characterized in that the release lever (6) has a grip section (12) protruding from the housing (2), in which a first arm (13) of the movement limiting element (7) is located, wherein the spring element (9) acts on the movement limiting element (7) such that the first arm (13) is biased in a direction toward the actuation flank (14) of the release lever (6).

7. Device according to claim 6, characterized in that a second arm of the movement limiting element (7), which is located in the interior of the housing (2), has a cam (15) which acts on the blocking element (5).

8. Device according to any one of claims 5 to 7, characterized in that a first arm (13) of the movement limiting element (7) partially protrudes from the pocket (11).

9. Device according to any one of the preceding claims, characterized in that the release lever (6) is mounted on a bearing journal forming the pivot axis (10) by means of a non-circular bearing eye (16) allowing for movement play, and the movement limiting element (7) is mounted on the bearing journal by means of a circular bearing eye (17) allowing for substantially no movement play.

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