US2981571A - Motion-conversion device - Google Patents

Description

April 25, 1961 J. E. MARTENS 2,981,571.

MOTION-CONVERSION DEVICE Filed Nov. 10, 1958 2 Sheets-Sheet 1 INVENTOR. JACK E. MA RTE/V5 /af. W

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J. E. MARTENS MOTION-CONVERSION DEVICE m Q E W K J 3? Filed Nov.

' April 25, 1961 United States Patent 2,981,571 MOTION-CONVERSION DEVICE Jack E. Martens, Gary, Ind., assignor to The Anderson Company, a corporation of Indiana Filed Nov. 10, 1958, Ser. No. 773,009

9 Claims. (Cl. 308-6) This invention relates generally to a cross-head bearing structure for use in motion-transmitting mechanisms.

Various types of cross-head bearing structures have been proposed and used successfully when operated within a limited range, such as to transmit forces along near- 1y parallel axes. However, when the angular variations between the directions of motions of the two parts become large or when vibration is introduced into the system during the transmission of the motion from one unit to the other, a binding or wedging action sometimes results which occasionally damages the operative parts of the mechanism.

One particular use of the present invention is in connection with power-driven apparatus for raising and lowering vehicle windows. 1

Among the problems created by recent automobile design is the one relating to the complex maneuvers involved in raising and lowering of certain of the windows. T 0 close a window, for example, may involve compound motions including first shifting the window rearwardly, tilting first one way and then the other while moving the window vertically, and finally shifting it forwardly.

In a well-known construction for operating vehicle windows, a pair of guideways are disposed forwardly and rearwardly with respect to the window within the vehicle body, and a pair of rollers carried by the front and the rear portions at the lower edge of the window roll in said guideways to produce the required maneuvers. The window is actuated by a motor driven threaded shaft disposed along a median path about which the maneuvers center. A nut structure is threaded upon the shaft and is connected to the window. In the embodiment herein disclosed, the cross head of my invention is interposed between the nut structure and the window.

It is a principal object of this invention to provide a cross-head type antifriction bearing structure that substantially overcomes the above-mentioned disadvantages of the prior art, requires a minimum of bearing elements, and has the bearing elements automatically repositioned to a predetermined starting location upon each shift in loading characteristics of the structure.

It is a further object of this invention to provide an improved cross-head type bearing structure of extremely simple design, operable for years without service, which can be fabricated at comparatively low cost.

A still further object of this invention is to provide an improved window-lift mechanism wherein the connection of the window to the threaded drive shaft permits both pivoting and endwise shifting of the window relative to the shaft without imposing binding stresses in the connection or upon the shaft.

These and other objects and advantages of the invention will become apparent as the disclosure proceeds. The invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawings. It is to be understood, however, that the invention is not to be confined to any strict conformity with the showing of the drawings and may be modified so long as such changes or modifications mark no material departure from the salient features of the invention as expressed in the appended claims.

In the drawings:

Figure 1 is a side elevational view of a vehicle door or vehicle panel section incorporating the improved crosshead type bearing structure of the present invention;

Figure 2 is an end view of the bearing structure with the carrier or channel member thereof shown in cross section;

Figure 3 is a view taken from the left of Figure 2 showing a segment of the drive shaft and its connection to the bracket structure;

Figure 4 is a detail view of the bearing structure, partly in section, showing the location of the bearing elements during a special phase of the window maneuver; and

Figure 5 is a perspective view of the bearing block with one end plate and the lower ball unit removed.

The invention as disclosed may be utilized in many different applications, such as in reciprocating oil well pumps, but is illustrated in the drawings as operatively associated with the window of an automotive vehicle. Referring to Figure 1 of the drawings, there is shown a panel 10 of an automotive vehicle or automotive vehicle door having window 11 mounted for movement into and out of said panel by means of power-operated mechanism 12. For the purpose of illustration, window 11 is shown guided in its movement by means of a pair of rollers 13 carried at opposite ends of the window and engaged in spaced tracks 14, supported by brackets 15 as shown. As the window is retracted into the door it will be moved first rearwardly, then downwardly and rearwardly, and after several endwise tiltings during its descent, it is finally pivoted about its rear corner into a completely nested position within the panel 10.

The power-operated mechanism 12 is composed of a motor 16 drivingly connected to a substantially vertical threaded shaft or screw 17 by means of belt-andpulley system 18. The screw is journaled at its opposite ends in bearings 19 carried by brackets 20, which are mounted on the inner side of panel 10 so as to have the axis of the screw at an angle with respect to the vertical, for a purpose to be explained hereinafter. A motion-transmitting nut 21 is mounted on screw 17 to be moved along the axis of the screw upon rotation of the latter. Nut 21 is operatively connected through the cross-head bearing mechanism of this invention to a frame 23 rigid with the lower portion of window 11.

In constructions of this general type, the base of the window is maneuvered in several different directions within the plane of the window. In the illustrated example, the dotted line 24 designates a path of movement of a given point on the frame 23 of the window. By arranging the axis of screw 17 in a predetermined position relative to the dotted line 24, it is possible to substantially divide the lateral deviations of movement of the point on frame 23 of the window equally on opposite sides of screw 17. In order to provide, in this situation, an operative connection between nut 21 and frame 23, it is especially desirable to interpose a cross-head structure which is capable of changing the direction of motion from along the axis of the screw into a motion along an axis disposed, at times, at an angle relative to and oifset from the axis of the screw.

As forecast, the cross-head mechanism of the present invention is arranged between nut 21 and the lower rigid frame 23 of the window, the detailed structure of which will now be described. Referring presently to Figures 2 and 3, it will be noted that nut structure 21 includes oppositely extending ledges or support arms 25. One leg of an elongate L-bracket 26 rests upon said ledges. The central area 27 of the horizontal leg of the bracket is cut away in order that it may stnaddle nut 21 and its ends 28 are secured to said ledges by screws 29, spot welding, or the like. For economy and appearance, the vertical leg 30 of the bracket is tapered at 31 to a peak portion 32.

The cross head of the present invention includes a carrier and a slide guided in the carrier. More specifically, numeral 33 designates an open-ended elongate carrier or channel member of generally C-shape in cross section, the intermediate wall 34 of the channel member being fiat. The channel member is formed from sheet metal with the inner walls of the upper and lower loop portions shaped to define opposed V-grooves or ways 36 for bearing elements 37, to be described hereinafter. Each groove or way 36 runs the length of the channel member.

A headed pivot pin 35 extends through an opening 39 formed centrally of the flat side wall 34 of the channel member, the rounded head 38 of the pin being disposed against the inner side of wall 34 within the confines of the channel member. A circular wear plate or washer 40 surrounds the body portion 41 of the pivot pin 35 projecting outside the channel member. The pivot pin is reduced in diameter adjacent its outer end to provide a shoulder 42. The extreme outer end of the pin passes through an opening in the vertical leg 30 of bracket 26 and is headed or swaged at 43 against said leg to clamp the bracket tightly against said shoulder. Plate 40 is selected of such thickness that the clamping of leg 30 will not restrain pivoting of channel member 33 on body portion 41 of the pivot pin relative to the bracket 26.

Frame 23 of window 11 has fixed thereto, as by rivets 44, a depending plate 45. A slide in the form of an elongate bearirrg block 46 is secured to the lower end of plate 45 by means of bolts 47, or the like, which pass through openings formed in plate 45 and threadedly engage tapped holes 48 in the side wall of the block. Block 46 is received in channel member 33, between the Ways 36 thereof. The upper and lower faces of block 46 are each formed with a V-groove or way 49 extending from end to end thereof and facing the correspondingly shaped ways 36 formed in the channel member. There is thus provided for the block upper and lower trackways each of generally diamond-shaped cross section in which antifriction elements, such as balls 37, may be imprisoned in rolling contact therewith. As shown, a minimum of two balls are required for each trackway, but additional intermediate balls may be incorporated, as desired. One face of block 46 is rabbeted at 50 to assure clearance at all times with the edges 51 of the channel member, and the opposite face is formed throughout its length with a groove 52 of arcuate cross section to provide clearance for the head 38 of the pivot pin 35.

An end plate 53 is secured as by screws 54, to each end of block 46. Each plate has a tapered portion 55 at each end thereof for closing the ends of V-ways 49 and to admit entry of the block and plate into the V-ways 36 formed in the channel member. Positioned in each way 49, between one plate 53 and one ball element 37, is a coil spring 56 loaded under compression to urge the ball in a direction away from the respective plate 53. Between the respective balls 37 is an additional coil spring 58 also loaded under compression to urge the balls against the action of the springs 56 so as to establish an equilibrium condition such as shown in Figure 5. The balls 37 associated with the springs 56 and 58 are disposed at such distance apart that the endwise movement of the block 46 in the channel member 33, incident to window operation, will practically never carry both balls to one side of pivot pin 38. Balls 37 are continuously urged by springs 56 and 58 to the normal position shown in Figure 5. Figure 4 depicts the position to which the balls roll when the window is shifted forwardly. As soon as the driving force is stopped, however, or upon reversal of motor 16, the loading upon the balls will be momentarily relaxed, whereupon the springs will restore the balls to the starting position of Figure 5. The balls will thus balance themselves on opposite sides of pivot pin 38 before each operation of the window. The simple arrangement described eliminates expensive races and assures balanced load upon each ball for each operation of the window. During the window-operation cycle, the channel member 33 may pivot on pin 38 to the several positions depicted in Figure 1. of transverse screw 17, as becomes necessary due to the forward and rearward shifting of the window. In Figure 1, numeral 60 designates the dotted-line path followed by the right-hand ball 37 in the V-way 49 as the window is moved from the lowered position to the raised position. It will be noted that the path of ball 37 is generally similar to, but not parallel with, the path of the point on the window frame used to subscribe the path 24.

In operation, upon energization of motor 16, nut structure 21 will be moved along shaft 17 and motion will be t'ransmitted from the nut structure through the bearing structure 22 to window 11. As the tracks 14 constrain the window to tilt, channel member 33 will correspond ingly pivot on pin 38. Likewise, as the window is shifted either forwardly or rearwardly, block 46 will move endwise upon the balls 37 interposed between the block and channel member, and will always transmit the applied force without canting or wedging one part of the bearing mechanism relative to another.

While a specific form of the invention has been shown by way of example, it is to be understood that the scope of the invention is to be limited only as recited in the following claims.

I claim:

1. A cross-head structure to be positioned between'a reciprocating driving member and a driven member movable along an irregular path in the general direction of movement of the driving member, comprising a channel member for arrangement transverse to the path of travel of said driving member, the opposed walls of said channel member being each formed with a groove extending substantially the length of the channel member and at least through a common end thereof, the channel member including pivot means at substantially the center of its intermediate wall for connection to one of the first-mentioned members, an elongate block movable in said channel member and having a portion extending outwardly of the channel for connection to the other of said first-mentioned members, said block being formed with grooves corresponding to and facing those of the channel member to form multiple trackways, the grooves in said block having closed ends, a plurality of spaced bearing elements in each groove of said block for rolling in said trackways, said elements being equal in number on opposite sides of the center of said block, and resilient means in the grooves of said block tending to urge said elements to a preset starting position, the outermost of said elements being at such distance apart that both will not roll to the same end of the block during a traverse of the driven member.

2. A cross-head structure for connecting a reciprocative driving member and a driven member subjected to compound motions as moved along a path in the general direction of movement of the driving member comprising a member of C-shape in cross section, the inner side of the loops of said C-shaped member each being formed into a V-groove extending the length of the member, a bearing block fitted between the grooves in said C-shaped member, the upper and lower surfaces of the block being each formed with a V-groove extending throughout the length of the block and facing the corresponding groove of the C-shaped member to form trackways, a plate secured at each end of said block, each plate having .V-

shaped portions closing the ends of the grooves in said block and projecting into the grooves of said C-shaped The block 46 can freely move crosswise member, a plurality of spaced balls in each groove in said block, helical coil springs disposed in each groove of said block and abutting said end plates and said balls for normally biasing said balls in predetermined positions relative to said end plates with the outermost balls spaced apart a preset distance, means centrally of said C-shaped member for pivotal connection with said driving member, and means substantially rigid with and extending transversely of the bearing block for substantially nonrotative connection with said driven member.

3. A cross-head structure for interposition between a reciprocative driving member and a driven member movable along an irregular path in the general direction of movement of the driving member comprising a channel member, the opposed walls of said channel member being each formed with a groove extending substantially the length of the member and at least through one end thereof, an elongate block arranged in said channel member, said block being formed with grooves corresponding to and facing those of the channel member to form multiple tracltways, means closing the ends of the grooves in said block, a plurality of balls in each of said grooves of said block, helical coil springs disposed in each groove of said block for resiliently spacing said balls from each other and from the means closing the ends of the grooves, an equal number of said balls being positioned on opposite sides of the center of said block with the outermost balls in each groove at predetermined spaced-apart distances, and means, carried centrally of the channel member and means carried centrally of the block for pivotally connecting the one to the driving member and connecting the other substantially nonrotatively to the driven member.

4. A cross head structure comprising a channel section, the opposed walls of said section being formed with a groove extending substantially the length of the section and at least through a common end thereof, an elongate block section movable in said channel section, said block section being formed with grooves corresponding to and facing those of the channel section to form closed trackways, the grooves of said block section having closed ends, elongate resilient means disposed in each groove of said block section and abutting the ends of the respective grooves, a plurality of bearing elements in each groove of said block and being spaced by said resilient means for rolling in said trackways, said elements being equal in number on opposite sides of the center of said block with the outermost elements at such spaced-apart distance as to stay on the respective sides of the center of the block during the designed operation of the bearing structure, pivot means centrally of one of said sections, and means substantially rigid with the central portion of the other section and projecting transversely therefrom.

5. A cross-head structure for interposition between a reciprocative drive and a reciprocative driven member comprising a channel member, means centrally of said channel member for connection of said channel member to said reciprocative drive member with the channel member transverse the path of movement of the drive member, an elongate block positioned between the opposed walls of said channel member, said block being formed with trackways having closed ends and facing each of said opposed walls, said block being provided with means for rigid nonrotative connection with said driven member, a plurality of bearing elements in each trackway, and resilient spacing means disposed in each trackway and tending to bias said bearing elements to a set starting position.

6. The structure as defined in claim 5 wherein said resilient means comprises a coil spring extending along each trackway and the bearing elements are arranged in position between the convolutions thereof.

7. The structure of claim 5 wherein said connection means of said channel member comprises a pivot pin for connecting the central portion of the intermediate wall of said channel member to said driving member, and said connection means of said block comprises a member fixed to the central portion of the block and extending transversely thereof.

8. A cross-head structure for transverse interposition between a reciprocating driving member and a driven member movable along an irregular path in the general direction of movement of the driving member, comprising a carrier section provided with opposed bearing surfaces, a block section having a portion fitted between said surfaces, said portion having grooves between the ends thereof facing the bearing surfaces of the carrier section, at least two bearing elements in each groove of said block, said elements being disposed in balanced relation on opposite sides of the lengthwise center of the block, resilient means tending to urge said elements to a set position upon each reversal of movement of said driving member, and means extending from the central area of each of said sections for pivotally connecting the one section to one of said members and substantially nonrotatively connecting the other section to the other of said members.

9. A cross-head structure for connecting a reciprocative driving member and a driven member guided, along an irregular path in the general direction of movement of the driving member, comprising a carrier having pivot means centrally thereof for connection to said driving member and having opposed walls for the reception of block means therebetween, block means fixed to said driven member and arranged between said opposed walls and having a member substantially rigid with its central portion for connection to said driven member, said block means being formed with grooves having closed ends and facing said opposed Walls, bearing elements in each of said grooves and rollingly engageable with said opposed walls, resilient spacing means operativelly positioned in each trackway and tending to urge said bearing elements to a predetermined position, and means extending from the central area of said block means for nonrotatively connecting said block means to the other of said members.

References Cited in the file of this patent UNITED STATES PATENTS 2,675,282 Mason Apr. 13, 1954 2,730,369 Steed Jan. 10, 1956 2,763,508 Gelfand Sept. 18, 1956 2,872,184 Wise Feb. 3, 1959

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