US2282201A

US2282201A - Lift truck

Info

Publication number: US2282201A
Application number: US361776A
Authority: US
Inventors: Jacob J Neuman
Original assignee: US PATENT DEV AND ROYALTY COMP
Current assignee: UNITED STATES PATENT DEVELOPMENT AND ROYALTY Co; US PATENT DEV AND ROYALTY COMP
Priority date: 1940-10-18
Filing date: 1940-10-18
Publication date: 1942-05-05
Anticipated expiration: 1959-05-05

Description

May s, 1942.

J. J. NEUMAN LIFT TRUCK Filed Oct. 18, 1940 4 Sheets-Sheet 1 Gttorneg May 5, 1 942 v J. J. NEUMAIN 2,282,201

LIFT TRUCK l J. J. NEUMAN -May s, 1942.

LIFT TRUCK Filed oct. 18, 1940 4 Sheets-Sheet 3 :inventor Lf. elw/@umm Gttorneg J. J. NEUMAN May 5,l 1942.

LIFT TRUCK Filed 001'.. 18, 1940 4 lSheets-Sheet '4 'wir Smaentor www . WEEE llalllllllll Ilcll.

lllllllll .l'lll'l PatentedMays;l

UNITED STATES PATENT v OFFICE LIFT 'muoril -Jacob J. Neuman, south salem, N. Y., signor tu United States Patent Development and Royalty Company, South Salem, N. Y. Application oete'ber 1s, 1940,-sem1' N0. 361,176

11 emma. (o1. er1-113) high tiers due to the inability of the operator from his position togauge the correct height `of the members in order to properly enter `the pallet. He thus very often has the members too high or too low and they strike and break the edge boards.

Another source of breakage to the pallets has been due 'to failure of the operator. when pulling the members out, to lower them lsufficiently or to lower them too much.

It has been attempted in the past to remedy these difliculties by protecting the pallet edge boards with steel angles, sheet metal, etc. This made the pallets too expensive and not wholly satisfactory. A further attempt to solve the problem was by making the members blunt to prevent splitting of the pallet'boards and while this latter attempt improved matters, the hard metal ends of the members still do considerable damage to the pallets.

It is an important object. of the present invention to provide load carrying members which will not he subject to the disadvantages above mentioned.

Another object of the invention is to provide the members with feeler and buffer means.

A still further object of the invention is to provide load carrying members which indicate to the operator of vthe truck when the members have been correctly or incorrectly applied.

A still further object is to provide buffer means which are simple and inexpensive and which are easily applied and renewed. A

, With the foregoing and other objects in view,

the invention will be more fully described here- Figure 2 is a fragmentary end view of the parts shown in Figure 1.

Figure 3 is a top plan view with parts broken away of the lifting member with the invention applied thereto.

Figure 4 is a side elevational view with parts broken away of the parts shown in Figure 3.

Figure 5 is a sectional view taken along the line 5 5 of Figure 3. 4

Figure 6 is a sectional view taken on the line 6 6 of Figure 3.

Figure 7 is a sectional view taken on the line 7 1 of Figure 3. l

Figure 8 is a top plan view with parts broken away of a lifting member with a modified form of the .invention applied thereto.

Figure 9 is a fragmentary top plan view of a lifting member with another modified formy of the buffer means applied thereto.

Figure 10 is a similar fragmentary top plan view with a still further modified form of the buffer means applied thereto.

Figure 11 is a side elevational view of the lifting means with the buffer Vmeans shown in Figure 9 applied thereto and showing an improved support for the lifting members.

Figure 12 is a cross-sectional view along the line I2-I2 of Figure 11.

Referring more particularly to the drawings and to the forms of the invention shown by Figures 1 to 8 inclusive, the numeral lo designates the tip portion of a lifting fork .Il forming part of the lift truck diagrammatically shown in Figure l. The lower face of the fork Il is given a taper I2 terminating in a beveled edge portion I3 while the upper face of the fork II, while not tapered, is provided with a beveled edge portion I4 similar tothat of I3, both of which are gradually reducedto zero.

Between these beveled portions the edge of the fork is provided with a substantially V shape channel I5 of varying depth as particularly shown'by Figures 5. 6 and 7. Beginning at a point designated by lines 5 5 in Figure 3, the channel is at its greatest depth forming a pocketI I6 and the channel gradually decreases in depth as designated by the line 6-6 corresponding to Figure 6 until the minimum depth is at the outermost edge of the tip portion I as designated by line 1-1 'and Figure 7. In referring to this channel of varying depth and to the various designations it is understood that the same variance is true on the other side of the tip portion of member il although the section lines have not been applied thereto. The corners of the channel are suitably rounded to eliminate cutting edges.

A section of standard V rope or other resilient material I1 if constant width but complemental in shape to channel l5 is arranged within the channel to form buffer and-feeling means for the fork il. The ends i8 of material I1 are received in the deepest part or pockets I6 of the channel and secured'to the fork il by clamping plates I9,

shake proof washers 20 and screws 2l, the latter o'f which are threaded into fork vI I.

The pockets IB being the deepest portions of channel I5 completely house the ends of the rope and their connecting elements to eliminate any protruding parts. In this manner the forks I I are not liable to be entangled in anything during their use or movement of the truck.

Accordingly the rope i1 from its attaching points in pockets I6 is given a gradually increasing areaof projection from the tip of fork EI. The greatest amount of rope projecting will be at the foremost portion of the tip ldue to the channel at this point being of the 'smallestidepth As this `foremost portion is the one that initially y comes into contact with the pallets, the greatest amountof protection is needed atthis point.

It will be noted that the outer face of the V-shaped rope is sufficient to guard the beveled portions I3 and id of the fork II and this is forks Il on the elevating carriage' 29. This ar-A rangement is designed to prevent the damage to the pallets due to failure of the operator, when pulling the forks vout, to lower them sumciently', orto lower them. too much. The vertical portion 3B of the fork Il is provided4 with a slot 3l through which a shaft or rod 32 extends. The rod l32 is journaled at both ends in the elevating carriage 29 forming part of the truck diagrammatically shown in Figure 1 of the drawings.

Each fork II is attached to the top of the elevating carriage 29 with springs A33 of sufficient strength to support the weight of 'the forks ii alone but not sumcient to support the forks when v they are carrying a loaded pallet. The connection of the upper ends of the springs 33 is made with an eye bolt 33 and nut 35. The nut 351s so adjusted that when the forks Il are unloaded they are supported at a height Where the rod 32 is at the midpoint ofthe slot 3l. It is thus seen that if the forks il are either slightly too high I. is provided with oppositely beveled recessed porstantially U-shaped plate 31.

necessary to give the tip of thel fork a substantially all resilient contacting surface.

The construction shown in Figure 8 is substantially the same as that described heretofore, the only difference being in the attachment of the rope ends I8. In this modification the rope ends I8 are secured to the tip portion I0 by the same shake proof washers 20 and screws 2| of Figure 3, the clamping plates22 in this instance being` any dam-age to the pallet or 'its parts.

l Referring to the modification shown by Figure 9, a molded buffer 23 having a radially projecting feeler ymember 24 is provided for the fork II. The manner of attachment of this -modication is similar to the manner of attachment described with reference to the buffer of Figures 1 to 8.

In the modification shown by Figure .10 the resilient buffer is comprised of two sections of rope 25, each rope section havinga radially extending y portion 26. 'Ihe extending portions 26 are joined together by rivets 21 to form a feeler member 28 similar to the feeler member 24 of Figure 9.

The operation of the cxclmstruction shown by Figures 9 and 10 is of cou vse similar to that de-` scribed in the' preceding' figures.

The

feeler members

24 and 28 of these latter constructions enables the operator to adjust the forks to the correct level before attempting to insert the main forks. If the flexible feelers 24 and 28 'strikethe [5 pallet boards no damage is done.

'tions 36 on its upper and lower face. These recessed portions 36 follow the contour of the fork and frictionally receive therein a slidable sub- The outer configuration of the plate 31 is arcuate to correspond with the arcuate tip portion of the fork. A substantially V-shaped groove is provided on the periphery of the plate 31 to accommodate a simi- I lar spaced buffer, such as that shown at 23 in resilient contact surface of the buffer is not impaired. In order to accommodate the nuts 49 the fork tip is provided with sockets di into which the nuts d@ will be received when the plate 31 has been forced to its limit within the i recesses 36.

The plate 31 is normally urged outwardly by means ofsprings 42 and 43 disposed within a bore 44 formed in the tip ofthe fork I I. This bore 44 extends from the edge portion of the tip and terminates in a housing 45 at a point beyond the recessed portion 36. The diameter of the bore 44 is larger at the tip portion than at its 'succeeding portions whereby shoulders are provided in the bore. The spring 43 is encircled about a rod 46 between two washers 41 and 48, the rod having a head portion 49. The rod isthreadedly secured to the 'central portion of the plate 31 andthe washer 41 -bears against a shoulder portion of the bore 44 whereby the plate and buffer are yieldingly supported. The spring 42 is disposed within the smaller diameter of the bore 44 in contact with the head 49 y-of rod 46 and the head 50 of a plunger 5I, The* In operation, when the buffer 23 strikes a pallet the. plate 31 and the rod 46 slide back, the

spring 43 is compressed pushing back the plunger I to operate the switch 52. This switch being in the forward circuit of the driving motor of the lift trucis'` and when operated stops this motor and applies the brakes. The operator must then back the truck away and adjust the forks to the correct elevation. backed away the spring 43 returns the plate 31 to normal position and the forward circuit of the lift truck driving motor is restored.

The length of the various springs and the plate 31 are so proportioned that the truck will stop before the plate is pushed back to the limit of its travel. The spring 43 is of a strength just sufficient to overcome the sliding friction of the plate 31 and return it to normal position while the spring 42 is even weaker being only of a strength to operate the push button switch 52. It is thus seen that when the buffer strikes a pallet these springs give and no damage is done.

While it has been stated in all forms of the invention that the .buffer means is preferably rope it is understood that any other type of material having inherent resiliency such as rubber may be substituted therefor.

The plunger 5I is rendered detachable from the head '50 or the switch 52 in any suitable manner, such as screw threads or the like. This will permit the plunger 5I to be first inserted in the bore 44 to be followed by the spring 42, rod 46 and spring 43. After these parts have been assembled the switch 52 may be secured to the plunger 5l whereby the complete assembly is provided.

It is obvious that various changes and modifications may be made in the details of construcf tion and design of the above specifically described embodiment of this invention without departing from the spirit thereof, such changes and modifications being restricted only by the scope of the following claims.

What is claimed is:

1. In a lift truck, in combination, a frame, a lifting member carried by an end of said frame and adapted for insertion between the faces of `a two faced pallet, said lifting member having a peripheral channel and pockets at the ends of said channel, a buffer element disposed in said channel to project beyond said lifting member, and'securing means for the ends of said buffer element, said securing means and ends of said buffer element being wholly disposed within said pockets.

2. In a lift truck, in combination, a frame, a lifting member carried by said frame and adapted for insertion between the faces of a two faced pallet, said lifting member having a peripheral channel of variable depth, said channel having its greatest depth at its ends to provide pockets and its smallest depth at the tip porion of said lifing member, a buffer element disposed in said channel, said buffer element having its vgreatest projecting portion at the tip of said lifting member,.the ends of said buffer element being housed within the pockets of said channel, and securing means for the ends of said buer element secured to said lifting member within said pockets.

3. In a lift truck, in combination, a frame,

load carrying .members extending from said frame and adapted for insertion between the faces of a two faced pallet, a channel on the peripheral portions of said lifting members, opposed deep pockets defining the ends of said channel, said channel progressively decreasing When the truck is and increasingt in depth between said pockets, a buffer element disposed in said channel, said buffer element having projecting areas corresponding to the channelv depths, and securing means for the ends of said buffer element, said securing means and ends being disposed within said deep pockets and secured to said load carryingmembers.

4. In a lift truck, in combination, a frame, load carrying members extending from said frame and adapted for insertion between the faces of a two facedpallet, a channel on the 'peripheral portions of said lifting members, opposed deep pockets defining the ends of said-channel, said channel progressively decreasing and increasing in depth between said pockets, a buffer element disposed` in said channel, s'aid buffer element having projecting areas corresponding to the channel depths, and securing means for the ends of said buffer element, said securing means and ends'being disposed within said deep pockets and secured to said load carrying members at an angle whereby said buffer element is drawn into said channel.

5. In a lift truck having a frame andan elevating carriage on said frame, lifting members carried by said carriage and yieldable connecting means between said carriage and lifting members, said connection comprising a spring secured to said carriage and `to a vertical portion of said lifting members, said lifting members provided with an elongated slot, a transverse rod in the slots and journalled to said elevating carriage, said yieldable connection normally biasing said members to raised position, and buffer means on said lifting members.

6. In a lift truck, in combination, a frame, adjustable load carrying members extending from said frame and adapted for insertion between the faces of a two faced pallet, a channel on the peripheral portions of said lifting members, a buffer element secured in` said channel and projecting beyond said lifting members to form a resilient contacting surface for the latter, and a flexible feeler member projecting from said buier element.

load carrying members extending from said vframe and adapted for insertion between the faces of a two faced pallet, a channel of progressively increasing and decreasing depth on the peripheral portions of said lifting members, pockets formed by the greatest depth of said channel, buffer elements in said channel to progressively project from the lifting members in accordance with the depth of the channel, one end portion of each of said buder elements being secured in said pockets, the other end portions of each of said buer elements being connected together to form a feeler member projecting beyond said buffer elements, and securing means recessed in said pockets for the first mentioned end portions of said buffer elements.

8. In a lift truck, in combination, a frame, load carrylng'members on said frame and adapted for insertion between the faces of a two faced pallet, a channel on the peripheral portions of said lifting members and a moulded buffer' element secured in said channel toproject therefrom.

9. In a power-driven lift truck, in combination,

a frame, adjustable load carrying members exto said load carrying members forming a resilient contacting surface for said members and normally in projected position, said buffer element adapted to 'be inserted between the faces of the pallet, and being retractable upon striking the pallet when said load -carrying membersare improperly adjusted, and means carried by said lifting members for stopping the forward motion of said lift truck, said means adapted to be actuated by said buffer element when in retracted position.

10. The combination with a power-driven lift truck having a frame, adjustable load carrying members extending laterally from said frame and adapted for insertion between the faces of.

ment adapted to be inserted between the faces of the pallet, and means for yieldably maintaining said buffer element in extended position, whereby upon failure of said load carrying members to be properly adjusted for lentry between the faces of the pa11et,said buler element will be retracted by striking the pallet to actuate said control means.

11. 'Ihe combination with a lift truck'having vertically adjustable load carrying members extending laterally therefrom and adapted for in'- sertion between the faces of a two-faced pallet;

of vbuffer means on the free ends of said load carrying members projecting ytherefrom and forming resilient contacting surfaces vfor said load carrying members vto prevent damage to the palv. let'upon failure of said load carrying members for actuating said control means, said butler ele- 20 to be properly adjusted, and feeler mea-ns projecting forwardly from said buffer means.

' JACOB J. NEUMAN.