US 4087101

Search Results

USPTO/patent databases: The patent is confirmed as US 4,087,101 A ("US4087101A"). No similar-number confusion was found — the only references returned (Google Patents, FreePatentsOnline, Justia, and a Baidu Scholar record) all point to the same patent.

CAFC 2026 docket search: I ran multiple searches for "4087101" combined with "CAFC," "docket," "litigation," "appeal," and "2026." No results were returned. This is consistent with the patent's status: it expired (lifetime) on May 2, 1995, long before 2026, so there is no plausible pending CAFC appeal involving it. I found no evidence of any CAFC proceeding concerning this patent.

Summary of US Patent 4,087,101

Abstract (verbatim):

"A frame assembly for a tractor shovel or the like includes a front frame and a rear frame having generally U-shaped cross-sections. The frames are pivotally joined by a vertical shaft. A rectangular parallelopiped hydraulic fluid tank is internally mounted in the front frame, and its side and front edges are secured by welding or the like to the front frame plates. Similarly, a rectangular parallelopiped fuel tank is internally mounted in the rear frame, and its side and rear edges are welded or the like to the rear frame plates. The arrangement offers increased frame strength and rigidity with no increase in weight, and the tanks are better protected by reason of their internal mountings."

Technology in brief: In prior-art tractor shovels, the fuel tank and hydraulic-fluid tank were bolted externally to the frame side plates, contributing nothing to frame rigidity (so frames had to be made thicker/heavier) and requiring separate installation work. The invention instead mounts box-shaped (rectangular parallelepiped) tanks inside the U-shaped front and rear frame halves of an articulated vehicle, welding/bolting the tanks' edges to the frame plates so the tanks function as structural members with a section modulus greater than an individual cross-member.

Plain-Language Overview of the Independent Claims

The patent has 5 claims; claims 1 and 4 are the independent claims (claims 2 and 3 depend from claim 1). Note: the Google Patents text provided to me shows claims 1–4 but lists a total of 5 claims; claim 5's text was not included in the available extraction, so I cannot summarize it with confidence.

Claim 1 — An articulated industrial vehicle (e.g., tractor shovel) with a front frame and rear frame pivotally joined by a vertical shaft through bearing members, wherein:

• Both frames have generally U-shaped cross-sections;
• The front frame has two opposed side plates plus a front plate;
• A rectangular (box-shaped) fuel tank is mounted inside the rear frame, spanning across it, and is securely fastened to it;
• A rectangular (box-shaped) hydraulic-fluid tank is mounted inside the front frame, spanning across it;
• The hydraulic tank's side edges and upper front edge are rigidly secured to the front frame's side plates and front plate, respectively;
• As a result, the tanks structurally reinforce and increase the rigidity of their frames.

In plain language: Claim 1 covers the core concept — instead of hanging the tanks on the outside, mount box-like fuel and hydraulic tanks inside the two U-shaped frame halves of an articulated vehicle and weld/bolt them to the frame plates so they act as load-bearing structural reinforcements.

Claim 4 — An articulated industrial vehicle with U-shaped front and rear frames pivotally joined by a vertical shaft, wherein:

• The rear frame has two opposed side plates plus a rear plate;
• A box-shaped fuel tank is mounted inside the rear frame, spanning across it;
• The fuel tank's side edges and upper rear edge are rigidly secured to the rear frame's side plates and rear plate, respectively;
• A box-shaped hydraulic-fluid tank is mounted inside the front frame, spanning across it, and is securely fastened to it;
• As a result, the tanks structurally reinforce and increase the rigidity of their frames.

In plain language: Claim 4 is the mirror-image counterpart of claim 1, emphasizing the fuel-tank side of the arrangement — the fuel tank in the rear frame is welded along its side and rear edges to the rear frame's plates, with the hydraulic tank similarly mounted inside the front frame, again using both tanks as structural stiffeners.

Uncertainty Notes

1. CAFC 2026: No docket entries found; the patent expired in 1995, so a 2026 CAFC appeal is highly unlikely, but I cannot absolutely rule out a legacy damages/royalty dispute that wasn't indexed under the patent number in my searches.
2. Assignee: "Toyo Umpanki Co., Ltd." is confirmed as the original assignee. Google's "TCM Corp" current-assignee entry is flagged by Google itself as potentially inaccurate and was not independently verified against USPTO assignment records.
3. Claim 5 was not present in the supplied patent text, so it is omitted here.