Clamping device, in particular in the form of a cartridge ejection device

Abstract

Clamping device with a support element (2) attached to a housing (1) and with a movable clamping element (4) attached to a push rod (3) supported by the housing (1), which can be moved stepwise in the extension direction of the push rod (3) by repeated actuation of an actuating lever (5), and with a return-position locking element (6) which can be moved by means of an actuating member (10) between a locking position, in which it prevents a return movement of the push rod (3) after a stroke of the actuating lever (5), and a release position, in which a return movement of the push rod (3) is possible, and which is supported on a housing-fixed bearing point (11) in at least one of the two operating positions, and with locking means (8, 9) which hold the return-position locking element (6) in its release position in a restraint position, wherein the return-position locking element (6) is held in the locking position by a return spring (18). is,which return spring (18) moves the return locking element (6) back from the release position to the locking position after the locking means (8, 9) are released, characterized in that the locking means (8, 9) are formed by the actuating member (10), which is displaceable relative to the return locking element (6) in a radial direction with respect to the bearing point (11).

Description

[0001] The invention relates to a clamping device according to the preamble of claim 1, namely a clamping device with a support element fastened to a housing and with a movable clamping element fastened to a push rod mounted by the housing, which can be displaced step by step in the direction of extension of the push rod by repeated lifting of a drive lever, and with a return displacement locking element displaceable between two operating positions, wherein one of the operating positions is a blocking position in which it prevents a return displacement of the push rod after a stroke of the drive lever, and the other operating position is a release position in which a return displacement of the push rod is possible.

[0002] A clamping device of this type is described in DE 197 31 579 A1. The clamping device described therein has a housing with bearing openings that support a push rod. The push rod can be moved within the bearing opening in its direction of extension. The housing forms a fixed clamping jaw. A movable clamping jaw is attached to the push rod. A stepping gear is located in the housing. By repeatedly actuating a drive lever, the push rod can be moved relative to the housing, whereby the movable clamping element attached to the push rod moves towards the support element attached to the housing. A return displacement locking element is provided, which is formed by a clamping plate. The clamping plate is supported on a bearing point on the housing.In a tilted clamping position, the return displacement locking element assumes a locked position, preventing return displacement of the push rod after a stroke of the drive lever. By actuating a release lever, the return displacement locking element can be temporarily moved from this operating position to another operating position, which is a release position, in which return displacement of the push rod and removal of the clamping element from the support element is possible.

[0003] US 5,615,807 A also discloses a generic clamping device with a return displacement locking element, wherein a locking means rotatably mounted on a handle fixed to the housing is provided to hold the return displacement locking element in its release position. An end portion of the return displacement locking element forms an actuating member for displacing the return displacement locking element between the release position and the locked position, wherein the actuating member is displaced in an azimuthal direction relative to a bearing point fixed to the housing during its displacement.

[0004] DE 36 07 384 A1, DE 198 50 495 B4 and EP 2 445 652 B1 disclose cartridge ejection devices which also have a return displacement locking element which can be temporarily brought into a release position by means of a release lever or a rod and which is designed as a clamping plate.

[0005] US 4 893 801 A describes a clamping device in which the support element is connected to the housing by means of two connecting rods which are parallel to each other and connected to the pressure rod.

[0006] US Pat. No. 5,390,831 A discloses a cartridge ejection device with a support element for holding a cartridge and a push rod, which forms a clamping element at its end for actuating an ejection piston associated with the cartridge. At the end of the housing opposite the support element is a retraction locking element, which, in a locked position, prevents retraction of the push rod. By applying thumb pressure against a free end of the retraction locking element, the retraction locking element can be moved into a release position.

[0007] DE 10 2012 216 965 A1 describes a cartridge ejection device, also with a retraction locking element, which has a free end that can be moved by thumb pressure. Here, the clamping plate forming the retraction locking element is mounted inside the housing and protrudes with its free end through a window in the housing.

[0008] DE 10 2013 101 479 A1 describes a clamping device with an additional braking device which is assigned to the housing and which acts on the pressure rod.

[0009] DE 10 2009 026 025 A1 describes a cartridge ejection device in which the support element sits directly on the housing and binds the end of the cartridge opposite the ejection opening to the housing.

[0010] DE 10 2009 026 033 A1 describes an electrically operated cartridge ejection device. An electric motor drives a spindle with a clamping element at its end that acts against the piston of a ejection cartridge. To prevent the pasty substance from flowing out of the cartridge, the clamping element can be moved back slightly after the ejection process is complete to release the cartridge's tension.

[0011] The invention is based on the object of further developing a generic clamping device in a manner that is advantageous in use.

[0012] The problem is solved by the technical features specified in the claims.

[0013] First and foremost, the problem is solved by restraining means that, in a restraining position, hold the repositioning locking element in one of its operating positions. In its other operating position, the repositioning locking element is preferably held by a return spring. This return spring is tensioned when the repositioning locking element is moved into one of its operating positions.

[0014] The subclaims represent advantageous developments. The subclaims also represent independent developments of the prior art.

[0015] The following preferred developments are provided: The return displacement locking element is a component of a release lever. The return displacement locking element can be a second clamping plate that is a component of a release lever. The release lever is moved from the locked position into the release position. The return spring is tensioned in the process. In the release position, the return displacement locking element can be held in place by a locking step that engages behind a locking shoulder. The locking step can be assigned to the release lever. The locking shoulder can be formed by the housing. An actuating member can be provided. The actuating member is preferably a component of the release lever. However, it can also be a component of the housing. It forms the locking means with which the return displacement locking element is held in place in one of its operating positions and in particular in its release position. The actuating member can be assigned to the second clamping plate.It can be displaceable relative to the second clamping plate. It is displaceably associated with the return displacement locking element. The release lever is preferably moved from the locked to the released position in an azimuthal movement relative to a bearing point fixed to the housing. However, the release lever can also be moved from its locked to the released position by a different type of movement, in particular a rotary movement. In addition to a lever movement, a sliding movement is also possible. The bearing point fixed to the housing is a support point against which the second clamping plate can be supported in its locked position. The actuating element is displaced in a radial direction relative to the bearing point when it is moved between the unlocked position and the locked position. The release lever is preferably mounted within the housing. The housing can be a plastic housing and has side walls and a rear wall.The side walls and the rear wall can continue to form a handle fixed to the housing. The drive lever and the handle fixed to the housing can be grasped by the hand of a user actuating the clamping device. The lifting movement that moves the push rod occurs by moving the drive lever towards the handle. For this purpose, the drive lever is preferably pivoted on the housing about a pivot axis. An arm of the drive lever extending into the housing acts against a clamping plate, which clamps itself onto the push rod by tilting, so that a linear displacement of the clamping plate is transferred to a linear displacement of the push rod. The displacement of the drive lever occurs against the return force of a return spring, which also moves the clamping plate back to its original position, in which the push rod projects unclamped through an opening in the clamping plate.The rear wall formed a bearing opening through which the push rod protrudes. Between the handle and the push rod there is a window in the rear wall. The window opening preferably extends in a plane running essentially transversely to the direction of movement of the push rod. The actuating member, which can be actuated by thumb pressure, is located in this window. The actuating member preferably protrudes out of the window in the locked position. In this position the restraining means are not in their restraining position. In this operating position the push rod can be displaced step by step by repeated lifting actuation so that the tensioning element arranged at the free end of the push rod moves towards the support element. The end of a cartridge, which has an outlet opening with a nozzle, rests on the support element.The clamping element engages in the opening of the cartridge opposite this end and acts against an ejection piston located inside the cartridge to press the pasty mass stored in the cartridge out of the spout. To press out a highly viscous pasty mass, the actuating element is in a position corresponding to the locked position. It protrudes from the window. In this operating position, the piston is gradually moved towards the spout so that the pasty mass is pressed out of the cartridge. If the drive lever is released after completing a stroke, the clamping element remains in the moving position. The pressure inside the cartridge is maintained. This does have the disadvantage that the pasty mass in the cartridge can escape from the spout even after the drive lever is released.However, it does have the advantage that even highly viscous materials can be pressed out. With such dispensing devices, part of the tension applied by the displacement of the clamping element is used to elastically expand the circumference of the cartridge, so that several strokes in immediate succession are required to press the material out of the cartridge. The second clamping plate, which forms the return displacement locking element, is held in a tilted position by a return spring. In this tilted position, it rests clamped against the push rod. The push rod can only be moved relative to the second clamping plate in the clamping direction. This is achieved by a linear displacement of the clamping plates clamped to the push rod, which is achieved by the stroke actuation of the drive lever. To press a less viscous material out of the cartridge, the return displacement locking element can be moved into its release position.This is preferably achieved by displacing the actuating member into the housing by thumb actuation in a direction substantially parallel to the direction of displacement of the push rod. The second clamping plate associated with the relocation blocking element is thereby positioned perpendicular to the push rod, such that the edges of the opening in the second clamping plate through which the push rod passes cannot form a clamped connection with the push rod. The relocation blocking element is still acted upon by the return spring, but due to the restrained mounting of the relocation blocking element in the release position, the force of the return spring does not have any effect of displacing the relocation blocking element. The push rod can move freely in both directions in the opening of the second clamping plate, which is permanently held in the release position by the restraining means.This means that after the drive lever is released following its stroke, the push rod can be retracted. The tension built up in the cartridge during the stroke of the drive lever can thus be released by retracting the push rod. This prevents the pasty mass from running out of the outlet nozzle after the stroke has been completed. The actuating element is preferably locked in the release position by moving the actuating element within the window towards the push rod. During this displacement, a detent step on the actuating element engages behind a detent shoulder on the housing. If the actuating element is moved from this restrained position away from the push rod, the locking connection is released.The compression spring acting on the retraction locking element and in particular the second clamping plate now pivots the retraction locking element or the second clamping plate into the locking position, in which the second clamping plate assumes a clamping position relative to the push rod, in which the edges of the opening of the second clamping plate rest against the push rod. Because the second clamping plate is only supported on one side at the bearing point fixed to the housing, the second clamping plate is reinforced when a clamping force is applied to the clamping element.

[0016] An embodiment of the invention is explained below with reference to the accompanying drawings. They show: Fig. 1 a plan view of the embodiment, Fig. 2 a section along the line II-II in Fig. 1, wherein a release lever 7 assumes an operating position corresponding to a locking position, Fig. 3 section III in Fig. 2, Fig. 4 a representation according to Fig. 2, but with a modified operating position of the release lever 7, which here assumes its release position, Fig. 5 section V in Fig. 4, Fig. 6 the release lever 7 from the viewing direction VI in Fig. 5, Fig. 7 a representation according to Fig. 4, but with actuated drive lever 5 and Fig. 8 section VIII in Fig. 7.

[0017] The clamping device shown in the drawings is a cartridge ejection device. It has a housing 1 and a support element 2. The support element 2 is connected to the housing 1 by means of two connecting rods 25. The connecting rods 25 run parallel to one another. A pressure rod 3 extends approximately midway between the two connecting rods 25. The pressure rod 3 and the connecting rods 25 preferably lie approximately in a common plane. The support element 2 has a receiving pocket for receiving the end of a cartridge containing a pasty mass, said end having an outlet opening. A nozzle associated with the front end of the cartridge can protrude through an opening in the support element 2.

[0018] The opposite end of the cartridge, which is open, points towards the housing 1. A clamping element 4 in the form of a clamping jaw, which is fastened to the end of the pressure rod 3, can project into the end of the cartridge in order to exert a clamping force on a piston arranged in the cartridge, which piston can be displaced by a linear displacement of the pressure rod 3 in the direction of the support element 2 in order to press the pasty mass stored in the cartridge out through the outlet nozzle.

[0019] A drive lever 5 is provided for the linear drive of the push rod 3. The drive lever 5 is pivotally mounted on the housing 1 about a bearing axis 22. The drive lever 5 can be pivoted toward a handle 14 fixedly mounted on the housing. This is achieved by wrapping one hand around the drive lever 5 and the handle 14.

[0020] An arm 23 of the drive lever 5 projecting into the housing 1 can act upon a first clamping plate 17. In the unloaded position ( Fig. 2, Fig. 3, Fig. 4, Fig. 5), the first clamping plate 17 extends approximately perpendicular to the direction of extension of the push rod 3, so that the edges of the opening 26 of the clamping plate 17 do not clamp against the push rod 3. The first clamping plate 17 is held in this unactuated position by means of a return spring 24. However, if the first clamping plate 17 is actuated on one side by the arm 23 by pivoting the drive lever 5 ( Fig. 7, Fig. 8), the first clamping plate 17 tilts and the edges of the opening 26 enter a clamping position against the push rod 3, so that the push rod 3 is displaced by a lifting operation of the drive lever 5.

[0021] If the drive lever 5 is released again, a handle return spring ensures that the handle 14 pivots back and the return spring 24 ensures that the first clamping plate 17 is moved back to the basic position.

[0022] The housing 1 has two opposing side walls 12 and a rear wall 13. Between the handle 14 and a bearing opening 15, through which the push rod 3 protrudes, there is a window 16 in the rear wall 13. The window surface of the window 16 lies approximately in a plane perpendicular to the direction of displacement of the push rod 3. An actuating element 10 is located in the window 16.

[0023] A return displacement locking element 6 is provided. The return displacement locking element 6 consists of a second clamping plate, which interacts with the push rod 3 in a similar manner to the first clamping plate 17. The second clamping plate 6 has a clamping opening 19 through which the push rod 3 extends. In a release position ( Fig. 4, Fig. 5), the second clamping plate 6 lies in a plane that extends approximately perpendicular to the direction of displacement of the push rod 3, so that the edges of the clamping opening 19 do not exert a clamping effect on the push rod 3. A return spring 18 is provided, which is penetrated by the push rod 3 and which holds the second clamping plate 6 in the release position.

[0024] If the cartridge ejection device is moved in this operating position of the return displacement locking element 6, it can be returned to its home position after the drive lever 5 and the first clamping plate 17 have been moved back. This relieves any elastic tension built up in the cartridge during the lifting and forward displacement of the push rod 3. This prevents the pasty mass from flowing through the outlet opening. This operating mode is used to press a silicone paste, an acrylic paste, or another pasty, particularly free-flowing, mass out of a cartridge, or when using a large nozzle opening.

[0025] If a highly viscous, pasty mass is to be pressed out of the cartridge, the tension built up in the cartridge must not be released after a stroke of the drive lever 5. To do this, the retraction locking element 6 is moved from the release position to the locked position. This is essentially achieved by pivoting the retraction locking element 6, i.e., the second clamping plate, around a bearing point 11, at which the second clamping plate 6 rests on the housing 1.

[0026] The second clamping plate 6 has two opposite free ends. One end rests on the bearing point 11 fixed to the housing. The other end supports the actuating member 10. Between the two ends is the clamping opening 19, through which the push rod 3 extends. If the actuating member 10 is displaced in an azimuthal direction—relative to the bearing point—by thumb pressure or the like, for which purpose the actuating member 10 is displaced into the window 16, the second clamping plate 6 is moved from a tilted position, which corresponds to the locked position, in which the edges of the clamping opening 10 exert a clamping effect against the push rod 3, into a release position. The return spring 18 is thereby tensioned.

[0027] The return displacement locking element 6 can be locked in the release position. To do this, the actuating member 10 is displaced in a radial direction—relative to the bearing point 11—in the direction of the bearing point 11. A locking step arranged on the actuating member 10 engages behind a locking shoulder 9 of the housing. As a result, the return displacement locking element 6 remains in the release position, in which the push rod 3 can be freely displaced through the opening 19 in both directions.

[0028] If the actuating member 10 is displaced in the direction away from the push rod 3, i.e., again displaced within the window plane, the locking connection 8, 9 is released. As a result of the second clamping plate 6 being acted upon by the return spring 18, the return displacement locking element 6 is pivoted from the release position back into the locking position.

[0029] The actuating member 10 is a slider that can be displaced in two essentially mutually perpendicular directions. The slider is located at an end portion 6' of the second clamping plate 6 and, in a first actuating direction, displaces the second clamping plate 6 into its locked position. The end 6' of the second clamping plate 6 has a longitudinal slot 20 through which a retaining screw 21 extends. The retaining screw 21 is screwed into the slider formed by the actuating member 10. The actuating member 10 can thus be displaced relative to the second clamping plate 6 in a second actuating direction, namely in the direction of extension of the longitudinal slot 20, in order to either move the restraining elements 8, 9 into a restraining position or to move the two restraining elements 8, 9 out of the restraining position, so that the return spring 18 displaces the return displacement locking element 6 back into the locked position.The longitudinal slot 20 is longer than the actuating travel of the actuating element 10. A guide rib of the actuating element 10 projects into it.

[0030] The above statements serve to explain the inventions covered by the application as a whole, which also independently develop the prior art at least by the following combinations of features, namely: A clamping device which is characterized in that the locking means 8, 9 are formed by the actuating member 10, which is displaceable relative to the return displacement blocking element 6 in a radial direction with respect to the bearing point 11.

[0031] A clamping device characterized in that the actuating member 10 is part of the housing 1.

[0032] A clamping device which is characterized in that the return displacement locking element 6 can be brought from the locked position into the release position by pivoting a release lever 7 and the release lever 7 is assigned a locking step 8 which, in the release position, engages behind a locking shoulder 9 in order to hold the return displacement locking element 6 in the release position against the restoring force generated by the return spring 18.

[0033] A clamping device, characterized in that the locking step 8 is arranged on the actuating member 10 and / or that the actuating member 10 together with the return displacement locking element 6 forms the release lever 7.

[0034] A clamping device characterized in that the return displacement locking element 6 is mounted within the housing 1, which has side walls 12 and a rear wall 13 which continue into walls of a handle 14 fixed to the housing, wherein the rear wall 13 has a window 16 between the handle 14 and a bearing opening 15 penetrated by the push rod 3, through which window the actuating member 10 projects in the locked position.

[0035] A clamping device characterized in that the surface of the window 16 lies approximately in a plane extending approximately perpendicular to the direction of movement of the push rod 3.

[0036] A clamping device characterized in that the actuating member 10 is displaceable in the plane of the window 16 in the direction of the push rod 3 and away from the push rod 3.

[0037] A clamping device which is characterized in that the support element 2 is connected to the housing 1 by means of two connecting rods 25 running parallel to each other and parallel to the pressure rod 3.

Claims

[1] Clamping device with a support element (2) fastened to a housing (1) and with a movable clamping element (4) fastened to a push rod (3) mounted by the housing (1), which can be displaced stepwise in the direction of extension of the push rod (3) by repeated actuation of a drive lever (5), and with a return displacement locking element (6) displaceable by means of an actuating member (10) between a blocking position in which it prevents a return displacement of the push rod (3) after a stroke of the drive lever (5), and a release position in which a return displacement of the push rod (3) is possible, which is supported in at least one of the two operating positions on a bearing point (11) fixed to the housing, and with locking means (8, 9) which, in a restraint position, hold the return displacement locking element (6) in its release position, wherein the return displacement locking element (6) is actuated by a return spring (18). is held in the locked position,which return spring (18) moves the return displacement locking element (6) back from the release position into the blocking position after releasing the locking means (8, 9), , characterized by that the locking means (8, 9) are formed by the actuating member (10) which is displaceable relative to the return displacement blocking element (6) in a radial direction with respect to the bearing point (11). [2] Clamping device according to claim 1, characterized by that the actuating member (10) is part of the housing (1). [3] Clamping device according to one of the preceding claims, characterized bythat the return displacement locking element (6) can be brought from the locking position into the release position by pivoting a release lever (7) and the release lever (7) is assigned a locking step (8) which, in the release position, engages behind a locking shoulder (9) in order to hold the return displacement locking element (6) in the release position against the restoring force generated by the return spring (18). [4] Clamping device according to claim 3, characterized by that the locking step (8) is arranged on the actuating member (10), and / or that the actuating member (10) together with the return displacement locking element (6) forms the release lever (7). [5] Clamping device according to one of the preceding claims, characterized byin that the return displacement locking element (6) is mounted within the housing (1), which has side walls (12) and a rear wall (13) which continue into walls of a handle (14) fixed to the housing, wherein the rear wall (13) has a window (16) between the handle (14) and a bearing opening (15) penetrated by the push rod (3), through which window the actuating member (10) projects in the locking position. [6] Clamping device according to claim 5, characterized by that the surface of the window (16) lies approximately in a plane which extends approximately perpendicular to the direction of movement of the push rod (3). [7] Clamping device according to claim 5 or 6, characterized by that the actuating member (10) is displaceable in the plane of the window (16) in the direction of the push rod (3) and away from the push rod (3). [8] Clamping device according to one of the preceding claims, characterized bythat the support element (2) is connected to the housing (1) by means of two connecting rods (25) running parallel to each other and parallel to the pressure rod (3).

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