LINEAR GUIDE, CARRIAGE, END CAP AND METHOD FOR LUBRICATION

Abstract

An end cap for a carriage of a linear guide. The end cap has a closed lubrication port which is openable by operatively connecting a lubrication fitting to the lubrication port. The is formed by injection molding and the closed lubrication port of the end cap is formed by rotary demolding.

Claims

1. An end cap for a carriage of a linear guide, the end cap comprising: a lubrication fitting; and a closed lubrication port being openable by operatively connecting said lubrication fitting to said closed lubrication port.

2. The end cap according to claim 1, wherein said lubrication port has a mechanism configured to create a lubricant passage to a lubrication channel of the end cap when said lubrication fitting is operatively connected to said lubrication port.

3. The end cap according to claim 1, wherein said lubrication port has a blind hole formed therein and is openable by inserting said lubrication fitting into said blind hole and exerting a force on a bottom of said blind hole.

4. The end cap according to claim 1, wherein said lubrication port has a threading and is openable by screwing said lubrication fitting into said lubrication port.

5. The end cap according to claim 1, wherein said lubrication port is puncturable by operatively connecting said lubrication fitting to said lubrication port.

6. The end cap according to claim 1, wherein said lubrication port has a protrusion configured for at least partially abutting on said lubrication fitting when said lubrication fitting is operatively connected to said lubrication port.

7. The end cap according to claim 6, wherein said protrusion forms a ramp having a contact section at an upper end for contacting said lubrication fitting upon operatively coupling said lubrication fitting to said lubrication port.

8. The end cap according to claim 6, wherein said lubrication port contains a predetermined breaking point.

9. The end cap according to claim 1, wherein said lubrication port contains an opening section configured for hinging upon operatively coupling said lubrication fitting to said lubrication port.

10. A carriage for a linear guide, the carriage comprising: said end cap according to claim 1.

11. A linear guide, comprising: a guide rail; and a carriage configured for linear movement along said guide rail and having said at least one end cap according to claim 1.

12. A method for producing an end cap having a lubrication fitting and a closed lubrication port being openable by operatively connecting said lubrication fitting to said closed lubrication port, which comprises the steps of: injection molding the end cap; and forming the closed lubrication port of the end cap by rotary demolding.

13. A method for lubricating a carriage of a linear guide, which comprises the step of: opening a closed lubrication port of an end cap of the carriage, by operatively connecting a lubrication fitting to the closed lubrication port.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0028] FIG. 1 is a diagrammatic, perspective view of an example of a linear guide;

[0029] FIG. 2 is a perspective view an example of a part of an end cap for a carriage of the linear guide;

[0030] FIG. 3A is a plan view of an example of a mechanism for opening a closed lubrication port;

[0031] FIG. 3B is a side view of the mechanism for opening the closed lubrication port; and

[0032] FIG. 4 is a cross-sectional view of an example of the closed lubrication port.

DETAILED DESCRIPTION OF THE INVENTION

[0033] Referring now to the figures of the drawings in detail and first, particularly to FIG. 1 thereof, there is shown an example of a linear guide 100 having a carriage 10 and a guide rail 11. The carriage 10 is configured for translation along the guide rail 11, i.e. along a longitudinal axis defined by the guide rail 11. To this end, the carriage 10 may house linear bearings containing rolling elements arranged (not visible) in between the guide rail 11 and the carriage 10.

[0034] The carriage 10 has two end caps 1 arranged at a front end and a rear end, respectively. The end caps 1 may fulfil various tasks in order to ensure smooth operation of the linear guide 100. For example, the end caps 1 may be configured for redirecting rolling elements of the linear bearing (not visible) from channels formed between the guide rail 11 and the carriage 10 into return channels (not visible) inside the carriage 10. Alternatively or additionally, the end caps 1 may be configured for sealing the inside of the carriage 10, in particular the linear bearing, from the outside such that particles as dirt or dust do not impair the operation of the linear guide 100.

[0035] Preferably, the end caps 1 are also configured for lubricating the carriage 10, in particular the linear bearing. To this end, they may comprise lubricant reservoirs from which lubricant is provided to the carriage, in particular the linear bearing, as required.

[0036] Alternatively or additionally, the end caps 1 comprise lubrication ports 2 and/or further lubrication ports 3, 4 for enabling a user to re-lubricate the carriage 10, in particular to refill the lubricant reservoirs (if present). For example, the lubrication ports 2, 3, 4 may be configured for connection with a lubrication fitting, respectively.

[0037] In the example shown in FIG. 1, the lubrication ports 2 are arranged on opposing side faces of the end caps 1, while the further lubrication ports 3 are arranged on a top face of the end caps 1. The further lubrication ports 4 are arranged on the front faces of the end caps 1. Exemplarily, a lubrication fitting 20 is also shown, the lubrication fitting 20 being operatively connected to the lubrication port 4 visible in FIG. 1.

[0038] It is preferred that these lubrication ports 2, 3, 4 are initially closed such that the user has to open them when first re-lubricating the carriage 10. This allows for an effective pre-lubrication of the carriage 10 upon manufacture. By means of the large number of lubrication ports 2, 3, 4 arranged at different positions on the end caps 1, the user has the freedom of selecting the lubrication ports 2, 3, 4 which suits him or the use of the linear guide 100 best, respectively.

[0039] Advantageously, at least a part of the lubrication ports 2 and further lubrication ports 3, 4, in particular the lubrication ports 2 arranged at the side faces of the end caps 1, are openable by operatively connecting the lubrication fitting 20 to the respective port 2. In other words, it is preferred when for opening the lubrication ports 2, no additional steps have to be executed by the user besides connecting the lubrication fitting 20 to the respective port 2. Particular, drilling or cutting or a similar machining step may not be necessary for opening the lubrication ports 2. This way, re-lubricating via the lubrication ports 2 may become particularly fast and easy.

[0040] FIG. 2 shows an example of a part of an end cap 1 for a carriage of a linear guide. The end cap 1 may act as a housing for various components, e.g. redirecting means configured to redirect rolling elements, lubrication reservoirs, sealing elements and/or the same. The part of the end cap 1 shown in FIG. 2 is preferably fabricated from a plastic material, in particular injection moulded.

[0041] The end cap 1 contains two lubrication ports 2 arranged on either one of two opposing side faces 1a, 1b of the end cap 1. The end cap 1 also has a further lubrication port 3 at a top face 1c of the end cap 1. Preferably, all of the lubrication ports 2, 3 are closed initially and can be opened upon first using the respective lubrication port 2 for re-lubricating the carriage.

[0042] As can be seen in FIG. 2, the further lubrication port 3 is closed by means of a lid 3a integral with the shown part of the end cap 1. For opening the port 3, the lid 3a has a recess 3b, allowing a user to position the tip of a drill. When the lid 3a is drilled open, the user can establish a connection with an external lubricant reservoir and a lubricant channel (not visible) arranged behind the lid 3a. For example, the user may connect a lubrication fitting to the further lubrication port 3.

[0043] In contrast, the lubrication ports 2 are preferably configured as blind holes 5, wherein the bottom of each hole closes the respective port 2. Advantageously, the ports 2 are openable by operatively connecting a lubrication fitting (not shown) to the respective port 2, in particular by inserting the lubrication fitting into the respective blind hole 5.

[0044] In the example shown in FIG. 2, the blind holes 5 each contain a threading 6, thus allowing to screw a lubrication fitting into the respective hole 5. However, other means of inserting and/or fastening the lubrication fitting into the blind hole 5, for example by press-fitting or sliding and gluing, are also conceivable.

[0045] Preferably, the lubrication ports 2 each comprise a mechanism (not visible) configured to open the respective port 2 upon connecting a lubrication fitting, in particular upon inserting the fitting into the blind hole 5. The mechanism is advantageously arranged at the bottom of the blind hole 5. The mechanism may be activated by exerting a force on the mechanism, wherein the force may be generated e.g. by screwing the fitting into the blind hole 5.

[0046] FIGS. 3A and 3B show an example of a mechanism 7 for opening a closed lubrication port. FIG. 3A shows a top view of the mechanism 7, while FIG. 3B shows a side view.

[0047] In the example shown in FIGS. 3A-3B, the mechanism 7 has a protrusion 8. The protrusion 8 may be arranged on the bottom of a blind hole forming the lubrication port, for example. The protrusion 8 has the form of a ramp 9, as is illustrated particularly well in FIG. 3B. The ramp 9 climbs up to a ledge 9a of the ramp 9, wherein the ledge 9a forms an upper end of the ramp 9. The ramp 9 has a contact section 9b at the upper end, as indicated by the hatching in FIG. 3A.

[0048] When a lubrication fitting is operatively connected to the lubrication port, the tip of the fitting may abut on the protrusion 8. In particular, the tip of the fitting may contact the contact section 9b of the ramp 9. The fitting may exert a force on the protrusion 8, in particular the contact section 9b. The resulting pressure may open the lubrication port, in particular the bottom of the blind hole. For example, by means of exerting the force on the protrusion 8, the lubrication fitting may puncture the bottom of the blind hole.

[0049] As the resulting pressure advantageously only or at least predominantly acts at the contact section 9b, the created opening may be slit-like and defined by at least a part of the contour 8a of the protrusion 8, in particular the ramp 9. A part of the contour 8a is indicated in FIG. 3A by a dashed line.

[0050] When the opening is large enough, the protrusion 8 may at least partially hinge relative to the bottom of the blind hole under the pressure exerted by the lubrication fitting. In particular, the upper end of the ramp 9, especially the contact section 9b, may be pushed down towards the bottom of the blind hole, thereby leading to a hinging of at least a part of the protrusion 8.

[0051] FIG. 4 shows an example of a closed lubrication port 2 of an end cap 1 for a carriage of a linear guide in a cross-sectional view. The lubrication port 2 is configured as a blind hole 5 and comprises a mechanism 7 for opening the lubrication port 2 to a lubrication channel 1d of the end cap 1. The mechanism 7 is activatable by operatively connecting a lubrication fitting 20 to the port 2, in particular by inserting the fitting 20 into the blind hole 5. To this end, the hole 5 preferably contains a threading 6 configured to mesh with a corresponding threading on the fitting 20.

[0052] The bottom of the blind hole 5 is preferably formed by a material layer 1e of the end cap 1. The material layer 1e separates the lubrication channel 1d from the lubrication port 2. The mechanism 7 preferably contains a protrusion 8 formed on the bottom of the hole 5, wherein the protrusion 8—and thereby the mechanism 7—is integral with the material layer 1e. Advantageously, the protrusion 8 has the shape of a ramp for providing a contact section at the top of the ramp (cf. FIG. 3). The contact section is configured to receive a force exerted when operatively connecting the lubrication fitting 20 to the lubrication port 2, i.e. when inserting the fitting 20 into the blind hole 5. Due to the limited size of the contact section, exerting a force onto the protrusion 8 may lead to a high pressure on the material layer 1e. This enables puncturing the material layer 1e such that a lubricant passage is established between the port 2, in particular the hole 5, and the lubrication channel 1d.

[0053] In order to facilitate puncturing, the lubrication port 2 may comprise a predetermined breaking point B. The breaking point B is preferably formed by a thinning of the material layer 1e. Advantageously, the breaking point B is arranged along at least a part of a contour of the protrusion 8, in particular in a region along the contact section (cf. FIGS. 3A-3B).

[0054] Upon puncturing of the lubrication port 2 by inserting the lubrication fitting 20 into the blind hole 5 and exerting a force onto the contact surface at the top of the ramp, the protrusion 8 or at least a part thereof may hinge towards the lubrication channel 1d. Thereby, an opening may be formed through which lubricant can flow from the lubrication port 2 into the channel 1d.

[0055] By showing both the lubrication fitting 20 and the lubrication port 2, FIG. 4 also illustrates a method for lubricating the carriage. As has been described above, by operatively coupling the fitting 20 to the port 2, in particular by screwing the fitting 20 into the blind hole 5 via the threading 6, the lubrication port 2 can be opened. Once the passage to the lubrication channel 1d has been established, a lubricant can be provided via the lubrication fitting 20.

[0056] The lubrication port 2, in particular the ramp (cf. FIGS. 3A-3B), may be obtained during injection molding of the end cap 1. Preferably, the lubrication port 2 is formed during rotary demolding. In particular, a pin having a recess corresponding to the protrusion 8 at its tip is pulled out of the blind hole 5. In order to create the threading 6, the pin is rotated upon pulling out of the hole 5. This is facilitated by the protrusion 8 having the form of a ramp.

[0057] The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention:

[0058] 1 end cap

[0059] 1a side face

[0060] 1b side face

[0061] 1c top face

[0062] 1d lubrication channel

[0063] 1e material layer

[0064] 2 lubrication port

[0065] 3, 4 further lubrication port

[0066] 3a lid

[0067] 3b recess

[0068] 5 blind hole

[0069] 6 threading

[0070] 7 mechanism

[0071] 8 protrusion

[0072] 8a contour

[0073] 9 ramp

[0074] 9a ledge

[0075] 9b contact section

[0076] 10 carriage

[0077] 11 guide rail

[0078] 20 lubrication fitting

[0079] 100 linear guide

[0080] B breaking point