Abstract:
A method is provided for manufacturing a fork carriage comprising: providing a fork-supporting bar having first and second fork-receiving hooks, wherein the second hook is of a larger size than the first hook; based on a size of one or more forks desired to be mounted on the fork-supporting bar, positioning the bar such that one of the first and second fork-receiving hooks corresponding to the size of the one or more forks is located outwardly to receive the one or more forks on the one fork-receiving hook; and coupling a reinforcement bar to a side of the fork-supporting bar opposite the side near the one fork-receiving hook. A carriage assembly comprising a fork carriage including an upper member comprising a fork-supporting bar having an outer fork-receiving hook and a reinforcement bar is also provided.

Description:
RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/017,328, filed Jun. 26, 2014, which is herein incorporated by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a carriage assembly to be movably coupled to a mast assembly of a materials handling vehicle comprising a lifting carriage and a fork carriage mounted to the lifting carriage and capable of lateral movement relative to the lifting carriage. 
     BACKGROUND OF THE INVENTION 
     Materials handling vehicles are known comprising a carriage assembly movably mounted to a mast assembly of a materials handling vehicle comprising a lifting carriage and a fork carriage mounted on the lifting carriage for lateral movement relative to the lifting carriage. A fork-supporting member of the fork carriage may be formed having a fork-receiving hook. It is known to form the fork-supporting member having the fork-receiving hook using a hot rolling process involving a specifically designed hot rolling die. The cost of the die is expensive and the cost of manufacturing the hot rolled material from which a plurality of the fork-supporting members are formed decreases with volume. 
     SUMMARY OF THE INVENTION 
     In accordance with a first aspect of the present invention, a method is provided for manufacturing a fork carriage comprising: providing a fork-supporting bar having first and second fork-receiving hooks, wherein the second fork-receiving hook is of a larger size than the first fork-receiving hook; based on a size of one or more forks desired to be mounted on the fork-supporting bar, positioning the fork-supporting bar such that one of the first and second fork-receiving hooks corresponding to the size of the one or more forks is located outwardly to receive the one or more forks on the one fork-receiving hook; and coupling a reinforcement bar to a first side of the fork-supporting bar opposite a second side near the one fork-receiving hook. 
     The method may further comprise selecting a size of the reinforcement bar based on a desired amount of weight to be supported by the one or more forks. 
     The fork-supporting bar may comprise an H-shaped bar. 
     Coupling the reinforcement bar to the fork-supporting bar may comprise welding the reinforcement bar to the first side of the fork-supporting bar opposite the second side near the one fork-receiving hook. 
     The reinforcement bar may be vertically offset relative to the fork-supporting bar such that upper and lower surfaces of the reinforcement bar are vertically offset relative to upper and lower surfaces of the fork-supporting bar. 
     Coupling the reinforcement bar to the fork-supporting bar may comprise making a first fillet weld between a side surface of the reinforcement bar and an upper corner of the fork-supporting bar. Coupling may further comprise making a second fillet weld between a bottom surface of the reinforcement bar and a lower side surface and a lower corner of the fork-supporting bar. 
     The reinforcement bar may span generally the entire length of the fork-supporting bar. 
     The method may further comprise machining notches in the one fork-receiving hook. 
     In accordance with a second aspect of the present invention, a carriage assembly is provided, which is adapted to be movably coupled to a mast assembly of a materials handling vehicle. The carriage assembly may comprise: a lifting carriage comprising a lifting carriage upper member including structure for laterally shifting a fork carriage; and the fork carriage mounted on the lifting carriage upper member. The fork carriage may comprise fork carriage upper and lower members and fork carriage first and second side members, wherein the upper and lower members may be coupled to the fork carriage first and second side members. The upper member may comprise a fork-supporting bar having an outer fork-receiving hook and a reinforcement bar mounted to a first side of the fork-supporting bar opposite a second side near the fork-receiving hook. 
     Notches may be provided in the outer fork-receiving hook. 
     The reinforcement bar may be vertically offset relative to the fork-supporting bar such that upper and lower surfaces of the reinforcement bar are vertically offset relative to upper and lower surfaces of the fork-supporting bar. 
     The reinforcement bar may be coupled to the fork-supporting bar via a first fillet weld located between a side surface of the reinforcement bar and an upper corner of the fork-supporting bar. 
     The reinforcement bar may be further coupled to the fork-supporting bar via a second fillet weld located between a bottom surface of the reinforcement bar and a lower side surface and a lower corner of the fork-supporting bar. 
     The reinforcement bar may span generally an entire length of the fork-supporting bar. 
     The reinforcement bar may have a vertical height greater than a vertical height of the fork-supporting bar. 
     The fork-supporting bar may comprise an H-shaped bar. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       While the specification concludes with claims particularly pointing out and distinctly claiming the present invention, it is believed that the present invention will be better understood from the following description in conjunction with the accompanying Drawing Figures, in which like reference numerals identify like elements, and wherein: 
         FIG. 1  is an exploded view of the carriage assembly of the present invention; 
         FIG. 2  is a rear view of the carriage assembly of  FIG. 1 ; 
         FIG. 3  is a front view of the carriage assembly of  FIG. 1 ; 
         FIGS. 4A, 4B, and 4C  are perspective views of portions of fork carriages and corresponding upper members of first, second, and third embodiments of the present invention; 
         FIG. 5  is a view partially in cross section of a portion of a fork carriage upper member constructed in accordance with the first embodiment of the present invention; and 
         FIG. 6  is a view of a materials handling vehicle including the carriage assembly of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration, and not by way of limitation, specific preferred embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and that changes may be made without departing from the spirit and scope of the present invention. 
     With reference to  FIGS. 1-6 , a carriage assembly  10  adapted to move vertically up and down along a mast assembly  100  of a materials handling vehicle is illustrated. As seen in  FIG. 6 , the carriage assembly  10  comprises a lifting carriage  20  coupled to the mast assembly  100  for reciprocal, vertical movement along the mast assembly  100  via a primary cylinder and ram assembly  101  mounted to the mast assembly  100  and a chain (not shown) coupled between the lifting carriage  20  and the primary cylinder and ram assembly  101 . A fork carriage  30  is mounted to the lifting carriage  20  for lateral movement relative to the lifting carriage  20  and for vertical movement with the lifting carriage  20 . First and second forks  140 A and  140 B are mounted onto the fork carriage  30  so as to move with the fork carriage  30 . 
     With reference to  FIGS. 1 and 2 , the lifting carriage  20  comprises first and second vertical members  20 A,  20 B and upper and lower support members  20 C and  20 D, all of which are coupled together via welding so as to move as a unit. The lifting carriage upper member  20 C comprises first and second separate internal cylinders (not labeled) receiving first and second rams  120  and  122 . End caps  120 A,  122 A are provided at opposing ends of the upper member  20 C to provide seals between the first and second internal cavities and the first and second rams  120  and  122 . Hydraulic fluid is separately provided to the first and second internal cylinders to effect movement of the rams  120  and  122  and, hence, the fork carriage  30 . Polymeric, low-friction, low-wear linear bearings  123  are provided on an upper surface of the upper support member  20 C, as shown in  FIG. 1 . 
     The fork carriage  30 , constructed in accordance with a first embodiment of the present invention, comprises first and second vertical members  30 A,  30 B and upper and lower generally horizontal members  30 C,  30 D, as seen in  FIGS. 1 and 3 . The first, second, and upper and lower members  30 A,  30 B,  30 C and  30 D are coupled together via welding to form an integral unit. 
     The fork carriage upper member  30 C, constructed in accordance with a first embodiment of the present invention, comprises a fork-supporting bar, which, in the embodiment illustrated in  FIGS. 1-6 , comprises an H-shaped bar  200 . While not illustrated, it is contemplated that the fork-supporting bar may have a shape other than an H-shape. The H-shaped bar  200  is a hot-rolled section. A specifically designed hot rolling die (not shown) is used in manufacturing the H-shaped bar  200 , the die for which is expensive to design and produce. With reference to  FIGS. 4A-C  and  5 , the H-shaped bar  200  comprises first and second fork-receiving hooks  202  and  204 . The second fork-receiving hook  204  is sized larger than the first fork-receiving hook  202  such that the second fork-receiving hook  204  is capable of supporting forks that are larger, e.g., Class 3 forks, than those forks adapted to be supported on the first fork-receiving hook  202 , e.g., Class 2 forks. For example, as illustrated in  FIG. 4A , the first fork-receiving hook  202  may have a height H 1  extending above a recess  206  of about 13 mm and a maximum width W 1 =16 mm. The second fork-receiving hook  204  may have a height H 2  extending above the recess  206  equal to about 16 mm and a maximum width W 2 =21 mm. In an alternative embodiment, the first fork-receiving hook  202  may have a maximum width W 1 =20.4 mm, and the second fork-receiving hook  204  may have a maximum width W 2 −27.0, with a corresponding width at the tip of each fork-receiving hook  202  and  204  of 16 mm and 21.5 mm, respectively. 
     In accordance with a first embodiment of the present invention, the fork carriage  30  and its upper member  30 C are constructed such that the first fork-receiving hook  202  is positioned outwardly away from the mast assembly  100 , as shown in  FIG. 6 , so as to allow the forks  140 A and  140 B to be mounted on the first fork-receiving hook  202 . The forks  140 A and  140 B may comprise Class 2 forks having a fork load supporting capacity ranging from about 3000 pounds to about 5500 pounds (ISO Class 2 1000-2500 kg). With reference to  FIGS. 4A and 5 , a reinforcement bar  50  is welded to the H-shaped bar  200  and positioned adjacent to a side  201  of the H-shaped bar near the second fork-receiving hook  204  to provide structural reinforcement to the H-shaped bar  200 . In the illustrated embodiment, the reinforcement bar  50  is vertically offset relative to the H-shaped bar  200  such that reinforcement bar upper and lower surfaces  50 A and  50 B, respectively, are vertically offset relative to upper and lower surfaces  200 A and  200 B, respectively, of the H-shaped bar  200 , as best seen in  FIG. 5 . 
     Because the reinforcement bar  50  is vertically offset relative to the H-shaped bar  200 , a first fillet weld  60  (shown in  FIG. 5  but not in  FIG. 4A ) can be formed between a side surface  50 C of the reinforcement bar  50  and an upper corner  200 C of the H-shaped bar  200 . Further, a second fillet weld  62  (shown in  FIG. 5  but not in  FIG. 4A ) can be formed between the bottom surface  50 B of the reinforcement bar  50  and a lower side surface  200 D and/or a lower corner  200 E of the H-shaped bar  200 . It is believed that the first and second fillet welds  60  and  62  provide enhanced structural integrity, rigidity and strength to the fork carriage upper member  30 C. The H-shaped bar  200  is also welded to the fork carriage first and second members  30 A and  30 B via fillet and groove welds. 
     In the illustrated embodiment as shown in  FIG. 4A , the reinforcement bar  50  has a height H 50  equal to about 63 mm and a width W 50  equal to about 6 mm. The reinforcement bar  50  spans generally the entire length L 1  of the H-shaped bar  200 , wherein L 1 =about 900 mm in the illustrated embodiment. The height H 200  of the H-shaped bar  200 , when measured near the second fork-receiving hook  204 , is equal to 60.5 mm in the illustrated embodiment. Hence, the height H 50  of the reinforcement bar  50  is greater than the height H 200  of the H-shaped bar  200  when measured near the second fork-receiving hook  204 , thereby providing increased structural rigidity and strength to the fork carriage upper member  30 C. 
     Further during manufacturing, a plurality of notches  202 A are machined into the first fork-receiving hook  202  to receiving corresponding mating structure (not shown) on the forks  140 A and  140 B. 
     As seen in  FIGS. 1, 4A-4C, and 5 , a protection shield  30 F is welded to the H-shaped bar  200  and the fork carriage first and second side members  30 A and  30 B so as to provide protection for the rams  120  and  122  of the lifting carriage upper member  20 C, which rams  120  and  122  are positioned behind the protection shield  30 F, and to increase the overall strength of the fork carriage upper member  30 C. The fork carriage  30  and its upper member  30 C of the first embodiment are designed to support up to about 4500 pounds. 
     The fork carriage  30  is mounted to the lifting carriage  20  by positioning the fork carriage upper member  30 C over the lifting carriage upper support member  20 C such that an inner cavity  203  of the H-shaped bar  200  is fitted over an upper surface of the support member  20 C including the linear bearings  123 , as shown in  FIGS. 1 and 4A . It is noted that the lifting carriage lower support member  20 D is provided with first and second polymeric, low-friction, low-wear linear bearings  120 D, which are engaged by the fork carriage lower member  30 D. As shown in  FIGS. 1  and  3 , securement blocks  210 , made from steel, are bolted to the lower support member  20 D after the fork carriage  30  has been mounted to the lifting carriage  20  to prevent the fork carriage  30  from coming off the lifting carriage  20 . 
     When the first internal cylinder within the lifting carriage upper support member  20 C is supplied with hydraulic fluid, the first ram  120  is moved outwardly, causing the fork carriage  30  to move laterally to the right in  FIG. 2 . When the second internal cylinder within the lifting carriage upper support member  20 C is supplied with hydraulic fluid, the second ram  122  is moved outwardly, causing the fork carriage  30  to move laterally to the left in  FIG. 2 . When fluid is provided to the first cylinder, fluid is not provided to the second cylinder and vice versa. As noted above, the H-shaped bar  200  is a hot-rolled section, which is expensive to manufacture. In order to reduce the expense of designing and producing two separate hot rolling dies to produce two separate fork-supporting bars with different profiles, the H-shaped bar  200  has been designed with the first and second fork-receiving hooks  202  and  204  to allow the H-shaped bar  200  to be used in the manufacture of separate fork carriages for supporting forks of different sizes and/or different maximum loads. 
     A fork carriage  130  constructed in accordance with a second embodiment of the present invention is illustrated in  FIG. 4B  and comprises a fork carriage upper member  130 C. The fork carriage  130  further includes first and second vertical members  30 A and  30 B and a lower member  30 D, which are substantially the same as like elements used in the construction of the fork carriage  30  illustrated in  FIG. 1 . 
     The fork carriage upper member  130 C, constructed in accordance with the second embodiment of the present invention, comprises a fork-supporting bar, which, in the embodiment illustrated in  FIG. 4B , comprises the same H-shaped bar  200  as used in the fork carriage upper member  30 C in accordance with a first embodiment shown in  FIG. 4A . The fork carriage  130  and its upper member  130 C are constructed such that the first fork-receiving hook  202  is positioned outwardly away from the mast assembly  100  similar to a first embodiment of the present invention shown in  FIG. 6 , to allow the forks  140 A and  140 B, e.g., Class 2 forks, to be mounted on the first fork-receiving hook  202 . Hence, the same size forks  140 A and  140 B are adapted to be mounted on the fork carriage upper members  30 C and  130 C of the first and second embodiments. A reinforcement bar  150  is welded to the H-shaped bar  200  and positioned adjacent to a side of the H-shaped bar near the second fork-receiving hook  204  to provide structural reinforcement to the H-shaped bar  200 . In the illustrated embodiment, the reinforcement bar  150  is vertically offset relative to the H-shaped bar  200 , as shown in  FIG. 4B . Because the reinforcement bar  150  is vertically offset relative to the H-shaped bar  200 , a first fillet weld (not shown in  FIG. 4B ; similar to a first fillet weld  60  shown in  FIG. 5 ) can be formed between a side surface  150 C of the reinforcement bar  150  and an upper corner  200 C of the H-shaped bar  200 . Further, a second fillet weld (not shown in  FIG. 4B ; similar to a second fillet weld  62  in  FIG. 5 ) can be formed between a bottom surface  150 B of the reinforcement bar  150  and a lower side surface  200 D and/or a lower corner  200 E of the H-shaped bar  200 , as seen in  FIG. 4B . The H-shaped bar  200  is also welded to the fork carriage first and second members  30 A and  30 B via fillet and groove welds (not shown). 
     In the second embodiment illustrated in  FIG. 4B , the reinforcement bar  150  has a height H 150  equal to about 63 mm and a width W 150  equal to about 10 mm. In an alternative embodiment, the width W 150  is equal to 13 mm. The reinforcement bar  150  has a width W 150  greater than that of the width W 50  of the reinforcement bar  50  of the first embodiment shown in  FIG. 4A , and hence, the reinforcement bar  150  of the second embodiment is larger than the reinforcement bar  50  of the first embodiment. The larger reinforcement bar  150  allows the fork carriage  130  and its upper member  130 C to support a larger load, e.g., up to 5500 pounds in the illustrated embodiment, than the upper member  30 C of the first embodiment. The reinforcement bar  150  spans generally the entire length of the H-shaped bar  200  in the illustrated embodiment. 
     Further during manufacturing, a plurality of notches  202 A are machined into the first fork-receiving hook  202  to receiving corresponding mating structure (not shown) on the forks  140 A and  140 B. 
     A protection shield  30 F is welded to the H-shaped bar  200  and the fork carriage first and second side members  30 A and  30 B, so as to provide protection for the rams  120  and  122  of the lifting carriage upper member  20 C, which rams  120  and  122  are positioned behind the protection shield  30 F, and to increase the overall strength of the fork carriage upper member  130 C. 
     A fork carriage  230  constructed in accordance with a third embodiment of the present invention, is illustrated in  FIG. 4C  and comprises a fork carriage upper member  230 C. The fork carriage  230  further includes first and second vertical members  30 A and  30 B and a lower member  30 D, which are substantially the same as like elements used in the construction of the fork carriage  30  in accordance with a first embodiment shown in  FIG. 4A . 
     The fork carriage upper member  230 C, constructed in accordance with the third embodiment of the present invention, comprises a fork-supporting bar, which, in the embodiment illustrated in  FIG. 4C , comprises the same H-shaped bar  200  used in the fork carriage upper members  30 C and  130 C in accordance with first and second embodiments shown in  FIGS. 4A and 4B , respectively. However, to allow the fork carriage  230  and its upper member  230 C to support forks larger than the forks  140 A,  142 A shown in  FIG. 6  and supported by the upper members  30 C and  130 C, the H-shaped bar in  FIG. 4C  has been rotated  180  degrees so that the second fork-receiving hook  204  is positioned outwardly away from the mast assembly, to allow the larger forks, e.g., Class 3 forks, to be mounted on the second fork-receiving hook  204 . The forks adapted to be mounted on the second fork-receiving hook  204  may comprise Class 3 forks having a fork load supporting capacity of from about 5500 pounds to about 10,000 pounds (ISO Class 3 2501-4999 kg). 
     A reinforcement bar  250  is welded to the H-shaped bar  200  and positioned adjacent to a side of the H-shaped bar near the first fork-receiving hook  202  to provide structural reinforcement to the H-shaped bar  200 . In the embodiment illustrated in  FIG. 4C , the reinforcement bar  250  is vertically offset relative to the H-shaped bar  200 . Because the reinforcement bar  250  is vertically offset relative to the H-shaped bar  200 , a first fillet weld (not shown in  FIG. 4C ; similar to a first fillet weld  60  shown in  FIG. 5 ) can be formed between a side surface  250 C of the reinforcement bar  150  and an upper corner  200 F of the H-shaped bar  200 . Further, a second fillet weld (not shown in  FIG. 4C ; similar to a second fillet weld  62  shown in  FIG. 5 ) can be formed between a bottom surface  250 B of the reinforcement bar  250  and a lower side surface  200 G and/or a corner  200 H of the H-shaped bar  200 , as seen in  FIG. 4C . The H-shaped bar  200  is also welded to the fork carriage first and second members  30 A and  30 B via fillet and groove welds. 
     In the embodiment illustrated in  FIG. 4C , the reinforcement bar  250  has a height H 250  equal to about 63 mm and a width W 250  equal to about 19 mm. The reinforcement bar  250  has a width W 250  greater than that of the width W 150  of the reinforcement bar  150  of the second embodiment shown in  FIG. 4B  and the width W 50  of the reinforcement bar  50  of the first embodiment shown in  FIG. 4A . Hence, the reinforcement bar  250  is larger than the reinforcement bar  150  of the second embodiment and the reinforcement bar  50  of the first embodiment. The larger reinforcement bar  250  and the larger hook  204  allows the fork carriage  250  and its upper member  230 C to support larger forks and a greater load, e.g., up to 6500 pounds in the illustrated embodiment, than the upper members  30 C and  130 C of the first and second embodiments. The reinforcement bar  250  spans generally the entire length of the H-shaped bar  200  in the illustrated embodiment. 
     Further during manufacturing, a plurality of notches  204 A are machined into the second fork-receiving hook  204  to receiving corresponding mating structure (not shown) on forks to be mounted to the second fork-receiving hook  204 . 
     A protection shield  30 F is welded to the H-shaped bar  200  and the fork carriage first and second side members  30 A and  30 B, so as to provide protection for the rams  120  and  122  of the lifting carriage upper member  20 C, which rams  120  and  122  are positioned behind the protection shield  30 F. 
     While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.