GB1561688A

GB1561688A - Slider/roller side shifter for use on a forklift truck

Info

Publication number: GB1561688A
Application number: GB4640476A
Authority: GB
Original assignee: Cascade Corp
Current assignee: Cascade Corp
Priority date: 1975-12-05
Filing date: 1976-11-08
Publication date: 1980-02-27
Also published as: DE7637832U1; AU498524B2; FR2333747A1; AU1979476A; NL7613255A; CA1051387A; JPS598640B2; IT1074978B; DE2654752A1; JPS5269150A

Abstract

SLIDER/ROLLER SIDE SHIFTER FOR USE ON A FORKLIFT TRUCK A side shifter frame unit for mounting on a forklift carriage includes sliding bearing shoes disposed in notches formed on a lip of an upper bar of the carriage. The sliding bearing shoes have a rear surface inclined at an angle steeper with respect to the horizontal than a front upper bar carriage lip surface so that a side shifting unit will not tend to "climb" when the unit is laterally displaced. A bottom plate of the side shifter utilizes a rolling disc rotatably mounted within a housing for rolling contact with a lower bar of the carriage. The rotatably mounted disc has its axis of rotation directed inwardly and inclined to the face of the lower bar. In one embodiment of the invention, a side shifter actuator is secured to a bracket which is demountably suspended from the upper bar.

Description

(54) SLIDER/ROLLER SIDE SHIFTER FOR USE ON A FORKLIFT TRUCK (71) We, CASCADE CORPORA TION, of 5319 S.W. Westgate Drive, Portland, Oregon, United States of America; a corporation organized and existing under the laws of the State of Oregon, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention pertains to side shifters used on lift truck carriages, and more particularly to bearings employed to facilitate transverse movement of a side shifter on the carriage.

Fork lift trucks have found wide acceptance in industry, and a particularly popular form of fork lift truck utilizes the so-called side shifter.

Side shifters typically take the form of an upper longitudinal plate connected to a lower longitudinal plate wherein the upper plate utilizes a hook arranged to slidably engage bearing shoes detachably secured within notches in a lip portion of an upper carriage bar. The lower longitudinal plate includes transversely movable, rearwardlyfacing sliding or rolling bearings which, under load, exert an extremely high compressive force against the face of the carriage. A hydraulic cylinder assembly interposed between the carriage and side shifter transversely displaces the side shifter frame with respect to the lift truck carriage upon actuation of the cylinder assembly. The forwardly-protruding forks or other carrying means are suspended by upper fork hooks arranged over the upper plate in order to hold a load.

One problem with existing forklift truck side shifter units resides in the fact that bearing wear is heavy and friction is relatively high. This problem is most notable in the area of the lower bearings because of the extremely high compressive contact stresses, accentuated by impact loading, at these points. This situation results in high maintenance costs, as well as in high energy usage in operating a side shifter.

A general object of the present invention is to provide a novel side shifter wherein friction is held to a minimum, and long-life performance is obtainable.

The present invention also seeks to provide a side shifter including a rolling contact bearing, this bearing is located at the bottom of the interface between the side shifter and the carriage. In one embodiment, the present invention seeks to utilize a particular type of rolling contact bearing which provides a larger radius of curvature of the bearing surface then most, if not all, known bearings so as to minimize the contact stress and to offer a high resistance to impact loads between the bearing surface and carriage while maintaining extreme thinness of the bearing assembly.

According to the present invention, there is proveded a side shifter adapted for mounting upon the front of a vertically movable lift truck carriage, of the type having a transverse mounting member adjacent the top of the carriage and a transverse forwardly-facing surface below the transverse mounting member, for mounting a load-handling attachment upon the carriage with the side shifter interposed structrually between the carriage and attachment so that the attachment is transversely movable with respect to the carriage, such side shifter comprising: a forwardly-facing front mounting member for mounting the load-handling attachment thereon; a first rearwardlyfacing mounting member connected to the front mounting member for mavably engaging the transverse mounting member of the carriage so as to vertically support the front mounting member and permit the front mounting member to move transversely with respect to the carriage; a second rearwardly-facing mounting member connected to the front mounting member, at a location below the first rearwardly-facing mounting member, for movably engaging the forwardly-facing surface of the carriage, such second rearwardly-facing mounting member comprising a substantially discshaped bearing having a rearwardly-facing generally convex bearing surface on one side thereof for rollingly contacting the forwardly-facing surface of the carriage and having a forwardly-facing surface on the side thereof opposite the convex bearing surface, and a bearing mounting member on the front mounting member, for rotatably mounting the disc-shaped bearing upon the front mounting member, comprising a rearwardly-facing surface for rotatably engaging said forwardly-facing surface of said discshaped bearing.

The present invention will be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a partial frontal view showing approximately one-half of the side shifter apparatus of the present invention mounted on upper and lower carriage bars of a forklift truck, the forklift truck not being shown; Figure 2 is a view taken aong lines 2-2 of Figure 1; Figure 3 is an enlarged view of the sliding bearing shoe contacting hook shown in Figure 2; Figure 4 is a partial frontal view of a side shifter unit illustrating the demountable side shifter actuator hanger bracket of the present invention; Figure 5 is a view taken along lines 5-5 of Figure 4; and Figure 6 is a view similar to that illustrated in Figure 3 and shows another hook embodiment.

Turning now to the drawings, and initially referring more particularly to Figures 1, 2 and 3, indicated generally at 10 is a side shifter apparatus in accordance with the present invention. While a forklift truck is not illustrated, it is to be remembered that upper and lower carriage bars 12 and 14, respectively, are secured to a vertical raising and lowering device on a forklift truck.

Upper and lower carriage bars 12 and 14 are connected together by appropriate joints (not shown). Upper carriage bar 12 is formed with a lip 12a which has an upper surface 12b, an inclined rear face 12c and a rear ledge 12d. Rear face 12c is constructed so that forks of a forklift truck may be releasably attached thereto. Upper carriage bar 12 is also provided with a plurality of notches 13 formed in lip section 12a arranged to receive sliding bearing shoes, to be hereinafter particularly described.

Side shifter apparatus 10 is constructed with an upper transversely extending plate 16 which is joined by appropriate cross pieces 18 (one of the cross pieces is not shown, in that Figure 1 illustrates only approximately one-half of a side shifter frame) to a lower transversely extending plate 20. Upper plate 16 is welded or otherwise attached to a connecting plate 22 which is secured to a generally inverted hook 24. While not illustrated, it is to be understood that another connecting plate 22 would be arranged on the right of side shifter apparatus 10 similar to illustrated plate 22. Hook 24 is arranged to slidably engage bearing shoes 26. Sliding bearing shoes 26 provide bearing engagement for sliding contact with hook 24. Sliding bearing shoes 26 may conveniently be constructed with a generally Z-shaped cross section and are removably mounted within notches 13.

As can be best seen from a consideration of Figure 3, sliding bearing shoes 26 have a first face 26a arranged for contact with rear face 12c. Shoes 26 are provided with lugs 26b which engage notches 13. Surface 26a is formed with generally the same angle with respect to the vertical as in face 12c. Such an angle, designated at A, may be approximately 20 . However, a second shoe face 26c is formed with a greater angle with respect to the horizontal than is face 26a.

For instance, angle B may be arranged at approximately 15 with respect to the vertical. As a consequence, face 24a of hook 24 remains in contact with shoe face 26c without tending to climb or ride upwardly when side shifter 10 is displaced laterally.

Furthermore, it is to be noted that hook 24 has a bottom face 24b which slidably contacts leg segment 26d of sliding bearing shoe 26. The sliding bearing shoes may be made of nylon filled with molydisulfide.

Lower side shifter plate 20 has connected thereto a housing 28 which envelops a rotatable, case hardened steel disc 30.

Rotatable disc 30 has a convex surface 30a for contacting lower bar carriage surface 14a and also has a concave inner surface 30b.

Additionally, housing 28 is disposed against lower carriage bar surface 14a. Disc 30 is set at an angle, i.e., the axis of rotatation C is set at an angle to face 14a. Thus, it can be appreciated that when side shifter 10 is laterally displaced, disc 30 rotates within housing 28 and rollingly contacts lower carriage bar 14 in a region 14b on bar surface 14a.

A housing seating cup 32 is welded or otherwise attached to a rear face of plate 20 and includes angled portions 32a, 32b.

Housing 28 is configured with abutments 28a, 28b which permit insertion of housing 28 into cup 32 as indicated. Thus, it may be appreciated that replacement of a roller disc 30 may be readily effectuated by removal of housing 28 and inserting a new housing and disc into cup 32. Housing 28 may not inadvertently be placed upside down in cup 32 because of the aforementioned abutments 28a, 28b. A further hook 34 is attached to a lower segment of cup 32 and is arranged to fit about carriage bar lip 14c to prevent substantial forward horizontal displacement.

A preferred embodiment of the present invention incorporates a plurality of replaceable wear shoes 26 and two housings, 28 and discs 30. Also, depending from upper carriage bar 12 is a mounting bracket 36 which mounts a hydraulic cylinder 38, the rod 40 of which is in turn connected to plate 18. Hydraulic cylinder 38 is connected to mounting bracket 36 by means of a pivot connection 37. As hydraulic fluid under pressure is admitted through fitting 38a from a source (not shown) rod 40 is displaced to the left thereby laterally displacing side shifter unit 10 to the left. Correspondingly, when fluid under pressure is introduced through fitting 38b, rod 40 is displaced to the right thereby laterally displacing side shifter 10 to the right.

An additional feature of side shifter 10 of the present invention is also shown in Figures 4 and 5 and includes a readily demountable side shifter actuator hanger bracket 42. Hanger bracket 42 is provided with a leg 44 including a hook 46 having a catch or lug 46a arranged to be disposed within a cut-away central portion or notch 13. A top surface 44a of leg 44 is constructed to lie beneath the top surface of sliding bearing shoes 26. Thus, it can be appreciated that no contact between a lower surface of hook 24 will occur against top surface 44a. Hanger bracket 42 is securely clamped to the bottom of upper carriage bar 12 by means of screw clamps 46. Connected to hanger bracket 42 is a mounting bracket 48 which is connected to cylinder 38. Cylinder 38 utilizes a rod 40 connected to plate 18 as previously described.

Removal of hanger bracket 42 may be accomplished as follows. Pin 50 is removed from bracket 52 to permit lateral displacement of side shifter 10 to the left for removal of same from carriage bars 12 and 14. Then clamping bolts 46 may be loosened from contacting the lower face of upper carriage bar 12. Hanger bracket 42 may then be sightly pivoted and pulled upwardly out of notch contacting position for ready removal therefrom. Thus, it can be appreciated that the novel configuration of hanger bracket 42 and central leg 44 provide for ready mounting and demounting of a side shifter actuator 38, 40.

With reference now directed particularly to Figure 6, there is illustrated a further embodiment of a hook connected to a side shifter. This hook is one that may be used in the setting of a side shifter like that shown in Figures 1-3, inclusive. Specifically, attached to upper bar 16 is a generally U-shaped hook 25 having a surface 25a contacting a top leg of sliding bearing shoe 26. Hook 25 includes an integrally formed leg 25b secured to upper plate 16. Hook 25 and leg 25b extend substantially continuously the length of the carriage.

In the embodiment shown in Figures 1, 2 and 3, hook 24 is continuous, and provides overhead protection for the tops of the wear shoes. This minimizes dust accumulation. A modification which could be made is to use one elongated connecting plate 22 with this hook, rather than two laterally spaced plates. Such a modification would further minimize dust accumulation. Further, it will be noted that discs 30 are substantially sealed against exposure to the environment.

In the embodiment shown in Figures 4 and 5, the hook still extends over a substantial portion of the wear shoes at all times, thus to provide protection.

WHAT WE CLAIM IS: 1. A side shifter adapted for mounting upon the front of a vertically movable lift truck carriage, of the type having a transverse mounting member adjacent the top of the carriage and a transverse forwardlyfacing surface below said transverse mounting member, for mounting a load-handling attachment on the carriage with the side shifter interposed structurally between the carriage and attachment so that the attachment is transversely movable with respect to the carriage, said side shifter comprising:: (a) a forwardly-facing front mounting member for mounting the load-handling attachment thereon; (b) a first rearwardly-facing mounting member connected to said front mounting member for movably engaging the transverse mounting member of said carriage so as to vertically support said front mounting member and permit said front mounting member to move transversely with respect to said carriage; ; (c) a second rearwardly-facing mounting member connected to said front mounting member, at a location below said first rearwardly-facing mounting member, for movably engaging the forwardly-facing surface of said carriage, said second rearwardly-facing mounting member comprising a substantially disc-shaped bearing having a rearwardly-facing, generally convex bearing surface on one side thereof for rollingly contacting the forwardly-facing surface of said carriage and having a forwardly-facing surface on the side thereof opposite said convex bearing surface; and

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. appreciated that replacement of a roller disc 30 may be readily effectuated by removal of housing 28 and inserting a new housing and disc into cup 32. Housing 28 may not inadvertently be placed upside down in cup 32 because of the aforementioned abutments 28a, 28b. A further hook 34 is attached to a lower segment of cup 32 and is arranged to fit about carriage bar lip 14c to prevent substantial forward horizontal displacement. A preferred embodiment of the present invention incorporates a plurality of replaceable wear shoes 26 and two housings, 28 and discs 30. Also, depending from upper carriage bar 12 is a mounting bracket 36 which mounts a hydraulic cylinder 38, the rod 40 of which is in turn connected to plate 18. Hydraulic cylinder 38 is connected to mounting bracket 36 by means of a pivot connection 37. As hydraulic fluid under pressure is admitted through fitting 38a from a source (not shown) rod 40 is displaced to the left thereby laterally displacing side shifter unit 10 to the left. Correspondingly, when fluid under pressure is introduced through fitting 38b, rod 40 is displaced to the right thereby laterally displacing side shifter 10 to the right. An additional feature of side shifter 10 of the present invention is also shown in Figures 4 and 5 and includes a readily demountable side shifter actuator hanger bracket 42. Hanger bracket 42 is provided with a leg 44 including a hook 46 having a catch or lug 46a arranged to be disposed within a cut-away central portion or notch 13. A top surface 44a of leg 44 is constructed to lie beneath the top surface of sliding bearing shoes 26. Thus, it can be appreciated that no contact between a lower surface of hook 24 will occur against top surface 44a. Hanger bracket 42 is securely clamped to the bottom of upper carriage bar 12 by means of screw clamps 46. Connected to hanger bracket 42 is a mounting bracket 48 which is connected to cylinder 38. Cylinder 38 utilizes a rod 40 connected to plate 18 as previously described. Removal of hanger bracket 42 may be accomplished as follows. Pin 50 is removed from bracket 52 to permit lateral displacement of side shifter 10 to the left for removal of same from carriage bars 12 and 14. Then clamping bolts 46 may be loosened from contacting the lower face of upper carriage bar 12. Hanger bracket 42 may then be sightly pivoted and pulled upwardly out of notch contacting position for ready removal therefrom. Thus, it can be appreciated that the novel configuration of hanger bracket 42 and central leg 44 provide for ready mounting and demounting of a side shifter actuator 38, 40. With reference now directed particularly to Figure 6, there is illustrated a further embodiment of a hook connected to a side shifter. This hook is one that may be used in the setting of a side shifter like that shown in Figures 1-3, inclusive. Specifically, attached to upper bar 16 is a generally U-shaped hook 25 having a surface 25a contacting a top leg of sliding bearing shoe 26. Hook 25 includes an integrally formed leg 25b secured to upper plate 16. Hook 25 and leg 25b extend substantially continuously the length of the carriage. In the embodiment shown in Figures 1, 2 and 3, hook 24 is continuous, and provides overhead protection for the tops of the wear shoes. This minimizes dust accumulation. A modification which could be made is to use one elongated connecting plate 22 with this hook, rather than two laterally spaced plates. Such a modification would further minimize dust accumulation. Further, it will be noted that discs 30 are substantially sealed against exposure to the environment. In the embodiment shown in Figures 4 and 5, the hook still extends over a substantial portion of the wear shoes at all times, thus to provide protection. WHAT WE CLAIM IS:

1. A side shifter adapted for mounting upon the front of a vertically movable lift truck carriage, of the type having a transverse mounting member adjacent the top of the carriage and a transverse forwardlyfacing surface below said transverse mounting member, for mounting a load-handling attachment on the carriage with the side shifter interposed structurally between the carriage and attachment so that the attachment is transversely movable with respect to the carriage, said side shifter comprising:: (a) a forwardly-facing front mounting member for mounting the load-handling attachment thereon; (b) a first rearwardly-facing mounting member connected to said front mounting member for movably engaging the transverse mounting member of said carriage so as to vertically support said front mounting member and permit said front mounting member to move transversely with respect to said carriage;; (c) a second rearwardly-facing mounting member connected to said front mounting member, at a location below said first rearwardly-facing mounting member, for movably engaging the forwardly-facing surface of said carriage, said second rearwardly-facing mounting member comprising a substantially disc-shaped bearing having a rearwardly-facing, generally convex bearing surface on one side thereof for rollingly contacting the forwardly-facing surface of said carriage and having a forwardly-facing surface on the side thereof opposite said convex bearing surface; and

(d) a bearing mounting member on said front mounting member, for rotatably mounting said disc-shaped bearing upon said front mounting member, comprising a rearwardly-facing surface for rotatably engaging said forwardly-facing surface of said disc-shaped bearing.

2. The side shifter of claim 1 wherein said rearwardly-facing surface of said bearing mounting member rotatably engaged said forwardly-facing surface of said discshaped bearing over an area substantially coextensive with said convex surface of said bearing so as to transmit forces from said front mounting member through said area toward the forwardly-facing surface of said carriage.

3. The side shifter of claim 1 wherein said bearing mounting member includes means for requiring said bearing to rotate about an axis of rotation which is inclined upwardly in a direction from front to rear.

4. The side shifter of claim 3 including means for detachably operatively mounting said bearing mounting member upon said front mounting member in an orientation requiring said bearing to rotate about said inclined axis, and for preventing the mounting of said bearing mounting member in any other operative orientation.

5. The side shifter of claim 3 wherein said rearwardly-facing surface of said bearing mounting member is inclined forwardly so as to require said bearing to rotate about said inclined axis.

6. The side shifter of claim 5 wherein said front mounting member includes a cup on said front mounting member for detachably accepting the insertion of said bearing mounting member therein, said cup and bearing mounting member having complementary-shaped surfaces for permitting the insertion of said bearing mounting member into said cup only in a single operative orientation such that said rearwardly-facing surface of said bearing mounting member is in said forwardly inclined position.

7. A side shifter adapted for mounting upon the front of a vertically movable lift truck carriage constructed and arranged to operate substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.