DCT
1:15-cv-00486
Hildebrand v. Henderson Truck Equipment
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: David L. Hildebrand (Colorado)
- Defendant: Douglas Dynamics Inc. (Wisconsin); Henderson Truck Equipment, a.k.a. Henderson Products (Iowa); Colorado Department of Transportation (Colorado); The City of Denver Colorado; The City of Longmont Colorado; The City of Fort Collins Colorado; The City of Loveland Colorado; The City of Greely Colorado; The County of Denver Colorado; The County of Weld Colorado; The County of Larimer Colorado
- Plaintiff’s Counsel: Pro Se
- Case Identification: 1:15-cv-00486, D. Colo., 03/06/2015
- Venue Allegations: Venue is alleged to be proper based on Defendants engaging in commercial, city, or county activities within the District of Colorado.
- Core Dispute: Plaintiff alleges that Defendants’ use, manufacture, or sale of snow removal and road maintenance equipment infringes a patent related to a support structure for heavy equipment.
- Technical Context: The technology concerns free-standing support structures designed to hold heavy, vehicle-mounted equipment (such as salt or sand spreaders) in an elevated state, facilitating loading onto and unloading from a vehicle bed.
- Key Procedural History: The complaint does not mention any prior litigation, licensing history, or other significant procedural events related to the patent-in-suit.
Case Timeline
| Date | Event |
|---|---|
| 1995-07-21 | U.S. Patent No. 5,651,527 Priority Date |
| 1997-07-29 | U.S. Patent No. 5,651,527 Issues |
| 2015-03-06 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 5,651,527 - Support structure for use with heavy equipment
- Patent Identification: U.S. Patent No. 5,651,527 (Support structure for use with heavy equipment), issued July 29, 1997 (the "’527 Patent").
The Invention Explained
- Problem Addressed: The patent’s background section describes a problem with prior art support structures used to hold heavy equipment for loading onto truck beds. Specifically, it notes that "improper positioning of the truck bed may cause the support legs to pivot prematurely which can result in collapse of the entire structure" (’527 Patent, col. 2:15-18).
- The Patented Solution: The invention is a support frame with pivotable front legs that can be locked in a ground-supporting position by a "stop element." This stop element is a separate component that can be selectively moved into a position where it physically obstructs the path of the leg, preventing it from accidentally pivoting into its stowed (horizontal) position during the loading process (’527 Patent, Abstract; col. 3:9-17). Once the equipment is safely on the truck bed, the stop element can be moved out of the way to allow the legs to be stowed for transport (’527 Patent, col. 6:20-24; Fig. 4c).
- Technical Importance: The invention provides a safety mechanism intended to reduce the risk of structural collapse when loading or unloading heavy equipment, which could otherwise damage the equipment or cause injury (’527 Patent, col. 2:15-26).
Key Claims at a Glance
- The complaint asserts infringement of Claims 1-20 (Compl. ¶13).
- Independent Claim 1 is directed to a support structure comprising:
- a support frame adapted to receive and support equipment;
- a first rigid leg structure including a first pair of legs each pivotally mounted to the support frame on a pivot axis;
- a second rigid leg structure mounted to the support frame; and
- a pair of stop elements, each being selectively movable into a region between the support frame and a respective pivot axis to define a stop position that obstructs the region to prevent the leg from pivoting into the stowed position.
- The complaint does not explicitly reserve the right to assert dependent claims, as it broadly asserts all claims 1 through 20 (Compl. ¶13).
III. The Accused Instrumentality
Product Identification
The complaint does not identify any specific products by name or model number. It refers generally to an "Invention... attached to snow removal and road maintenance equipment" (Compl. ¶10).
Functionality and Market Context
The complaint does not provide sufficient detail for analysis of the functionality of the accused instrumentalities. It alleges only that "All Defendants are currently either using, manufacturing and/or selling" the patented invention as part of this equipment (Compl. ¶10, ¶12). No allegations regarding the products' commercial importance are included.
No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
The complaint alleges that Defendants infringe Claims 1-20 of the ’527 Patent by "making, using, selling, or offering for sale" the invention described therein (Compl. ¶13). It does not provide a claim chart or detailed infringement contentions. The following summary is based on the broad allegations against the accused "snow removal and road maintenance equipment" (Compl. ¶10).
’527 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| (a) a support frame adapted to receive and support said equipment in the stored state; | The complaint does not describe a specific infringing functionality, but alleges that Defendants' equipment embodies the claimed invention (Compl. ¶10, ¶12). | ¶10, ¶12, ¶13 | col. 4:40-53 |
| (b) a first rigid leg structure including a first pair of legs each pivotally mounted to said support frame on a respective pivot axis... each of said legs pivotable between a support position... and a stowed position...; | The complaint does not describe a specific infringing functionality, but alleges that Defendants' equipment embodies the claimed invention (Compl. ¶10, ¶12). | ¶10, ¶12, ¶13 | col. 4:54-68 |
| (c) a second rigid leg structure mounted to said support frame; and | The complaint does not describe a specific infringing functionality, but alleges that Defendants' equipment embodies the claimed invention (Compl. ¶10, ¶12). | ¶10, ¶12, ¶13 | col. 5:3-9 |
| (d) a pair of stop elements each being selectively movable into the region between said support frame and the respective said axis... to define a stop position wherein said stop element obstructs the region thereby to prevent pivoting of said respective leg into the stowed position... | The complaint does not describe a specific infringing functionality, but alleges that Defendants' equipment embodies the claimed invention (Compl. ¶10, ¶12). | ¶10, ¶12, ¶13 | col. 5:48-68 |
- Identified Points of Contention:
- Evidentiary Question: A central question will be whether discovery reveals that any of the accused "snow removal and road maintenance equipment" actually incorporates the specific combination of elements recited in the claims. The complaint provides no factual basis—such as product photos, manuals, or technical descriptions—to support the conclusory allegation that the accused equipment meets each limitation.
- Technical Question: Assuming the accused products have pivotable legs with some form of locking mechanism, a key technical dispute will concern the "stop elements." The infringement analysis will turn on whether the accused products possess a distinct component that is "selectively movable into the region... to... obstruct" the leg’s pivoting motion, as opposed to a more conventional locking pin or a fixed structural brace.
V. Key Claim Terms for Construction
- The Term: "stop element"
- Context and Importance: This term describes the core inventive feature that distinguishes the claimed structure from prior art. The outcome of the case will likely depend on whether any feature of the accused products can be characterized as a "stop element" as that term is construed. Practitioners may focus on this term because its definition will determine whether a wide range of leg-locking mechanisms fall within the claim scope, or if the scope is limited to the specific movable barrier shown in the patent.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: Claim 1 defines the term functionally as a component that is "selectively movable into the region... to define a stop position wherein said stop element obstructs the region thereby to prevent pivoting" (’527 Patent, col. 8:14-18). A plaintiff may argue that this functional language should cover any movable structure that performs this specific blocking function, regardless of its particular shape or mechanism.
- Evidence for a Narrower Interpretation: The specification consistently depicts the "stop element" (100) as a distinct, L-shaped plate that pivots on a crosspiece into a position behind the support leg (’527 Patent, Figs. 3, 4a-4b; col. 5:48-64). A defendant may argue that the term should be construed more narrowly to require a structure analogous to this disclosed embodiment, which acts as a movable physical barrier rather than, for example, a pin that passes through the leg.
VI. Other Allegations
- Indirect Infringement: The complaint does not contain a separate count for indirect infringement, nor does it allege specific facts to support the knowledge and intent elements required for such a claim.
- Willful Infringement: Willfulness is alleged based on the assertion that Defendants continued their infringing acts "after having been notified of the fact that said acts infringed U.S. Patent 5,651,527" (Compl. ¶15). The complaint does not specify whether this alleged notification occurred pre- or post-suit.
VII. Analyst’s Conclusion: Key Questions for the Case
The complaint’s lack of factual detail means the initial phase of the case will likely center on fundamental evidentiary and pleading challenges. The key questions that emerge are:
- Evidentiary Sufficiency: The primary threshold issue is factual: can the Plaintiff produce evidence that the accused "snow removal and road maintenance equipment" contains the specific combination of a support frame, pivotable front legs, a second set of legs, and, most critically, a "selectively movable stop element" that physically obstructs the pivoting motion as claimed?
- Definitional Scope: Assuming some evidence of a leg-locking mechanism is presented, a dispositive legal question will be the construction of "stop element." The case may turn on whether this term is interpreted broadly to cover any mechanism that prevents pivoting, or more narrowly to require a distinct, movable barrier that physically blocks a region of space, as depicted in the patent’s embodiments.