1. Field of the Invention
The present invention relates to a roller holder, and more particularly to a roller holder having rollers arranged in different directions for engaging between two moving members and for increasing the contact area between the two moving members and for facilitating the sliding movement between the two moving members.
2. Description of the Prior Art
Typical screw shafts comprise a screw member threaded into a nut member, or relatively, a nut member threaded onto a screw member, and a number of balls engaged in the threads of the nut member and the screw member for facilitating the rotational and/or sliding movement between the nut member and the screw member. Normally, the balls are simply disposed in the threads of the nut member and the screw member without any ball holders or retaining devices such that the balls may not be stably retained in place to each other.
Typical motion guide devices, such as linear motion guide devices or other motion guide devices also comprise two moving members, such as a track rail and a slider slidably engaged with each other, and a number of balls or rollers engaged between the two moving members for facilitating the sliding movement between the two moving members.
For example, U.S. Pat. No. 5,947,605 to Shirai disclose one of the typical linear motion guide devices comprising a number of balls engaged between two moving members for facilitating the sliding movement between the two moving members. However, the balls are in point-contact with the two moving members such that the abrasion or scraping between the-two moving members may be increased.
U.S. Pat. No. 6,390,678 to Shirai discloses another typical linear motion guide device comprising a number of rollers engaged between two moving members for increasing the contact between the two moving members and for facilitating the sliding movement between the two moving members. However, the rollers are normally held in place with a roller holder device and are all arranged or disposed in the same or identical direction, such that the rollers may resist the force in only one direction between the two moving members.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional roller holders for the screw shafts or for the linear motion guide devices.
The primary objective of the present invention is to provide a roller holder including a number of rollers alternately disposed and arranged in different directions for engaging between two moving members and for increasing the contact area between the two moving members and for facilitating the sliding movement between the two moving members.
In accordance with one aspect of the invention, there is provided a roller holder for engaging between two moving members, the roller holder comprising an outer holding device, a number of first rollers disposed in the outer holding device and partially extended out of the outer holding device, and a number of second rollers disposed in the outer holding device and partially extended out of the outer holding device and disposed alternately between the first rollers and arranged in different direction relative to the first rollers for engaging with different directions between the moving members and for facilitating the sliding movement between the two moving members. The first rollers and second rollers may be stably disposed and retained in the outer holding device in the stable or predetermined position relative to each other.
The outer holding device includes a number pairs of spacers disposed alternately relative to each other for retaining the first and the second rollers between the spacers. The pairs of spacers each include opposite curved recesses for rotatably receiving the first and the second rollers between the spacers.
Each pair of the spacers include a lateral curved recess formed in one side and facing toward each other for rotatably receiving the first rollers between each pair of the spacers. The lateral curved recesses of the spacers are in plan-contact or in line-contact with the first and the second rollers.
Each pair of the spacers include a vertical curved recess formed in one side and facing away from each other for rotatably receiving the second rollers between different pairs of the spacers. The vertical curved recesses of the spacers are in plan-contact or in line-contact with the first and the second rollers.
The outer holding device includes a first rod and at least one second rod disposed parallel to each other, and the pairs of spacers are disposed between the first and the second rods and arranged alternately relative to each other. The first and the second rods are preferably disposed on opposite edge or diagonal portions of the pairs of spacers.
The outer holding device further includes at least one third rod disposed parallel to the first and the second rods, and the pairs of spacers are disposed between the first and the second and the third rods.
Further objectives and advantages of the present invention will become apparent from a careful reading of the detailed description provided hereinbelow, with appropriate reference to the accompanying drawings.
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Each pair of spacers 20, 30 further include a curved recess 22, 32, such as a vertical curved recess 22, 32 formed therein, such as formed in the other side or outer or second side thereof, and facing away from each other for rotatably receiving a vertical roller 50 between different pairs of spacers 30, 20, in which the lateral or horizontal rollers 40 are arranged in different direction relative to the vertical rollers 50 or perpendicular to the vertical rollers 50, best shown in
The lateral or horizontal rollers 40 and the vertical rollers 50 may thus be alternately disposed or received in the outer holding device 11 and partially extended out of the outer holding device 11, and arranged in different direction relative to each other, such as perpendicular to each other for engaging between the two moving members 80, 81 or 84, 85, and for facilitating the sliding movement between the two moving members 80, 81 or 84, 85 that will be moved or slid relative to each other.
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Accordingly, the roller holder in accordance with the present invention includes a number of rollers alternately disposed and arranged in different directions for engaging between two moving members and for increasing the contact area between the two moving members and for facilitating the sliding movement between the two moving members.
Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made by way of example only and that numerous changes in the detailed construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.